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MG ZR ZS ZT Technical - HGF ZR Diesel

Hi Guys,

Anyone out there had an HGF on a ZR Diesel yet. I'm on 38,000 Miles and here we go with an HGF (loosing max to min in water over 100 Miles with no physical external loss of coolant).

Does anyone have the ZR Diesel manual so I can see how to wip the head off in slow time and replace the head gasket. This is the L series landrover diesel engine and not the old K series.

Many thanks,


never heard of HGF on a diesel before, and replacing the head gasket won't be in the car manual, unless you mean one of those by Haynes(right spelling?) that you can get from Halfords. HGF is normally refered to on original MGF's because of their rear mid engine layout. There should be some other clue, look for oil mixing with water, it looks like mayonaise. But really, any good garage should give the car a quick once over for you first to see what the problem really is.

Hi Gary plus any others,

HGF is an acronym for Head Gasket Failure. A Head Gasket is a thin templated washer that can withstand all the different heat stresses thrown at it and mates and seals the piston bores to the head, oilways and waterways. Many race engines don't use head gaskets as the tollerances are so close between head and block that this is not required. Also a head gasket acts like a fuse in an engine or weak point, so if their are any problems with the engine, then it will be shown here.

What has HGF got to do with mid engines?????!!!!Yes my F has a head gasket and yes it did fail at 60,000 miles some years ago, but please be aware all standard cars have a head gasket and they can fail.

I am familiar with water and oil mixing to form a whitish gunge commonly referred to as mayonaise. I don't have this or any apparent leaks, but hey this was also not the case with my F. I may have caught it early or the water could be passing through to the bores and being burnt off.

When I ask "manual", I do not refer to "The Drivers Manual", I refer to "The workshop Manual". I have an MGF one for my MGF, I have a midget one, I have a Forgeye one, I have a MGA one. I have a MGB one and many more, but I don't have a ZR Diesel one.

Anyway, since this "shout", my good friend Mat has come up with a Workshop Manual on electronic format for me. The whole idea of this exercise is not to go to a MG garage and pay 400-500 for this, with many bad experiences behind me from the past with an HGF on an F that took an MG Dealer 3 attempts to find costing me much time and money.

Do you get the feeling I don't have much faith in an MG service garage. You're right. Perhaps it's the fact that I take far greater pride in my MG's than the standard garages.

Thanks for the response anyway. I do appreciate it, even if it doesn't help at all. Is there a technical ZR bulletin board??

Have a good day,


does the engine still sound the same, and and does it still pull with the same amount of power as before? This would be a clue if water was escaping into one of the bores - a friend was telling me this when it happened to his engine, though it was petrol and not diesel.

Without pulling the engine apart, there is a pressure test to ascertain HGF. Why not try Nationwide Auto Centre?

This thread was discussed between 26/04/2004 and 27/04/2004

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