Watching your video made me realise the front engine cover has always been missing !!!! so i have asked Fraubenz in the UK if she has one, A very good video and i have already sent a request for parts to autodoc, I had to take the AC condenser out to take the rad out, as a single unit , unfortunately i have put everything back in before watching this video, it would have been an easy job, of course sods law says the engine tries to start but doesnt so i am squeezing under the car to get to the pump assy, I will change everything i hope its a pump problem and not a blocked fuel line, , With Luck and a pass of the gov test i should be back on the road this July 2023, Best regards Cheshire UK. A short story, i drove my SL from Manchester UK to Pendeen near Lands end Cornwall, its around 360 miles one way, the car was perfect no complaints but on arrival i had a stinking headache, i took some meds only realising later i accidentally took a double dose, crap i peed blood later that evening , I was down that way paying respects to my late parents grave in Pendeen Church. I stayed at the beach hotel in Hayle where we would go as kids with mum and dad, Upon my return i had a full check up, kidneys and bladder scans and was down with bladder cancer, i had two operations small by all accounts they used a laser and zapped the growth, this was 13 years ago, during covid, the system signed me off as a low grade risk without any check up whatsoever , next month i return to my retirement home in Thailand, for a few weeks , and i will pay the £450 cost to have my bladder check up done in Bangkok, I can no longer trust the system in the UK. This will be the third time i have used this particular BKK hospital, As for the SL the straight 6 is great and i had to renew half the exhaust with stainless steel, it sounds the business, I have been very lucky so far over this bladder cancer it was caught in the very early stage due to my accidental overdose of paracetamol, so enjoy life and drive a R129, any engine size, for me the straight 6 is pretty good. Cheshire UK.
Thank you. I view some of those other channels more as entertainment than information. Each has its' place. Still "car people", just, well, there are a lot of roll-up doors in the Grand Garage of Car Enthusiasm. Plenty of room for all.
Yikes! But you know, I can believe it. the parts are pretty expensive alone (I think I paid $150+ just for the plug wires) and to do it right takes a little time at whatever the shop rate is. But I do love to hear it when people can save money by watching my videos! Thanks! Alden
good video, only thing I would do different, is to also replace the insulator cover when the cap and rotor are replaced. A single 5mm hex screw hold the rotor mount in place,. It must be removed to remove and replace the Insulator cover. With the insulator cover removed, look for oil seepage coming from the cam end seal, (o-ring). If there is any oil inside this housing area, replace the cam o-ring seal.
In removing and replacing spark plugs on this particular engine model I normally used a magnetic spark plug socket, its handy and nothing to worry about.
I changed my plugs no problem but wish i had seen your video first, next up as you recommend will be renewing the cap and leads etc, once again my thanks.
Glad it helped. I found the leads to be surprisingly expensive. The OEM brands, like Bosch and Beru were over $150. Very good quality, but still more than I'd been used to paying. Cap & rotor were about average, I thought.
Interesting that you are using platinum plugs with good results, I was always under the assumption they would not work well in these old engines. I'm a little scared at the price of the EZL's for these m104's so bought up all the remaining stock of the new old stock OEM copper core bosch plugs when i redid my ignition system.
Hi! Well I took a look at my old receipts. The set of platinum plugs I took out in the video were ones I put in March 2010 at about 66K miles. This footage was actually shot in 2015 and the odometer was 166K miles, so they went 100K, with no problems. And I now have 199K on the car. so the set that you see installed has 33K on them. I have had zero problems with the plugs running with the rest of the ignition system. I started using the 4-prong Bosch plugs in my 1970 Fiat 124 years ago because they just didn't foul. (the old engine needed valve guides and would load up and start to miss in 3K miles) After I swapped in a rebuilt engine to that car, I kept the same type plugs & they work great. That said: they cost more, and they do not list versions for every engine. So maybe they do cause problems in some applications. Alden
Very interesting indeed. I doubt the original spec copper core plugs would of lasted that long without severe degradation of performance and erosion of the core and tip so clearly they do last a long time. Here in Australia we have a company that makes a complete plug in replacement injection and ignition control system for laptop tunability of the old KE-Jet system. If my EZL ever blows on my m104 I'm going to go down this path.
The sad part is that the plug-in replacement system is probably cost competitive as an EZL alternative. It shows how expensive some of these old electronic components can get! Alden
I am going to tentatively say Yes, no problem. I had no issues with the two sets I installed in my car, but I don't know what changes might have been made in the EZL ignition modules between 1990 & 1995. The EZL seemed to be the concern on the forums & message boards about using the Bosch platinums +4. I had good results and no problems. YMMV
Hard to say. Down on power could be just about anything, from a clogged fuel filter, to low engine compression. For me, tune-ups usually helped the most for things like starting easier, better gas mileage and smoother running. I'm sorry I can't be much more help over the internet.
