[ColmO]

The car was in storage for a while and when I started it up the engine management light was flashing and the car sounded like a diesel. My indy has done some processes of elimination, coils , sparks etc but he thinks it might have jumped a link on the timing chain when I started her up..... Anyone had a similar issue before I get him to change the timing chain with its associated costs ?

 

[CanyonLakeJags]

Jumping a link... I'd think that's pretty hard to do unless the timing chain was stretched / tensioners had failed. On my 4.2 Jags, you generally got some notice that the tensioners were failing because, for a while, right after you started the engine, you got a nice unhealthy growl from the engine. Plus, checking for such a problem is pretty easy by popping the valve covers; you don't need to commit to replacing the chains. How many miles are on it?

I also would expect a compression test would demonstrate a possible timing problem.

I never had this problem on my 5.0 X350 / X358s, but I did have a situation similar to yours on one of my 4.2 XJs when I had a fuel injector failing. It cranked funny, and when it finally fired, it ran really, really rough.

 

[ColmO]

Jumping a link... I'd think that's pretty hard to do unless the timing chain was stretched / tensioners had failed. On my 4.2 Jags, you generally got some notice that the tensioners were failing because, for a while, right after you started the engine, you got a nice unhealthy growl from the engine. Plus, checking for such a problem is pretty easy by popping the valve covers; you don't need to commit to replacing the chains. How many miles are on it?

I also would expect a compression test would demonstrate a possible timing problem.

I never had this problem on my 5.0 X350 / X358s, but I did have a situation similar to yours on one of my 4.2 XJs when I had a fuel injector failing. It cranked funny, and when it finally fired, it ran really, really rough.

Really appreciate the feedback. I don't remember any growl but I will get him to do a compression test and check the injectors, we will see how we go. There are 110K miles on her.... Again many thanks.

 

[TheVoices2]

This is stupid question, but did you drain the tank and put new fuel in prior to starting the car ?

Petrol deteriorates over time, if the car has been in storage and you started it up with the 'old' fuel, I would expect an engine management light and poor running as a result.

 

[CanyonLakeJags]

Oh very good point by TheVoices2. OP didn't mention how long it's been in storage, but I was just talking to my Jag mechanic yesterday about fuel and he said that he's starting to get old fuel stank in as little as 3 months these days (especially with formulations for California). The starting carb on my Mark IX sticks after it sits for a while even though it was recently rebuilt, and he's thinking old fuel may be the culprit.

If this car was laid up for a few years, I could easily imagine crappy fuel being the problem.

 

[ColmO]

I put fresh petrol in the tank prior to starting it up so I don't think that's the problem.
Thank you for the input though..

 

[MrKis]

I’ve never heard of a 4.2 having any timing chain setup issues.
Late 4.2s have, on rare occasions, had VVT units fail. Check everything else first.

 

[Dodsy]

Its sounds like you've already checked this but worth mentioning. I had an engine light come on and the engine sounded like a bag of spanners, I was convinced it was terminal it was that bad.

Turned out two of the spark plugs were knackered (I didnt get them back from the garage so not sure exactly what was wrong). New set of plugs and problem solved.

Interesting that when I dropped it off I was discussing it with the mechanic and I was talking about valve issues or maybe coil packs and massive misfiring. All he said was 'it will be the plugs give me a couple of hours to get some sent over be done by this afternoon'. Might be giving him too much credit as he knew those plugs had been in there for >100k miles ........

 

[ColmO]

Its sounds like you've already checked this but worth mentioning. I had an engine light come on and the engine sounded like a bag of spanners, I was convinced it was terminal it was that bad.

Turned out two of the spark plugs were knackered (I didnt get them back from the garage so not sure exactly what was wrong). New set of plugs and problem solved.

Interesting that when I dropped it off I was discussing it with the mechanic and I was talking about valve issues or maybe coil packs and massive misfiring. All he said was 'it will be the plugs give me a couple of hours to get some sent over be done by this afternoon'. Might be giving him too much credit as he knew those plugs had been in there for >100k miles ........

Thanks for the reply, apols for not getting back sooner but I was out of the country on biz. I am assuming that is the first thing my guy checked but as they say... Assumption is the mother of all f... ups, so I will phone his and just double check.... Cheers mate.

 

[t0m4ever]

There should be codes that can be read if the EML light came on.