Hi Everyone,
I was quoted between £2-4k for repairing a head gasket failure (bank b). The garage originally advised the £4k top end was if the heads required welding etc. They had also advised that both heads should be done (which sounds sensible).
The first head is off and isn’t badly corroded (looks pretty good). The failure looks to be due to the gasket itself, although there is evidence of overheating as the head gasket material is baked to the head.
The head obviously will need to be planed, but no drastic repairs. Being advised that the valves will need replacement (rather than refinishing, lapping etc.) and bedded along with new stem seals (which are peanuts).
They are now advising the cost will still be at the top end of that, despite the good condition and have stated 30 hours was spent removing the first head. It took me ~2 hours to take everything off the top of the engine when I was doing the cam cover gaskets, so 28 hours to remove the cam gear and head (they have the head lifting jig) sounds excessive?
Thoughts on whether 4k + VAT (£4,800!!!) sounds reasonable (for R&R of two heads and cleaning up valves, lapping seats etc)? Be good to hear other experiences / cost.

 

Touch wood my head gaskets are ok on my Jag but I did have to replace the head gaskets on a Triumph Stag V8 a few years ago. Once the heads were removed which was the difficult part as both were stuck fast I had them both skimmed at a local engineering shop. Cost for the skimming and a couple of replacement valve stems was around £150 the whole job including new gaskets was around the £250 mark. I know I done the work myself and that the Jag V12 is a bit more complicated but 4K bloody hell.
Rob.

 

I thought the 2k was reasonable. The heads aren’t straight forward to remove and there’s double the amount to R&R. Good to hear other people’s thoughts/experiences. Especially if you’ve had done recently.

 

If you can get the heads off ok then that’s most of the battle won. Why do the valves need replacing? I can only speak from my experience with the stag engine in that all those valves needed was a clean up and lap and re shimming which isn’t all that difficult. A couple of valve guides were loose and replaced when the heads were skimmed. I actually really enjoyed putting it all back together but I’m mechanically minded. If your not then I don’t know what the cost would be.
Rob.

 

agreed, I wouldn’t expect to have needed to replace valves unless damaged.

 

Perhaps the timing chain tensioner snapped when they released the chain? (very easy to do as it is brittle plastic) That's an expensive part + extra labor to pull the front engine cover off.

I paid my machinist $600 this year to completely rebuild a pair of LS2 cylinder heads for my truck. £4000 to remove, rebuild, and refit the heads seems a bit excessive if you already stripped the engine down to the heads. If they were starting the job from the beginning, then £4000 might be more reasonable.

FWIW I just pulled the heads off a V12 a few weeks ago. It took me about 3 1/2 hours to remove the cams and pull the heads with the special jig. Using the correct JD38 tool, and being uber careful, my tensioner still snapped.

 

They are doing the full job. Claiming 30 hours spent taking the parts off the top of the engine and removing one head so far (with the head removal jig).

The first head hasn’t been affected by corrosion and looks good. Just need head gasket that’s baked on removed. They’re saying valves need replaced versus time to clean up (which I would have expected to be necessary).

They snapped one head stud (in block), they haven’t damaged the tensioner. They are farming the head and value clean-up to a machine shop.

 

The last V12 I rebuilt was from a car with very little TLC in its lifetime.
The heads took about 15 hours each to pull off the block.
That was with the engine on a stand, it would have been totally impossible with that engine still in a car.
Both heads were so badly corroded they were scrap.
I bought brand new OEM heads at a reasonable price, and used all the old valves and valve gear.
For dph928 I doubt there is a need to buy new valves as the heads so far look good.
The head may not need skimming if the firing rings are good and the sealing surfaces for coolant are good.
Most V12 engined cars are owned by people of an age where lots of power or excessive mileage is not required.
If you are paying others to work on the engine do not go overboard spending money.

 

This is really useful input and aligned to what I’d have expected. I typically would do all the work myself, the time of year was the main driver for giving it to a garage.

 

A few random remarks, all "FWIW".....

Many years ago, just out of curiosity, I went to one of the better known labor time guides (Chilton? Motors? I can't remember which) and look up head gasket replacement on an XJS V12. It showed something like 33 hours...both heads, including grinding the valves and resurfacing the heads. At a conservative $150/hour that's $4950 (£4144) in labor. Then add parts.

Sometimes a repair shop will quote a very high price in hopes the customer will say "no". They really don't want to take on the job. They'd rather take on easier jobs. But if there's enough money in it, they'll slog through.

Oftentimes a shop will quote a very high price to cover contingencies.

In many areas it can be difficult finding a shop to work on Jaguars at all. If xxx-shop will take on a job that nobody else will......IOW no competition.....they can "get away" with charging high prices.

Cheers
DD