Every DIY person is at some point a head gasket virgin. There is always the first one.

But, what I am getting at is that even in that case you did not go from checking tyre pressures to a head gasket.

Somewhere along the way were experiences with smaller jobs that built confidence and knowledge. Changing spark plugs, carburetors, alternators, etc. Those are the single afternoon jobs where how to swing a wrench are learned. Changing a head gasket uses many of the same skills, and pushes into new territory. But, it ought not be the first job after checking tyre pressures.

If the OP is game to go, then that's fine. But, we cannot expect everyone to be comfortable with the job.

 

I agree, definitely not for someone that does not have wrenching experience, but...........

All the information, and "how to" is available at one's fingertips. Something that was only a dream few "short" years ago. Even the precise timing instructions, plus the tools needed to lock the flywheel, and cams are available on the web.

The key to the job like that is the outmost ORGANIZATION of the workplace. Every nut, bolt, accessory, tool, etc needs to be documented, as it's removed. Cell phones can take pictures of all the phases of the operation (for the reminder on assembly), and every part removed needs to be ziplocked, and marked. Going slow, and documenting evrything, is the key. One can even voice record the removal of the components, and point to oneself the noteworthy details.

No, it's not as easy as changing the wheel, but definitely doable for the organized, and mechanically inclined person.

 

You're quite right to advise caution, Plums.
My 'take' is that the car is probably worth only scrap with a blown head gasket so he's got nothing to lose (except time and knuckles) even if the job beats him. But point taken.

 

Since the O/P has put £1000's into the car to restore the bodywork to almost showroom condition, then there's only really 1 option-to repair the engine.

Scrapping the car wouldn't raise much cash & then if he did find another car it could also blow it's head gaskets in the future. Not only that, but another car may also have bodywork problems that might surface later & could scrap the car due to rust etc.

So realistically the best option is to keep the car with it's immaculate bodywork & just fix the engine.

If the O/P has no experience or interest in mechanical work then he wouldn't find the motivation to start spannering anyway-so the best option is just to get the garage to remove the cylinder heads & then report back with their findings.

Once the heads have been removed & the nature of the damage verified, then he can take stock of the situation & then plan the next step in the repair procedure.

If he did have a change of plan, then he's quite able to request that all the dismantled engine parts be boxed up & returned to him and for the car to be towed back to his home for further consideration.

If the garage are paid for the dismantling & inspection work they've done so far, then the car can be removed & towed away from the garage premises as there's no obligation to leave the car at the garage for repair.

The O/P has a car with immaculate bodywork & a new MOT for a year, so he might as well keep it as it may well just be the head gaskets that need replacing. That will be an expensive job, but a lot less expensive than scrapping the car & starting from scratch with an unknown quantity car-which may also require mechanical work & wouldn't have bodywork in as good a condition as the O/P's current car.

Keep the car & fix it

 

Ok so I’ve booked the car in at the local Jag specialist, they want a full week on the car,a day to take apart and examine the damage, a couple of days awaiting parts after decision to repair or replace engine has been made and acouple of days putting it back together.

It goes in on the 11th march could be sooner if they ring due to being shortof work.

I do like playing around with engines such as cleaning the throttle body and MAF sensors and replacing the discs and pads like the other weekend. These are just little maintenance jobs I wouldn’t have the organisation to take apart half the engine, then there’s knowing what to look for in terms of corroded pistons/linings, cracked chains and metal tensioners, all of which I’ll belooking at replacing when the engines undone if need be.

Just hoping if the engine is repairable the work/skimming etc doesn’t decrease engine power/BHP and it runs as sweet as it always did.

I will update on the 11th with the results of what needs doing, fingures crossed its just typical HGF work.

 

Good luck with it, I'm hoping it's just the head gasket.

With head skimming there's a theoretical bump up in compression ratio, meaning more power, but it's in the tenth's of 1 HP, depends on how much material needs removing to get flat, cheaper to replace the head usually. They might have one they can just swap.

It didn't read like you'd driven it until it was roasting hot in there, it might be just gaskets, if it gets hot enough for warping the head, then valve seats usually drop leading to top end noises.

So get a price on head skimming if they say it needs it, and how they've confirmed it.

If they say bore/liner damage, take pictures and post here.

Get shots of the original timing equipment too.

There's nothing wrong with a knowledgeable customer, asking the right questions as your paying for the work, it's your right to know what your paying for exactly.

