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MG MGF Technical - H.G. shortage?

Is it true that theres a shortage of new style head gaskets at the moment?

my SECOND failure occurred this morning, only 6 months after I replaced the last one. Not a happy chappy.

any ideas why it might have happened? (I mean, the usual mistakes that get made, bad bleeding etc.)

OR, clutching at straws, could it possible not be an HGF? Steam from exhaust, oil traces there, and water on the dipstick (no 'mayo' yet though).

I really can't afford this car anymore. i saw the last hg replacement as 'an investment' in many more years motoring in it. oh dear. at this rate i'll have to take our another mortgage...
Julian

I started the HG-shortage scare, as Mantles are having a hell of a job getting hold of one for me. I suspect that this is part of the general MG-Rover-changing-parts-supplier fiasco, rather than a shortage of HGs in particular.
David Bainbridge


Hi Julian,
sorry to hear about what has happend to You ! If it IS a "normal" HGF are You the first one to suffer a HGF with the new gasket + steel dowels then ??? Surely the new one + dowels was fitted if it was only 6 months ago ?
Best of luck , Carl.
Carl

Yes Carl, it had the new gasket with steel dowels.

I await a verdict. I can't think of a logical reason for it going, I think it was bled correctly. Maybe there is something else that was missed at the time?

Any suggestions?
Julian

The cooling system may not have been properly cleaned out. We all know what oil does to rubber. The sealing beads on the HG is made of that.

I experienced the same last year after just a couple of thousand kilometres. An MS competition gasket went one month after it was fitted. Then there was oil left in the cooling system which I am pretty sure was the cause of the failure.
Jon

I think the silicon seal is designed to "seal" the oil galleries as well - so oil on rubber etc argument may not be valid - I think !???
tony

Hi Julian,

now I recall. Have looked up the archives.

August 13th until mid of September, and we all did our best :(

Now what can have gone wrong ?
It is a VVC and you gat in first step:
--------
Cheers guys
Here are the part no.s & costs I've got so far...
(all VVC)

Head Gasket set (revised)
GUG701207HS £72 +vat
Cambelts
GTB9003XS £48.04+vat
GTB2018XS £24.16+vat
Stretch Bolts (ea.) (x10) £6.50 +vat

The thermostat, the guy in parts was unaware of a mod. which fills me with confidence!
GTS301 £6.24 +vat
Can anyone confirm whether the thermostat part no. is for the old or new?

Ta.
Julian
-------------
Thermostat got sorted later.

Mmm, may be troubles with the cam bolt ?
Or may be the head is bent out of specs ?

:(
Dieter
Dieter Koennecke

Tony
Interesting point about the silicon strips supposed to seal oil galleries. Yes, I think you're right. But still my MS gasket that was ruined after just a short distance showed all the symptoms of the deteriorations of rubber that has been exposed to oil.
Another thing is the fact that oil floats on top of the water and collects at the top of the cooling jacket which is right where the vulnerable HG resides.

Spring steel head gaskets - has anybody tried it?
Jon

>Or may be the head is bent out of specs ?

Julian - do you know if the head was skimmed last time?

Paul
P9 VLS
Paul

Hi all

Sorry, I'm more 'online' during the daytime - so apologies for the delay.

Thanks Dieter - I hope your last 2 suggestions are wrong! That would be expensive I think.

Paul - yes, the head was indeed skimmed last time around. oh boy.

Can anyone confirm one way or another whether the flushing of the cooling system really could be a cause if it were not done sufficiently?

I should be getting the engine to pieces tomorrow, so I should soon know how expensive this will be...

ANY suggestions welcome - esp. if there is nothing 'unsual' we find (warped head etc) beyond what we saw last time.

Thanks

Julian


Hi Julian,
not much help offered from me in this post but it would be VERY informative if You could get the old gasket and let us know if it was gone in the "normal" place, i.e at the far right corner above alternator. It might be that we will see a new "opening area " now when there are steel dowels and re-designed gasket !
Hopefully You will have some goodwill from the garage and possibly only pay for parts and some labour ?
Surely there will be no needs for new bolts as they were replaced last time...

Best of luck and try to get hold of the old one ( it is by all means paid for) !
Regards , Carl.
Carl

Carl,

Julian wrote an email.
Head got skimmed the other year.
System not flushed, as far as he assumes.
Repair got not done in an official workshop, but in an independant workshop.
I sent some pdf files the other year, you may know which.

