I think its the most common oil leak which many garages mistake for a Oil Cooler Leak which is obviously at huge expense so it is worthwhile checking first.....mrix
Noticed oil on my drive, took it to a specialist who had recently given the car a B service (so they must have removed this part to change the fuel filter!), was told it was oil cooler seals £1100 to replace. My mate showed me this video so checked this, and lo and behold the seal had two massive cuts in it and the small plug on the pipe was almost hanging out where the ridges had worn away. Replaced both and so far so good.
Hello, I think garages explain its the oil cooler seals often, at the end of the days its going to be very difficult for them to actually know for sure as the oil cooler is in the deep part of the V part of the engine, because of this I am wondering if they are being disingenuous simply for the price tag of repairing it ? but as I say I dont think they know for sure but being a garage they should really be checking other potential places like the turbo oil seal etc, getting back to your vehicle you may still see signs of a small leak for a few days because there will be a certain amount of oil still draining down over the engine from the prior leak you had... anyway thanks for the feedback.... mrix
@@mrix I`ve heard about quite a few turbos being falsely replaced because of this issue as well,,, Also heard of workshops telling customers they`ve got a leaking rear main oil seal in the engine when it`s the oil cooler seals,,, They`re a good engine, just misunderstood,,,
I have a similar leak on my Ml350 2012, its only done 70k miles and I found a leak on my drive as well. I will have to follow this video and see if that resolves it. Great video.
Have the same kind of watery oil but it's appearing on the driver's side of the motor on the bottom cover. Thanks for the pointer that it could be from the PCV, will investigate more.
Yes technically a catch can is the way to go, unfortunately on the C350 there is no position to add a catch can in the position you mention, I did attach a catch can but it caused no end of black smoke for whatever reason so decided not to go down that route but I could not add a catch can where you suggested unfortunately.....mrix
My garage also said to me it was the oil cooler seals when it was not.... I wonder how many have spent a small fortune on the oil cooler seals when it was simply a turbo seal leaking ? ....mrix
To be honest when I investigated the jubilee clip was loose so I just tightened it. There was oil underneath so cleaned that and will check again in a couple of months. The same garage had replaced turbo so assume they hadn't tightened jubilee clip.
Hi, I did think about it but at the end of the day its rubber silicon so I think it should be ok, I highly suspect it will simply just pull away or scrap off but that maybe wishful thinking.....mrix
If you add an oil catcher it needs to be one without a breather. This is a sealed system, any air going in will not be measured by the MAF sensors and will confuse the ECU
Oh thank you so much, it did mess my system right up! If I run into any issues at any point I will try without a breather, thanks so much, fortunately its been running fine to date with no leaks..... thanks again.......mrix
Quite possibly, the trouble is the PCV Valve on older cars does not really work and do the job anymore, I replaced mine with a brand new Mercedes PCV valve and it never made any difference regarding the amount of oil coming from it, I dont think the PCV valve can handle the amount of blow by on a older engine.
Hi, did you think of, or analyse the root of this seal going bad, again and again? Im not a mechanic, but I got so sick&tired of the incapable mechanics, so I took my car home and opened it up… Found the same issue, but it’s important in my world is to look for the reasons… The result: Broken Pressure Control Valve, A6420101891. (R-class - W251)
Hi, that part number is the crack case breather which I have already replaced twice, Personally I think its a design fault whereby the car runs great from New but over the years with more blow by the breather valve fails to work with the increased blow by, this is why many opt and decide to go with a catch can, I dont think anything can fix it unless you use a catch can, I am likely still getting this blow by oil which is reaching the turbo but then reaching the turbo but its getting burnt off, at least the oil is no longer draining down to the bottom of the engine. I tried a catch can myself but it messed with the Maff sensor so I had to remove it but recently I had a reply in a comment made that you are required to use a catch can that does not include a breather... if you have success then brilliant but after a few months remove the turbo seal and see if its still working, I get the feeling it will not be.... however all the very best....mrix
Hello, initially I thought I never fixed it but it was simply the excess oil draining down, after a few hundred miles that drained away and stopped, if anyone else decides to do the same you will have to give it some time etc.... mrix
If you reroute the crankcase breather hose away from its stock location right in front of the turbo intake and through a catch can and then back to the fitting it originally came from the leaks will stop and the new seals will work fornearlyever. This will also stop the oil vapor combining with the intake soot produced by the EGR and coating the whole inlet system with black sooty putty. I had the same problem on our Jeep GC with this engine but where i live we could delete the EGR, do the little mod i just described to fix the turbo hoovering all the oil out of the engine and delete the swirl flaps after the oil running out of the turbo intake destroyed the little motor. Only thing left was to do the oil cooler seals, which hadn`t started leaking but were found to be the bad ones (orange colour) So i replaced those too (Bastard of a job),,,
