May I add that another cause of white coolant spots is overfilling the expansion tank. On a cold engine, the coolant should be barely visible and sitting at the very bottom of the tank. Upon heating up the coolant rises or "expands" to the top of the expansion tank. That is what it is for. Some people fill it right to the top and the coolant has nowhere to expand therefore it finds different spots to leak out of unnecessarily, and folk starts getting paranoid. Only fill the expansion tank so it sits at the very bottom of the tank and never fill to the top.
The expansion tank has a level indication float, but once it reaches max fill it stops moving. Yes, if it’s filled beyond the max mark it can cause the tank cap to pressure relive, but in a lot of cases it can cause the expansion tank to split too
Love my m54. Great video you certainly know what you’re talking about, first person to say the gasket is usually not the issue and it’s the head bolts. Many people think it will be easy head gasket replace , then when they go to pull the bolts they notice the absolute lack of torque or shorn female threads in the block. These are great engines truly, just surrounded by a pretty unreliable cooling system. Luckily very easy to replace
We used to drill and tap a little hole right next to the oil pump nut, effectively locking it in place with a little hex screw and of course oil resistant loctite and in combination with a s54 oilpump chain tensioner kit you're way more freely to Rev the engine higher because the chain harmonics are damped and don't kill the axle or make the nut come loose
Used to have a 02 330xi 5 speed man. Although I did find myself replacing gaskets and hoses etc all over the engine all the time, the engine itself to me was reliable and strong. I got 157k miles on that engine before taking a careless spirited drive one day and thew my excessivly sloppy shifter into third by accident, bending the valves. Since then upgraded to a g20 330imsport., its a welcoming upgrade.
Yes, they are good engines. My old E53 X5 has about 280,000kms on it now, still going strong. Wish we got the 3&5 series Xi from that generation in this part of the world
Timeserts done properly are 100%. A Boeing 747 has over 250,000 helicoils and timeserts installed from the factory in its aluminum substrate components so the moving threads are steel on steel.
So true, I had a rad hose blow when the car was idling in my driveway. Left the car for 25 minutes. Left it for so long because car hadn't driven in a while so thought I would charge the battery. It did overheat. Not sure of the outcome yet as the car hasn't been driven much. Feeling really dumb.
Now the battery is the least of your worries right! Get it checked out for hydrocarbons in the coolant, that will identify if the head gasket has failed or not. Good luck!
I thought it was pretty funny when you talked about the K series head gasket considering I have a 530i touring and also an MG TF (with a leaking head gasket lol)
I have had my engine over heat once because the aux fan switch was broke and i was learning to drive manual at a parking lot. Luckily my bmw has had about 1k miles on it since and no problems. Will do and inspection
100% on the cooling components, was so paranoid I did water-pump, thermostat, expansion tank, upper/lower hoses, temp senosr, coolant level sensor, and fan blade lol ! Always read that the oilpump nut issue mostly affected cars that constantly sustained + 6000 rpm (eg tracked cars), and was only an issue on m54b30 (harmonics unique to it). And on top of that the only real solution was the OEM Motorsport oil-pump (ridiculously priced😫). You should be safe if you aren't constantly tearing the streets up, I didn't stress about it myself 👍🏽 Great vid!
I'm not certain if it's related but my 03 330xi m54 threw a few codes but I drove it anyway. There's four a p0505, p1619, p0030, p0102. I got in it this morning and now the car will only rev once and then totally ignores the gas pedal, doesn't rev at all. I'm entirely at my wits end with it. Could it be in limp mode? No new codes also.
My e46 reservoir was throwing out coolant but my car doesn’t overheat and it doesn’t run hot either. It stays in the middle, maybe it was overfilled? I recently bought it for $500 so don’t mind putting in some money into it. I think I’ll just re do the full cooling system and intake system
Great Video Mate. I subscribed. I have my m54B30 fully rebuilt by end next week. Yes we will locktite and wire the oil pump nut. New head gasket, new piston rings, new crankshaft bearings, new hydralic lifters. Head has been bored intake and outtake. Please give me your advice on best way to run in the engine.