I think the flush case needs some more investigation/explanation. I do also not believe that oil drops hurt the silicon seam direkt, but ..
Small oildrops in water explode like bombs, cause they get much hotter than the water when they meet the hot parts at the liners and head. So may be any oil could have been anywere in a 'gap' and produced constantly airbubbles from boiling. Is that theory complete bullsh*t, or reasonable ?

I wonder how much miles were between last October repair and the new failure ?

Due to the gasket, I think you mean the look and thickness of the seams at both sides and at the fire rings ?

Dieter
Dieter Koennecke

was 7000 miles since the last repair.
Dieter Koennecke

hi guys

Your interest is reassuring. I will endeavour to get some pics of the 'old' (well its only 6 months old!) gasket etc. on my digicam and post them up.

i really am keen to get a general opinion on whether the flushing thing may have caused the problem as I'm now almost certain that it wasn't flushed out.

Other things that may have been missed also, so that they're not missed again.

I'm still afraid that the actual head may be the problem and that (sharp intake of breath) it will need replacing.

no holidays this year then.
Julian

Julian

Correct me if I am wrong!

But I seem to remember that your *F* was a rebuilt car (write-off or accident victim) if so is it not possible that the engine and/or cooling system were also damaged and are now showing it.

Just a thought!

Ted
Ted Newman

You're right it was an insurance w.o.

But the car was not sufficiently damaged for anything like that. Absolultely zero engine repair was needed. Cooling system - radiator replacement only. Beyond that it was panels and one shock absorber.

On top of that, the car had only done 3.5k and the first hg went at 37k. So the chances of the hgf being related to some damage sustained then are slim.

however, the chances of this second one going as a result of an inexperienced (relatively to an MG mech) mechanic are greater. Thats why I'm after ideas. (And of course, you see I have no guaruntee from the first job either so want to avoid a repeat!)

I had thought of the possible improper bleeding, but the car never got hot - even after I noticed the problem.

Julian

Fair enough!

Whilst I am almost certain that something happened during the repair of the first HGF to affect the life of the replacement gasket I am also almost certain that it would be difficult prove!.

Ted
Ted Newman

Hi,

When a head is lifted it's just about impossible to avoid some oil entering the coolant passages, and vice-versa, as the stuff runs all over the place. When I changed the HG on my 214 (7000 miles ago) I filled up with water and ran the car up to temperature to check that all was OK, then drained it and refilled with the proper coolant mixture. There was still some oil in the system as after a few days a ring of grime had appeared in the expansion tank, which I wiped off with a paper towel. All has been OK since. I don't think that failing to flush would cause the gasket to fail unless a significant amount of oil had entered the cooling system. After all it is flushed when it's drained.

As for reasons for Julian's second HGF, it would be interesting to find out where it failed, as Carl says. The elastomeric seal on the gasket is very prone to damage during installation. It takes some effort to manipulate the head back on without catching the seal, so it could be damaged in this way.

Any advice for the repairs? Apart from taking great care, I would tighten all the bolts up in order to 10 Nm, then repeat to 15 Nm, then to 20 Nm before continuing with the next step in the process. If you take the first bolt straight up to 20 Nm, then the second and the third and the fourth, the first may have lost much of its tension. This is because it's taking all the resistance from the entire gasket seal, any tightness on the locating dowels, any resistance from the other bolts and possibly from the crush rings on the bores and the compression limiters.

Regards, Kes.
Kes

>>>Maybe there is something else that was missed at the time?<<<

Were all the bolts checked for their fitted height whilst the head was removed and if so how close to the 97mm between the block face and underside of the bolt head were they. In addition how much was removed from the face, and was this as a result of calculation following measurement of the head face and finding distortion, or simply a skim to be sure it was flat?

Having found some variation in the bolts on numerous heads now removed, difficult winding into their threads and the fact that some have stretched quite close to that cut off measurment, I always have in the garage some spare brand new through bolts. (German made incidentally Dieter)

Rog
Roger Parker

Roger - all bolts were replaced - is that what you mean?

The skim was to ensure it was flat.

So, is 97mm the MAXIMUM allowed length between face and bolt head? Please explain.

Julian
Julian

This thread was discussed between 10/04/2002 and 16/04/2002

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