2001 CLS with 177K
Open ended question.

Engine has never had an oil leak until.....

During oil change about 2 weeks ago, when finished the tech said there was a slight oil leak that looked like maybe it was the gasket, could not say for sure. 1st time i had ever used this tech, previously i always stood under car with different tech who is great about talking shop and showing me as he is working. Did not stand under car this time.

Took car to excellent engine mech for check of leak source. He said the oil pan bolts were all fine, but he found a bolt on the timing cover was loose and leaking oil. The bolt that an allan wrench tightens. By a lot. Like half a turn, maybe even 3/4ths of a turn. Car seemed to not leak for a week, but now damn it's back.

I don't own a hoist so cannot say where exact leak source is, but it shows itself on the pavement about a foot in towards the engine from the front tire of the passenger side. About the size of a quarter, and it does not seem to continue once the "quarter" has formed in the 1st couple minutes after engine is shut off. Does not continue to leak when engine is off.

Any ideas what is causing leak, and better yet what a cure may be?
I know that is general, but just getting some ideas.

We will look at the leak again tommorow or Tues depending on mechs availability.

If you have thoughts on what to look for when car is on the hoist, please post!

 

Only places I know that will leak oil from under the timing covers will be cam or crank seal unless it's run off from somewhere else.
Not many tools, I would clean the engine on that side and dry.and look for leak.

If you got tools pull the timing covers to investigate.
They will have to come off to change either cam or crank seal anyway.

 

Nothing on the timing cover would cause a leak or has the possibility to leak. For us to help you better you need to try to get a picture of where its leaking from.

 

is it oil or power steering fluid? i have seen the suction line that runs from the power steering reservoir to the pump get hard and start leaking that the pump. it will drip down right on and around the crank.

 

Working on pics. Additional info:
I had used 5 - 30w dino oil up until 130K or so.
130K - 170K Royal Purple 5-30.
170K - 175K for the 1st time, 100% full synthetic Castrol.
175K - 176K (two weeks ago oil change til now), 2nd time 100% full synthetic Castrol but i zoned out and bought 5 - 20w instead of 30w. Could this thinner 5 -20w oil have worked its way thru a couple years worth of caked on gunk? Mech irrigated and ungunked the hell out of the area so should know in another day or two a more precise leak spot. He did not have time to put on rack so no pics yet.

Power steering fluid i will replace along with the suction line, thank you fourtrax. It's due anyways, been about 18 months. Do i need to replace any gaskets as long as i'm in the area?

 

Hey NightHawkBlue


here's my story.
I recently changed the top half of the engine due to driver error.
I installed a new timing belt since I was already deep into the engine.

after completing the engine rebuild; I had to change oil several times to check if I did things correctly. (making sure coolant isnt in oil.)


anyway; so I drive it for a few weeks, all is fine.
but then I notice an oil leak.

it's coming from the oil drain plug.
but at first, I was confused because I saw oil up along the back side of the engine and even on the timing belt cover.

the drip from the oil drain plug gets blown back by air when you drive, making it hard to diagnose a leak.



your issue could very well be the drain bolt being over torqued, like mine...

or it could be this:

https://acurazine.com/forums/problem...repair-761581/

 

no gasket, just replace the suction line (53731-S3M-A00) just look the part up and you should see a diagram of where it goes. if the clamps (91405-SS0-003) are in good shape reuse, else replace. might check the other hoses around there and if they are hard replace them to prevent a future leak.

 

Any updates or pics of your leak, NighthawkBlue?

 

Timing cover gasket is the leaker.
So now, in search of a DIY for timing cover gasket and the seal that is part of the replacement process. I believe there is only 1 seal.

No pics. I'm still in smartphone user college plus my neck is currently flocked up.

 

You sure nighthawk?

 

No. I'm going by what mechanic says. He did let me walk under the car, but as you know viewing that timing cover is like one of the most awkard looks on the car. We had put dye in, that is where he traced it to. The timing cover gasket.

 

I'm pretty sure the timing cover is just a cover to protect the timing belt and cam gears from debris etc. it can't leak. Things under it can.

 

I'm a new guy here so I'm probably overstepping my bounds but I can't recall any engine I've ever worked on that used the t-belt cover as part of the engine lubricating system. It's basically a dust seal. It's already been pointed out that the only things under the cover that would leak oil are the cam seals or crank seal. I'd be having serious doubts about the mechanic at this point. Dye shouldn't be necessary to find which seal is leaking. Replace all three if there is any doubt. The belt needs to be replaced also. Pretty sure it isn't the rear main either unless these cars are built really odd

 

Mike88 is spot on.

When you say "timing cover is the leaker" what you most likely are trying to say is that something is leaking from behind the cover or possibly from above and what you are seeing (since you are not removing the cover) is the effect.

So the main purpose of the timing belt cover is to keep dirt and other foreign objects from getting onto the timing belt and and pulleys and/or all else under the cover. Take the timing belt cover off and what you should see is no trace of oil under the cover unless on top seals behind the camshafts are leaking or near the bottom around the crankshaft.

If you remove the cover and see oil - change the seals...which means removing the TB and other related parts as required.

The other possibility is that the power steering is leaking down on the cover since it is basically directly above.

 

That mechanic is a big joke..

Likely the leak is coming from the crank seal on the oil pump..