Nice work! For running it in, first 500 miles keep the rpm’s below 4000 rpm, listen to the engine and keep an eye on the temp gauge. Change the oil at 500 miles, and again at 1000 miles & 3000 miles 👍
Interesting.... I have a 2003 e39 530i , i love it to bits. Is the oil pump nut issue an issue in general on the M54 engine? or is it usually associated with higher millage and frequently driving the motor hard / at high revs that causes this to fail? If it is of any importance my engine has done 112k
Ok awesome so im in a kinda safe space with my 2.2. Although i have performed a mini durance test high speed and rev over 5000-5500 rpm during 20 a 30 minutes...... German highway. Of course i had warmed up the engine carefully during more then 1 hour driving normally. Then pulled over at a gas station. Filling up the gas tank and after paying. Checking oil level and making sure the dipstick is just near mac indicator point. The i took of and had a very enjoyable moment. I also love the m54 engine.
Just keep the water system fresh! Also change the expansion CAP! If it does not release the pressure it can cause a failure! Oil chain pump tensioner. DISA repair KIT! Rod bearings after 300.000km replace!
Just gonna say I’ve gone into the red many times and have now fixed the issue, but the car is been running fine with no head gasket issue for over a year now
my m54b30 has gone to the red like 5 times due to various issues, although no apparent head gasket issues. Is there anything i should check that could have been affected.
Please correct me if I’m wrong, aren’t you supposed to heat red loctite to remove the bolt you’ve put it on? And if so, do engine temperatures get close enough to the heat needed to relieve the red loctite?
I’ve never had an issuer removing bolts cold that were installed with red loctite, this nut is so skinny that cold removal wouldn’t be an issue. Red loctite is good for temps beyond M54 engine operating temps
My 2003 525i has white all over expansion tank and numerous cooling hoses. It overheats roughly twice a month. I top it up with coolant when it over hears and move on with my life. Bought car at 180k have 340k now, it's been like thay since day 1. Should I be concerned about engine failure?
It can happen on high mileage M54B30 engines, the check valve in the nozzle can cause issues. If you found one broken I would go through and replace them all
I’m about to buy E39 Touring 2001, how to know if there’s any engine failure? What is the most common problems that i need to check and ask to test it??
Hi mate I am going to get one of the P1 gauge systems that plug into the obd port, you can then monitor your coolant temp from the dash. What coolant temp level would you say the engine is overheating or starting to over heat thanks mate
That’s not a bad idea, reminds me of an old device used to be able to get called a “coolant snitch” Operating ramp 95C (give or take) If it gets to approx. 115C start getting worried!
Just had my M54 overheat a few times. She's fine, but these are the general temps for my m54b25 engine. 80-108 - normal temp 108-114 - Uh... Go back down pls? 115 - Oh shit, is it gonna go back down? Worry, but sometimes the aux fan will cool it back down. This is when you wanna check coolant levels and your hoses and radiator if you see this often. 115-120 - Pull over, NOW. If you expose the engine to
On the verdge of selling my bmw x5 e53 3.0i (m54 engine I believe) a customer road tested my vehicle and suddenly oil started leaking. Its as if pressure from the engine caused it to leak. strangely, I started to noticed I had oil inside the expansion tank. Isit true that there are no oil coolers in this engine? & possible that the gearbox cooler failed to cause the mix? Worse case the cylinder head which im not hoping because the vehicle was ready to be sold! - Any thoughts would be much appreciated as im thinking to keep this vehicle now.
These M54 engines can leak from various places (valve cover gasket, oil pan, VANOS hose, oil filter housing, power steering lines) Oil in coolant is either trans cooler mixing, or if the engine had recently been overheated it could be the head gasket
I occasionally get a low oil pressure warning. Have taken it to a specialized bmw mechanic but no success in finding the issue. Anyone have any advice? Thanks!
