Cylinder head gasket replacing
1991 G300 GEL Auto
WDB 46322827080407
High milage,second motor.
Oil in the header tank.
Contacted the seller and he was of the opinion that it was left over from a previous incident.
Flushed coolant twice. No luck
Removed radiator as I was told it may be the problem due to the shared cooling functions.
Radiator replaced on the advice of the radiator specialist .
Flushed again
Still have oil in the coolant and now also a coolant leak at the rear o/s corner of the block where the head and block join.
Seems as though the cylinder head gasket will need replacing
I have so far got all but two of the exhaust manifold nuts loose from the head. Have now loosened the spring clamps on the exhaust manifold as it seems that I will not get the offending nuts to cooperate.
Have the tappet cover off and undone the four bolts that hold the inlet manifold to the block.
The question is:
Where do I go from here ?
Can the head be removed without removing the whole inlet assembly ?
Which parts need to be removed to remove the head ?
Is there a workshop manual that I can buy, borrow or copy ?
Does MB do a cylinder head replacement gasket set and what does it contain ?
there is a Haynes manual covering the w124 that includes this engine
Head Gasket Kit from MB is part number A103 010 54 20/
It basically comes with the Head Gasket, Inlet and Exhaust Manifold Gaskets and all small gaskets and seals and washers etc. that fit directly to the head.
The only items that are missing are the Rocker Cover Gasket A103 016 04 21 the Front Bridge Seal A103 015 02 20 and the Front Cam Seal if required A018 997 79 47.
The only other items are the Valve Stem Seals, these come in a kit part number A103 050 01 58.
Thermostat is part number A102 200 19 15 and comes with the rubber seal ring, also the Oil Filter is A104 180 01 09 if you need to change these as a matter of good practice.
Hope this helps
Gav
Hi Gav,
The parts were ordered last Wednesday arrived Saturday.
I am glad to say the Cyl head gasket is back in place.Still have to do all the bits around the head and order a few nut and bolts and vacume hoses.
Thank you,
Michael M
Hi Michael
Good job....
Make sure you get that vacuum system sorted and hooked back up correctly.
They can be a PITA and cause no end of issues if not
Gav
Please can anyone recommend a garage in London or the South East who can replace the head gasket?
I have exactly the symptons described by Gw4mike - oil in header tank, which results in engine overheating after only few miles. I've had it flushed once in past 2 months and previously used K-Seal mixed with coolant as an interim measure (it worked for 2 years), but now feel it's time to get the problem sorted properly.
I have neither the tools or the knowledge to do this myself. Any recommendations please?
Vehicle> 1993 G300 GES Auto. 71,000 miles from new.
Hello WillB,
I know of two people in the Wembly area I would entrust this work to. One is a current GWOA member who has his own garage and has Mercedes Benz back ground, the other is (declaring interest) is my own cousin, who is not a Mercedes Benz specialist but a competent mechanic form East Africa and mechanics from there are very apt to mechanics.
If this area is of interest please advice me.
Alternatively, I could search the web site in the Hampshire area to filter for you some specialists. None of whom I would have had dealings with.
As a suggestion, I would advice the renewal of your thermostat when replacing the head gasket. Further, I would strongly advise to have your current radiator to be flow tested and either have it re-cored or renewed as necessary. Depending upon the mileage of your engine, before stripping the head, get a compression test of the engine and have an evaluation on the state of engine and establish if any work is needed to work the head by either, and, or to replacing at minimum the valve stem seals or if needed have more involved work such as valve seating or at worst having the valve guides replaced as well.
Take this opportunity to establish if the timing chain is stretched and have this replaced. These things will add to cost but if needed, just replacing the head gasket in light of these potential work required to be done could be a false economy.
Hi
I understand GWOA member LEONIDAS has had this work done to his 300GE M103 last year by a very competant garage that works on a few G Wagens... a quick PM would source the details i am sure....
I believe he lives inside the M25 in the South West section...
Hope this helps
Gav
Duplicate ....
Hi
The OM 603/M103 engine in the G wagon and W124 saloon are prone to premature head gasket failure as a direct result of poor preventative servicing ultimately causing serious overheating
It all starts with using tap water as the coolant which leaves a residue over time ( the harder the water the quicker the problem). Limescale and other impurities settle in the coolant galleries and in the horizontal core of the radiator disrupting circulation and creating cavitation that causes the engine to overheat ( max 95c in any operating mode )
this puts ALL the gaskets under stress and invariably warps the radiator / oil cooler interface which results in either water entering the gearbox ( auto only ) or oil contaminating the coolant galleries
the remedy is NOT just replacing the head gasket
purging the oil from the system ( including the heater matrix) is not easy / changing the numerous gaskets ( like crankshaft seals which may have degraded from superheated oil) valve guide seals / oil filter interface gasket and replacing the water temperature sensing probe.( also cold start management sensor in the M103 engine)
the inlet manifold can warp on the M103 engine causing vacuum problems resulting in the
K Jetronic fuel system developing problematic fuel management faults
""" ALL BECAUSE OF USING THE WRONG COOLANT"""
(50% water and 50% antifreeze flushed/changed yearly)
Minor point, worth mentioning for the M103 is while you're at it, replace the short hose between the cylinder head and water pump, as it is a royal pain to change without the head or pump out if it fails later.
Hi Pistonhead, Thank you for the recommendations. And for the advice about renewing the thermostat plus having radiator tested. The radiator was replaced with a new one about 9 years ago - so whilst I will have it tested I'm hopeful it will still be functioning correctly. Points noted also about replacing the valve stem seals as well as checking the valve seating and guides. Also I appreciate what you say about checking all these items as the labour involved to replace the head gasket is considerable so worth replacing other associated components too.
Many thanks, WillB
Hi Gav,
Very much appreciate your help on this - thank you so much. I will try to contact Leonidas via PM.
Thanks again, WillB
Hi fixwin38,
Thank you for such a comprehensive overview of the head gasket replacement issue. All those years when I topped up the coolant tank with anti-freeze and ordinary tap water... I often wondered wether I should have used purified water. Now I know. Once I have had the work done I will know better next time.
Many thanks for the advice.
WillB.
Hi M2dxb,
I appreciate your advice, thank you. I will make sure to replace the hose between the cylinder head and water pump at the same time as all the other work.
Thanks again, WillB.
tap water is arguable where you have very soft water like South Wales, but London and much of England has hard water
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Thank you, that will help.