I've been driving a '99 XK8 4.0 in New Jersey since 2018 as a daily driver... I'm insane, right? Fact is I took pity on it when I found it at a local dealer (some fool had just traded it against an Escalade...) My car at the time was toast. I needed a ride. I was determined to be the first of my line to own a proper motorcar. It had 119,000 on the clock and not a scratch on it. Gorgeous English walnut dash. Most comfortable driving position on earth. Leaper. No puddles underneath -- oh, and my wife called it "pretty" the second she saw it. It was always going to happen.

I thought I stole it for less than $6,000. Then the, ahem, "fun" started. I've been glued to this forum for the past five years, and it has proven mighty helpful on a lot of fronts. But I still ain't found the answer to the one chronic issue that now has me at the end of my rope. So I joined up in order to post the whole saga and hopefully get the benefit of you seasoned sob's who can fix literally anything you lay your hands on.

Here's The Big Problem: Start the motor from cold; it purrs like a kitten. Run it 20 minutes/10 miles. Park it while hot. Go to restart 10 minutes later and it shakes like San Andreas, smokes out the tailpipes, revs bog down below 500 rpm often to the point of stalling out completely. Alternatively, it'll start reasonably well; but then you push the brake, shift to reverse and the revs bottom out to the point of stalling. This now happens 50% of the time. BTW, car now has 167,000 on the odo. There is no check engine light even when stalling out and only code showing on Advanced Auto's reader is (a patronizingly insulting) P1111. Yeah, right. All systems go my ***.

Note: it's only while hot that it does this. It also threatens to stall when coming to a complete stop at intersections and redights when the motor is hot. It hates multiple short trips on the same day. Driving in town is now nerve-racking. It has progressed to the point where it can't be driven further than 8-10 miles without threatening to stall at a standstill or on restarting. The most frustrating thing is that, when the car's in motion, it runs exceptionally well with great response and pep right up through the rev range. It only gets an attitude when you take your foot off the gas, cruise to a stop and sit at idle. Then it acts like it's full of unburned fuel and choking itself to death. (I can smell fuel in the cabin after each episode.) My cats must be filthy by now.

Here's some history of recent repairs/issues: 4 years ago, had transmission refurbished by ZF-experienced indy. It was floating for a heartbeat before kicking me up the butt away from standstill. 36 months ago, replaced part load breather hose (cracked) and intake mani. gasket (leaking) plus valve cover gaskets and front crank oil seal. Fuel trim dropped from +20% at idle to 5%. Noticeable rise in power/throttle response; drop in smoking at tailpipe on startup/kickdown. 24 months ago, sudden coil failure cyl 4; replaced all 4 original coils in that bank (with cheaper STI coils for government-related reasons) plus all 8 plugs (NGK Platinum). Misfire cured. Sluggishness at low rpm persisted but not too bad. Idle has always been kinda rough/vibey (Engine mounts known to be "shot" - can't afford labor to replace). This winter, battery died flat after extreme cold snap when it sat for four days. It was a decade old. Replaced with same rated battery (higher cold-cranking). 4 weeks ago, another gradual coil failure on opposite bank; replaced remaining 4 coils with STI and all 8 plugs with NGK again. Replaced fuel filter same time. Misfire cured but noted remaining sluggishness at low rpm under load. Then (after doing a full-on emergency stop to avoid T-boning yet another white Lexus) developed random misfire with no code while idling but not when driving or under load. Tore out another fistful of hair. Down to three or four fistfuls left.

2 weeks ago took it to local indy and asked him to read all current codes and check trims at idle. No f***ing codes. Trims still at 5% with closed throttle, zero vacuum issues. He asked me about coils; I told him they were all new. He said, "New don't equal good. Are they OEM?" I 'fessed up. They're STI from AutohausAZ. His opinion was it's shitty coils, given the heat-related dropout when first applying load and no other readable problems. So I bit the bullet, said so-long to a kidney and bought 8 Denso coils from SNG Barratt and another 8 NGK plugs. Fitted them four days ago. Idle misfire completely disappeared. Pickup fantastic under load. I started hunting for the fistful of hair in the footwell thinking I might still be able to save it. Then I pulled up to a redlight 15 miles away and it almost f***ing stalled out!! AAAARGH. Hot stalling problem persists and is, if anything, worse than ever.

Known remaining issues with car: EVAP purge valve seized. Has been since 2019. Advised it was "ancillary" and wouldn't affect performance. Now I'm not so sure. ABS light and traction control lights are on. I've never driven anything with ABS or trac.con. before. I don't notice their absence. I've noticed blowby oil in both full- and part-load breather hoses. It's a 24-yr-old motor with Nikasil coatings - hardly surprising it might have compression issues but never had it tested yet (can't face it). Also have the right-rear turn signal failing under braking because of poor ground issue.

Question: WTF is going on with my car? Will any of the above as-yet unfixed issues add up to a hot stalling problem? It feels electrical to me but also acts like a breathing problem at zero throttle. TPS? My indy says his computer thingy would have spotted any discrepancy between throttle angle, trim, and TPS. Should I believe him? I plan to clean part load breather and replace MAFS (cleaned regularly with CRC MAFS cleaner) as well as purge valve at earliest opportunity. What else should I try?

I'd appreciate any response from anyone who has limped this far down the freakin' page. Thanks in advance, Mark.

 

Welcome to the Forums.

Insane, NO WAY, Jags are all daily drivers in my family, kids included, and always have been.

I suggest a repost of the issues in the XK8 (X100) Tech Section, OR, wait for GGG to see this and assist you.

Good luck.

 

Hello, Mark,
I don't think you'll find a single member who thinks you're "insane" for buying a Used Jaguar!
You merely moved from basic transportation to Class.
We're ALL slaves to our Jags! Every single one of us whether we like to admit it or not. And sometimes our cats take advantage of our good humor as yours seems to have done. Your stall problem is intriguing.

It sounds like you're familiar with these forums, so asking your question over in the XK8 section will get you some specific suggestions/answers.

Welcome to the forums from ElinorB.
(';')

 

Welcome to Jaguar Forums Mark,

Good to have you with us.
Enjoy the forum.

If you haven't done so already you should add your car details to your signature to help others to help you.
If you need help with getting around and using the forum follow this link for some help Forum Help

 

welcome to the forum - enjoy!!

 

Thanks for the welcome! I’ll get my bearings on where to post stuff as I go along. Glad to find so many like-minded addicts who can’t be pulled out of their Jags for love nor money. Even if they occasionally should be…

 

Welcome aboard Mark.