Blown Head Gasket On 1999 XJR
Discussion
Slight misfire, condensation from offside exhaust, exhaust gasses in coolant and was building up excess pressure in cooling system. I had just had the thermostat and the header tank cap replaced, but 50 miles after that during a 'spirited' blast down a long straight, the temperature gauge went near the red and coolant poured out of what I have been told is some sort of expansion bottle near the front of the car (sorry I'm no technician!). When the thermostat and the cap were replaced the previous day, there were apparently no gases showing on the sniff test. All this has happened just a couple of days after having a straight through stainless cat back exhaust fitted, just in case that's relevant. I just want to be sure that if I am spending the money on getting it running again, I don't end up with another problem!
'Fraid that sounds like a headgasket to me.
Are you sure it's not just a coincidence you've had the problem soon after the work on the cooling system? Is the new thermostat faulty? Was the cooling system refilled properly with the reseviour topped up to the brim and double checked once it had cooled down again? Are you sure the low coolant level warning light works?
You might have had a airlock form in the cooling system if the work was not done correctly and coolant level re checked after a few mins running and again when quite cold - which'll pop the headgasket in next to no time.
Wondering this as you say there was no trace of gasses in the coolant so it was obviously OK when the work was done yet very soon after the gasket goes...
I'd certainly - especially as the engine has overheated - have the secondary tensioners replaced with the metal bodied type if it's not been done yet, a very carefull check of all the timing chains and the waterpump will not go amis either. The affected head will need checking for warp too, if it's bad and needs skimming you might be better off fitting a good second hand one that not been skimmed. You'll need an oil change or two for peace of mind to both ensure there's no traces of coolant remaining in the lube system and that all the overheated oil has been drained out.
You may want to take advice and consider having both gaskets changed whilst it's all in bits as that might be more cost effective in the long term. Certainly sounds like one has gone, the other may be fine forever or could just be hanging on by the skin of it's teeth and if that's the case it'll almost certainly go once the cooling system has been through a few heat and pressure cycles.
Are you sure it's not just a coincidence you've had the problem soon after the work on the cooling system? Is the new thermostat faulty? Was the cooling system refilled properly with the reseviour topped up to the brim and double checked once it had cooled down again? Are you sure the low coolant level warning light works?
You might have had a airlock form in the cooling system if the work was not done correctly and coolant level re checked after a few mins running and again when quite cold - which'll pop the headgasket in next to no time.
Wondering this as you say there was no trace of gasses in the coolant so it was obviously OK when the work was done yet very soon after the gasket goes...
I'd certainly - especially as the engine has overheated - have the secondary tensioners replaced with the metal bodied type if it's not been done yet, a very carefull check of all the timing chains and the waterpump will not go amis either. The affected head will need checking for warp too, if it's bad and needs skimming you might be better off fitting a good second hand one that not been skimmed. You'll need an oil change or two for peace of mind to both ensure there's no traces of coolant remaining in the lube system and that all the overheated oil has been drained out.
You may want to take advice and consider having both gaskets changed whilst it's all in bits as that might be more cost effective in the long term. Certainly sounds like one has gone, the other may be fine forever or could just be hanging on by the skin of it's teeth and if that's the case it'll almost certainly go once the cooling system has been through a few heat and pressure cycles.
It could well be a coincidence. I only bought the car privately a few weeks ago and it transpires that there must have been some issues as when my garage fitted the new (genuine part) stat, they found the old one was non genuine, incorrect, and had beeen hit with a hammer to make it fit, then surrounded by silicone. There was also no trace of anti freeze in the coolant.
I will certainly have both sides done and the tensioners if they aren't the steel ones, they have said they will send the head away to have it machined and will probably get them to do the water pump, even though they have told me that the current part plastic one looks fine. The gaskets, o-rings etc will all be genuine parts.
Should I have the rad replaced too while I am at it, or do you think having it flushed out will suffice? I have obviously bought someone else's troubles, once fixed, the big question is do I try and get some motoring out of it for all the money I have spent, or do I move it on? I've had cars before where I fix problem after problem, hanging in after each repair thinking 'Surely nothing else can go wrong now!' only to be let down again. It's already had the auto box reconditioned 9 months ago, so I suppose that should be one less minefield to worry about and for about a thousand miles it drove like a dream.
What kind of intervals do you suggest for these oil changes and would a used head definately be a better bet than having my existing one skimmed?
I will certainly have both sides done and the tensioners if they aren't the steel ones, they have said they will send the head away to have it machined and will probably get them to do the water pump, even though they have told me that the current part plastic one looks fine. The gaskets, o-rings etc will all be genuine parts.
Should I have the rad replaced too while I am at it, or do you think having it flushed out will suffice? I have obviously bought someone else's troubles, once fixed, the big question is do I try and get some motoring out of it for all the money I have spent, or do I move it on? I've had cars before where I fix problem after problem, hanging in after each repair thinking 'Surely nothing else can go wrong now!' only to be let down again. It's already had the auto box reconditioned 9 months ago, so I suppose that should be one less minefield to worry about and for about a thousand miles it drove like a dream.
