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Hello fellow JEC members. I have successfully quenched my mid-life crisis thirst by being the proud owner of a 1994 V12 6.0 XJS. I bought this vehicle in early March 14 and it drives and looks pristine with 106k on clock. Since my first and faultless collection journey of 128 miles, the car has failed to retain any coolant. I cannot see a leak but I obseve that I am adding to the coolant every journey following coolant warning light activation. In addition to this once the car is fully warm and driven for a number of miles, it starts emmitting plumes of blue smoke from exhaust whilst at idle or when you roll off the gas. It doesn't bellow, it's more akin to a steam engined train emitting steam whist stopped. No loss of performance. Completely adore the car. What should I check?? Has it all gone wrong?? Can I still drive it?? Please help. Andrew

first of all , welcome

secondly , congratulations on buying an XJS , and a V12 at that ( pictures are required......its the law )

your problem could be several things, and i wouldn't drive the car again until you have sorted the issue, as overheating can twist the heads on the V12 , and then its a coffee table candidate,

the engine has so much coolant it requires an expansion tank , and also an overflow tank that acts as an atmospheric recovery bottle ( the engine sucks back from this when cooling ) , this system needs to be perfect for correct operation

also turn the inside heater to on and hot, to ensure full coolant flow round every system ,


is the coolant to the correct level >
this is done using the two pressure caps and filling in a particular order,

remove both filler caps , one at the front of the engine, and one on the expansion bottle tank on the left inner wing , using the correct coolant ( but water will suffice for testing ) fill the system from the front engine cap , do this until the coolant runs out of the other cap on the wing , make sure you do this on level ground. then fit the cap on the wing , and then continue to fill the front engine pipe until the level is just below the cap , then fit this cap ,

your system is now primed,

you can start the engine, and let it tick over , if working correctly , it will start at about 1200-1500 revs then drop down to 750 revs , this is normal , if it hunts, then thats another problem we can sort later,

the coolant will now be being pumped round the system , with the mechanical thermostat shut , the coolant will bypass the radiator until the thermostat lets it through ,

let it run for a few mins, just to distribute the coolant,

turn off the engine and then check the front filler tube again , if the level is low, then top it up , you can't put in too much as it will overflow automatically to the overflow tank and out onto the floor behind the passenger front wheel ,

keep doing this process until your confident that the coolant level is full as designed,

btw , the level sensor is mounted on the left wing tank , this is what brings on the dash light if the tank is dry ,

other things to check for is the pump belt on the front of the engine, as the water pump is belt driven , ensure the pump pulley is spinning when running, keep your fingers clear though !!
and then the thermostats ( mechanical ) need to be proven , the radiator should get hot during this , but they could be stuck , i would change them anyway , but prove the system first

then i would run the car up to temperature while ticking over , monitoring the temperature and listening out for the fans to kick in ,

if you have an original viscous fitting fan behind the rad, check that it spins freely when cold without the engine running, and is grabbing when hot ( right after you turn off the engine, )if not then this has failed and its time to convert to full electric cooling like i have done

as for steam out the exhaust, this is normal for the first five mins of starting a V12, but it should then stop

if you do indeed have steam , then that means one or both head gaskets have failed into the cylinders, and require immediate work to stop complete failure of the engine

good luck

BB

Brake Buster-thankyou so much for your most comprehensive reply and in such timely fashion. You may have detected that I am not only new to the XJS V12 experience but also to Forums and like minded enthusiasts. I will undertake the cooling process you described tomorrow. Whilst adding water to top up the coolant on every trip as previously stated I have watched the temperature gauge obsessively and it has never risen above half way between N and Red, before settling on to N for most of the journey. I do have steamy exhaust as you stated following initial start which does disappear after 5 mins as you predicted. I have observed the other steamy effect once I have reached my place of work approx. 30 miles away. Minor research suggests that Head Gasketts are commonly encountered. Is this common for 106k miles? Is it a big job (specialist garage) and if so roughly what could I expect tom pay? To save investigation, would you recommend that I have the Gasketts replaced anyway for piece of mind? The thought of this wonderful machine being off the road as summer approaches is unthinkable. I totally have the bug. I am still at the "visit the garage just to check that it is still there" stage. In addition to this I am motor car mechanically illiterate bit willing to attempt minor jobs. Thank you once again for taking the time to answer my questions. I will post pictures as soon as I learn how to transfer them from my phone to the Forum. If this sounds like I have missed the computer revolution....you'd be right!!

Andrew,

Welcome to the club and to the XJS section of the JEC Bulletin Board!

As BB has pointed out, you really don't want to drive an overheating Jaguar V12, as sadly, if it overheats and blows the head gasket, it's very likely that it will have warped the heads.

It's really important to know if you're seeing steam or blue smoke in order to understand if you're getting coolant leaking through a head gasket split.

I would start by making sure the coolant is filled properly and then running the engine to see if you can find any coolant leaks from the hoses, radiator and pipes. If you can't find the problem that way, then I would do cylinder compression tests. That's fairly time-consuming on the Jaguar V12 but could help to identify if you have a head gasket problem. The other thing you can do is to get a coolant pressure test undertaken by a good garage.Without wishing to alarm you, if you have cylinder head gasket splits on both banks, you need to seriously consider if the heads are warped.

