The Joys of XKR Ownership

The Joys of XKR Ownership

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ford prefect

Original Poster:

159 posts

236 months

Tuesday 25th November 2003
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Well after owning my 98 XKR for 9 months and 15K miles (43K total) I should have guessed that trouble free motoring couldn't last.

Driving along a local A road when suddenly the engine completely died on me - rolled off the road and shifted into park and the engine is just idling at about 200 revs but nothing happened when I pressed the throtle. Turned ignition off and back on, engine starts immediately and everything back to normal.

No problems for about a week when it does it again in the middle lane of the M40 at 8 am - not funny!! Contact dealer "Drop the car in and let me check for error codes on the ECU - if no error then almost certainly it's the old oil on the electronics in the throtle body problem". Drop car into dealer - no error codes so dealer orders a new throtle body (really lucky I've got a Jaguar extended warranty cos this part is a bit expensive). Part should arrive after five days - that was five weeks ago and I'm still waiting.

After four weeks and two or three more engine cut-outs (been using the train a lot to avoid frightening the living daylights out of myself) I contact dealer who suggests I contact Jaguar parts. I contact Jaguar parts who investigate and call me back to assure me that the part will arrive at the dealers last week. Part doesn't arrive (not really surprised - Unipart are the supplier!!)so back on to Jaguar Parts this morning who investigate. Jaguar Parts call me back to advise that a number of this part arrived and accidently they forgot to send my dealer one and now they've none left!! "But we are really sorry sir and we are expecting some more by the end of this week and we will get one sent to your dealer either on Friday or Saturday - well probably we'll be getting some more by the end of this week - anyway we'll call you to let you know at the end of the week".

That will be six weeks I've been waiting whilst I assume the factory have been fitting bloody hundreds of the things into new XKRs. Am I being unreasonable or is this prity crap customer service from Jaguar??

>>> Edited by ford prefect on Tuesday 25th November 02:27

thepipesmoker

94 posts

212 months

Wednesday 26th November 2003
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My XK8 dies occasionally. It seems to happen mostly on cold days and usually if i'm a bit too enthusiastic with the 'fun' pedal before the engine has warmed up. The car stalls and won't respond until i come to a complete stop and turn the engine off and on again. It works fine after that. I think there is an engine protection system kicking in that does this. Last time Jaguar found some dirty part under the bonnet that was causing it, cleaned it up and it was perfect for 12 months. It's just started happening again. Unfortunately I can't remember what the offending component was.
The worrying bit though is when your 2 ton missile loses all power and you have to coax it to safety without the benefit of power steering. Not for the faint hearted!

ford prefect

Original Poster:

159 posts

236 months

Wednesday 26th November 2003
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Dealer tells me that my problem is the oil breather pipe from the top of the engine back into the inlet via the throtle. The pipe brings oil vapour into the throtle body and this is deposited on the electronics (of the stepper motor I assume). The net effect is that it causes the ECU to go into some "abnormal state" which is resloved by turning the ignition off and on causing a reset of the ECU - sounds convincing anyway.

However, I have two issues with this diagnosis, firstly replacing the throtle body is not going to resolve the oil vapour being deposited on the new set of electronics (when I finally get it that is).
Secondly, if this is oil depositing on the elctronics then this must be causing some sort of shorting in the circuitry. If this is the case then why does turning the ignition off and on resolve the problem as the oil is still siting on the "electronics".

As a temporary fix is it possible to get at these "electronics" and clean them up and if so how easy a job is it?

PlenumPete

96 posts

231 months

Wednesday 26th November 2003
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fordprefect, I don't have an XKR (unfortunately) but on my XJR-6 at 70,000 miles I had similar cutting-out symptoms when the throttle body became gummed up internally (gumming caused by fuel deposits). Bascially this caused the throttle butterfly to temporarily stick and also affected the Idle Speed Control Valve (ISCV)(what you've called the stepper motor) giving a lumpy idle. This problem was simply solved by removing the throttle body and cleaning with carburettor cleaner solvent.

The only electronics in the XJR-6 throttle body is the Throttle Position Sensor, which is contained in the plastic housing at the end of the throttle butterfly shaft. When cleaning inside the throttle body great care must be taken to not contamintate this sensor! Perhaps it's this sensor that the dealer is decribing as the electronics.

I wouldn't have thought there would be a great deal of difference between the XKR and XJR-6 (except the throttle body is common to two S/Cs?). Also the only hose I can think of that goes into the throttle body is the cruise control vacuum hose!

