I changed out the fuel filter and the engine still have the 'stutter' or 'shudder' once it gets warm. I also got the P0420 code once again after the fuel filter was changed out.

So I went looking for my coils. I found the easy ones under this plastic cover.

(Pics are all thumbnails. Click them to open larger image in another window.)

(BTW: Nice job of making that cover look like metal - Jag!) It pops off easily with finger grabs on the sides and a gentle tug.

Just look for the 7-10 cap. It is right next to that. See.



I'm glad I am finding my way around under this hold of this Jag!

Here are all three coil packs (and plugs under them) in a row on this side.



Unfortunately the other three are much harder to get to. (I'll show you in another post.)

It looks like Jag must use FORD coils. Two of the three are made by FORD.



The first two are from FORD factory "EE03A". Which lists as being made at the "FORD EED YPSILANTI" plant.

That second line is the part number. The third line shows the production date: 1C1183. One site of the iNet said it means these two original coils were produced in 2001 (1), in March (C), on the 118th day of the Julian calendar during the third shift. The year and months sound right. Anyway...

The third coil, actually the one closest to the front, looks to have been replaced.

No label over the pot and the plastic injection mold seems to be different as well.

Which brings the questions: How often do coils actually go bad? If a coild is bad, would the computer throw a 'P' DTC? I thought there is a misfire sensor. Would it pick up a bad coil normally?

More Qs: What is this guy down in there, right next to the 7-10 cap?



And what is this guy, on up the row a bit?



I did not pull the plugs yet. The engine was too hot. I want to pull these three and take a look to see if the plugs are original or not and what kind of condition they are in. The error code I am getting is for the Cat on the other side. But I have to wait for gaskets and o-rings to arrive before I can break into that side. So I want to look at those I can right now.

Does anyone know what plugs I should expect to find if they are the originals? (I was surprised to find FORD coil packs.)

The other bank, 'Bank 1' is buried under the intake manifold...

All this has to come off to get to them.



While I am asking questions, what is this?



And are these coolant lines? The thin lines furthest to the left in the pic going into the intake manifold?



The JTIS says I need to drain the coolant system to remove the intake manifold. Is that true?

Thanks again for all your help. Hopefully these pictures will help others down the road. (Pics are all thumbnails. Click them to open larger image in another window.)

 

I'm a bit rushed but yes there is a "misfire monitor" in the software and you should be able to read the misfire counters using OBD. These are all cleared if the codes are reset or the battery disconnected. There's a fairly simple algorithm that decides whether a misfire is serious enough to throw a code, and a few other things but the various counters etc can all be read using the appropriate software.

(It's such a shame all this stuff can't just be displayed on the satnav screen!)

 

I meant to add - I know you've disconnected the battery when changing the fuel filter, so you've lost all the data

With quite a bit of (varied) driving, the various monitors will all gather data and either be prevented from running to completion (due to errors) or will once again start logging values. You can read the readiness status and such data as is available using the OBD socket.

 

The coils with the yellow stickers are original coils.
Those "guys" you had mentioned......the one up close to the front of the car is the VVT solenoid, and the one at the rear is the knock sensor.
You don't have to drain the coolant to take off the manifold.....

jagv8 is right, although to get misfire data back to where you can read it (because it's always counting), you must run, IIRC, at least 5 of the 7 monitors and 5 of the 7 MUST be completed and checked off as so in order to see accurate data of the misfire count. On your scanner, it could say "readiness status complete" for each complete monitor.

IMO, the original coils should be replaced, then have the 02s monitored on bank one, where your catalyst effeciency code is pointing to. P0420 is a bank 1 cat. effeciency code. Having defective coils can send raw, unburned fuel into the cat and eventually that fuel will compromise it's operation. However, if you replace your coils right away, reset the PCM, and drive it around, recheck readiness and all looks good you may be able to save that cat.

