M110.990 Mixing Fluids

[tgolden]

Hi,

My '84 280SL with M110.990 is mixing coolant and oil. Is this likely a cracked block or just a bad head gasket?

Has anyone experienced this on the M110?

Whatever the case, I think I'm going to have to pull the engine and do a complete rebuild. I've had problems with overheating in the past and I've replaced the thermostat and flushed the cooling system per the MB protocol in the past. I'm thinking that the worst case scenario is a cracked block.

My car only has about 60k on the odometer. It's likely been sitting too long.

Regards

[C.Doner]

How long have you had the car? Any history. Low miles on a old car means its been sitting a lot. I would bet the head gasket is all you need. Without any prior history it is tough to tell.
You could pull off the cylinder head and see if you find the problem. There may be some tests you can do to see where the issue is without disassembly but i'm not for sure. You can search it on google, the issue is not Benz specific. I think if there are any tests available they are universal to all makes

[C.Doner]

Was it sitting in Va or FL. If the coolant froze you could be in trouble. you can do a leakdown test to see if that tells you something. It may or may not since the compression may be good and the cylinders not affected by the leak. It is worth a try for sure.
Does it have oil in the coolant or vice versa, or both. Its important to find out. If its oil in the coolant it could be transmission fluid. Then you need a new radiator and a trans flush.
Dont drive it either way, or else something will be ruined for sure.

[tgolden]

I've had the car since March 1985. It doesn't start. The coolant is in the oil. The car is garaged in Virginia. I don't believe freezing has ever been an issue. If anything could be to blame, it's likely being overheated due to a thermostat issue that was resolved years ago. It got hot a few times and I had to stop to add water to the system. I subsequently replaced the thermostat and flushed the system. It wasn't mixing fluids at the time, but started doing so several years later. The damage to the block or head gasket likely happened at that time and the effects manifested several years later.

It's been sitting for several years. I'm going to pull the head to check the head gasket. Hopefully, it's just a gasket. If the block has a crack, I've read that they can sometimes be repaired by welding or sleeve.

I'm interested to know if anyone with a M110 has experienced this before and where was the leak or leaks coming from.

Regards

[CA-280SL]

Originally Posted by tgolden

I've had the car since March 1985. It doesn't start. The coolant is in the oil. The car is garaged in Virginia. I don't believe freezing has ever been an issue. If anything could be to blame, it's likely being overheated due to a thermostat issue that was resolved years ago. It got hot a few times and I had to stop to add water to the system. I subsequently replaced the thermostat and flushed the system. It wasn't mixing fluids at the time, but started doing so several years later. The damage to the block or head gasket likely happened at that time and the effects manifested several years later.

It's been sitting for several years. I'm going to pull the head to check the head gasket. Hopefully, it's just a gasket. If the block has a crack, I've read that they can sometimes be repaired by welding or sleeve.

I'm interested to know if anyone with a M110 has experienced this before and where was the leak or leaks coming from.

Regards

Just read ur thread. I recently finished overhauling a M110 engine. You head may be severly corroded like mine was due to the coolant eating up the head to where you cannot have the head resurfaced. I ended up getting another head and having it reworked, new rings, bearings, timing chain, tensioner, rails and seals, you are looking at over $2500.00

[DieselPaul]

I have a complete euro m110 pulled out of a 1984 280TE if you ended up needing any hard parts.