When you check the actual dipstick, is the level ok? Is the problem you’re describing, the yellow oil warning, and does it happen on startup and then turn off soon after? If yes to both of the above, it could be a bad oil level sensor. There are plenty of videos addressing replacement on YT. Good luck.
@@VincentMMoore0 no. It shows up on the I drive system occasionally and says to stop driving immediately. It’s only happened once in the last 5 or so months, so that’s good. I had the sensor changed a year or so ago, so it’s not that. And the level looks good
Had my friends water pump shaft break, serpentine belt wrapped around the fan clutch and started overheating. He said he turned it off immediately and it does start even though I told him not to. What are the chances he didn't blow the head gasket and I can just replace the water pump, belts, etc?
these things are about bullet proof. watch your oil and your cooling system. I have 203K miles on mine. It has overheated one time (thermostat failed closed) but I was able to shut it down fast enough to not get too hot.
@@MTechGuy No longer than 5 minutes. Got the leak fixed the next day and there doesn't appear to be any fault codes. Just drove from swansea to london and everything seemed smooth. How long would it take for problems to start to show if there was damage?
@@MTechGuy it dropped a little bit. Maybe 100/200ml or so. Not the 4 litters a day like it was before lol. Hopefully it isn't leaking through head gasket? Or maybe it's just air pockets escaping since it was newly flushed.
I had my radiator cracked on my 325i and it overheated now the engine still runs but it doesn't seem to be as smooth so idk if it needs a rebuild as if it does I'd rather build a new/lower mileage motor. I want to turbo my car in the future. My question is ,is it worth rebuilding the potentially damaged motor or building a new motor? And what's the best way to diagnos if it it damaged?
Check the head bolt torque, if the threads are pulled through overheating- get a replacement motor. If the threads/torque are ok, if it’s not showing signs of head gasket failure it should be ok
It night sound stupid I know but ive done a lot of research but haven't seen this video.. I tried to drive my 04 X3 3.0 to the shop around 7-9 miles going around 50 on the freeway when I realized she didn't want to go that speed it was to late I was on a 2 lane bridge with no shoulder on the freeway n I took the first exit I could and as I slowed down off the ramp she siezed up I parked and let it sit now it will crank up still sounds like she wants to turnover but she wont it did leak all the oil and antifreeze but added a little oil before trying... No milky stuff anywhere just missing compression in 123. Any advice or negative remarks??
Hey man, that sounds like a bad day! If it seized and spewed all the oil and coolant there won’t be much coming back from that unfortunately. These engines are relatively cheap and plentiful, fit a good used replacement
On my M52Tu i replace water pump thermostat belts pullys oil filter housing gasket only radiator and expansion is from 2000, Iam waiting for them to fail 😂, i wanted to replace but radiator need to wait about a week so i didnt want to wait
Hello mate, I have an e46 325i and it bucks at low rpm feels as if i’m shaking a bit in gear 2/3 in the higher gears it’s fine what do you reckon that may be? many thanks for any advice or help!
Please explain how in the world, by aluminum block can lower the torque on bolts when overheated? Ok, u did, but still, I'm sorry but that is not possible whatsoever, that bolt will only deform under 1000s of degrees. If you have worked on bmw cars, and I'm sure that You have, for example suspension component which are aluminum.....heating aluminum to remove the bolts does not work, to be honest based on my numerous experiences, I have noticed that it might even increase the torque, but I'm not making the statement a fact. But, the reason why head gaskets fail on M54 motors is misdiagnosis. I have personally have purchased at least 4 vehicle that I can only recall at this moment with "blown head gasket" and every single one of them had faulty Thermostat. Only way I can see head gasket fail on those engines is running it with zero coolant in it for.......I'd say an hour. And the reason why gasket will fail is due to it deteriorating under high heat.