You haven't detailed in your profile where you are based, so if you let us know, we may be able to recommend a good independent Jaguar specialist to whom you could take the car for examination.

Good luck, Andrew. Let's hope it's just a hose leaking somewhere. Also, when you get a moment, do please remember to update your membership record with your car details.Post back here if you can't work out how to do that and we'll advise you.

Paul

Hello Paul and thankyou very much for your reply. To be honest am proper spooked now. In fact truly petrified that I have bought a dog. Certainly the condition of the vehicle/affluence of the previous owner/buying experience would suggest otherwise. The car has a fully stamped JAG service history but no receipts. Will fill coolant today as BB kindly suggested and observe. Please do recommend a quality specialist garage. I live in between Winchester and Alton in Hampshire with a Post Code of SO24. Please do advise re updating vehicle details. I probably omitted to do so in all the excitement of my XJS acquisition. Thanks again for your support. I need this 'boys-toy' project to be a success. Here's hoping.

Andrew.

Andrew,

Let's hope it is something minor such as a leak. Stay positive!

I do have a suggestion of somewhere local that specialises in Jaguar where you could take the car and they can do a "sniff test" to check for combustion gases in the coolant.

If you're interested, give me a call at home.

Paul

Paul, thank you so much for your personal support yesterday on the telephone. I have to conduct some more research but it looks like my mid life crisis project that had an unprecendentidly fabulous start, has come to a crshing hault!!

In short, I followed the instruction kindly detailed by BB and successfully primed the coolant system. I'm no mechanic (clearly) but I thought this is taking a LOT of water, but finally it was primed as described. Then it all went horribly wrong. Bear in mind I parked it in the garage purring perfectly, all be it a bit steamy/smokey. When I fired it up it was a completely different motor. Lumpy and spluttery and I limped out of the garage to investgate further. Then I saw it. Water being ejected in 'sploshes' out of the right exhaust pipe!! After a few minutes I turned it off to discover my previously full coolant system had lost nearly all of his water, obviously out of the exhaust!! I contacted a local specialist kindly suggested by Paul and we're already talking thoushands!! I am in genuine shock. This could be the 'Classic Car Horror' that I so wanted to avoid. Saying that the pleasure I received when it was working was un-rivalled (certainly in the boys toys arena!!). The car still looks amazing. More research today. Will keep you posted as have realised that my newly acquired Jaguar addiction still needs feeding. Will need to 'man-up' and sort a recovery stratergy. But today....just miserable.

damn , thats terrible news , and i feel for you

the engine was obviously running without any coolant ( or very little ) , and when cold would run ok , but when it got to critical temperature the engine would effectivly start to seize , as it wasnt being cooled , the bule smoke and lumpy running was a sign of this

best thing to do , if you have the space, is to get someone to take off the heads to inspect the damage,

worst case scenario is warped heads and or damaged pistons, best case is just blown headgaskets which need replacing and then all putting back together , as as it was only the right hand exhaust , i would start with that bank ,

with limited mechanical experience, this is a tricky job , but you can always call on the help of fellow JEC members for advice and help , especially if your willing assist , even it its just bacon rolls and mugs of tea ,

head gaskets come in around £100 , you will need a top end gasket set to do it properly , replacing any that are damaged to remove other items , especially on the induction side ,

labour ,

well , a weekend to take everything apart to inspect and check , then its down to what needs replacing , though a special tool is required to pull the head off correctly ,

did you buy the car from a garage ? is there any warentee at all ?

you may be able to get something back if you havnt had the car for long


again , sorry for being the bearer of bad news

BB

Andrew,

I'm sure we all sympathise with the problem that you now have. When we spoke yesterday, your description of water being pumped out of the exhaust did really concern me as clearly there is significant water escaping into the combustion chamber and thence out in to the exhaust. The one good thing is that rather surprisingly, the engine didn't seize. My initial thoughts are that perhaps the car could just about run ok when the coolant level was really low as there wasn't enough coolant to even get to the level of the head gasket (although that seems surprising in itself as I thought even a small level of coolant would still get pumped around the cylinder head?). Perhaps when you filled the system, it now had coolant all around the head and could seriously leak.

As you bought the car privately, I think (but don't know) that you have very little recall on the vendor. Was the coolant light on right from when you bought the car? Do you know if the coolant was full when you bought the car? These might be important considerations in trying to gain recompense. If you're a member of the AA or similar, you might be able to talk to their people to get some consumer advice.

As regards moving forward, as BB has said, it may be just that you have a significant leak on one cylinder head gasket and the car hasn't overheated and warped anything. Let's hope. It does seem that you need to get the head off on that side and, as a minimum, get a compression test done on the other side as it's possible that the other side is ok.

In total cost terms, it will depend if you have:

- one head gasket gone, head not warped (cheapest)
- both head gaskets gone, heads not warped
- head gaskets gone and heads warped (most expensive)

In my limited experience, I would guess (and it is only a guess) that if one head is warped through overheating, the other one would have gone as well. Perhaps others can comment on this?

