My 87 560 sel has been sitting for about a week as I await some new rotors and pads for the rear. I started it up today just to get the engine running and noticed a few disturbing elements. First, when I turned the key the car did not start and made a type of purr. After the 4th turn of the key, the car turned over but was emitting a knocking sound form the engine when cold. As the car warmed up, the sound almost disappeared but I could still hear it faintly. The car is leaking oil from the valve cover and rear main seal. I should have my brakes in the next few days and am wondering if it will be safe to drive the vehicle when that job is done. The car has ran like a top for the last 4 years but it seems that problems are starting to pop up right now.

I am ordering some valve cover gaskets and will work on trying to stop some of the leak.

As well, after driving on the highway I notice a big blue cloud of smoke after starting up from a stop light. Obviously I'm burning oil. I am not burning any coolant however and there is no oil in the coolant reserve tank. Anyone with ideas on how I am burning oil?

I am resonably handy but have not worked on automobiles very much. Where should I start looking. I have access to a 450 slc this summer so I'll have some time to spend on my 560.

Smoke when opening the throttle after decelerating is often caused by worn valve guides and/or stem seals. This is cheaper and easier to fix than worn rings, pistons, and cylinders.

The "knocking" sound you heard and still hear faintly... could it be more accurately described as "ticking" or "tapping?" I'm assuming (someone correct me if I'm wrong) that the '87 has hydraulic lifters. If they are getting worn one or more could have leaked down while the car was sitting. This would cause a loud tapping for a few minutes. If the lifter is bad, the tapping may not ever completely disappear. If many of the lifters had leaked down the car would be difficult to start and would sound "funny" while you were cranking it with the starter. I think this is unlikely however in a car that has only sat for one week without running.

Don't overlook some simple things, too. If the car seems to be leaking oil from many places, check your PCV system. If the crankcase pressure is high, it will push oil past the seals and maybe even the valve cover gasket. It can also exacerbate marginal valve guides/stem seals. Smoke can also be caused by a failed transmission modulator, although the smoke tends to be whiter rather than blue and will be present even when the car is sitting and idling.

__________________
1987 W201 190D

How many miles? How's the maintenance been? What kind of oil have you used, and how often has it been changed? Was it every run low on oil? Did it ever overheat?

__________________
1987 W201 190D

The "knock" almost makes the car sound a little bit like a diesel engine.

One other thing I noticed was I had to drive the car in reverse for about 100 yards. After about fifty yards, I noticed a considerable leak of oil on the pavement. I say considerable as it left quite a trail in the parking lot at my work and then leaked for a while after the car sat for a couple of hours.

For certain I have a leak at the valve cover as the seam between the head and the valve cover has a significant build up of oil. When the car is running, the heat from the engine burn the leaking oil and creates quite a bit of smoke.

The car has been low on oil but has never lost full pressure. I use 10w40. Regular oil changes as well.

I have a feeling this engine needs serious service very very soon or its going to die an early death.

Things coming to mind: Leaking/failing oil lines, timing chain and guides....

If you blow the timing chain its all over.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Timing chain was done 2.5 years ago so not overly worried about that. Will make sure not to drive it in reverse for too long as I hear that those cars don't like the heat. I have one spark plug that wouldn't come out at last service so I think it might not work anymore. My mechanic thinks I'll put $$$$$$$$$$$$$$$$$$$$$$ into it if I take it to him. I just want to make sure I can drive it without killing it.