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Oil in hte coolant reservoir

1K views 6 replies 5 participants last post by  Josh 
#1 ·
Hi all,
I got engine oil in my coolant reservoir but no coolant in my crank case i.e. no sign of milky stuff on the cap or dip stick, could someone tell me if it could be the head gasket or as someone told me the intake manifold gasket?
Thanks
 
#2 ·
I think both could produce the issue, both have to come off either way on a v8, I suspect you will as well. Get onsite opinions and I am sorry to hear of this.
 
#3 ·
It's probably time to do the head gasket. Your M103 motor is shared with the W124 and W201, so you can search up threads on those chassis which will off up some DIY threads on the matter. This is also a good time to freshen up the intake manifold gaskets as well.

Head gaskets failures on these motors can run about $1000-1500 if you have a shop do it for you, but it really is a straight forward job. Just take your time going through the process.

Has the car been overheating in any fashion? If not, you may just be fine with pulling the head and slapping on a new gasket; otherwise, you may consider sending it off to a machine shop to check it for any warping. Factor in anywhere from $150 to $500 for that, depending on the shop and what needs to be done.

Be sure to get the updated gasket, as earlier gaskets had a design flaw.

The fact that there isn't any sign of coolant in the crank is good, because extended duration of running the car with water/coolant in there can cause damage to those internals. Seems you're safe on that note.
 
#4 ·
I had the same issue, it was the head gasket (it usually goes from the back of the engine, you can check if you also have en external oil leak there). I did not trust myself to do the job; it would have been a great learning process though so I kind of regret it now...
 
#5 ·
Hi Ken,

Sorry to hear.. Oil in the coolant tank I have found a daunting sight..

In addition to the knowledgeable MB assistance already rendered, I wonder if there is a possibility.. that the oil is coming from a failing heat exchanger in the transmission cooler inside the radiator? I certainly have had this on another brand of european car and the fluid mess was not red in that coolant tank.. though one might expect that with ATF… I did look at an image(s) for the radiator for you car and its set up that way..

Anyways, its a thought perhaps worth investigation as you research what's next?

I wish you best of luck.

MBL
 
#7 ·
In addition to the knowledgeable MB assistance already rendered, I wonder if there is a possibility.. that the oil is coming from a failing heat exchanger in the transmission cooler inside the radiator?
This is another common thing among W124s with the M103.

If you can swing it financially, I'd refresh the whole system. With the updated gasket, you shouldn't have to worry about the head gasket for a very long time.
 
#6 ·
Radiators are cheaper than the head work, good call! (you might need one anyway and since you might remove it to get at the fan removal etc etc)
 
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