I followed these directions, However, my '92 SL500 has a larger 24v 470uf, a smaller 24v 100uf, and a larger 24v 47uf capacitor NOT 2 100uf. So now we order and wait again.
Yes, there was some variance over the years. The dashboard I repaired was for a 90 300SL, with the 6-cylinder engine. The undeniable caution is to not use a lower voltage than what is in there when you open it up. Mine took 16V caps, but if you see 24V ones on your car, by all means, go with that or higher. The resistance is actually less important. A lower voltage cap will just fry . Also, your 92 must be an early build, because many cars of the later months of 92 (November ?) had a different odometer and circuit board. The fix really only works for cars with a mechanical odometer, not the LED-looking one.
The same engine. Died on freeway, wont start up now. Cranks, but no start. No matter, cold or hot. What could be the issue? Sensors, Ignition module, distributor?
So many possibilities, hard to diagnose over the net. I'd first check the for the fuel pump & relay. First notch on the key, you should hear it cycle, if not start by checking the fuse & relay. The scariest (for me) would be if the EZL ignition module has died. Can be Big Bux to replace. You can check for spark by working your way back from pulling a spark-plug and moving towards the distributor & coil. I have had the coil fail on an M103 engine before. Hope this helps.
I would try any of the usual suspects, like eBay, Craigslist or FB Marketplace. Just don't limit your search to specifically the 300SL, the M104 engine was used in several other models and the cover will be the same. Best luck!
Watching your video made me realise the front engine cover has always been missing !!!! so i have asked Fraubenz in the UK if she has one,
A very good video and i have already sent a request for parts to autodoc, I had to take the AC condenser out to take the rad out, as a single unit , unfortunately i have put everything back in before watching this video, it would have been an easy job, of course sods law says the engine tries to start but doesnt so i am squeezing under the car to get to the pump assy, I will change everything i hope its a pump problem and not a blocked fuel line, , With Luck and a pass of the gov test i should be back on the road this July 2023, Best regards Cheshire UK.
A short story, i drove my SL from Manchester UK to Pendeen near Lands end Cornwall, its around 360 miles one way, the car was perfect no complaints but on arrival i had a stinking headache, i took some meds only realising later i accidentally took a double dose, crap i peed blood later that evening , I was down that way paying respects to my late parents grave in Pendeen Church. I stayed at the beach hotel in Hayle where we would go as kids with mum and dad,
Upon my return i had a full check up, kidneys and bladder scans and was down with bladder cancer, i had two operations small by all accounts they used a laser and zapped the growth, this was 13 years ago, during covid, the system signed me off as a low grade risk without any check up whatsoever , next month i return to my retirement home in Thailand, for a few weeks , and i will pay the £450 cost to have my bladder check up done in Bangkok, I can no longer trust the system in the UK. This will be the third time i have used this particular BKK hospital,
As for the SL the straight 6 is great and i had to renew half the exhaust with stainless steel, it sounds the business,
I have been very lucky so far over this bladder cancer it was caught in the very early stage due to my accidental overdose of paracetamol, so enjoy life and drive a R129, any engine size, for me the straight 6 is pretty good. Cheshire UK.
What a lovely calm and collected commentary, far better than some of the raucous jocks who populate UA-cam. I will follow your guidance. Thanks!!
Thank you. I view some of those other channels more as entertainment than information. Each has its' place. Still "car people", just, well, there are a lot of roll-up doors in the Grand Garage of Car Enthusiasm. Plenty of room for all.
Thank you sir! Same job cost me at the local mechanic $930 parts and labor!!!
Yikes! But you know, I can believe it. the parts are pretty expensive alone (I think I paid $150+ just for the plug wires) and to do it right takes a little time at whatever the shop rate is. But I do love to hear it when people can save money by watching my videos! Thanks!
Alden
good video, only thing I would do different, is to also replace the insulator cover when the cap and rotor are replaced. A single 5mm hex screw hold the rotor mount in place,. It must be removed to remove and replace the Insulator cover. With the insulator cover removed, look for oil seepage coming from the cam end seal, (o-ring). If there is any oil inside this housing area, replace the cam o-ring seal.
Excellent idea! Thank You!
In removing and replacing spark plugs on this particular engine model I normally used a magnetic spark plug socket, its handy and nothing to worry about.
That's an excellent technique. These spark plugs are in a pretty deep, narrow well on the M104.
