www.jec.org.uk

Hello,
I am looking at a probable cylinder head gasket failure on my car as she is using water. There are no apparent leaks in the system and the indications are that water is being forced under pressure basck out through the pressure cap of the expansion tank. The underside of the bonnet at the front shows signs of condensation which in turn looks as if it's the steam that has been expelled from the cap. System is also under pressure when cold as can be seen when the cap is taken off. Pungent smell also emits from the water inside the tank.

Been experiencing this now for around 6 weeks and had it in and checked out with my regular garage. Very rough costs around 12 to 1500 pounds for repairs ( that would be both heads which I presume i would have to replace gaskets with ). Car is losing around a 100mls of water over say around 300 miles and drops the water level below the sensor which then inturn activates the Low Coolant Warning on the dash. Still consulting with the garage ( been going there years, they know the car outside in and I trust them fully ). Their view is, big job, expensive to do, is car worth it commercially? probably not.

Had a similar experience before with a Sierra Cosworth a while back and I suspect it may be time to go as I don't fancy getting into a situation of throwing a lot of money at this like the last time. 86000 mile on the clock and still runs very sweet, really messing my head up as it's looking great as well and the trade in price will be a pittance.

Any thoughts anyone ?

You seem to have done a pretty though diagnosis and covered all the usual lines of investigation.

Almost anything is repairable given enough time, money and effort. As you say, is it worth it?

Most certainly both head gaskets should be changed if you decide to repair.

Maybe a warranted second hand engine may prove a slightly cheaper option. There are plenty of them around. Prices typically £500-800. The advantages are a quicker, simpler and perhaps less labour intensive swap over.

Eurojag can supply from a accident damaged cars with a short warranty. It is also worth contacting Neville at North East Jaguar Spares to see what he might have available. Ebay might also provide but you will have to be rather more careful before you part with any cash.

It doesn`t take much to make an aging car an uneconomic proposition nowadays. Breakers yards are stacked with perfect looking cars that have suffered just one major component failure. Always a shame that otherwise good cars meet the crusher for such reasons.

Best of luck with your deliberations.

Mike

it does sound like you have gone through a thorough inspection process, that said these V6 engines are usually bullet proof, this mileage is low for a failure, 200K miles is not uncommon on these engines

David Marks does not repair them, he uses second-hand engines as Mike says from EuroJag, they are a trusted supplier and will give a short warranty, a cheaper and easier process

Give David a call and seek his advice as well

As to the viability of repair, really your choice, how much does the car mean to you??, if you are not too attached and the failure is confirmed, bail out, buy another, loads of good S Types out there at sensible money

Hi again,
Thanks for the speedy replies and much appreciated information.

Think I am pretty well decided on course of action as I have surface rust issue on both front wings ( wheel arch areas ) which will require attention shortly incurring more expense. My thoughts are on checking out a couple of S type diesels ( 56/57 reg. both with around 45k/50k respectively on them ) to see what kind of deal I can do. Makes more sense anyway now that I tow a fairly big caravan ( well within the car's limits though ). Be nice to have the extra torque. Funny thing is that's when this started to show up, on a trip down to Haggerston Castle, don't know if it's a coincidence or not. Perhaps something that's been ready to happen and the additional pressure from towing brought things to a head.

Anyway, be in touch shortly I would think.

Haggerston in 20 minutes from me, so if you want to call in anytime just say so, we are on the A1 just north of the border, 10 miles north of Berwick

check diesels very very carefully, read up on DPF's and the problems they can cause, tractor juice cars best used on long journeys and need some regular long journeys

Pre DPF cars are the best if like myself you do short journeys. Have a Re-Map done and you'll have a good powerfull and reliable motor!

Jeff

Hi,
Thanks for the information and interest. Situation now is that the car is in with RJM in Glenrothes. This is a garage that a lot of our group members use for their cars whether they be older or later model Jaguars.

They are going to pressure test it over the weekend, carry out various checks and we should know Monday / Tuesday latest as to position.

Garage also provided me with a reasonable ball park figure for replacing head gaskets should it need it.

Be in touch shortly.

The cause for failure needs to be established before repairs are effected.. A few ideas here.

Simple low water level.

Leaking header tank.

Thermostat shut. Overheated engine causing failed thermostat and head gasket failure.

Failed engine cylinder head temperature sensor..

Poor flow through blocked radiator or other blockage..

Failed water pump.

Corroded out or cracked cylinder head castings due to lack of corrosion inhibitor/antifreeze.


Hope that helps.

Mike

Hi,
Update on L17MCA.

The garage ( RJM in Glenrothes ) have had the system on pressure test all weekend and could find no issues as everything was normal. Engine running sweet with no apparent water problems in any of the cylinders.

Took off the under trays under the engine and found evidence on the front cross member of a water leak. Dried and cleaned it up, Took it for a couple of test runs and found fresh water on it again after the harder drive to push the engine a wee bit harder. Checked the pressure cap on top of the expansion tank and found it was faulty ( which we had suspicions of). Replaced it today with a new one, did some rigorous testing again and seems okay now.

I will be monitoring it obviously and keeping everything crossed. Glad I hopefully don't need to trade in.

Cheers and thanks for the interest.

First time I`ve heard of a cap failing on these cars.

The system is now under full pressure again. Suggest you keep a very close ete in the header tank for a while. As you will probably know , these tanks are notorious for splitting due to age precipitation, heat and pressure. the classic tell tale sign of splitting is puddle of coolant behind the off side front wheel on early cars.

On the later cars,(of which yours is and example) the stub pipe below the pressure cap is prone to failure. The pipe is of small dimensions and has little or no reinforcement where it exits the tank. If it fails, a repair is almost impossible and a new tank will be needed.

Glad you got it fixed.

Mike

Thanks Mike,
Interesting comment about the hose.

Thing is the warning light came back on this morning on way into work. Distance is about 14 miles on an A road with all the normal flats and gradients on it. Light came on after about 1 mile and stayed on for another 7 or 8 miles after which it went out and stayed out. Temperature gauge as before stayed right in the middle and never moved.

Checked the water level about 3 hours after I got into work and it's sitting well above the level in the tank as it should. Very strange. I will be keeping an eye on it to see how it goes and will no doubt have this checked out should the problem persist.

John

That could be an air lock that's sorted itself out.

Jeff

Kinda thought that at the time.

Done about a couple of hundred miles since I got the car back on Tuesday and apart from the blip on Wednesday morning the car seems fine. Water level is stable and no more warning lights.

Can't get away with the caravan for about 3 weeks because of commitments but that should be the ultimate test for it.

John,

Update on this thread. Head went finally. Got a replacement " good " engine from Eurojag. Had the garage switch engines and got the car MOT'd at a cost of just under £1800 all in. Did just under 20 miles on test run with new engine and couldn't believe when it boiled up. Thought maybe water pump had packed in but lo and behold when we checked it out again second engine has suffered head gasket failure. At least I got my money back from Eurojag. Bit cheesed off and probably sell it for scrap.

Not good news.

I wonder if this car needs a new radiator due to blockage and poor flow. A shame indeed that a second hand engine has gone West.

Mike