Hi gents, so long story short, i bought XJS month ago, and due to where i live, there is no market for XJS (mb 1-2 cars for sale at a time) , so we usually import cars from UK(if you want something unique or different from toyota corolla), and with that you dont have much options to make a good car check, except some photos, videos and dealer words (which are never true). So it is what it is, its a price we pay for living on the island

i got XJS 5.3 1992, facelift
its my 2nd classic car, and on this one i plan to do all (i hope so) work myself, not sure if i will be able to, nore if i will have enough time, but at least thats the plan

So what i have as of now
Car temp gauge shows half way to red zone, basically i assume its 110-115, dont have laser thermo, cant check. i immediately stoped driving it, bought all the parts to service entire cooling system as per Grant manual.
Coolant level is ok, it has some bronze pieces in it, i assume prev. owner was adding that sealant according to the manual?
How can i know if that overheat damaged anything?

Car runs fine, i can notice with my butt a very very slight vibration some times at idle, like every 4th second. missfire?
otherwise it runs really good, as far as i can tell without driving another xjs

steering feels a bit hard and kind of not smooth, more like ticking. fluid? pump replacement?

no major leaks, valve cover small leak, underneath the car steering fluid on the frame, but nothing is on the driveway, so no major leaks, but still that needs to be sorted at some point

another worrying thing, car has huge vibration on the speed, around 100km/h . i really hope its because one of the tyre is 235, while other 3 are 225, in the trunk i found 4th 225 destroyed.

all rubber parts are almost gone, BUT car drives smoothly!

Please help the beginner to plan my work on the car, what to check, what to do as 1st priority and etc

for now i need to replace the entire cooling system, get new tyres, balance, wheel alignment, to see where is shaking coming from.

I dont want to put car on the jacks for years to fix everything, i want to get it running , enjoy it, and slowly progress.
Sorry if im asking too much like that, but some guidance will help me a lot!

 

Definitely get a Laser Thermometer, this side of the pond they're only 20 dollars US. Anyway whatever the cost it's cheap insurance, as then you'll know if it's getting hot or not. If you have an overheating problem. That must be fixed first.

 

First, I would get a thermometer and verify the gauge reading. That being said, there are known trouble spots on the V12's cooling system:

- first is thermostats. Most of the thermostats specified for the V12 are wrong, the foot does not extend far enough to block off the bypass, so that means the coolant circulates within the block and never goes through the radiator. There have been a number of posts here about correct thermostats. As a point of interest, the Waxstat ones supplied by a Jaguar dealer are incorrect.

Second: you'll need to drain the coolant and remove the radiator. The space between the radiator and AC condenser very frequently gets full of debris, blocking the airflow. I have pulled some out that were more than 50% blocked. There are no shorcuts here, the radiator must come out to be completely cleaned.

Third: While the radiator is out, you'll also have to have removed the fan clutch and fan. Inspect the plastic fan blade very closely for cracks, and if there are any replace the fan blade with the newer style black one. Also replace the fan clutch while you are there, as they do age and do not provide as much cooling as a new unit.

These 3 things will take some labour, but will cure 95% of any cooling problems with a V12 Jaguar.

 

Thanks, all that is already planned! What the best way to check the engine health, if there is any missfire?

 

The misfire will be cured by:
New HT leads
New cap and rotor
New plugs
Extra earth strap from engine to frame
A good strong does of injector cleaner AND
Drive the thing like you stole it!

Replacing worn suspension bushes, if they need it, is also something to do, after the cooling and engine basics.

 

Gotcha! added to the plan.

Originally i was planning to stick to post-purchase guide written by Greg, but it seems like then i wont be able to drive a thing for a year)

 

Could be a coil too. I cured a misfire with a new coil.

 

Thank you guys for all the tips, but im not even sue if its a missfire, thats why i asked, how do i easily check engine health, that all cylinders are firing ?

 

No need to. Just do the fixes and drive it. The engine mechanically is indestructable.
Also, I forgot to add, clean oit the sump tank under the battery, new filter (behind the spare wheel). Worth a new B ank FPR as a precaution too.

 

Well don't be forgetting now that the fuel system if not addressed is an invitation to a Jaguar barbeque .... how to tell if all cylinders are firing - best way is hand in front of tailpipe, any uneven pulses or gaps - really an experience thing your ears can mislead.

Cooling is the least of the concerns on an aging cat .... all the items that need to be addressed as above plus the underbonnet wiring harness, replacement of all fuel hoses, cleaning out of fuel system and service of injectors, at the same time make sure to replace vacuum hoses, set up the throttles and ensure the inlet manifolds are correctly torqued (they come loose) - air leaks will cause hot running due to weak mixture, weak mixture can destroy V12's ... do not drive it like you stole it until you are 100% sure the mixture is not lean ....

Not trying to scare you - awakening an aging cat is a journey, Grant is the guru and his documents invaluable, seek out the "Experience in a Book" publication by Kirby Palm also.

