I've found lots of great information on this forum, and its helped me fix my '02 S Type 3.0's coolant tank and window regulator. Now I'm having an issue that I don't really see described anywhere.

I bought the car about a year ago with 65k on it, and soon after I bought it I noticed an occasional slight hesitation. It seems to happen under load at lower RPM's, like going up a hill in a high gear. I find that if I step on the gas and get the trans to downshift, raising the revs, it runs smooth again. I read up on misfire issues and whatnot, but didn't have any codes. Then about 2 months ago, the check engine light came on and the code was misfire on cylinder 4. I found the cylinder numbering diagram on the forum and #4 is on the drivers side, which is readily accessible. So I got a new coil and plug from NAPA and swapped them out, cleared the code, and no more check engine light. The seal on the old coil was damaged or molded wrong and there was oil down around the plug, so I figured this was the issue.

Well, the hesitation is still here (in fact it's getting more common) and no more codes. What should I do? I'm now at almost 80k, so doing a complete tune up with all new plugs is probably a good idea, especially considering the car is 10 years old. Is there something else that can cause this issue other than a misfire? Why aren't I seeing any codes?

As always, thanks for the help!

 

Hi Nathan. The cam cover gaskets and spark plug well gaskets must be replaced. The oil is shorting that cylinder...a CEL is soon to come. Also swap in a new fuel filter and possibly replace the IMRC gaskets, as these are prone to fail on the 3.0 Rick, our moderator, is well versed in the 3.0 and will chime in shortly.

 

There's a hose whose elbow tends to perish, maybe it'll be that. Your original symptoms were classics for a misfire so well done finding it.

Search with terms like
hose elbow
hose leak

might get you suitable threads here.

 

Yeppers, you need new cam cover seals (gaskets) as stated. Also mentioned are the IMT O-Rings, and the elbow hose under the lower intake. Might as well replace the lower manifold seals (gaskets) and upper plenum seals (gaskets) as well with all new spark plugs.

Should be around $200.00 in parts. The lower elbow can be found at most Ford dealerships. The IMT O-Rings are Jaguar dealer or www.motorcars.com about $3.50ea. (you need 2). Fel-Pro has aftermarket seals (gaskets) for everything else, any big box autoparts store.

 

Well thanks, all, for your advice. Somehow I hadn't run across the breather elbow issue before, but it all makes sense. So the only question is do I replace all of the coil packs while I'm in there? Anything else? I'd rather do this once and have it in good shape for a few years.

Thanks!

 

You would want to replace all the "difficult" ones, you have already replaced one, so just two to ponder on.

 

Up to you. Apart from the cost it's a good idea. Keep the old coils - especially if you use aftermarket replacements! They seem to be quite poor in some cases.

 

This link will explain more on the rubber breather elbow:
JagRepair.com - Jaguar Repair Information Resource <-- Thank you Gus!!

 

So I have all of the parts and am ready to do the tune up Saturday, but the IMT o rings I got are black. I have seen discussions on the forum about the green ones, which are supposedly better. Should I get the green ones? Or is there really no difference? The black ones came from Motorcars LTD.

Thanks.

 

According to motor cars ltd. the black IMT O rings are the new style, you should be fine.

 

First of all, thanks to this great site and everyone who contributes! On Saturday I was able to pull the intake and plenum, swap plugs, coils, gaskets, breather elbow, etc and got everything buttoned back up. The only thing that went wrong was the bolts for the cowl brace that I snapped off and had to drill out.
The car seemed to run fine and then on the way to work this morning, it started in with the same old skipping once everything warmed up, maybe even a bit worse. Still no CEL. What happened? Did I fix one vacuum leak only to cause another one somewhere, or was there 2 of them? The breather elbow was caved in and split, so that was definitely causing some of the problem before. Two of the plugs had a decent amount of oil around their threads, so the gaskets did need to be replaced.

What do I do now?