How long should a replaced 124 head gasket last?

[WDB124066]

30,000 miles, two years, five years...??

What is the general consensus on their longevity once replaced...?

 

[whitenemesis]

Surely, it should last at least as long as the original one?

 

[grumpyoldgit]

Impossible to say I would think. Depends on the condition of the head and the block. Did you have it skimmed?

 

[John Jones Jr]

200K/20yrs provided everything else is in order.



Edit: I see you drive a W124/M104?, my comment was in relation to the M103. M104's seem to be a bit of pot luck, 150k/15yrs?

 

[grober]

As above indefinitely if done correctly [ head trued up/ skimmed/leaktested/ new cylinder head bolts, MB or REINZ [oem] gaskets, new coolant/cooling system flush, radiator/water pump checked]http://www.victorreinz.com/EN/Products/Cylinder-head-gaskets.aspx

 

[hotrodder]

Pretty much what everyone else said... the design was revised at some point improving at least one of the origional gasket weaknesses so as long as everything else is order then i'd expect soooo many miles/years 'indefinitetly' is apt

 

[WDB124066]

Thanks Gents, so it would be normal to expect that the typical 124 head gasket leaks can more or less be permanently fixed.

Did MB really upgrade the parts to give longer life or is it necessary to go to something like grober posted...?

 

[coupe deville]

Yes, gaskets were redesigned, but as Graeme said, the head needs to be true. Had mine done at SPR Stockport about 5 years ago, skimmed, new bolts, been perfect ever since.

 

[WDB124066]

How many miles on it, if I may ask...?

 

[grober]

Afaik MB used a modified gasket as better technology became available and to address a CHG problem which had become apparent in many cars at high miles . Some argue that bigger inline 6 cylinder cars are always going to be susceptible to this sort of thing particularly with the combination of alloy cylinder head and grey iron block. In terms if doing all the things I suggested were necessary it really depends on how bad the problem is in the first place???? Worst case scenario is a cracked/corroded head casting which needs repair. Its always a good idea to get the head skimmed true'd up because a damaged head gasket might have caused localised heating meaning a warped head surface [ this is one thing I would insist on or you will be back again in 12months to do the same again] Cylinder head bolts " stretch" - there is a measurement which tells you if they can be re-used but why not just use new if you want the best job? The radiator/water pump/ coolant/fans thing is merely to check what may have precipitated the failure in the first place [ again fail to check and back in 12months to do the same again]

.
Summing up

MINIMUM [ otherwise wasting money imho]
MB or REINZ gasket [= same thing] do not skimp on this and CYLINDER HEAD skimmed/trued
BETTER
AS ABOVE plus NEW cylinder head bolts
BEST
AS ABOVE plus maybe a NEW/RECONDITIONED WATER PUMP if the old one is "tired" [ 6 cylinder water pumps are a pita to do in situ so its a good opportunity

All plus new coolant and thorough radiator /cooling fans etc check

 

[coupe deville]

How many miles on it, if I may ask...?

About 130,000 when it was done, it's got 150,000 on it now

 

[WDB124066]

Thanks Dave.

Best has been done grober. Now there is a tiny weep from back of head. Is it possible to do a final [release and] nip-up on the head bolts to see if this alters things at all...? Is this a done thing in the motor trade...?

 

[coupe deville]

There is a school of thought that cylinder heads should be checked and re torqued after a few hundred miles, but to be honest, mine hasn't been done.

 

[grober]

I would not advocate "releasing" any CH bolt because these bolts are designed to " stretch" slightly at their recommended torque. I guess you could try tweaking up the rear bolts slightly but its one of these risk/benefit unknown consequences thing. I don't rebuild engines for a living so not in a position to give you a realistic success rate. You could snap the bolt? Can you live with it as is ? What do the engine rebuilders say?
recommended torquing all bolts is
1rst stage 55Nm
2nd stage 90degree
3rd stage 90 degree

One error that can evidently occur is that people don't allow enough time between bolt "tightenings" for stretch bolts to " settle" to their new length before the next tightening stage- this would mean the next " tightening" wouldn't stretch the bolt further to the correct extent. Its a bit of an art this cylinder head business. http://www.gomog.com/allmorgan/HeadBoltTorquing.pdf

 

[BlackC55]

Regular coolant changes help too as coolant has anti-corrosive properties. On a 124 its every 4 years

 

[Scott_F]

Summing up

MINIMUM [ otherwise wasting money imho]
MB or REINZ gasket [= same thing] do not skimp on this and CYLINDER HEAD skimmed/trued
BETTER
AS ABOVE plus NEW cylinder head bolts
BEST
AS ABOVE plus maybe a NEW/RECONDITIONED WATER PUMP if the old one is "tired" [ 6 cylinder water pumps are a pita to do in situ so its a good opportunity

All plus new coolant and thorough radiator /cooling fans etc check

Plus an oil and filter change as the existing oil will probably have become contaminated with coolant.

 

[optimusprime]

Info

Wdb check the lifting eye thats bolted to the cylinder head at the rear .Its as a 0 ring on inner part . It is for the hot water, inlet for your heater ,its held on with to cap screws .I have just replaced my coolant pump and was still loosing coolant under the car.It was weeping fron the pipe that is joined to the lifting eye. I was about to remove the head.Located the leak thank god on this tube .As you remove it you will find an O ring ,mine had perished.Clean it all up before you refit.I used Hylomar on the item as i put it back on. See picture and good luck.

 

[del320]

30,000 miles, two years, five years...??

What is the general consensus on their longevity once replaced...?

I believe CHG issues were a known weakness on 124s even before the loom fiasco. It was claimed that the car would continue to go on forever with just a slight weep at the rear of the engine.

I had just such a leak about a month after buying the coupe when it was just on five years old with 60k. The gasket was replaced under warranty and 13 years on and a further 68k, I am unaware of any problems.

 

[optimusprime]

info

The O rings cost £1 . Before i found this i was just about to throw the rag in,after spending over £1000 up to now .And the car as not been the road yet.Just finished replacing all the brakes. You name the problem this car as come up with it .But realy worth it in the end. I hope its the o ring .

 

[optimusprime]

info again

Wdb dont remove the head untill your sure it is the problem.Clean all water from rear of cylinder head ,with paper towel .The water leaks from the heater tube down and along the joint of cylinder head and the block, and falls on the bell housing , and then drops on to the floor under drivers side.This is because engine is on a slight angle in situ.