dbogdan

I was looking at purchasing a 2005 E500 for 4500$, the one I was looking at has about 145k miles on it and everything seems sound except for the engine seems to have an oil leak, whereas after a few minutes of idling and some slight revs there was some smoke coming from the engine and some squeaky noise as well. Also noticed some gunky residue near the head gasket, I;m interested in the car but obviously I dont wanna be out of an engine in half a year. So I guess my question would be is that a common symptom for an oil leak, and would a head gasket replacement be the proper solution and what would be my rough estimate in repair costs?

tjts1

If it's an M113 it's most likely leaking from the valve covers onto the exhaust manifold causing the smoke. It's very common. Valve gaskets are about $30 and a couple of hours to replace. M112 and M113 are extremely reliable and long lived.

SethP

I can't say it is the same thing, but my E550 was leaking a small bit of oil due to cam seals that had gone bad. I actually detected it due to a burning smell.

ollo

I Also had a similar small oil leak problem on the wife's W220. First noticed smell of burning oil that got stronger & eventually there was some smoke. Dealer said was probably seepage from a valve cover gasket but humored me & cleaned/dusted all around the area with a white powder & instructed me to check back after passage of time. Problem persisted, wife grew unhappy but I could not see any seepage around the gasket edge. Examined all around the area with light & mirror. Was fortunate to spot a small drop of black oil on bottom of a breather hose. Hose was rock hard & had a small split that dripped oil which eventually gravitated down to the exhaust manifold. Got a breather hose kit from Amazon and replaced all the breather hoses and got no more smell or smoke.

This was on a 2000 model year S430, occurred at around 92,000 miles on 2+ years ago. Car's M113 engine also had a very slight seepage showing around rear main oil seal beginning around the 60,000 mile mark. I watched it for years but didn't replace the seal on advice of a tech who told me they almost never fail. Ours finally began to drip a year ago at around 102.000 miles, so replaced it. Only other repairs were an alternator replaced under warranty at year 2, a water pump at 92,000, then lower control arm + ball joints & bushings all around 105.000 miles. I realize most owners don't average just 5,500 highway miles per year, but this car has been one of our most reliable. Still has a very good looking exterior and interior and is nearly as smooth/quiet as new. It is still our main travel car. My 2004 W211 wagon is the daily driver and I have the stacks of parts & repair receipts to prove it! Don edit: just remembered we replaced rear O2 sensors around 80,000 miles when originals got lazy & set a CEL.