Hi I did try going down the catch can route but it never worked out, I had a lot of blowing back smoke and trying to find a place to place the catch can was impossible, I would love to find out what catch can you used and where you placed it ? thanks for the feedback......mrix
@@mrix I used a Provent catchcan but had lots of options for stowing it in the Jeep Grand Cherokee engine bay. For a while i just ran a large diameter fuel hose directly from the PCV valve outlet to under the truck with a couple of coils in the hose to catch the worst of the discharge. Lots of fumes floating around waiting at the lights like in the old days so that idea didn`t really fly. Also worth doing some research on the intake seals you changed on your vid. I got mine from "ID Parts " in the USA and there are some available that use a red compound that is superior to the OEM ones. I got the whole oil cooler seal replacement kit from them with new intake seals as extras and it was only 10 days from the US to my letterbox in NZ. If you can solve the fumie discharge problem, then you can fit a set of good seals and avoid the dodgy silicon deal and also avoid the swirl flap motor change which will happen if the oil keeps dripping out of the turbo intake down onto the little electric motor underneath. Apparently, it`s expensive to replace. I deleted mine, very cheaply,,,
Huge thanks for your in depth reply, I shall have another think on what and if I shall proceed with a catch can again, presently everything seems fine and the engine is running sweet...mrix
Hello the sealant is a very strong heatproof silicone, been working very well since... the seals on a older engine no longer work, I have already replaced the orange seal 4 times and this is why I took this route which appears to work so far..... mrix
Hi on these engines I am sure its clear to many that the crankcase breather no longer works, it may of been suitable on the engine when it was New but its clear it cannot cope with the amount of blow by you get with a older engine, I have replace the crack case breather twice now and I can assure you its not going to help on these aged engines, you stop the blow by oil by using my method or a catch can.... nothing else will help.... mrix
Really helpful, thanks - Combined with replacing the PCV Valve this has resolved the oil leak my garage couldn't find!
I think its the most common oil leak which many garages mistake for a Oil Cooler Leak which is obviously at huge expense so it is worthwhile checking first.....mrix
@@mrix especially as my oil cooler seals have already been done!
Absolutely I loved it to watch your videos 👍
Glad you like them, thanks mrix
Noticed oil on my drive, took it to a specialist who had recently given the car a B service (so they must have removed this part to change the fuel filter!), was told it was oil cooler seals £1100 to replace. My mate showed me this video so checked this, and lo and behold the seal had two massive cuts in it and the small plug on the pipe was almost hanging out where the ridges had worn away. Replaced both and so far so good.
Hello, I think garages explain its the oil cooler seals often, at the end of the days its going to be very difficult for them to actually know for sure as the oil cooler is in the deep part of the V part of the engine, because of this I am wondering if they are being disingenuous simply for the price tag of repairing it ?
but as I say I dont think they know for sure but being a garage they should really be checking other potential places like the turbo oil seal etc, getting back to your vehicle you may still see signs of a small leak for a few days because there will be a certain amount of oil still draining down over the engine from the prior leak you had... anyway thanks for the feedback.... mrix
@@mrix I`ve heard about quite a few turbos being falsely replaced because of this issue as well,,, Also heard of workshops telling customers they`ve got a leaking rear main oil seal in the engine when it`s the oil cooler seals,,, They`re a good engine, just misunderstood,,,
I have a similar leak on my Ml350 2012, its only done 70k miles and I found a leak on my drive as well. I will have to follow this video and see if that resolves it. Great video.
Have the same kind of watery oil but it's appearing on the driver's side of the motor on the bottom cover. Thanks for the pointer that it could be from the PCV, will investigate more.
All the very best of luck..... mrix
This oil leak is best fixed installing an oil catch can between the out of the pcv valve and before the turbo intake.
Yes technically a catch can is the way to go, unfortunately on the C350 there is no position to add a catch can in the position you mention, I did attach a catch can but it caused no end of black smoke for whatever reason so decided not to go down that route but I could not add a catch can where you suggested unfortunately.....mrix
Turns put I had same problem after professional mechanism diagnosed oil cooler seals which had already been done. Thanks for tip.
My garage also said to me it was the oil cooler seals when it was not.... I wonder how many have spent a small fortune on the oil cooler seals when it was simply a turbo seal leaking ? ....mrix
Has your repair fixed the leak?
To be honest when I investigated the jubilee clip was loose so I just tightened it. There was oil underneath so cleaned that and will check again in a couple of months.
The same garage had replaced turbo so assume they hadn't tightened jubilee clip.
What happens if you need to replace the seal again would imagine it will be difficult to remove the old silicone.
