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MG MGF Technical - 2nd Head Gasket Failure

Just last night, at 16.55hrs, at 60 mph in 5th gear, the head gasket went again for the 2nd time.
I am TOTALLY gutted!!
I had the new 'modified' one fitted exactly 12 months ago, and the car was only serviced 2 1/2 months ago.
Can anyone point me in the direction of anyone who can help ?? Limited funds for repair I'm afraid.
Or, can anyone email me the full details of doing it yourself ?? I'm an OK DIY mechanic with plenty of time on his hands !!!
Any help or suggestions would greatfully appreciated.

A devastated,


Richey
Richey

Can't offer much technical advice, but can offer condolences :-(

I've had one HGF and that was bad enough. Two is just wrong, wrong, wrong!

Hope you get it fixed OK.

Fiona
Fiona

May be the main reason for the second failed is dropped or loose cylinder liners ?.

For DIY a workshop manual might be useful, but it doesn't tell all you need.
Check out the data collection at
http://www.mgfcar.de/hgf/index.html
Several links on, but no full instructions.

... and get the new introduced Land Rover Head Gasket this time.

HTH
Dieter
Dieter

Maybe it's time to investigate the Landrover HG fix. Certainly sounds like they have investigated and engineered what they must think is a solution.
Ken Waring

How silly to own a car which two HGF in a row. Sorry don´t want to be mean but is very sad. The very same happened to me and I really tried to stick to the MG marque and still own a B. My advise may you be interested is get a MX5 and you will enjoy a beautiful very similar car with a soft top, but without the many problem of the troubled MGFs. A fact is that every MG WILL come to HGF. Another fact is that HGF very seldom occur on every other sports car.
T.D. Benson

The job isn't beyond an enthasist as long as you have the right tools.

You need:
Cam locking tool (£10)
torque wrench
2' Breaker bar
star bits
arms of a child ;-)
A valve spring compresser (£20) (if you need to get the head skimmed)

I would also invest in some ratchet spanners and a reasonable socket set - everything is metric

The engine manual is available for free download as part of the Lotus Elise service manual
Will Munns

I have the workshop manual on CD if you want a copy email me.
jim kenny

If the cause os low liners then the new LR MLS gasket is less tolerant than the conventional one. If the root cause of failure is not addressed when replacing the gasket then the failure will simply repeat itself. My guess is that your liners are too low or the head is soft.

Dave
Dave Andrews

<If the cause os low liners then the new LR MLS gasket is less tolerant than the conventional one.>
Interesting. Why would that be?
K Waring

At least the new shim with the LR MLS gasket set should be a 'fix' for a softened head...

Check the liner heights - it may be that the block deck height needs machining down in order to ensure a reliable replacement of the head gasket (3rd time lucky?)
Rob Bell

Not good is it?
this HGF business could see our f's heading towards real bargain basement prices in the future, like £500 a car prices. Who else would want a ticking timebomb of a car?

The LR fix looks to be the only way bt get the liners checked.

I hope the Chinese fix this problem before they start knocking K series out by the million or else there will be a lot of frustrated chinamen

Neil

Machining the block surface may cause a timing problem particuarly for the VVC where there is no way of altering the timing to compensate. Plus it is very expensive as it has to be engine out.

If the head has been softened by over-heating I would scrap it. The new metal shim may resist longer but ultimately may well fail. My understanding is that this shim is intended to restore the head height after a skim rather than fix a soft head.

Add up cost of labour + gasket + shim (not cheap) and you don't want to do this job twice!

Just shows you need to be very careful how the HGF is fixed. 1999 & earlier seems to be the vintage to avoid. The plastic head locating dowel has much to answer for!
Derrick Rowe

T.D. Benson, perhaps we all like a challenge, perhars the car is worth the challenge? We choose to be different, if the MX5/MR2 set choose the safe sensible route who can blame them? Nowt wrong with Sheep IMHO.
roy bridge

Here is a cross posting from Seloc about the MLS gasket, the new shim will not solve a soft head problem, it will just delay failure.



As promised I have spoken at length with the ex-Rover/Powertrain contact(s) mentioned on the earlier HG thread. I wanted to be sure that the information that I give is in line with their experience and inside knowledge before posting it; some of the information I have known for some time but I have been reluctant to post until it has been confirmed and cleared by my source(s).

