Hi I have a 2000 xjr I found a coolant leak not to long ago. however the coolant level is very slowly still going dawn. I suspect this is the head gasket I have found small bubbles In the coolant header tank and there is small amount of white smoke coming from the exhaust which isn’t clearing after warm up. It’s not letiing me attach a video due to file size but I’ll see if I can compress a video. Dipstick is ok. Any advice greatly appreciated. Thank you.

 

All the head gaskets I have done seem to be on the SUPERCHARGED engines with the fibre gaskets.
I replace them with the MLS gaskets that are fitted to the later engines.

 

Is the underside of your oil filler cap coated with a milky goo?

If a scan tool reports misfire codes in one or more cylinders, that is a clue.

With an inexpensive chemical test kit like the one shown below, you can test for exhaust gasses in the coolant, which would confirm head gasket failure:





To confirm at which cylinder or cylinders the head gasket has failed, you can pull and inspect the spark plugs - a really clean plug is a clue that coolant is steam-cleaning the plug.

If you have an endoscope, inspect the tops of the pistons - a clean piston is being steam-cleaned by coolant.

If that is inconclusive, a compresssion test may confirm the failed cylinder or pair of cylinders.

You can also pressurize the cooling system with a test kit and look for coolant leaking into any cylinder.

Cheers,

Don

 

Do you know how hard the job is to do and how much I should pay if I take it to a shop? Thank you

 

thank you for the response. I’ll check the car when I get back home I’ll give a response in about 2-3 hours. I have plugged in an obd scanner that’s showing cylinder 7 and 8 misfire is this an indicator that it’s probably those cylinders? Thank you

 

Years ago I replaced both X308 and X100 head gaskets on 4 liter SuperCharged but as the years passed I found myself only replacing the X100 because the customers just did not want to spend the money on a sedan worth half of the Coupe/Convertible cars.
Jaguar warranty time was about 13 hours labor plus parts.
The customer pay in REAL WORLD would be closer to 19 or 20 hours.
I would suggest replacing the timing components if they are the original plastic versions which would add a little time and parts to the bill.

Unfortunately the repair bill will likely meet or exceed the value of the car unless you do the work yourself?

 

Yes, that's a good clue that the leak is between cylinders 7 & 8:




On your 2000, what your scan tool is calling cylinders 7 and 8 are probably what Jaguar referred to at the time as cylinders (2)-3 and (2-4), or cylinders 3 and 4 in Bank 2, or the left bank as viewed from the driver's seat.

 

what’s your recommendation to do? I can probably spend 500 max on a repair at the moment. the car drives fine as is I’ve not noticed anything up with the car performance wise. I have no access to another car, likely going to be a year until I can afford to get it done or find proper garage space for the car however don’t mind improvising.its only leaking maybe 2 inches of the header tank per 100 miles and hasn’t had any problems starting after a month. I have seen you can get some internal fillers do you think this would be appropriate as a temporary solution that should be less then 10k miles?

 

I can't in good conscience recommend that you use a head gasket sealant, but it's your car and your decision. I have certainly seen many online reports of owners experiencing positive results with sealants, at least in the short term. One downside to be aware of is that a product that can seal a failed head gasket or warped head can also clog your heater core and other small passages in the cooling system.

You might check out this video before making a decision:


Cheers,

Don

 

Those sealers will not work on head gaskets blown between cylinders, which yours appears to be.
I had a Chevy 350 LT1 with a similar situation and got to it too late. The compression was very high
and it had formed a channel into the block between the affected cylinders. No repair of the block was
possible so it was new block time.

 

My friend had it done at a repair shop on a 2003 Ford F150 using that expensive $60 a can stuff and it seems to have repaired his truck as it's been a number of months since the fix. Don't fool with those cheap head gasket products that only plug leaks as it will clog the radiator. You only really have one shot at a fix by sealant can, in my opinion.

 

Thank you everyone for your time. I will try and use sealant as a temporary fix. Has anyone got any advice on brands differing to what was said in video? Thank you.