So it looks like the dealer is solving the problem by fitting a new throttle body under warrenty using the black box approach.

Good luck.

ford prefect

Original Poster:

159 posts

236 months

Wednesday 26th November 2003
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Pete, your answer sounds a lot more convincing than the dealers and would explain the approach they are proposing. I suspect it is the sensor you mention particularly as the problem always occurs after I have been accelerating and then taken my foot off the throttle. When I re-apply the throttle the engine is dead (or at least idling at about 200 revs and won't react to the throttle) and I just coast to a halt.

All I have to do now is wait for Jaguar Parts/Unipart to come up with a replacement part - maybe they're hanging on so that they can send it to me as an Xmas present!

PlenumPete

96 posts

231 months

Wednesday 26th November 2003
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ford prefect said:
All I have to do now is wait for Jaguar Parts/Unipart to come up with a replacement part - maybe they're hanging on so that they can send it to me as an Xmas present!


Apparently, early XK8/Rs are prone to this "engine stalling" fault and it has been generally attributed to the design/reliability of the Throttle Position Sensor. And guess what, Jaguar don't sell the TPS as a separate item, only a complete throttle body. The usual course of action is to clean the throttle body (why not ask the dealer to do this?), and if this doesn't cure the problem then the throttle body is replaced. On the electronics side, there are a lot of control inputs acting upon the throttle and its position, traction control for instance, which can cause problems (these should show error codes).

ford prefect

Original Poster:

159 posts

236 months

Wednesday 26th November 2003
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Pete, Do you think there would be any advantage once the sensor/throttle body is replaced in using a "better" quality fuel like Optimax to reduce the fouling of the sensor in future?

Many thanks for your input, you obviously know a lot more about this than I do. I will talk to the dealer about cleaning the existing body if the part doesn't turn up at the end of this week....John.

Marki

15,763 posts

237 months

Thursday 27th November 2003
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thepipesmoker said:
My XK8 dies occasionally. It seems to happen mostly on cold days and usually if i'm a bit too enthusiastic with the 'fun' pedal before the engine has warmed up. The car stalls and won't respond until i come to a complete stop and turn the engine off and on again. It works fine after that.



Ahaa i had an XKR and it did exactly the same thing , again only if got a little to happy with the gas ,not like thrashing it from cold .

Never did got it sorted as it happened about 8-10 times in 2 years .

Very strange that it seems quiet a normal fault on these marvelous cars

PlenumPete

96 posts

231 months

Thursday 27th November 2003
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ford prefect said:
Pete, Do you think there would be any advantage once the sensor/throttle body is replaced in using a "better" quality fuel like Optimax to reduce the fouling of the sensor in future?


Big Jaguars may run better on Optimax anyway, but I'm not convinced. If you do have concerns check that the fuel filter is attended to according to the car's service schedule. Also check your service invoices, there under Specialist Work should be an item "Add Fuel System Cleaner to Fuel Tank".

Also I've heard that the gumming up of the throttle body interior can form as striations, or ridges, which may cause the butterfly to stick. I think these ridges may be caused by repeated use of cruise control, but that's just my theory.

BTW another symptom of gummed up throttle body is slight resistance at the start point of the throttle movement, especially when cold.

dcb

5,505 posts

232 months

Thursday 27th November 2003
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PlenumPete said:

Apparently, early XK8/Rs are prone to this "engine stalling" fault and it has been generally attributed to the design/reliability of the Throttle Position Sensor.


My XJ8 went through a phase of stalling every now & again. Not fun on the motorway.

Jaguar main dealer diagnosed same problem, and quoted 800 quid plus fitting for a new throttle body.

What a bunch of comedians !

In my opinion, the fault is just a bit of muck, and a dose of WD-40 will sort the problem.

ford prefect

Original Poster:

159 posts

236 months

Thursday 27th November 2003
quotequote all
We have progress - got a call from Jaguar Parts to tell me that the throttle body arrived at the dealers yesterday. Funny that the dealer hasn't contacted me ... Can't decide if I'm a total cynic or just a realist!

ford prefect

Original Poster:

159 posts

236 months

Thursday 27th November 2003
quotequote all
Pete, Hadn't noticed slight resistance at start of throttle movement but your comment about cruise control is very interesting. The previous owner of the car apparently owned several cars (hence only 27K miles at 3 years old)and used the XKR to drive back and forth to the south of France - nice work if you can get it! But my point is that driving back and forth to the south of France probably involved using the cruise control a lot.......