The purpose of this thread is to post useful information for interested parties from people who were actually involved in the development and testing of the MLS gasket/shim and uprated ladder. The information is candid and correct to the best of their knowledge. While they were at Rover/ Powertrain they would have been constrained from giving these views due to contractual obligations, they are no longer bound in that way.

Firstly the MLS gasket. This was originally engineered to help overcome the problems with the elastomer seal on the original gasket, the MLS layers attached to the gasket cannot break away and will form a much more reliable barrier against coolant leaks both against the outside of the block and the bolt/drain holes. There is nothing magical about the gasket; its thickness is much the same as the original and it works in much the same manner as any other MLS gasket.

During testing it was found to be less tolerant of uneven and low/high liners than the original type of gasket and was considered a shot in the foot. Another common cause of failure was ‘Queen Mary syndrome’ where the liners are all slightly tilted back like the funnels on the Queen Mary; this causes a step between the trailing edge of the leading liner and its neighbour. There was also talk of the MLS gasket being more sensitive to thermal shock testing than the original but my contacts couldn’t be 100% sure.

At the time of it’s development Ford were putting tremendous pressure on Rover for a solution to the HG problem following Watchdog’s airing of the problems. They wanted to implement the new gasket even before proper testing was completed in order that they could announce a solution. As it was the liner height accuracy could not be guaranteed on the lines so the bulk of them continued to use the original gasket while a separate line was setup to produce the LR units. Because of the methodology used on this line the accuracy and fit of the liners could be much better controlled and the heads skimmed by the appropriate amount to maintain the CR.

In terms of it’s ability to stop leaching across the fire ring, the new gasket is no better or worse than the original, so if you have low or uneven liners you are better off using the original gasket which is more tolerant in other areas. If your liners are low, then judicious thinning of the compression bars at each end of the old style gasket will help although it is not a guaranteed solution.

Secondly the shim. This is provided with the gasket to act as a barrier between the fire ring and the head surface, this should prevent fire-ring dig in, any damage caused by local boiling of the coolant with consequent undermining of the material at the fire ring and the affects of voids, ash and porosity at the fire ring with subsequent failure. It is essentially the same as the ‘saver shims’ that have been on the market for some time except that it has a coating of dry sealant. This requires a heat cycle or two to become fully effective. The gasket should be used with the shim; the shim can be used with an early type gasket if needed. Within the factory the shim had to be referred to as ‘the sixth layer’ since Rover/Powertrain had always damned the use of shims as a partial solution to HGF, to be seen to supply a shim ex-factory would mean much egg-on-face. There was talk of the shim being bonded to the gasket to disguise its nature, but cost prevented this from happening.

Thirdly the stiffer oil rail/ladder. Several stiffer/uprated oil rails were developed within Rover/Powertrain; these were originally intended for use on the turbo and supercharged versions of the K series where higher clamping forces were mooted to help to contain the head gasket. Tougher bolts were planned with special washers together with a steel inserted oil rail and higher clamping forces.

It was at this point that testing showed that the towers within the head that support the bolts were in fact the weak link in the chain and would collapse under the extra clamping load, following this yielding the clamping force would return to the original level or less so the tougher bolts and increased loads were counter productive. The hardening process on the bolts also caused the bolts to distort… The current stiffer ladder was being developed at this time from 356 alloy rather than LM25 as in the original. 356 has marginally better mechanical properties than LM25 but the practical difference between the two is minimal.

In the opinions of both of my contacts the stiffer ladder is unnecessary, in practice on a working engine it makes little or no difference and just adds weight. It is not measurably better than the old ladder and the best-produced old style ladder will be tougher than the worst produced new type. Mechanical failures of ladders would be soleley down to casting anomalies rather than any structural problem with the material and in that respect the new ladder is no less prone to failure.

Around the time the ladders were produced some minor changes were made to the bottom of the block that included the deletion of a couple of chamfers at the bottom of the boltholes. This would have a more productive affect on the engines stiffness than the retro fitting of an uprated ladder. Neither advocated the new ladder’s use. One believed that the ladder was a smokescreen offered to Ford to show that something was being done in the face of tremendous pressure, the ladder was already developed and available and it couldn’t do any harm. At the time it would help to show that a lot of effort was being made to solve the HG issues.