Be prepared for a roller coaster ride.

Won't be able to drive for a year - optimistic - for me it has been two already.

 

Change all fuel hoses immediately. Do not drive until you do. Mr. Injector sells a kit. Buy an Infrared thermometer.

"all rubber parts are almost gone, BUT car drives smoothly!"

Your faint vibration (if not a misfire) will likely be solved by renewing all the rubber components in the suspension, including front subframe and engine rubber mounts. You think it drives smooth now, it will be night and day with new mounts & bushings.

 

Greg, thank you for the advise, regarding new cap and rotors suggestion, does it apply also to marelli system?

 

Even moreso!

 

Congrats etc. Vibration at 100 km/h might be tire flat spots. That might improve by driving, or new tires if they're old. Mismatch tire sizes don't sound good, especially on the rear I think. ((Diff thinks the car is always turning around a corner and LSD needs to work more than normal - something like that). Its probably not a good idea to have mismatch tire sizes on the front either due to asymmetric braking The temperature gauge isn't a "idiot gauge" like modern cars, which stay nailed to center all the time. This gauge will move up and down a bit through normal driving. If the gauge is accurate (IR thermometer helps confirm), and a bit over the "N", it shouldn't be overheating causing damage. Definitely replace the fuel injection hoses. I had the injectors cleaned at the same time. Also, flush the cooling system. I used a Gano cooling system filter kit to pull out the sealing crud from mine and flushed the system many times with water. Once it was clean I replaced the cooling hoses and had the radiator rebuilt. I also needed to replace the heater core. Plugs cap, rotor arm as already mentioned (Mine's a Lucas - I use genuine parts. The Marelli system does best with genuine parts also). Don't forget the oil change (that can be a big debate - I used GTX 20/50 so far, and Jaguar filters). I also changed all the other fluids as well to "reset" everything (gearbox, axle, brakes). Definitely drive it with some enthusiasm once its warmed up. These cars get better with driving, and like to rev to blow the cobwebs out!

HTH, Dave

 

thank you, basically thats the plan for now)

by the way, regarding injectors, mine doesnt look like anything else i see here, i dont have those small hoses on top of each injector, injectors are connected directly to the rail, no idea what that system calls, or if it became standart at some year. Anyway, this already planned, to change all fuel hoses and clean injectors

 

Those are the later injectors but the other fuel lines remain a liability, the injectors still contain filter baskets though I've never had one in my hand I would be surprised if they don't - plus the O rings on them have been there how long.

 

Hey forum, new day, new findings from previous owner/s
Got both thermostats out, A bank looked pretty clean, proper, with jiggle pin.
But when i got to the B one, first , it took some time to get the housing , then i found brown dirty water still sitting inside (a bit) , checked thermostat, it was wrong, without jiggle pin.
Also now i remember, that when i felt that car was missfiring a bit, i felt like it was B bank, based on hand feeling and exhaust sound.
Now it all comes together, wrong length thermostat, no jiggle pin.
Also take a look on the block, no leaks on B bank. So, could the damage been already done?

 

Could the damage be done is a tough answer since we don't really know the damage but yes would have to be the answer. finding any water behind the stat in a drained system would be a concern but I don't know how much you found. It isn't the jiggle pin you care about ( a simple small hole will suffice ) but it is the open length, if not long enough it does not seal correctly which is a really common error, there are many that offer sensors for these engines but also many that are not suitable because of the length. It is my understanding that B bank always runs hotter because of the cooling system design and is why there are recommendations to switch the sensor locations (see Kirby Palms guide page 176) to prevent bank A running lean.

This is a classic example of why Grant's to do list on obtaining an XJS is so important. You never know what the car has been subjected to before you receive it, especially older 'high end' vehicles that have been run by those that really can't afford the experience - not snobbery just a fact.

This is precisely why my XJS is still in pieces 2 years after doing a tiny job, that became a slightly bigger job, then a large job and then a to hell with it job - but once it goes back on the road I will know 100% the condition and status of every pipe / hose / bush / sensor / joint / harness .... and so on.

Don't let scope creep get the better of you - flush that sucker out and button it up with the right stuff - an engine tear down is not somewhere you want to go unless 110% sure that is the only option - getting the heads off V12's is no fun at all and it can't be done with engine in the car.

 

Thanks! Will go with it as it is and then we see what happens, i actually bought this car to drive.

Regarding the amount of water sitting behind thermostat was very very little, but very brown.

 

Very brown means rust, rust means poor maintenance, very little is pretty much expected, had you said it poured out I would have said the block is choked (if that was the case no amount of flushing will resolve and a tear down is the best option).

These cars should use a 50 / 50 coolant mix year round, many use just water or a lower ratio which is a truly bad idea, especially just water.

I totally disagree with the install a filter nonsense - if you maintain the system properly you don't need filters - fix the problem not the symptom.