The decision now is how best to get the head removed in a cost-effective manner. I guess the options are:

- Find colleagues who could help you do that at home
- Pay someone to come round and do it
- Get the car trailered to somewhere you trust to undertake the work.

I can't offer you any personal help on this unfortunately, but there may be other members who can advise or offer assistance. I would also contact your local regional representative - Go to the Home Page and look up Regions for details - who may have some ideas or know of local specialists.

I suspect you're feeling a bit low at present but he good news is:

-you have a desirable rare model
- the rest of the car sounds good
- it sounds as if the repair cost will be worth it

I'm sure everything will seem better tomorrow!

Good luck

Paul

Hello Paul and BB-once again thank you for your rallying words of support.

I have contacted most of the engineers suggested by Paul and have managed to persuade one of them (begrudengly) to undertake an internal inspection of the engin to ascertain the damage caused. All who I have spoken to with reguard to Head Gasket replacement grimmace at the thought of what they consider an un-pleasant job. This engineer, who seems very knowledgable, has detailed a list of other potential nightmares that may need resolving before the car can return to full operational status but the only way to discover this is to take the head off and inspect. So I feel that I must undertake this work so at least I know. This particular engineer suggsets that I should replace just the one Head Gasket if only one has gone (but to check the status of the other one naturally). This would keep the cost down but any thoughts on this stratergy being false ecomomy would be most gratefully received.

With regaurds to my assessment of the vehicle prior to purchase, I don't believe I would qualify for any redress. I took the car on visual and substancial test drive (10 miles+) inspection and found nothing untoward. The coolant light was not on and I looked for signs of smokey exhaust at three different stages of the test drive which I have to add was faultless. By then of course I was just a dribbling wreck staring ,in complete ore, at this beautiful machine-itching to part with my money and claim it as mine!! You have probably encountered many like me before. Should any fellow JEC membwer have a collection of 'Crystal Balls' that I may borrow prior to any such future impulsive actions, that would also be most gratefully received.

The sun has just come out and refreshed my sense of dismay. Still I have made a positive decision to seek an inspection. I'm informed that it's not all bad.......the worst that can happen is that I need an entire new engin and someone willing to fit it. "PPHHLLUUMMPPP" (that was the sound of me falling to the floor once again).

Will keep you posted.

Andrew
Whilst no doubt you are very upset take solace that the best advice available is here.
All things pass and once you have overcome this problem you will have a beautiful car to enjoy!
Good luck

TonyS

The blue smoke issue concerns me. I wonder if a gasket has blown between an oil and waterway?

What condition is the engine oil? Is it clear as normal or is there evidence of water inclusion ie what is commonly know as mayonnaise or cappuccino? Yellow /white sludge is the visual and is quite distinctive. Suggest you check inside the oil filler cap and dip the oil via the dipstick. Don`t drive the car if the oil is contaminated in this way.

As regards only changing one head gasket, I would regard this a a false economy. There is a considerable amount of stripping out needed to change one gasket. Obviously there is more work involved in doing both gaskets. My rule is to do to one side of the engine what you do to the other. It is almost a dead cert that having just done one gasket, failure of the other is highly likely to follow thereafter. To do all that stripping over again.......

Mike K

How disappointing for you but you are not alone in your misery, a lot of us have been there (or are currently paying there another visit!) and all you can do really is hope for the best but prepare for the worst.
A rebuild is going to be expensive, both on parts and labour so it might be worth thinking of swapping the entire lump; there is one from an XJ40 (I presume that it will fit?) on ebay at the moment - http://www.ebay.co.uk/itm/JAGUAR-XJ40-V ... 2a3ac0362b - .
Just a thought.

this is tricky , and the owner is between a rock and a hard place ,

either way its going to cost money , and there is no certainty that a replacement engine is any healthier than the existing one , my instinct would be to stick with what you have untill proven otherwise ,

first step is to pay out the minimum amount to get the failed engine inspected to see how much work is required , then its weigh up the options , but the major cost of either method will be labour , as this is the only way to save money by doing it yourself , which i dont think the owner is in a postion to do

BB

Tony S/Mike K/Steve M/BB-Thank you all for taking the time to comment.

Checked Engin Oil + Filler Cap before 'Meltdown Day' and the cap was good and the oil looked clear and fit for purpose.

The 'Change both Head Gaskets whilst you have the engin in bits' statergy makes logical sense to me but of course there will be additional financial implications. Would you recommend that when I get the engin inspected, should I direct the engineer to fully report on the faulty cylinder bank first or strip the lot and examine both cylinder heads as part of the initial inspection?

Further more I have been consistantly advised not to start the motor again and this therefore means trailering to wherever I choose to have the work undertaken. Now that I have to convey this vehicle I'm thinking maybe I should widen my search for a recommeneded engineers.

Does anyone know of a 'National XJS Master' if you would? Someone dependable, honest, an exepert in the field of XJS engines and of course fairly priced? Better still who has mobile garage facilities.

I will make contact with regional advisor as a starting point.