oil in the coolant...
 

New guy here with his first '87 300SDL. Just discovered oil in the overfill tank for the coolant. Bought it like this, just checked the level without touching it. Just prior, i did an oil change, have checked the level 3xs after about 500 miles of driving with no noticeable change in level. No gauge-indicated problems with overheating. The oil looks like "old stuff" as it is VERY black, though hard to tell i guess. The new oil ( synthetic ) is already dark ( from in the cooler i guess during draining ) with no noted "tint" of coolant ( though again it would be hard to tell ). Head gasket? Hope not, how do i tell and does using "Shout!" to flush the system really work? I've read some other threads about replacing the many quarts of new fluid carefully, though i'd like to clean it out first. If NOT a head gasket, then what? Sloppy mechanical work on a job previous? Any thoughts? Thanks.:wacko:

oil
 

the oil in a mercedes 300sd always looks black like a paint... it turns that
way within 15 minutes of an oil change. So just pay that no attention.

Oil in the coolant is always a sign of a bad headgasket. One of your cylinders
will have oil migration from an oil port over to a water port. When you take off the old headgasket you will see a white line from one port to another port.

it is a long shot but it is possible the head gasket was changed and the system not flushed out.

i wouldn't count on it though

tom w

super, thanks
 

I'm an incurable optimist. That did cross my mind as the salesman did mention there was major work done recently but couldn't back it up or tell me exactly what.

Guess it would be worth it to flush, refill, drive, look. It's coming up on an inspection, would it pass like it is?

Thanks for your responses.

thanks, i'll try the more hopeful approach, as the salesman did mention work was done recently...

anyway, thanks, i'll look for the line...send pics too just for fun.

well
 

i changed a head gasket on a car last summer and it still has
water in the oil....

oh boy
 

luckily this is a project car so i'll go slow and drain everything first...raising the right side high to completely drain the radiator fluid is said to help. Then i'll let it sit like that over night and hopefully avoid water in the oil thing.

oil
 

i have heard about water in the oil but i have never seen it...

changing a head gasket is fun... and fairly easy and a great learning
experience....

Once the head is off and you get to looking you will see holes that allow the water and oil to travel to the head.... they will be maybe an inch apart.
You will see a little line where the migration is occuring.

changed the head
 

if the previous owner changed the head gasket you should be able to look at it and tell that it has been done... just by looking at the side of the engine..

funny you should mention that...
 

tinkering out there again, i did notice on the driver's side of the block, it all looked brand new. don't know if the plate would be replaced, but looked new and all the bolts had yellow paint lines on them. Maybe done so you could do it later without a torque wrench?

Also, discovered a leak where the bottom hose goes into the block. Seems to be coming out of the lowest bolt. Maybe just that gasket will fix it or some "stop-leak" product after i flush the oil out of the system.

Defininely gonna flush and seal before assuming the head gaskets done. And hopefully the repair now presumably done was done correctly!

If i'm reading your post's right, you first said you changed the head gasket and the oil now has water ( coolant? ) in it. And here, you say you have never seen it...I'm confused, though thanks for the encouragement.

How long ago did you buy the car? Was the head off recently? Would the dealer take it back?

Fluids mixing are a tell tale sign of not only a potential bad head gasket. But since its a 603 their is a potential of a cracked head. I would bring it to a good shop that knows 603's well to diagnose the problem. You may want to consider some action against the dealer if inded it does have a cracked head. Since it will cost you the better part of $3k to repair it.

A good start would be to send a sample of the oil out to a lab to see if coolant shows up.

Also is their pressure in the cooling system after the car has been sitting overnight?

maybe
 

Did buy it knowing about the potential head issue. Looks like was redone recently and was told so. Dealer may work with me, though i'm gonna try a few things first, namely fix the apparent leak on the bottom bolt on the bottom coolant intake from the radiator. Flush and refill the radiator too, though with the new leak discovery, perhaps maybe the shop is the way to go. Have to start looking for a good one here in Lancaster PA.

Will also check prssre overnight.

And now i'm totally confused. Just let some coolant out of the bottom of the radiator via that blue drain plug and it was perfectly yello-green. How can the oil be ONLY in the overfill tank unless it wasn't cleaned out properly during the last fix? Now i'm tempted to clean JUST the tank and re-install to see if the problem is misleading. None of the overfill goes BACK to the radiator, right? That's pretty much a one-way thing. I would expect a LITTLE oil to come out if there was a current leak. Oil floats, yet it also clings. So ill clean the resevoir tank re-install and in week look for more oil ( or rather look for NO oil ). Anyway, thanks for all the feedback.

What revision head?
 

My understanding is that if you have any reviision other than the "14", the head has been replaced (along with the gasket). The '87 300SDL was just this way with a #17 head. It had some oil in the expansion tank. It has no build up of pressure from a blown head gasket, so I took the gamble that the oil was from the previous blown head gasket/cracked head. I took the expansion tank off and cleaned it out, flushed the radiator (which is fairly recent , it appears) and block. I used SHOUT, I didn't know someone else here had tried SHOUT, but it sure gets the oil/grease out of my jeans! Used a whole refill size bottle in the system. Also, it doesn't foam up. I blew out the heater core each time I flushed/rensed by removing the heater line near the oil filter... just make sure to properly let it cool down between flushes.....(before putting the garden hose to it or final fill.)

Do check for the build up of pressure. When the motor is cold, there should be no pressure. If there is you my have a blown head gasket. When cold, release any pressure on the expansion tank, then replace the cap. Start the motor, let it idle, rev slightly, then check the cap to see if pressure has build up in the first 30-40 seconds or so. If you have pressure in the expansion tank that quickly, it is not from heat but from a blown head gasket.

thanks, this forum rocks for newbies...
 

good to hear your experience. i've decided to clean the resevoir tank with gas and replace. i'm not going to flush as much as you did, i'm assuming the oil floats and with a clean overfill tank, i'll see in a week if any new oil arises. i do hope the small leak i found at the bottom aint a problem.

i'll also check the pressure the way you suggested, seems to make sense.

thanks again.