What kind of intervals do you suggest for these oil changes and would a used head definately be a better bet than having my existing one skimmed?
Re your gearbox, i think Mercedes now recommend new fluid every 40k. Its not the minefield you might think to change the fluid on the 'R', no need to do the hot/cold, quick filling, going through the gears palava that the ZF boxes need.
I managed to source 8 litres of the proper Merc fluid for £24, and bought the connecting plug, filter and gaskets from Merc main dealer for sensible money. Dipstick off ebay was £10, not a brilliant one, but did the job. So about £70 all in. Cant say i noticed a huge improvement in gearchange smoothness, but certainly peace of mind.
I managed to source 8 litres of the proper Merc fluid for £24, and bought the connecting plug, filter and gaskets from Merc main dealer for sensible money. Dipstick off ebay was £10, not a brilliant one, but did the job. So about £70 all in. Cant say i noticed a huge improvement in gearchange smoothness, but certainly peace of mind.
slippery said:
It could well be a coincidence. I only bought the car privately a few weeks ago and it transpires that there must have been some issues as when my garage fitted the new (genuine part) stat, they found the old one was non genuine, incorrect, and had beeen hit with a hammer to make it fit, then surrounded by silicone. There was also no trace of anti freeze in the coolant.
I will certainly have both sides done and the tensioners if they aren't the steel ones, they have said they will send the head away to have it machined and will probably get them to do the water pump, even though they have told me that the current part plastic one looks fine. The gaskets, o-rings etc will all be genuine parts.
Should I have the rad replaced too while I am at it, or do you think having it flushed out will suffice? I have obviously bought someone else's troubles, once fixed, the big question is do I try and get some motoring out of it for all the money I have spent, or do I move it on? I've had cars before where I fix problem after problem, hanging in after each repair thinking 'Surely nothing else can go wrong now!' only to be let down again. It's already had the auto box reconditioned 9 months ago, so I suppose that should be one less minefield to worry about and for about a thousand miles it drove like a dream.
What kind of intervals do you suggest for these oil changes and would a used head definately be a better bet than having my existing one skimmed?
If there's been no anticorrosion protection in the cooling system for any length of time then there's a chance the radiator will be compromised - it could also be the cause of the headgasket failure in the first place.I will certainly have both sides done and the tensioners if they aren't the steel ones, they have said they will send the head away to have it machined and will probably get them to do the water pump, even though they have told me that the current part plastic one looks fine. The gaskets, o-rings etc will all be genuine parts.
Should I have the rad replaced too while I am at it, or do you think having it flushed out will suffice? I have obviously bought someone else's troubles, once fixed, the big question is do I try and get some motoring out of it for all the money I have spent, or do I move it on? I've had cars before where I fix problem after problem, hanging in after each repair thinking 'Surely nothing else can go wrong now!' only to be let down again. It's already had the auto box reconditioned 9 months ago, so I suppose that should be one less minefield to worry about and for about a thousand miles it drove like a dream.
What kind of intervals do you suggest for these oil changes and would a used head definately be a better bet than having my existing one skimmed?
You might need to discuss with somebody who really knows what they are talking about regarding the V8 having both heads skimmed by an equal amount to preserve the balance of compression ratios between the two banks.
Gearbox oil changes are worth doing every 40/50k.
As far as the big question goes - do you keep it or get rid - only you can answer that. You don't say how many miles the car has done but the fact the gearbox has been reconditioned suggests it's done a fair few, it's an earlier car so percieved wisdom is that it's not worth very much and it seems that the cowboys have been at it so who know what else they've f
ked up as well as the fact you're already spending a lot on repairs.If I'm brutaly honest on the face of it that does not paint a very pretty XJ picture and common sense and you wallet says get rid of it, but it's a fact there's nothing sensible about running old Jaguars anyway - I know that and so do most of the other PHers on this forum - they are cars you tend to own with your heart not your head so it really depends on what it's worth to you.
What else could go wrong?
Throttle bodies are suspect on older cars, buy have been subject to a recall so yours may have been changed, 'diffs can get whiny and really need regular oil changes, if driven hard an XJ especially the R will eat tyres, brakes and suspension components, random electrical problems can occur, some cars suffer from severe corrosion behind the front shocks where the reinforcing place carrying the rear front subframe mounting joins the body.
A well maintained XJ in good condition is a unique car and worth preserving IMO. A bad one needs to go in the classifieds asap.
Mmmmm. Father in law is offering me his mint 'garage queen' 40k mile 2003 X350 XJ8 4.2 for £8k to 'help out'. It looks and drives like it just came out of the box, is BRG which I don't mind, but has the rouched style Sovereign seats fitted which were apparently an extra, but I'm not a fan of. My car has done 107k now and is pretty rot free by the way, although there are signs of a fair amount of paintwork over the years. I'm expecting to have £10-20k to spend on a car in the next 3-6 months, which makes things even more complicated!