I'm surprised at the low numbers of V8 cars needing head gaskets - the XK 6 pot engines are a different matter.

 

If the repair has been done properly then the engine power should not reduce-if anything it may even feel slightly better as the failed head gasket will have been 'bleeding off' combustion pressure in the affected cylinders, which would reduce gas pressure on the piston crown & hence reduce engine power.

When I repaired my Bentley it felt noticeably more powerful than before the failure-prior to the failure you could feel hesitation on sustained full throttle as one of the cylinders was losing combustion pressure to the cooling system.

If you get the car back & it feels worse than it did before the overhaul, then it hasn't been put back together correctly & you have cause for complaint with the garage-PROVIDED they didn't inform you beforehand that there were any problems with the Nikasil bores...

If they take the heads off, confirm the blown head gaskets & also confirm that the Nikasil block is alright with no bore corrosion, then there should be NO REASON for the engine power to be less when it's repaired.

If they give the car back to you all repaired & it's running worse than before the repair, or is down on power, then it's THEIR fault unless they SPECIFICALLY inform you of any other problem they discovered during the stripdown, overhaul & repair...

 

I feel sorry for your predicament, and lots of really good advice has been given already.

My initial reaction was if the car is a peach, fix it.

Unfortunately, as another member mentioned, a valuation of £3000 may be rather optimistic under the circumstances.

So, heart or head ?

It's really difficult, I know.

My dear Old Red popped a head gasket just last week. She was my daily driver. Definitely a steel linered engine as the original Nikasil was replaced.

So my heart says fix it, my head says scrap her, but I've had her for 10 years! She is part of the family

As other members rightfully advise, you know your own car, and that creates value (for you at least).

Members also correctly note that few cars that are sold don't need some expenditure to bring our new pride and joy up to spec. So you would face some costs there in addition to the price for another car.

You face the same dilemma.

Old Red is no peach, although she was. I know the decision I have to make. I gave my previous V12 away to an enthusiast, and will be willing do the same with Old Red. Were my engine OK you could have it

Prior to your gasket issue, if that's what the problem is, did you intend to keep the car for a long period ?

If so, my advice would be to fix it. These cars have far too much character for such an ignominious end.

From reading your thread, the advice I can give you is don't let anybody loose on your engine that doesn't know exactly what they are doing, including yourself. Jaguar engines are not for beginners.

Best wishes,

 

A well written and argued post, thanks Rojie.

 

Thanks Rojie, I'm definitely going to keep the car, I’ve had her for 6 long years, coming from a man that got bored of a car within 12 months, these include TT Supras and C5 Corvette's, the Jag continues to put a smile on my face.

I found out today that my Jag should have the steel lined engine as I discovered this (see below) when I was searching though my engine with a torch. So definitely worth repairing fingers crossed I have the metal tensioners and my chain is in good condition to save on extra expenditure.

I will keep my post updated with any progress, but its going to be a long 3weeks till I get my car back

 

As a percentage of the overall cost, using new upper tensioners would add very little. There would be no additional labour except if the valve cover on the other side is not being removed. Definitely worth doing even if they are already the metal but not fresh. The same goes for spark plugs and similar where there is no extra labour.

Also don't forget to check the cooling system.

FINALLY ... REPLACE THE COOLANT HOSES UNDER THE SUPERCHARGER WHILE YOU HAVE ACCESS ... MAYBE THE KNOCK SENSORS TOO

You do not want to have to pay a second time to remove the SC if the hoses let go. You might go so far as to send out the fuel injectors for cleaning. The list goes on ... but the general idea is to avoid repeat labour charges.

 

Quick update....

The work is underway nicely, the heads have been sent off to be skimmed due to slight warping, one gasket had failed on the right bank (you can see the clean piston from the pic) but the other banks gaskets wasn’t far behind it so both will be replaced.

The linings are steel so that turned out to be good news in the end and theres no corrosion on the pistons or linings.

The Jag man has suggested replacing the bolts that holds the head onto the engine, he said 5 have broke/not worth putting back in and would recommend changing the rest while doing it, unfortunately these bolts are £7.44 each and there’s 20. An expense I didn’t see coming.

He’s also recommended changing the plastic tensioners out for metal ones and while the chain and guides look ok on the surfaces he recommended replacing these also while he's at it.

He’s yet to check the water pump and pipes, he'll be doing this afternoon along with working out the final price for me.
He's very thorough in his work and always gives you the worse case scenario straight which is not a bad thing I guess.

