On Bank 1 specifically

My car is a 2001 XK8. Just turned over 100k miles this week.

 

Could be misfires on those cylinders, rough/horrible running, pinging, bent valves, busted pistons, all could happen from a jumped timing chain

 

Thanks for responding. I'm at AutoZone typing this. The worker here just pulled up the codes. Numbers 1 through 4 cylinders on Bank 1 are misfiring. It's idling rough.

 

I guess it could also be a vacuum leak, or a possibility something with the wiring, or even possibly the ECM computer.

 

Could also be fuel pressure related, or even cam or crank position sensors? I'm not sure exactly how the computer receives and sends the firing information to the different sides

 

If you think it slipped a tooth, DO NOT START it. with that being said, I'd be surprised if you didn't hear some valve train/chain noise if it did.

 

One tooth difference will probably induce slightly rough running. You would also likely get a cam position sensor code.
One tooth will not make valves hit pistons, clearance isn't that close.

How old are your coils and plugs? I'd look there first.

 

Yeah I wasn't sure how tight it was in there lol. I figured also that jumping a tooth vs jumping time are used alost interchangeably on forums a lot of times and it's always possible that it jumped more than one tooth. Would seem kinda coincidental to me for one side of plugs or coils to just go out at once, but anything is possible

 

Thanks for responding. I'm smelling big time gas fumes outside my drivers door at start up. Odd!

 

I would assume the worst case just to be safe. Smelling raw gas may mean bent exhaust valves and more than one tooth jumped. Stop running the engine and remove the cam cover for inspection. You may have damaged the pistons .

 

I would also suggest doing a thorough visual inspection of fuel lines to see if you might have a leak somewhere too.

 

Pull the spark plugs and examine them for any difference between plugs. While the plugs are out, do a compression check. There is no specific pressure that you're looking for, just that all cylinders should be within 25% of each other. This is easy and I would bet that it will tell give you some direction.

 

If it were me, At minimum, I would pull the valve covers and see if any of the tensioners have been damaged or if they have been replaced. I wouldn't turn an engine over if I thought it may have issues with slipped timing chain, etc., as further damage could occur. If they are the original plastic bodies, it's probably time.... I'm doing the change right now to the new gen tensioners and updating my cooling system at the same time.

Mine had the plastic bodied tensioners and it's also a 2001.

 

The gas smell seems to be towards my rear right tire. I only smell it at cold start-ups. I had a new fuel pump installed in December.

 

Not getting any cam position sensor codes. Just cylinders 1,2,3, and 4 misfiring. I don't know how old the coils or plugs are. I've had the car over a year and a half now but I've never had any problems like this before. It's always run with great acceleration and zero hesitation at any speed. All I did was go shopping one day, parked the car, came back and cranked it and it started missing immediately. On the carfax report it's really never had anything done to it except new rotors put on, a fuel evaporator ,and an alignment.

 

I thought the 2001's had upgraded second generation timing tensioners that were much more reliable than the first generation tensioners.

 

I could see codes on one bank happening if you have VVT Solenoid issues too but need to test.

Negative. I don't think they were changed until manufacturing dates on the engine late in 2001 but need to read the sticky. Basically, all 2001 cars have the plastic bodied tensioners, and I can assure you mine Did. Just replaced them this weekend.

 

Thanks for responding. Where did you get your cam locks at and timing chain tensioners?

 

A loose or broken chain tensioner can cause the misfire - it doesn't necessarily mean the chain has "jumped a tooth", but DO NOT start it until you pull the covers and replace. At 100k it is due. My 2002 XKR had the dark red plastic tensioners, so who knows what is in yours.

 

I took it to a shop that does work on European cars and just dropped it off. They're going to look at it. They put a diagnostic on it and it told them it needed numbers 1,3, and 4 coils replaced and probably needs new plugs. They said it was nothing to do with the timing. I hope they're right. They'll call me if they run into a problem other than that.