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I have engine oil leak on right/passenger side which I can't track. The leak is not from oil cooler. I have inspected the engine block with endoscopic camera, everything above engine mount bracket is dry. If I look from under the car, I can see the leak is coming from area between engine and front differential. Does anyone has any clue where the oil may come from?
Might be coming from the back of the block, ie facing the firewall. There is a Oil and Air separator(PCV) that is bolted there. This is the piece if you have a newer OM642: https://www.pelicanparts.com/More_In...=0&SVSVSI=7323
PCV is new, I replaced it two months ago, and it is not leaking from there. I'm suspecting upper oil pan, or through the screw which is holding crankshaft bearing cap, but this is very unlikely. I want to be 100% sure because it is very intense job to remove upper oil pan. As far as I know there is no weep hole on that side of engine so the leak has to be from outside.
If it was leaking from the oil fill cap, it would be really obvious. I had an oil leak from the filler cap washer, and it left an oil stain there. Oil cap filler cap.
The timing chain tensioner is on that side. Behind the alternator, basically 10 inches under the oil cap. It’s sealed with a crush washer like any normal oil drain plug. I’ve seen them leak. Also, intake lines, boost hoses etc. Brake boost the engine with someone who knows what they’re doing looking for boost/oil leaks. Do you have pictures? Best bet is to clean it with brake clean, and I like to use leak trace powder. It’s a sprayable powder that turns white when it drys, and makes any leaks super obvious because they turn the white powder dark/wet
It is not from tensioner I already check that. Thanks for the sprayable powder suggestion I'll try that. I don't have photo of the leak, I'll try to take some photos this weekend. Here is photo of similar engine. Basically everything above red line seems to be dry. But if I look from under the car there is oil between engine block and front differential.
Having worked on these engines since they’ve come out, I have about 50-60 oil coolers under my belt. The line you drew looks like it’s probably a boost pipe or O-ring leaking. Do like I said, clean it really well and leak trace powder the front/side. Brake boost the engine and start searching for traces of oil
Hi I also have a oil leak on the passenger front area of the engine, its seems wet under the housing that the engine oil dipstick bolts to . I dont know what that thing is ?? the large black hose is also there? is this the oil cooler ? or is the boost pipe ?? Thanks in advance, Joe
Hello, i had simular oil leak from my om642.826, rear of engine, rigth side behind engine and gearbox. This leak driv me nuts in two years, becauce i could not figure out. Cooler was sucpect, but i used boroscope, and it was not the cooler. Replaced turbo inlet seal (big red) but did not help. I finally find out, it was the backside of the oilcap at engine was leaking. The o-ring in the cap was hard / bad. Over time oil go backwards, and rear of the rigth sylinder head behind the rear right injector its a drain hole. This hole ends up at rigth side between engine and gerabox.
I have been driving my car without the splash cover since I fixed this issue. The rainy season is about to come, I lifted my car to reinstall the cover. Interestingly the drain plug was again leaking the oil very very little (no drops on my garage floor, but around the drain plug, it was slightly wet with engine oil). I applied proper torque when fastening the drain plug (30Nm).
What could be possible reasons it leaks again? Maybe the guys who worked on engine oil applied too much torque (I don't think that they used a torque wrench) and messed up the plug?
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