Hi, I did think about it but at the end of the day its rubber silicon so I think it should be ok, I highly suspect it will simply just pull away or scrap off but that maybe wishful thinking.....mrix
If you add an oil catcher it needs to be one without a breather. This is a sealed system, any air going in will not be measured by the MAF sensors and will confuse the ECU
Oh thank you so much, it did mess my system right up! If I run into any issues at any point I will try without a breather, thanks so much, fortunately its been running fine to date with no leaks..... thanks again.......mrix
Hey !
I wondering if a bad PCV valve can affect the EGR valve ?
Quite possibly, the trouble is the PCV Valve on older cars does not really work and do the job anymore, I replaced mine with a brand new Mercedes PCV valve and it never made any difference regarding the amount of oil coming from it, I dont think the PCV valve can handle the amount of blow by on a older engine.
Its a C320 model 2008 by the way
@@mrix Because under the PCV valve, there is another part-the breather cap A6420107215-which also needs to be replaced.
Hi, did you think of, or analyse the root of this seal going bad, again and again? Im not a mechanic, but I got so sick&tired of the incapable mechanics, so I took my car home and opened it up… Found the same issue, but it’s important in my world is to look for the reasons… The result: Broken Pressure Control Valve, A6420101891. (R-class - W251)
Hi, that part number is the crack case breather which I have already replaced twice, Personally I think its a design fault whereby the car runs great from New but over the years with more blow by the breather valve fails to work with the increased blow by, this is why many opt and decide to go with a catch can, I dont think anything can fix it unless you use a catch can, I am likely still getting this blow by oil which is reaching the turbo but then reaching the turbo but its getting burnt off, at least the oil is no longer draining down to the bottom of the engine.
I tried a catch can myself but it messed with the Maff sensor so I had to remove it but recently I had a reply in a comment made that you are required to use a catch can that does not include a breather... if you have success then brilliant but after a few months remove the turbo seal and see if its still working, I get the feeling it will not be.... however all the very best....mrix
Did this fix the oil leak in thr end?
Hello, initially I thought I never fixed it but it was simply the excess oil draining down, after a few hundred miles that drained away and stopped, if anyone else decides to do the same you will have to give it some time etc.... mrix
If you reroute the crankcase breather hose away from its stock location right in front of the turbo intake and through a catch can and then back to the fitting it originally came from the leaks will stop and the new seals will work fornearlyever. This will also stop the oil vapor combining with the intake soot produced by the EGR and coating the whole inlet system with black sooty putty. I had the same problem on our Jeep GC with this engine but where i live we could delete the EGR, do the little mod i just described to fix the turbo hoovering all the oil out of the engine and delete the swirl flaps after the oil running out of the turbo intake destroyed the little motor. Only thing left was to do the oil cooler seals, which hadn`t started leaking but were found to be the bad ones (orange colour) So i replaced those too (Bastard of a job),,,
Hi I did try going down the catch can route but it never worked out, I had a lot of blowing back smoke and trying to find a place to place the catch can was impossible, I would love to find out what catch can you used and where you placed it ? thanks for the feedback......mrix
@@mrix I used a Provent catchcan but had lots of options for stowing it in the Jeep Grand Cherokee engine bay. For a while i just ran a large diameter fuel hose directly from the PCV valve outlet to under the truck with a couple of coils in the hose to catch the worst of the discharge. Lots of fumes floating around waiting at the lights like in the old days so that idea didn`t really fly. Also worth doing some research on the intake seals you changed on your vid. I got mine from "ID Parts " in the USA and there are some available that use a red compound that is superior to the OEM ones. I got the whole oil cooler seal replacement kit from them with new intake seals as extras and it was only 10 days from the US to my letterbox in NZ. If you can solve the fumie discharge problem, then you can fit a set of good seals and avoid the dodgy silicon deal and also avoid the swirl flap motor change which will happen if the oil keeps dripping out of the turbo intake down onto the little electric motor underneath. Apparently, it`s expensive to replace. I deleted mine, very cheaply,,,
Huge thanks for your in depth reply, I shall have another think on what and if I shall proceed with a catch can again, presently everything seems fine and the engine is running sweet...mrix
Ohh man! Be careful , because turbo dont like to eat silikon bitter.
Hi, so far so good, but yes it can be risky... just a matter of taking it easy with the silicon..... mrix
What kind of silicone you used?
O dear, silicone sealant that'll break down and enter the eturbo/engine, just buy a new seal they dont cost much
Hello the sealant is a very strong heatproof silicone, been working very well since... the seals on a older engine no longer work, I have already replaced the orange seal 4 times and this is why I took this route which appears to work so far..... mrix
This wasn't a good idea... Maybe you should have switched the crank case breather valve instead. 😉
Hi on these engines I am sure its clear to many that the crankcase breather no longer works, it may of been suitable on the engine when it was New but its clear it cannot cope with the amount of blow by you get with a older engine, I have replace the crack case breather twice now and I can assure you its not going to help on these aged engines, you stop the blow by oil by using my method or a catch can.... nothing else will help.... mrix