Most common cause of overheating for these engines is failure of a component of the cooling system. Can cause head gasket to give out if driven overheated, in some cases the threads for the head bolts (the threads in the block) can soften and proper head torque will be compromised, even helicoiling won’t last in some cases. No only is it possible, there are many M54 engines out there that this has happened to
May I add that another cause of white coolant spots is overfilling the expansion tank. On a cold engine, the coolant should be barely visible and sitting at the very bottom of the tank. Upon heating up the coolant rises or "expands" to the top of the expansion tank. That is what it is for. Some people fill it right to the top and the coolant has nowhere to expand therefore it finds different spots to leak out of unnecessarily, and folk starts getting paranoid. Only fill the expansion tank so it sits at the very bottom of the tank and never fill to the top.
The expansion tank has a level indication float, but once it reaches max fill it stops moving. Yes, if it’s filled beyond the max mark it can cause the tank cap to pressure relive, but in a lot of cases it can cause the expansion tank to split too
Love my m54. Great video you certainly know what you’re talking about, first person to say the gasket is usually not the issue and it’s the head bolts. Many people think it will be easy head gasket replace , then when they go to pull the bolts they notice the absolute lack of torque or shorn female threads in the block. These are great engines truly, just surrounded by a pretty unreliable cooling system. Luckily very easy to replace
We used to drill and tap a little hole right next to the oil pump nut, effectively locking it in place with a little hex screw and of course oil resistant loctite and in combination with a s54 oilpump chain tensioner kit you're way more freely to Rev the engine higher because the chain harmonics are damped and don't kill the axle or make the nut come loose
Thanks for sharing Mick, I’ve not heard of that S54 tensioner trick before 👍
Just bought a 2003 325i 5 speed manual sedan. Thanks for the tips mate!
Thanks for checking out the video man
Just subscribed, really like your no nonsense approach
Thanks man, appreciate it. Glad you’re here. Thanks for watching!
Used to have a 02 330xi 5 speed man. Although I did find myself replacing gaskets and hoses etc all over the engine all the time, the engine itself to me was reliable and strong. I got 157k miles on that engine before taking a careless spirited drive one day and thew my excessivly sloppy shifter into third by accident, bending the valves. Since then upgraded to a g20 330imsport., its a welcoming upgrade.
Yes, they are good engines. My old E53 X5 has about 280,000kms on it now, still going strong. Wish we got the 3&5 series Xi from that generation in this part of the world
Timeserts done properly are 100%. A Boeing 747 has over 250,000 helicoils and timeserts installed from the factory in its aluminum substrate components so the moving threads are steel on steel.
When these engines get cooked, it anneals the alu block. Depending on how hot it gets- in a lot of cases the helicoils won’t last unfortunately
So true, I had a rad hose blow when the car was idling in my driveway. Left the car for 25 minutes. Left it for so long because car hadn't driven in a while so thought I would charge the battery. It did overheat. Not sure of the outcome yet as the car hasn't been driven much. Feeling really dumb.
Now the battery is the least of your worries right! Get it checked out for hydrocarbons in the coolant, that will identify if the head gasket has failed or not. Good luck!
I thought it was pretty funny when you talked about the K series head gasket considering I have a 530i touring and also an MG TF (with a leaking head gasket lol)
Lol, standard for a K series engine from that era!
@@MTechGuy apparently these engines are ok if not ragged from cold and well maintained
I have had my engine over heat once because the aux fan switch was broke and i was learning to drive manual at a parking lot. Luckily my bmw has had about 1k miles on it since and no problems. Will do and inspection
Should be OK if I’d didn’t get too hot and the vehicle wasn’t driven far
I appreciate your direct approach. Cheers mate
100% on the cooling components, was so paranoid I did water-pump, thermostat, expansion tank, upper/lower hoses, temp senosr, coolant level sensor, and fan blade lol !
