First Mercedes, heating issues

[BOYKO]

Hello,

First of all I want to say thank you for having such nice place with so mich useful information.

I just bought my dream car- W220. My luck was only with the S280, but I feel like I did the right choice. However, I hope I chose the roght car. Not too sure yet. Anyway, now to the question...

First thing I check whwn buying a car is the coolant/ expansion tank. There was mixture oil/water in there. Blown headgasket... No, no- previous (first as well) owner insisted- no problems with gasket. I pour oil in by accident 3 years ago... Fair enough ?! Ok, started up the engine, no smokes, no strange noises, no overheating. Drove the car for 80 miles back home, no issues.

I am reading for couple of days now, but I cannot find anything related with my troubles so far... I hope you will be able to help.

Right, flush and new coolant time. Yes, you can predict now what happes next... Did 5 flushes befoere I got somewhat clear water out... Top it up with antifreeze, heating works, lovely. But, the temperature gauge stays still at 80° at any time when warm. Right, new thermostate. Ordered.

Whilst waiting for the thermostate to come I am experiencing some strange events... I cannot explain to myself why and what happens.

Start from cold- heating from blower comes out on the 2nd minute. Until I get too hot inside and I switch the climate control off. Arrive at destination, turn heating back on - blows cold. ?! Temperature gauge still shows 80. Giving it 5 or evenmore minutes- warm engine, no coolant loss, but no heating.

Is there something specific that prevents it from lowing hot air when engine is hot?

And the other thing is even after 3 more hours of flushing I still trend to get oily plast on top of the coolant in expansion tank.

I have had the car for month, I have done 1500mi so far and topped up 1L oil, shortly after the oil change. I am observing oil level on daily basis now, as I am suspecting that oil goes to the cooling system. How should I diagnose this?

Thank you very much for your time.

PS: Picture with temp gauge is after 30 mile trip @70mph when all the way it was sat still at 80° that what happened after 2 minutes on idle, stationery. Still, no heat from blower.

 

[GordonTarling]

I can't offer much help with the oil in the expansion tank, but you should fit a new cooling system thermostat for a start - that should see normal temps up to 85 - 90 degrees. As for the lack of heat from the blower, perhaps you have developed an airlock in the heater system somewhere. It would also be worth getting a cooling system pressure test done by a garage.

 

[Stratman]

Welcome to the forums

I'd be very sceptical of the "I poured oil in the water" excuse and have a compression test done. At best it will rule out a blown head gasket, at worst it will reveal the truth, namely that some people aren't entirely honest.

 

[BOYKO]

Thank you very much on the advises gentleman.

I did 40 miles with clear coolant and when I stopped I saw how over the trip it has put about 500ml of oil in the coolant. Also I got the Check engine light on. I left the car aside and orderes head gaskets and bolts for it.

I had to order the parts from Germany, so I had plenty of time to do extwnsive research online. Found very interesting tread somewhere about a guy in South Africa with the same issue. He got head gaskets replaced, but the prolem was still goin on. Then he had to take timing chain cover out, where aplarenrly are some o-rings by waterpump, which have been missing. Thats where his story ends.

So I decided before I take the heads off, removing water pump and inspection on these "canals" that go for the water pump. Taking timing chain cover might require heads to be taken out first.

However, I got cold this weekend and I could not start on the car yesterday, neither today. But will keep you updated on what is goinog on.

Thank you! Have a succesful week!

 

[PobodY]

If the engine seems to be happy enough, but there's no heat coming through the vents, that suggests to me that coolant isn't getting to the heater matrix.

Any change the hoses are gunked-up between the block and the heater matrix? - That would be a relatively cheap and easy think to replace before taking the head off.

Although reading you last post, it seems like maybe the engine isn't happy.

 

[BOYKO]

Oops, I have missed a pre- story from the past couple weeks. Heating was coming on only when revin the engine and when in motion. And because I was getting oil in coolant, my first suspect was oil cooler.

I took the oil cooler out and used the tap to get water going through it so I could check for leaks. Well, no water came out with tap fully open. ?! Wow... Lets change the direction of the flow... Booom. It was like a gunshot. (See picture) Got the cooler out of the system, I put hose to replace it and drove like this for approximately 40mi without oil cooler. Everything was fine, ultra nice heating, brilliant working temperature. But was still getting oil in coolant so I just left it for now. That is the only issue oil in coolant. Engine oil is clean just like from the tub due to the daily topping up since I have the car.

 

[stwat]

That looks like k-seal or similar. Used to bodge leaking head gaskets.

 

[rorf]

What engine is this S280 - a V6 or Inline 6?

 

[BOYKO]

What engine is this S280 - a V6 or Inline 6?

It is M112 E28 2.8 V6

 

[rorf]

Not common for M112 and M113 engines to have cylinder head gasket problems, unless the cooling system has been really abused with poor coolant maintenance. Yes I have also read the South African guy's problem with the timing case O rings but we never heard the final result. I have heard of similar problems where the front of the engine has been damaged in frontal collisions.

Best bet is to have the coolant system system pressure tested. The other likely area for oil to leak into the coolant is at the oil cooler which is just under the oil filter (not all of these engines were fitted with them).

 

[BOYKO]

Outcome

I have not been active for a while now, but you will find out I have been quite busy...

I kept on getting oil in the coolant and one Friday I just started stripping the engine down. Got the heads off, checked the gaskets. The gaskets were looking fine, however there was twist in both heads, where oil path could join coolant system. L/H head had twisted at the back, R/H head has twisted at the front. As I was skimming them I could see where the problems have been.

It took me a while to completely dissasemble everything, clean out, prepare heads and put everything back together.

But... It was worth it. :bannana:

One week so far engine is running great, heating is coming on much quicker. Temp gauge varies between 85°-92°with the new thermostate. I do not have to top up any fluids, 500mi run, no fluids loss.

Roughly costs for head gasket change on M112 E28 S280 W220
Head gaskets 2x £45
Bolts £30
Thermostate £15
Rocker cover gaskets L+R £28
RTV seal for the breathers £5.
Oil+filter and coolant £45
Emery cloth sheets £3
TOTAL: ~£220. No labour cost, as I did it all myself.

Thank you for your help guys. Now this has been done I can concentrate on transmission, drivetrain and suspension.

 

[PobodY]

Well done. I've never been game to take the heads off before.

 

[BOYKO]

It is pretty straight forward really,nothing to worry about. I was expecting it a lot harder, but they have engineered this engine to be easy for working on. Special tools needed were socket 1 13/16 for the oil filter body and torque wrench 20-50Nm.