lux_r

26 posts

210 months

Tuesday 20th January 2004
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I have an XKR never had this problem 110K miles. however it did drop a cam chain tensioner at 73K. I use the cruise control loads and its not unusual for me to see the traction control doing its stuff. However i had a "cracked fuel metering pipe" whatever the heck that is, that caused the motor to hunt at tickover and to sort of miss a bit occasionally during hard acceleration

roger94503

3 posts

209 months

Friday 6th February 2004
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I have a 1998 XJ8 which was experiencing the occasional stall - and what a prob this was is the outside lane of the M25. In July 2002 my dealer 'ungummed' the throttle housing - it didn't help and a week later they told me it needed a new throttle housing - 900 down the pan! In August 2002 I had a seizure (epilepsy) and was unable to drive for 12 months, so put the car into professional storage. I got it back last August and I've probably had 6 stalls in the last 5 months. I took it to the dealer last week (for another problem - more of that follows)they told me they would 'ungum the throttle housing again - result ws it wasn't gummed up, so they said they would have to replace the throttle housing again at a cost of 1000! - I pointed out it had only been driven for 5 months (12,000 miles) since they previously did it - but as over a year had elapsed they were unsympathetic. I did tell them I was writing to Jaguar about the two problems and yesterday the dealer phoned to say there was ome adjustment they could do in the throttle housing which wuld probably do the trick - when questioned he said that this adjustment was not possible on the original housing, but I am highly suspicious of this - anybody got any views (other than Main Dealers are like hospitals - you go in with something trivial and they find major problems to sort out - at huge expense) - I will post details of the more serious problem separately - it's to do with 'the Nikasil problem' which was a known prob with the '98 model and means I have to replace the engine

Geoff

EonBlue

5 posts

209 months

Tuesday 10th February 2004
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Hello, I am a Jaguar technician. I am responding to the 1998 XJ8's with the stalling problem. This is a known problem with this year model Jaguar. I have worked on and fixed at least 8 of these stalling problem cars. The problem is in the throttle body assemblies, on every fifth deceleration the butterfly in the throttle body closes completely, thus going through a cleaning process. The motor in the throttle body is not strong enough to overcome the engine vacuum and re-open, thus causing the engine to stall. I have worked with a field engineer to figure out and fix this problem and none of the cars we had do it, ever returned for this problem again. There is a fix for it and yes it's true Jaguar has no interest in rectifying this problem. I would more than happy to help someone out with this if they need it.

I hope I don't over step my bounds here by giving my email address if so please feel free to delete it. I can be reached at suisyco@jam.rr.com.

EonBlue

5 posts

209 months

Tuesday 10th February 2004
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Replacing your engine WILL NOT cure this stalling problem I can assure you. I have been there and done that. Also....that dealer is feeding you a line of bull if they tell you they can't perform the adjustment on your current throttle body. I have repaired throttle bodies that were originally on the car and have had no problem doing so. Anyone that is even slightly mechanicaly inclined can repair this problem with the right directions. If you need help email me I assure you I can help you get this fixed.

roger94503 said:
I have a 1998 XJ8 which was experiencing the occasional stall - and what a prob this was is the outside lane of the M25. In July 2002 my dealer 'ungummed' the throttle housing - it didn't help and a week later they told me it needed a new throttle housing - 900 down the pan! In August 2002 I had a seizure (epilepsy) and was unable to drive for 12 months, so put the car into professional storage. I got it back last August and I've probably had 6 stalls in the last 5 months. I took it to the dealer last week (for another problem - more of that follows)they told me they would 'ungum the throttle housing again - result ws it wasn't gummed up, so they said they would have to replace the throttle housing again at a cost of 1000! - I pointed out it had only been driven for 5 months (12,000 miles) since they previously did it - but as over a year had elapsed they were unsympathetic. I did tell them I was writing to Jaguar about the two problems and yesterday the dealer phoned to say there was ome adjustment they could do in the throttle housing which wuld probably do the trick - when questioned he said that this adjustment was not possible on the original housing, but I am highly suspicious of this - anybody got any views (other than Main Dealers are like hospitals - you go in with something trivial and they find major problems to sort out - at huge expense) - I will post details of the more serious problem separately - it's to do with 'the Nikasil problem' which was a known prob with the '98 model and means I have to replace the engine

Geoff