Im going mad here,

quick run down, paid in full for my s type 4.0 v8 2002 3 weeks ago took delivery of it and instantly noiced misfire on tick over. Brought it home and noticed at 45 mph exactly in top gear at 2000 rpm it was stuttering/juddering rocking me back and forward like a 2 stroke when cold spluttering.

Took it back the next day and havent seen the car since.

Its been to 3 different garages and nobody can diagnose the fault.

They found a rocker cover gasket leaking into the spark plug wells, so they replced gasket and spark plug seals, and im not 100% sure but i think they replaced 3 coils? Like i said not sure.

Replaced the fuel filter, tomorrow it is going to a 4th garage who is a jaguar specialist but im slightly worried.

Any ideas would be great


Darren

 

It's more likely someone with the actual car will diagnose it than any number of us on the net!

Sounds like misfires but could be failing cats or any number of other things, even a failing battery or bad connections to it that vibrate loose.

edit: this isn't going to help but lots of cars can have similar symptoms (quite rare for any car) and are equally hard to diagnose. What helps are faults that throw codes but not all faults are so helpful

 

theanks jagv8, im under the impression this jaguar specialist where the car is heading tomorrow has all the correct diagnostic equipment, just seems to be a very common problem with these 4.0 v8 s types,

what baffles me the most is that 3 other mechanics/garages have failed to diagnose the problem, but like you say the proper diagnostic equipment help, but then i have read time and time again sometimes these v8s dont throw up any fault codes, which really is what i dont want to hear!

One thing to add just before i took delivery of the car the dealer replaced th ebattery because the original was dead, howeve they replaced with with one they got from Hendy ford truck garage, now Hendy told them battery is more than powerful enough, but its half the size!

 

Half the size is very unlikely to be enough! Still may not be the problem cause, but sounds a suspect.

 

Agreed. Make certain that your replacement battery is the proper class and size. These cars draw battery power like vampires suck blood, and insufficient or weak batteries can and will create all sorts of different problems....

 

That's a big +1 on that small battery. Same thing happened to me - had an Interstate battery (1/2 the size) installed - it was ok in the beginning but the electric demand fried 2 of the 6 cells in the battery. I went with the Bosch battery - same class and size as OEM with a bigger punch - what a difference.

But, besides the battery that may be a contributor to the issues... I believe you are suffering from one or more misfiring coils...As far as to how to isolate the misfiring - a COP (Coil On Plug) tester will help you diagnose which coil(s) are acting suspect. Also, if you need to replace coils - go with OEM Jaguar or OEM Ford - Motorcraft Coils - all the other aftermarket coils suck...Good Luck.

 

Well done abonano!!

I agree on absolutely all counts. My money bets verifying the coils they replaced are genuine, and replacing the rest accordingly will likely fix this car. Then make sure the plugs are correct and not eroded to a wider than normal gap. That will make sure it doesn't happen again soon.

Good luck!

 

Car went to jag specialist and they found the fault.
Plastic tensioners gone and it jumped one tooth. So hopefully will be great after it been repaired.
Any thoughts on this. 3rd gen kit being used.

 

Wow, how many miles on the car?

 

It's an interference engine so very bad things indeed happen if the timing is out

Anyone know if 1 tooth is survivable? If it's not, just changing tensioners etc will be no good.

BTW, mileage is not the issue so much as number of hot/cold cycles and just age. The plastic deteriorates.

 

95000 miles.

Jagv8 you say 1 tooth may not be survivable?
How would I know?

 

darren, if the chain skips too may sprockets, the valves can collide with the piston. The mechanic will definitely notice if this happened upon start-up.

 

I had another 2000 S Type V8 I purchased a few years back (with 89K miles) that the owner stated the engine had misfiring issues (motor sounded horrible) in speaking to the shop that worked on the car they informed me the chain skipped 1 tooth - eventually, I sold the car off for parts - the engine wasn't salvagable... but... you might luck out but JagV8 and bfsgross bring up very valid points. Since you were driving it around with that chain skipping a tooth - you may have some internal damage already....

Let's see is a tech can chime in here...

 

Thanks guys for your help.

The car is with s&c in hamble Southampton. And my 1st impression us that they know what they are doing as 3 other garages couldn't find a fault. And Sean found it in under a hour. So I'm taking comfort in the fact I'm sure they won't let the car go out of the workshop with internal damage etc. plus I still have 6 month warranty.

Still would be Interested in what a tech has to say.

 

You beat me to it!! I was going to suggest tensioners too!!

If it only jumped one tooth you might be alright. Several people have had this happen with no piston/valve contact. But first pull the plugs and use a borescope to see if the piston is all banged up or not.

It's a pretty big job to change them. We have several sets of nice instructions in the sticky section. They are quite a bit better than the JTIS instructions with pictures and hints.

Please see attached.
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You probably got lucky! If the slipper can get off the tensioner without breaking the chain, that's lucky strike number one. If it can get out and not jump more than a tooth or two, that's lucky strike number two.

If they can run a cylinder leakage test and pass all eight cylinders, that's lucky strike three, and you're outta there....... cheap. Not everyone is so lucky.

Good luck, and let us know how it goes.

 

ok, so when i get the car back is there anything i shoud be looking for or listening for?

The problem is i will NOT be collecting the car from the garage who are carrying out the work i will be collecting it from the dealership i purchased it from and we all know they know nothing about mechanics as it were lol..

 

ok going to collect car in a little while fingers crossed its all good, one thing though apparently i have a 2nd gen water pump and i have been advised to keep an eye on it. Any thoughts please? Known issue with these?

 

Did you read the first attachment I posted?? It talks about water pumps on the 4.0 V-8. Please take a look. It's another problem that the later 4.2L V-8's don't have as Jaguar improved the pump.
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well collected car and it seems to drive fine very annoyed though because the yellow warning light engine management is on.

Dont know what to do now?