Always read that the oilpump nut issue mostly affected cars that constantly sustained + 6000 rpm (eg tracked cars), and was only an issue on m54b30 (harmonics unique to it). And on top of that the only real solution was the OEM Motorsport oil-pump (ridiculously priced😫). You should be safe if you aren't constantly tearing the streets up, I didn't stress about it myself 👍🏽
Great vid!
Your a bloody good mechanic
Cheers Rich! Thanks for watching
Just bought WU06TJX and hoping to keep her for a long time. First e46 and subbed as know how important the maintenance is 👍
Great cars the E46! Thanks for the sub, I’m glad you’re here
I'm not certain if it's related but my 03 330xi m54 threw a few codes but I drove it anyway. There's four a p0505, p1619, p0030, p0102. I got in it this morning and now the car will only rev once and then totally ignores the gas pedal, doesn't rev at all. I'm entirely at my wits end with it. Could it be in limp mode? No new codes also.
My e46 reservoir was throwing out coolant but my car doesn’t overheat and it doesn’t run hot either. It stays in the middle, maybe it was overfilled? I recently bought it for $500 so don’t mind putting in some money into it. I think I’ll just re do the full cooling system and intake system
Too much coolant, twist the cross next to the coolant cap to release pressure and coolant to allow for good functioning. Make sure to tighten back
@@MarcusLeon92this ^
Great Video Mate. I subscribed. I have my m54B30 fully rebuilt by end next week. Yes we will locktite and wire the oil pump nut. New head gasket, new piston rings, new crankshaft bearings, new hydralic lifters. Head has been bored intake and outtake. Please give me your advice on best way to run in the engine.
Nice work! For running it in, first 500 miles keep the rpm’s below 4000 rpm, listen to the engine and keep an eye on the temp gauge. Change the oil at 500 miles, and again at 1000 miles & 3000 miles 👍
Interesting.... I have a 2003 e39 530i , i love it to bits. Is the oil pump nut issue an issue in general on the M54 engine?
or is it usually associated with higher millage and frequently driving the motor hard / at high revs that causes this to fail? If it is of any importance my engine has done 112k
Any M54 that has seen sustained high revs for a long duration
More common in 3.0’s too
@@als5995 Yes, it seems to be the 3.0’s that suffer
Ok awesome so im in a kinda safe space with my 2.2. Although i have performed a mini durance test high speed and rev over 5000-5500 rpm during 20 a 30 minutes...... German highway. Of course i had warmed up the engine carefully during more then 1 hour driving normally. Then pulled over at a gas station. Filling up the gas tank and after paying. Checking oil level and making sure the dipstick is just near mac indicator point. The i took of and had a very enjoyable moment. I also love the m54 engine.
Just keep the water system fresh! Also change the expansion CAP! If it does not release the pressure it can cause a failure! Oil chain pump tensioner. DISA repair KIT! Rod bearings after 300.000km replace!
Just gonna say I’ve gone into the red many times and have now fixed the issue, but the car is been running fine with no head gasket issue for over a year now
my m54b30 has gone to the red like 5 times due to various issues, although no apparent head gasket issues. Is there anything i should check that could have been affected.
Check your coolant for exhaust gas
Please correct me if I’m wrong, aren’t you supposed to heat red loctite to remove the bolt you’ve put it on? And if so, do engine temperatures get close enough to the heat needed to relieve the red loctite?
I’ve never had an issuer removing bolts cold that were installed with red loctite, this nut is so skinny that cold removal wouldn’t be an issue. Red loctite is good for temps beyond M54 engine operating temps
Red loctited mine and replaced with the Turner motorsport drilled nut and wire.
My 2003 525i has white all over expansion tank and numerous cooling hoses. It overheats roughly twice a month. I top it up with coolant when it over hears and move on with my life.
Bought car at 180k have 340k now, it's been like thay since day 1.
Should I be concerned about engine failure?