 

I used lincoln bolts, much less $$..

Get the hoses to the rear of the car while he has it torn down, if they go its a lot of time ($$Labor) to replace.

 

I used the lincoln bolts from parts geek too. This was my first heads off rebuild and its the support of Dsnyder, sean B, and dutch courage that got me through it.
It sounds like you love your car like I love mine, so good luck with the rebuild.

 

He has given you good advice. All the points he touched on are meant to save you money or protect your investment in the long run. Make sure you include the hoses. The plastic tensioners are a definite must. The head bolts, well 5 are gone anyways ... might as well have all the same. The water pump, guides and chains are parts only as he has them apart anyways. It is just a matter of choosing between putting back old or new. Same labour.

 

All your explanations lead up to ttwo things, a buggered thermostat and a possible stuffed water pump....thes two are the only things that will upset the cooling system in the fashion you have described....the external temp is irrelevant, as if the system is working correctly it will self compensate.
get apressure check done and an exhaust gas sniffer test.
These systems work very well when operating normally....no second guessing!

 

As the head gaskets have clearly blown on the O/P's car, it's possible that when they were failing they pressurised the cooling system-blowing the coolant out until the level drops below the coolant temp sensor, which may be the reason the O/P said the temp gauge didn't rise as there was no coolant touching it.

When my Bentley blew it's head gaskets last year a similar thing happened. The combustion gasses escaping past the breached head gasket into the cooling system caused the coolant to be blown out of the expansion tank past the rad cap & down the overflow pipe, causing the coolant level to fall.

When I took the heads off, I also had a shiny piston crown on the cylinder where the head gasket had been breached-with the other 7 piston crowns looking normal with carbon deposits on them.

Your mechanic is giving good advice-with the engine dismantled it's an easier job to replace the tensioners & any other parts required-this should be a 'once in a lifetime' top-end overhaul.

I would definately use new head bolts-I once re-used head bolts on a BMW straight-six engine when refitting the head. Shortly after the repair, the engine started to give the symptoms of a blown head gasket again-but one of the head bolts had sheared flush with the block, so I had to take the head off again to remove the thread in the block.

My advice-use new head bolts!!!

Other than that, your rebuild seems to be progressing nicely without having to replace the complete engine. The top-end rebuild should give the engine a new lease of life, and together with all the work you've had done on the body of the car & the paintwork you should have one heck of a good car when it's all rebuilt.

After all the £1000's you've put into the ar on the bodywork, as well as the cost of the head gasket repairs so far, it just isn't worth the risk to re-use the old head bolts, especially as 5 have already failed. If one of your old bolts fails & shears flush with the block, then you'll have to take the complete head off again to extract the remains from the block.

Head bolts are a critical part of the engine & will ruin your day if old ones fail, so it's well worth fitting a complete new set-even if they aren't cheap...

 

Now he’s come back to me with a couple of prices.

First price is the minimum things will cost, this includes thefollowing:

Labour X 20 hours (in real terms he said this is more like 30)
Skimming of both heads
New engine head bolts X 20
Top tensioners X 2
Head gaskets
Total £1554

The second price includes replacement of some of the none essential items but in the long run It might make sense doing them now, this includes:

Labour X 20 hours
Skimming of both heads
New engine bolts X 20
Top Tensioners X 2
Head gaskets
Bottom tensioners X ?
New Chain and guides
New Oil and filter
New Gasket for water pump
New Coolant hoses under supercharger X 2
Total: £1900 (tops)

I have chosen to go for the second option, not sure if this is the right plan for now as it’s a stupid amount of money to spend on a car that on the market today is probably only worth £3000 bearing in mind I have a £500 exhaustfitted last month. But I think it’ll bring piece of mind in the long run, the only major fault that could happen with the car next on this kind of scale after having £1900 spent is gearbox failure (touches wood).

Your opinions are always welcome….

 

It's market value is irrelevant really.
It boils down to how much is the car to you personally?
Where else are you going to get such performance value for the money along with classy style few other cars of this vintage exhibit or posess.
I know what I would be doing.......

 

If that is a picture of your car, it looks great. I would not worry about the market price of the car, or over capitalisation, it is a Jaguar which will give you a great deal of pleasure over the coming years. Sure, it has cost some money to restore, but now you KNOW that it is a good car, and can enjoy it. If we wanted safe and boring we would drive a toyota echo.