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MG MGF Technical - HGF TF160

My 21k MY04 TF160 has been 'using' a bit of water. There are no obvious leaks and there is no water in the oil (nor oil in the water). Sometimes a sweet smell in the cockpit, but only when the engine is running. New cap on the reservoir, correct coolant, etc.

It's been to the local garage today (Renault Dealer) and they've diagnosed a small HGF on the basis of a sniffer test. I've talked to the mechanic, and he's shown me the evidence.

Q1 - is this common, ie a cylinder/water failure, particularly on a car with a PRT?

I'm going to run the car for a week to see how much water level drops, but I think we've decided that the gasket needs replacing. The car is under warranty! The garage is a Renault Dealer (the warranty is a Renault warranty, has to go to a Renault Dealer) but their 'sister' garage (a few miles down the road) is an old Rover/MG Dealer.

Q2 - what's the state of the art when it comes to gaskets these days? Is the strengthened lower rail still rated, or is the new gasket 'good enough'? Bear in mind that the car is used on high days and holidays, but used hard...

I'm going to change the reservoir for a new one with provision for a level switch. Cambelts done 1,000 miles ago. Anything else worth doing at the same time eg water pump?

Oh, and the good news is that they fixed the air conditioning!

Thanks for any comments...

Neil
Neil22

Unlucky with the failure. I can't furnish you with figures, but the later TFs had much lower frequencies of HGF than earlier cars- particularly as yours has a PRT.

The current "state of the art" gasket is the LandRover MLS gasket and up-rated oil rail. Land Rover fit these as a matter of course to all Freelanders with failing gaskets. I'd probably go for one of these for your car.

One thing to watch for is the cylinder liner stand proud - ensure that all are within tolerance of one another (i.e. they're all the same height above the block). Apparently, these MLS gaskets are a little more sensitive to this than the original gasket type.

Coolant level-equipped expansion tank is a great idea. I have the Brown and Gammons one, with an audible warning. It's excellent, and would highly recommend it. It's almost certainly saved the engine and head gasket at least once (leaking water pump)!

Replace the water pump by all means, and if the tensioner wasn't replaced last time, do that too.

Hope this helps
Rob Bell

It does, thanks.

Is replacing the rail much 'extra' work ie am I going to have to persuade the warranty people that it needs to be done. I'm going to have to pay for the part I suppose, but is there much extra labour involved?

Neil
Neil22

Hi All,
Ive just checked my HG bill, and the uprated oil rail has only added £60 to the final total.
Its worth that to know its not blocked!
John
J E Reed

Not a huge amount. The engine through bolts are removed, and the sump dropped to gain access to the oil rail, than can then be removed and replaced. It's not a huge amount of extra work to be honest, and worth doing. In fact, if using an MLS gasket, it is strongly advised (some say manditory) to fit the upgraded oil rail.
Rob Bell

Okay, thanks.

Left the car there today for the fix. They showed me the blurb they'd got from X-Part which says they need to fit the MLS gasket and oil rail. And have the head skimmed apparently.

Fingers crossed....

N
Neil22

I wouldn't say that having the head skimmed is an automatic requirement - if there is no evidence of warping (use an engineer's straight edge, and look at clearance under it across diagonals and axis), and the liners have not excessively marked the cylinder head, then a skim is probably unnecessary.

In fact, some say that skimming a head - particularly the later ones - could introduce a significant risk of running into problems. Essentially, the castings are not perfect - there are voids within alloy (part of the casting process; I'm no expert at metalurgy, but there are some interesting articles on the 'net with more details of problems that can arrise with alloy casting techniques), and skimming the head can expose this, leading to significant porosity around the fire ring landing - leading to, you guessed it, head gasket failure.

What cylinder head experts like Dave Andrews suggest is to peen around the fire ring before sending off the head for skimming. This collapses any potential voids, and thus reduces the risk of porosity in the rebuilt engine. There's a nice video on YouTube of Tim Woolcott doing exactly this: http://mgf.ultimatemg.com/group2/engines/head_strip/index.htm#Video

Good luck, and fingers crossed :o)
Rob Bell

This thread was discussed between 19/02/2010 and 08/03/2010

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