I have the hot/cold/hot/cold etc. symptom, but I don't think I'm venting coolant. But then again, I don't drive that many miles. I'll have to check.

 

If it is passing the combustion gas test and there is no water leaking into the oil or leaking to the outside of the block, forget about the head gaskets. That is going to be one expensive nightmare that may not fix the problem. Does anyone know how prone these are to trapping an air bubble after a thermostat replacement? It might be wise to follow the coolant air bleed procedure, if there is one, or to use a vacuum bleeder like the radkitplus.

 

I'd love to add "FIXED" to the title of this thread!!

 

Thanks so much for following along. Tried everything, even changing one-way valves to core. After a longer, and slightly harder drive when engine was hotter, exhaust products finally showed up in coolant - very positive, sadly. It's the head gasket after all of that..... Might as well see if the secondary tensioners are in good shape once the engine is apart. A whole host of other issues are apparent once under the car on a lift. Beautiful body, and scary low milegage, but it's now evident that the prior owner knew a lot more than he was willing to share.

 

Cheers, Jim. You are a good man. I will be back in due time to share.

 

You are going to have the timing cover completely off, most likely, so its probably high time to look at the primary tensioners, the tensioner arms, and the chain guides. Good luck and I am very sorry to hear about the combustion gas test failure

Just noticed you said it has low miles, the guides are "probably" good Like you said though, I would look into upgrading all 4 tensioners and chain hardware so you dont have to worry about it for like 200k

 

I think the car is a goner, I'll be honest. I will not be a bit surprised if there is a crack in the block once we get deeper. What is seen of secondary tensioners so far looks good.

 

Update: two of the cylinder heads were warped, and will need to be milled (positive change in temp strips) - looks like the previous owner let it overheat, and then saw there was a perpetual coolant leak (and airlock in coolant as a symptom), then they sold it, hoping to get away with it. No crack in the block. So, it needs machined cylinders, new head gaskets, I can confirm the water pump HAS been changed, but the secondary tensioners are the original plastic ones and should also be replaced.

I KNEW there must have been a major issue with this car - most things that seem too good to be true, usually are. Can't believe all this started with perpetual coolant push out into recovery tank. No loss of performance or loss of gas mileage.

Would you guys get the repair? I can't stomach 'dumping' this on another poor person. The repairs will cost around 50% of what I paid for the car (1998 XJ8 VdP, purchased a year ago). Seems silly to change all of the above and know I am leaving the old secondary tensioners in there and thet are not cracked. Pristine body. 58K on clock but new jag engine placed in it at 20K (so it's only done around 38K).

 

Man, that engine is almost brand new I would probably do the headgaskets and upgrade all of the timing components, it would probably be cheaper than swapping in another motor. If it was cheaper to do an engine swap (used engine of course) I would try to find the newest/strongest swappable engine with the lowest mileage.

 

As the saying goes, the devil you know is better than the devil you don't know. If you buy another Jaguar, you could be starting all over again. If the body and interior are in nice shape, I would fix it up. Do some serious checking around to get good prices on the repairs.

 

Man, thats such a shame, I feel your pain.

As has been said though, better the devil you know that the devil you don't know......sounds like there is a heck of a lot going for this car.

We've had similar stories with the X and S type where there's been a team ( 2-3 ) of top DIY'ers, who've got together over a weekend, brought tools. loaded the fridge with beer and stocked up with steaks for the barbie and did the whole repair ( usually with a write up and or pics / vid ) saving the OP $$$$..............
This usually after several guys have chimed in, identified the best / cheapest places for parts ( saving more ).....I think we're long overdue for a similar story in the XJ section!!
Who do we have in the New York area??

Sending positive vibes your way my friend

 

If only I was closer, I'd be on this like Jim suggested, just keep the beer coming;-)

Now you know for sure what the issue is, gather the parts and find the right guys to carry out the repair. If you manage it in the right way then you'll have a car as it's meant to be. The VDP still can't be beaten for value, they really are fantastic cars for the money. Find a machine shop that's familiar with skimming heads, make sure they take the minimum off. Use O.E.M gaskets.

Jaguar have just added X308 parts to their Heritage site, which can be ordered through their worldwide network
Genuine Jaguar Parts and Jaguar Accessories for Classic Jaguars
You don't pay V.A.T (value added tax) so some things might b worth buying, i.e. gaskets, from them.

You've done the best you can so far, and that's credit to you. It's a sickener to find heads warped, but consider that the fault can be much worse, like dropped valves. I just think what a hero of an engine, telling you something's not right, but still trying to perform. That's how good they are, imagine it 100%.

