Head Gasket Replacement 12v S2, Links to progress pictures now available

Hello all,

Well my XM arrived home last Sunday on a flat bed. My wife had the car on a trip to Melbourne and back and the rear head gasket failed during the return trip. I have determined it is number 5 cylinder that has failed. Removed the spark plug and power to the injector and the car fired up with the additional feature of having a temporary fountain!

I am in the process of sourcing prices for parts here in Aus, but can get very little information on the technical processes of doing the job.

Does anyone know if there is information available electronically and if so please point me to it?

Also, has anyone done this job before and left the engine in situ?

It is a ZPJ 12 valve engine and aircon is fitted to the car - just to add to the complications.

I am also considering replacing timing chains etc at the same time as the car now has 215 000km on it.

Any guidance would be appreciated so that I can add this to the valuable information I am already gathering from others on aussiefrogs.com

Thanks

This post has been edited by UFO on October 05, 2006 07:26 am

With respect, I would suggest that this mail should appear in the section for V6, possibly in addition to here.

Hi UFO,

I'm hoping someone posts some good info for you - I have a V6 with a similar problem. I initially bought it for parts but it is in pretty good condition so I might fix the head. I just need to learn how. My other XM (2.1TD) is currently the subject of litigation after a mechanic bent the valves during servicing and I'm not going to get it back anytime soon.

Good luck.

Regards,
Kiwi

Sorry, that should be an SFZ engine. whoops!

And that was me responding while not being logged in

Well in spite of the copious responses here, we commenced the job. You may wish to view the result so far via:

http://craigdeb.com/xm.htm

There is a link to the head gasket replacement job and as a bonus a link to a job I did earlier this year to replace the heater core on the same car.

Hi Graig, well ,congratulations for the attempt and many thanks for the foto presentation. One think, I recollect that when Laszlo (writes in XML) did his 24v prv gaskets, he also replaced the cooling V-pipe (next to the Y-shaped u show) with a new one. I think the reason is because they get rusty internally. Perhaps u would want to look into that as well...

cheers and keep us posted.

George

We have inspected the pipes and they are in very good condition. No replacement required there, but thanks for the comment.

In Aus we are quite stringent about ensuring we use good coolant and try to use demineralised or rain water whenever possible.

Hi Craig,

Thanks for the great info. I look forward to the rest of the story. Any thoughts on why it blew the gasket? I guess you have checked the radiator etc?

Regards,
Kiwi

Well, we got it all back together, except....

It is running like the roughest rough thing which was ever rough, to paraphrase Blackadder.

We seem to be getting no spark on no 2 and almost nothing on 5 or 6. It will start, has no power to speak of and pulling the plug lead on 2 or 5/6 seems to make no difference while 1, 3 and 4 go very near to stalling it.

I have checked and checked the electronic connections and plug leads and proven that the spark plugs are ok.

The car has a new dizzy cap and rotor as supplied by GSF (thanks GSF - ordered 6 days ago and arrived at home, 80km south of Sydney, today)and all leads are in the correct order.

So at this stage I am stumped and off to bed soon.

All thoughts appreciated.

As you have just changed the distributor cap, perhaps you ought to refit the old one, just to prove that you have a suitable replacement (not that I can see that it would not be, but you never know!)

The engine is running no worse or better with the new cap and rotor so I think I can rule that out.

From analyses elsewhere it is sounding like the timing is out

So that means a partial deconstruct

Hello fellow colonial,

How are you getting on with your V6?

Regards
Kiwi

Mongrel damn car! Get me the petrol and matches!!!

The engine has gone back together beautifully BUT it will still not fire on cylinders 2 and 6. There is NO SPARK at all on these cylinders and leads have been swapped etc etc. There is not even a spark at the dizzy plug end.

With long mobile phone calls to two other aussies, the best we can arrive at is that the crank angle sensor is dead or very close to. It will only very occasionally read 0 ohms resistance and most of the time when you test the connectors you get 1 - meaning open circuit.

Can anyone else offer an opinion?

Got access to a personally owned ELIT computer and did some tests tonight. It confirmed that the crank angle sensor is pushing up daisies. Replacement module on the way from an Aussie wrecker. Perhaps here tomorrow and I will be able to drive my XM for the first time in 2 months by about 9pm tomorrow!!