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MG ZR ZS ZT Technical - Uprated head gasket in Z cars?

Hi, Z types!

I am thinking of buying a ZS120 as a sensible family car (oh yes!), and I have a question. As my MGF has just had a head gasket failure in the very same engine that powers the ZS120, does anyone know if the new uprated head gasket is being fitted to the ZS?

I'd assume the answer is 'yes', or MG-R are just piling up a whole new bunch of expensive warranty claims. But I just thought I'd check...

David Bainbridge

I thought the reason MGF's blow head gaskets was down to ineffieciant cooling into the engine bay??

Neil
Neil Turner

Not sure if ineffective cooling in the engine bay is the only possible reason for HGF. I had a HGF on my R416.
Now driving a ZS 120.
JLD

All that can be said with certainty about HGF in the MGF is that there have been lots of theories put forward to explain it! eg:

1. the HG's crap
2. poor bay cooling
3. long pipe runs to back of car from rad
4. positioning of thermostats/valves
5. K series overstretched at 1.8
6. and many others that I'm sure I've forgotten
7. a combination of a random selection of the above

I am just trying to find out if the combination of front-engined and uprated HG would improve matters.
David Bainbridge

If it really was that bad how come we haven't heard horror stories of HGF on 1.8 versions of the Rover 75, 200Vi, Rover 618 and Freelander?? or have we??

Neil
Neil Turner

Neil,

Well, I sort of asked this on the F forum, and the answer seems to be that there have been some HGFs, but not loads.
David Bainbridge

During my visit to Powertrain yesterday I was interested to note the huge full boxes of steel dowels and familiar standard head gaskets introduced with the steel dowels that has been well discussed on the MGF BBS. This was at the station where heads are fitted to the assembled lower block assemblies. It was also interesting to ask the very knowledgable people there how long they had been using the steel dowels and the quote back was about a couple of years now. All engines go through the same station!

It was also interesting to have a degree of confirmation of the actual problem which was illustrated and it did relate to the plastic dowel allowing far too much movement between head and block when the engine was hot and under load. Excess 'fretting' between the head and block simply wiped out the head gasket silicone tracks.

I also know from personal expereince in the hundreds of queries received each year from owners, plus discussion with MGR people that the issue of head gasket failures was mainly an MGF characteristic, not a FWD saloon issue of significance. The change to the steel dowels added further insurance to the FWD range and helped to finally reduce the MGF issues to acceptable rates. This issue has been further addressed with the increase to cooling system heat exchange capacity with the MG TF.

Rog
Roger Parker

Sounds good enough for me. Now where's that ZS order form....?
David Bainbridge

I would consider that apart from the steel dowels Rog has mentioned above the F seems to suffer from a marginal cooling system, fine if in A-one condition but can and will show its weakness when not.The TF has a more efficient system.Goodbye HGF's???
Mike.
mike

>>>fine if in A-one condition but can and will show its weakness when not<<<

Agreed, and so from around 2006 when all MGFs are out of the warranty envelope we shall see!

Rog
Roger Parker

Oh as a side issue, I have a lovely picture of a pile of head gaskets and thousands of steel dowels at the station where heads and blocks meet on the K series production line. The part number on the gaskets is the same as youy curtrently get from dealres spares depts.

Rog
Roger Parker

This thread was discussed between 19/03/2002 and 24/03/2002

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