I'm in the 'stay with it' camp, but I rebuilt mine, I'm bonkers.

 

I want to thank everyone that helped me - particularly JimC64 and Sean B for their kind thoughts.

I will try to attach a photo. The head gasket was warped, and there was coolant residue on the cylinders. There was no loss of performance at all. Two cylinders needed to be milled. The secondary tensioners (amazingly) were NOT cracked or distorted, but I took everyone's advice and replaced them anyway - this was an expensive job and I needed a Jag expert with the right tools, so it was costly. I also learned some history about the car that was notably absent when I bought (like a new engine was put in at 20K, a new transmission and new gearbox at 22K, so the engine has done 40K). The Jag tech has worked on these cars for 30 years, and says he's never seen a problem like mine (perpetual coolant push out into recovery tank and an airlock in the heater) present so subtly as a head gasket issue. The couple of months of diagnosis I did with the help of you guys pointed him to it as he could not find an issue when I first took it to him. The prior owner must have let it overheat.

So, new head gasket, milled cylinders, secondary tensioners, thermostat + housing, full flush, and Jaguar coolant. I still laugh when I think that the Jag tech was so frustrated that he took several parts out of his own car and put them in mine to figure out what the issue was before billing it as a gasket job. I made several great friends over there, and they really know their stuff. I'll be around.


Can finally say fixed.

 

Sean -
The link to "Genuine Jaguar Parts" is conspicuously lacking in any information regarding sales to North America. If you look under "other country" and look up, say, secondary tensioners, all you see is a message "contact us."

Looks to me like Jaguar does not want to help NA customers directly. Or am I missing something....

 

Good job, happy driving

 

@ Scottish Chap - WELL DONE!

@ Boomer - see here,

The Jaguar Classic Parts (JCP) team have just returned from a week long trip to the United States, promoting Jaguars Classic Parts Programme at a dealer conference in San Antonio, Texas.

The dealer only event provided a great opportunity to meet with major dealers and promote the value of authentic parts.

JCP exhibited for 5 days, attracting a lot of interest from American dealers who were pleased to learn that when they buy from JCP, a percentage of the profit goes directly to the Jaguar Heritage Trust (JHT), helping to keep the spirit of Jaguar going well into the future.

Philip Williams, Global Sales and Marketing Manager of Jaguar Classic Parts said, "It was a great experience visiting the San Antonio conference. We spoke to a lot of people and I think we got our message across – when you buy from us, you buy from Jaguar, no copies, no imitations, just authentic Jaguar parts.

"I think a few people were surprised about our connection with the JHT, we're glad to support it because it gives us a real sense of pride, it's only right that by selling genuine Jaguar parts for the most well known classic cars of all time, that we are helping the future of Jaguars heritage and story grow and develop."

For more information about the Jaguars Classic Parts Programme, get in touch via parts{at}jaguarclassicparts{dot}com

they do have a presence in the USA - I'd drop them an e-mail as see what they suggest. It's Jaguar you're contacting, you have to be pro-active!

 

How I wish Scottish Chap had found a solution...I have exactly the same problem and still no solution...
Thanks for the info so far, but has anyone found the answer?

 

Sorry guys, didn't look to the end of the thread before I said that...

Here goes with the heads on mine....

 

Calamity. Blowing own trumpet comes to mind. After all the good things I've said regarding this engine, suddenly, out of the blue, up pops this very same problem. Pressure tested ok, and no sign of coolant in engine bay or on the floor. level topped up, then two days later, low coolant on again. Checked and level well down again. As far as I know, it has not overheated, but don't know for sure (damn those jag temp gauges) Mileage since tensioner/chains job about 200 or so, and between low level warnings maybe 12. Not looking forward to the hunt, ( nor the possible cost) Praying it's not heads or gaskets. Runs a treat, smooth, quiet, comfortable. What CAN it be?

 

Hi Scottish chap your coolant story I have just read sounds just like my recent life story with my 2000 XJ8 .have done all yours things but always drips under the recovery tank have new cap and expansion tank as well as Thermostat and housing. Perhaps I have been filing the expansion tank too much and now know there is an overflow on the recovery tank so learnt a bit from reading your excellent detailed reports and from Jim's advice as well . I was scared about head gasket but no normal signs or loss of pressure in system oil and and pressure test no leaks . Getting very stressed but having done everything will let level be a little lower in expansion tank hoping low coolant warning does not come on . When put new coolant top hose outlet and thermostat worried have not bleed system properly but know the full procedure from your post which is about what i did to bleed system .
Will keep trying
Cheers
Nigel