If you own one of these it’s standard procedure to check the oil level and coolant atleast once a week 😄
Subbed, I like your style
Cheers, I’m glad you’re here
I have problem with oil spraying noozzle or oil squirting,my was broke, i cant find any video on yt about them
It can happen on high mileage M54B30 engines, the check valve in the nozzle can cause issues. If you found one broken I would go through and replace them all
I’m about to buy E39 Touring 2001, how to know if there’s any engine failure?
What is the most common problems that i need to check and ask to test it??
If you have any concerns, arrange for a reputable garage to carry out a pre-purchase inspection
Oil Pump Nut I think is a M54B30 issue not the 25.. if the 2.5 has the issue mine should have failed by now
Only really an issue on the 3.0 at sustained high RPM’s for long periods
They should make stage 8 locking fasteners for the valve cover header bolts
Hi mate I am going to get one of the P1 gauge systems that plug into the obd port, you can then monitor your coolant temp from the dash. What coolant temp level would you say the engine is overheating or starting to over heat thanks mate
That’s not a bad idea, reminds me of an old device used to be able to get called a “coolant snitch” Operating ramp 95C (give or take) If it gets to approx. 115C start getting worried!
Just had my M54 overheat a few times. She's fine, but these are the general temps for my m54b25 engine.
80-108 - normal temp
108-114 - Uh... Go back down pls?
115 - Oh shit, is it gonna go back down? Worry, but sometimes the aux fan will cool it back down. This is when you wanna check coolant levels and your hoses and radiator if you see this often.
115-120 - Pull over, NOW. If you expose the engine to
@@MTechGuy thanks mate great video. Still going back over all the maintenance you talk about. Cheers
@@joseherrera5264 cheers mate interesting post
On the verdge of selling my bmw x5 e53 3.0i (m54 engine I believe) a customer road tested my vehicle and suddenly oil started leaking. Its as if pressure from the engine caused it to leak. strangely, I started to noticed I had oil inside the expansion tank. Isit true that there are no oil coolers in this engine? & possible that the gearbox cooler failed to cause the mix? Worse case the cylinder head which im not hoping because the vehicle was ready to be sold! - Any thoughts would be much appreciated as im thinking to keep this vehicle now.
These M54 engines can leak from various places (valve cover gasket, oil pan, VANOS hose, oil filter housing, power steering lines) Oil in coolant is either trans cooler mixing, or if the engine had recently been overheated it could be the head gasket
I occasionally get a low oil pressure warning. Have taken it to a specialized bmw mechanic but no success in finding the issue. Anyone have any advice? Thanks!
When you check the actual dipstick, is the level ok?
Is the problem you’re describing, the yellow oil warning, and does it happen on startup and then turn off soon after?
If yes to both of the above, it could be a bad oil level sensor. There are plenty of videos addressing replacement on YT. Good luck.
@@VincentMMoore0 no. It shows up on the I drive system occasionally and says to stop driving immediately. It’s only happened once in the last 5 or so months, so that’s good. I had the sensor changed a year or so ago, so it’s not that. And the level looks good
I get yellow light on the start up, goes away about 30 seconds. But I replaced oil pressure sensor, and did the job.
Had my friends water pump shaft break, serpentine belt wrapped around the fan clutch and started overheating. He said he turned it off immediately and it does start even though I told him not to. What are the chances he didn't blow the head gasket and I can just replace the water pump, belts, etc?
Should be ok if he shut it off fairly quickly. Replace the broken parts and see how it runs
these things are about bullet proof. watch your oil and your cooling system. I have 203K miles on mine. It has overheated one time (thermostat failed closed) but I was able to shut it down fast enough to not get too hot.
overheated my m54. Went into red for a couple seconds and i immediately turned it off. Is it game over?