I changed my plugs no problem but wish i had seen your video first, next up as you recommend will be renewing the cap and leads etc, once again my thanks.
Glad it helped. I found the leads to be surprisingly expensive. The OEM brands, like Bosch and Beru were over $150. Very good quality, but still more than I'd been used to paying. Cap & rotor were about average, I thought.
Don't forget the air grooves mod on the cap. My cap collected quite a bit of condensation.
Interesting that you are using platinum plugs with good results, I was always under the assumption they would not work well in these old engines. I'm a little scared at the price of the EZL's for these m104's so bought up all the remaining stock of the new old stock OEM copper core bosch plugs when i redid my ignition system.
Hi! Well I took a look at my old receipts. The set of platinum plugs I took out in the video were ones I put in March 2010 at about 66K miles. This footage was actually shot in 2015 and the odometer was 166K miles, so they went 100K, with no problems. And I now have 199K on the car. so the set that you see installed has 33K on them. I have had zero problems with the plugs running with the rest of the ignition system. I started using the 4-prong Bosch plugs in my 1970 Fiat 124 years ago because they just didn't foul. (the old engine needed valve guides and would load up and start to miss in 3K miles) After I swapped in a rebuilt engine to that car, I kept the same type plugs & they work great. That said: they cost more, and they do not list versions for every engine. So maybe they do cause problems in some applications.
Alden
Very interesting indeed. I doubt the original spec copper core plugs would of lasted that long without severe degradation of performance and erosion of the core and tip so clearly they do last a long time. Here in Australia we have a company that makes a complete plug in replacement injection and ignition control system for laptop tunability of the old KE-Jet system. If my EZL ever blows on my m104 I'm going to go down this path.
The sad part is that the plug-in replacement system is probably cost competitive as an EZL alternative. It shows how expensive some of these old electronic components can get!
Alden
MMWA hey im interested in than replacement System May i know the company's name?
I use Beru non-resistor plugs sourced from MB. Cheap and correct. Why pay more?
Great video.
Can I use the same plugs ,cap and rotor that you used ,in my 1995 SL320 R129 ? I read you've had no issues with them and I'm impressed.
I am going to tentatively say Yes, no problem. I had no issues with the two sets I installed in my car, but I don't know what changes might have been made in the EZL ignition modules between 1990 & 1995. The EZL seemed to be the concern on the forums & message boards about using the Bosch platinums +4. I had good results and no problems. YMMV
Mine is really sluggish with only 60K miles. Will this help ? Just purchased the car and don’t know if it has ever been tuned.
Hard to say. Down on power could be just about anything, from a clogged fuel filter, to low engine compression. For me, tune-ups usually helped the most for things like starting easier, better gas mileage and smoother running. I'm sorry I can't be much more help over the internet.
Are you sure the 4418 will work in this engine Bosch says they are discontinued and most charts say they will not fit the 104.
Lovely video
I followed these directions, However, my '92 SL500 has a larger 24v 470uf, a smaller 24v 100uf, and a larger 24v 47uf capacitor NOT 2 100uf. So now we order and wait again.
Yes, there was some variance over the years. The dashboard I repaired was for a 90 300SL, with the 6-cylinder engine. The undeniable caution is to not use a lower voltage than what is in there when you open it up. Mine took 16V caps, but if you see 24V ones on your car, by all means, go with that or higher. The resistance is actually less important. A lower voltage cap will just fry . Also, your 92 must be an early build, because many cars of the later months of 92 (November ?) had a different odometer and circuit board. The fix really only works for cars with a mechanical odometer, not the LED-looking one.
@FlashDriveFilms Yes, mine are 25v, however, it still has a mechanical odometer.
ein danke schön, und ein lieben gruß, 🤗🍂
The same engine. Died on freeway, wont start up now. Cranks, but no start. No matter, cold or hot. What could be the issue? Sensors, Ignition module, distributor?
So many possibilities, hard to diagnose over the net. I'd first check the for the fuel pump & relay. First notch on the key, you should hear it cycle, if not start by checking the fuse & relay. The scariest (for me) would be if the EZL ignition module has died. Can be Big Bux to replace.
You can check for spark by working your way back from pulling a spark-plug and moving towards the distributor & coil. I have had the coil fail on an M103 engine before.
Hope this helps.
Hello i 300 sl 24v how you think can i use same spark plugs as yours ?
I’m looking for a new spark plug wire cover for Mercedes 300SL.
Any idea where i can Find one ?
I would try any of the usual suspects, like eBay, Craigslist or FB Marketplace. Just don't limit your search to specifically the 300SL, the M104 engine was used in several other models and the cover will be the same. Best luck!
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