One of these contacts who runs a high powered K uses neither the new gasket, nor the uprated ladder on his engines despite having free access to them.

Dave
Dave Andrews

Thanks for that Dave. If your contacts are right then it won't be long before HGFs start to occur with new gasket and oil rail:-(

On some Renault engines and others I believe, shims are used to correct liner height was that ever considered for the K?

K Waring

I have used shims to correct liner heights but they are very difficult to make. Once the liners and pistons are out the block can be linished in-situ to give the correct liner heights, it's messy but effective provided the block is masked to prevent ingress of any spoil from the linishing it works a treat.

Dave
Dave Andrews

Very easy for me to say, but it sounds like some decent quality control at Powertrain would have saved a lot of people a lot of heartache, including MGR.
roy bridge

Dave, can you tell me what type of failure you get from uneven liners and what the liner hights should be

Cheers
Will Munns

Thank You Dave.

Will, I recall there's a special english word for this measure. *I forgot*, Err....
You will find recommended measures in the archives with that key word.
Was anything with 3 tenth of a mil (IMO).

However, over to Dave please.
Dieter

The correct liner height is 4-5 thou (0.1mm to 0.125mm). Uneven liners can cause two types of failure, leaching of combustion gases into the coolant with resulting pressurization of the coolant, (this can also occur when liners are overall too low) and break away of the elastomer seal round the bolt holes/at the edge of the head between the cylinders where the liner heights differ.

Dave
Dave Andrews

Great posting there Dave, thanks! :o)
Rob Bell

:-(

so it isnt the hallowed solution we were all hoping for!

Neil

No, it isn't. But it remains a good gasket solution - albeit one that needs understanding and due attention to liner heights.

Get it right, and this MLS gasket set will serve you well - of this I have no doubt.

When I get around to building my supercharged K, I plan to use this gasket set :o)
Rob Bell

so as I have a failure around the alternator, this gasket should fix that as it is prolly not the liners.

I will check the liners anyhows
Will Munns

and the new LR bottom Rail?

I wonder if there is any value in manufacturing a top rail, if such a thing could be produced for the head?

Neil

The cam ladder is a two part item that is machined as a matched set - and as one half of the cam ladder just happens to be the cylinder head, you are talking quite a substantial undertaking Neil!

So no, no chance of a new upper oil ladder.
Rob Bell

thought so!

just get used to HGFs people

N
Neil

Or fit a PRT ;o)
Rob Bell

The other fix to consider is a remote thermostat kit. With some fettling the Eliseparts kit can be fitted; this is what I have on my '02 TF 160 since my HGF a year ago. A simpler option (which I wish I'd known at the time) is prolly the QED remote thermostat kit.

Both of these are ways of rectifying the design problem with the K Series engine, namely that the thermostat location on the inlet side means that the thermostat is reading and trying to manage the temperature of the radiator, rather than the temperature of the engine. This problem is worsened by long coolant runs with the radiator a long way away from the engine, as in the F/TF and Elise.
James Reinhardt

OK Rob for me and others could you give us the full gen on fitting a PRT , where to get one how much and the task of fitting one
Think I have to do it, the car has got to that dangerous mileage of 56k

Neil

It's something that I need to do too. Carlos on SELOC has a site dedicated to all things cooling - and includes instructions for installing the LR PRT to an Elise. With some modification to these instructions, you can apply this to the MGF too. :o)
Rob Bell

> namely that the thermostat location on the inlet side
>means that the thermostat is reading and trying to
>manage the temperature of the radiator, rather than the
>temperature of the engine.

this is clearly ar*e, and I wish people would stop trotting it out. The diffrence is that the thermostat manages the temp of the water in, not the temp of the water out. Both are bad if you manage the temp by restricting the flow, because when there is a big differential between engine temp and outside temp then then this gradient appears across the engine, in the inlet version directly, and in the outlet version by temp cycling.

What the PRT does is to ensure the water flow is kept high even if the radiator is shut off, thus ensuring the water is not heating unevenly in the block.
Will Munns

This thread was discussed between 11/02/2006 and 24/02/2006

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