Father in law is offering me his mint 'garage queen' 40k mile 2003 X350 XJ8 4.2 for £8k to 'help out'. It looks and drives like it just came out of the box, is BRG which I don't mind, but has the rouched style Sovereign seats fitted which were apparently an extra, but I'm not a fan of. My car has done 107k now and is pretty rot free by the way, although there are signs of a fair amount of paintwork over the years. I'm expecting to have £10-20k to spend on a car in the next 3-6 months, which makes things even more complicated!Have a drive and see if you like it - an X350 4.2 will not be far off an X308 XJR performance wise in the real world and will go further on a gallon too.
The X350s are pretty reliable, air compressors can occasionally fail and you'll need to check all over the bodywork - especially the leading edge of the boot, ABC pillars, wheel arches and door bottoms for any signs of paint bubbling. Some of the ally bodied cars have metal contamination from the panel presses in the bodywork which causes corrosion to occur and a 2003 car will be out of warranty now.
Been looking for a pristine X350 myself.
I really like BRG too. If you don't want it I might...
The X350s are pretty reliable, air compressors can occasionally fail and you'll need to check all over the bodywork - especially the leading edge of the boot, ABC pillars, wheel arches and door bottoms for any signs of paint bubbling. Some of the ally bodied cars have metal contamination from the panel presses in the bodywork which causes corrosion to occur and a 2003 car will be out of warranty now.
Been looking for a pristine X350 myself.
I really like BRG too. If you don't want it I might...I'm going to give the garage the go ahead for the work tomorrow, both banks, tensioners, water pump, rad, both heads skimmed the same amount to balance the compression between the banks etc. Then, when I pick it up I'm going to cross my fingers and drive it (700 miles a week) and see how it 'feels', making sure I heed the good advice you chaps have given me with regards to oil changes. Here's hoping! I'm not sure if Father In Law is up for selling his P & J if I don't want to buy it, but I will ask! It even smells new, but when I tried it, I missed the low slung driving position of the X308.
slippery said:
straight through stainless cat back exhaust fitted
That must be pretty loud? I have just had a longlife stainless cat back "mild to mid" sports exhaust fitted which has slightly smaller than standard silencers fitted, and that is enough to give a nice burble. Interested to know how yours sounds.Hope you get it back up and running soon.
Chris
The centre box was replaced with a x-pipe and the 2 boxes after that were removed, leaving just the last two in place, so I suppose I shouldn't have strictly described it as straight through. It sounds great at idle and wafting around and isn't really loud on the motorway at a steady pace, but I am wondering if I've gone a bit too far as it does seem very loud under full load. I didn't get a chance to get someone to do a drive by in it to actually assess it before I had the problems! It actually sounded like it was misfiring when accelerating with the window open and did seem to be down on power. I put it down to a lack of perhaps necessary back pressure, but with everything that has just happened, I hope I am going to be piloting a very different animal when I get it back!
Edited by slippery on Monday 20th September 21:29
Exhaust science can be difficult to understand.Soundwave patterns aid power by assisting induction but that depends on primary and secondary pipe length and diameter, with the former linked in firing order.E.G. on a 6 cylinder, 1,5,3 into one secondary, 6,2 and 4 into another straight out of the head.Difficult on an 8 cylinder jag because there is no room to link the pipes from bank to bank. There are a good many systems out there which are crap to be honest.You really need someone who has the knowledge to build a system which actually works and not just make alot of noise.Discuss with a proffessional exhaust builder involved in touring car, for example.
NormanD has had new exhaust manifolds made but even he couldn't find the space to have a balanced set fitted.
The main art of boosting the performance in the exhaust is to setup a harmonic in the pipework such that when an exhaust valve opens there is a low pressure zone in that part of the pipe at the time, sucking the spent gases out of the cylinder. As Paul says, this is highly complicated, particularly on a road engine where you want a good spread of torque across the rev range.
On the inlet side it is easier to make variable length inlet tracts. Does anyone do that for the exhaust?
Short of this, I guess, it is just a case of trying to make the exhaust as free flowing as possible to reduce static back pressure, but a proper tuned exhaust literally sucks the gases out of the engine.
The main art of boosting the performance in the exhaust is to setup a harmonic in the pipework such that when an exhaust valve opens there is a low pressure zone in that part of the pipe at the time, sucking the spent gases out of the cylinder. As Paul says, this is highly complicated, particularly on a road engine where you want a good spread of torque across the rev range.
On the inlet side it is easier to make variable length inlet tracts. Does anyone do that for the exhaust?
Short of this, I guess, it is just a case of trying to make the exhaust as free flowing as possible to reduce static back pressure, but a proper tuned exhaust literally sucks the gases out of the engine.
TheD said:
I don't want to hijack the thread 
. But I was wondering what kind of costs are involved in a new head gasket job. I think I have the same problem and I have the same dilemma as to whether to fix or get rid.
I was told to expect a bill of just about £1500 with the tensioners, plus the new rad and water pump if I want those changed.. But I was wondering what kind of costs are involved in a new head gasket job. I think I have the same problem and I have the same dilemma as to whether to fix or get rid. Gassing Station | Jaguar | Top of Page | What's New | My Stuff