Sounds like you might be alright, depending on how far you drove it with the gauge past the half way mark before it went onto the red
@@MTechGuy No longer than 5 minutes. Got the leak fixed the next day and there doesn't appear to be any fault codes. Just drove from swansea to london and everything seemed smooth. How long would it take for problems to start to show if there was damage?
@@callmeJAF If there was a problem it would have come about during that trip, if the coolant level looks OK, it should be fine
@@MTechGuy it dropped a little bit. Maybe 100/200ml or so. Not the 4 litters a day like it was before lol.
Hopefully it isn't leaking through head gasket?
Or maybe it's just air pockets escaping since it was newly flushed.
I had my radiator cracked on my 325i and it overheated now the engine still runs but it doesn't seem to be as smooth so idk if it needs a rebuild as if it does I'd rather build a new/lower mileage motor. I want to turbo my car in the future. My question is ,is it worth rebuilding the potentially damaged motor or building a new motor? And what's the best way to diagnos if it it damaged?
Check the head bolt torque, if the threads are pulled through overheating- get a replacement motor. If the threads/torque are ok, if it’s not showing signs of head gasket failure it should be ok
@@MTechGuy thanks, also awesome response time. Appreciated
I appreciate this video mannnn
Im looking into the 330i touring for my first car
Good choice. These cars are getting old now though, and will need some work so know what your getting yourself in for!
@@MTechGuy yeah i know
Is a 03 model
I can't even put transmission fluid
It night sound stupid I know but ive done a lot of research but haven't seen this video.. I tried to drive my 04 X3 3.0 to the shop around 7-9 miles going around 50 on the freeway when I realized she didn't want to go that speed it was to late I was on a 2 lane bridge with no shoulder on the freeway n I took the first exit I could and as I slowed down off the ramp she siezed up I parked and let it sit now it will crank up still sounds like she wants to turnover but she wont it did leak all the oil and antifreeze but added a little oil before trying... No milky stuff anywhere just missing compression in 123. Any advice or negative remarks??
Hey man, that sounds like a bad day! If it seized and spewed all the oil and coolant there won’t be much coming back from that unfortunately. These engines are relatively cheap and plentiful, fit a good used replacement
you are the fucking mannn i love this
On my M52Tu i replace water pump thermostat belts pullys oil filter housing gasket only radiator and expansion is from 2000, Iam waiting for them to fail 😂, i wanted to replace but radiator need to wait about a week so i didnt want to wait
three leader three therdy?
This is 2.5 or 3.0 ? B25 or b30
3.0
Only difference is the intake manifold and the camshafts i believe also brakes.
Hello mate, I have an e46 325i and it bucks at low rpm feels as if i’m shaking a bit in gear 2/3 in the higher gears it’s fine what do you reckon that may be?
many thanks for any advice or help!
Scan for codes and go from there
You either have vacuum leak or bad maf. Unplug the maf sensor to see if it fixes issue
Please explain how in the world, by aluminum block can lower the torque on bolts when overheated? Ok, u did, but still, I'm sorry but that is not possible whatsoever, that bolt will only deform under 1000s of degrees. If you have worked on bmw cars, and I'm sure that You have, for example suspension component which are aluminum.....heating aluminum to remove the bolts does not work, to be honest based on my numerous experiences, I have noticed that it might even increase the torque, but I'm not making the statement a fact.
But, the reason why head gaskets fail on M54 motors is misdiagnosis. I have personally have purchased at least 4 vehicle that I can only recall at this moment with "blown head gasket" and every single one of them had faulty Thermostat.
Only way I can see head gasket fail on those engines is running it with zero coolant in it for.......I'd say an hour. And the reason why gasket will fail is due to it deteriorating under high heat.
Most common cause of overheating for these engines is failure of a component of the cooling system. Can cause head gasket to give out if driven overheated, in some cases the threads for the head bolts (the threads in the block) can soften and proper head torque will be compromised, even helicoiling won’t last in some cases. No only is it possible, there are many M54 engines out there that this has happened to