 

BugDoc, having a Ford 5.4L motor, we have constant problems with the coil packs (COPs) failing. They are very similiar to these. One thing that I would tell you to do is to look at the tops of the COPs. What you want to look for is any sort of crack in the clear epoxy on the top of the COP. It has been shown that when a crack develops in these, water will enter the COP and cause it to short out internally. Then your engine runs rough and you can get codes like you are seeing. If all your COPs look good, then you may need to pull the plugs and look at the tips to see if one is different than the others. that would be an indication of your misfiring cylinder.

If you need more help, let me know. I will pass on what ever information that I have.

 

Wow Greg, there is quite a difference in the 3.0 motors. The various sensors right and left camshaft sensors, and I am going to guess the others are oil presure,and cooling, again my '05 sensors are in different locals.

I did NOT drain cooling system when I replaced my intake gaskets, you will loose maybe a half pint or so of cooling juice and just plug the hoses with some spare bolts and the clamps.

 

That being said, I guess I should point out that these pics are of an 2002 3.0L in an S-type. I still have not figured out if mine is the early or late '02 model. (How do I determine that? Thanks.)

Good advice. Thanks Joycesjag and all of you. Good advice. I am ordering 6 new COPs too. Do I need ROBbers while I am ordering (or is that who I am ordering them from)?

 

Thanks Thermo. I think while I am replacing the coils I will just replace the plugs too. Since the gaskets are $70 bucks and have to be replaced each time the intake comes off, I might as well put in $70 bucks worth of plugs while I am in there. Those in there will have 93-94K on them by the time I get in there, if they are original.

I really appreciate all your insight and experience. Hopefully one day, I will have more experience with this car and be a help to others as well. (Since I am a poor college professor who likes to drive nice cars, I get to do most of the work on it myself to save whatever $$$ I can.) Thanks for helping me save some $$! Much appreciated.

 

Thanks PoBoyBlues. VVT? Can you spell that one out for me? Thanks. Solenoid I understand.

I did not see any misfire codes before I disconnected the battery or celared the codes. I will check it again this afternoon or tomorrow.

I am going to take your advice on this one. They are easy to change and not to expensive. Someone on this forum recommended a seller on eBay. Have any of you used COPs from eBay? About $135 for six... half price. I guess knowing they are just FORD COPs makes me feel like some parts can be had somewhat more cheaply than through mail-order from the Jag dealer.

Thanks again for your help and insight.

 

I'm fairly sure the MY (model year) is for the last 6 characters of the VIN:
2001 L86902-M45254
2002.5 M45255-M62935
2003 M62936-M94764

I am guessing that means that MY2001 extended into 2002.

A search for:
Jaguar Vehicle Specifications
may get you more data if you're interested and look fairly hard.

 

VVT is variable valve timing. I think it's probably in JTIS but if not you'll not have trouble finding it.

 

BugDoc, if you are at 94K miles, then the plugs are due to be replaced anyways. The platinum plugs from the factory are "only good for 100K miles". So, you may find that your misfire issue is related to the older plugs. Some people have managed to get away with up to 150K miles, other don't trust them beyond about 50K miles. So, take that for what it is worth. Remember to replace the plugs with more platinum plugs. If you go with the cheaper (non-platinum) plugs, you will be back in changing the plugs in another 30K miles. So, a little now, a lot later.

 

It actually feels a bit like there is a combustion happening in the exhaust manifold or Cat. That is what made me think that unburnt fuel might be getting through... I also read on the iNet that the P0420 code I am getting can be from oil or unburnt fuel getting to the Cat and igniting there.

If I block the intake ports with cardboard or something, can I turn the engine over to test the cylinder pressure at the plug holes? I do not have a bleed-down tester. I only have a tester that can test the PSI with the engine turning over. I might be able to rig it and use pressurized air, but I am not certain I can find TDC on this engine.

I hope this works.

The only other thing I can think of, is the timing chains. If they are stretched, I supposed gas could get through if the exhaust valves are not closed when they should be, allowing gas to escape into the exhaust. Does that seem possible? Please tell me it is not probable!

At what point does Jag recommend the timing chains be replaced on the 3.0L (Probably around 100K I would guess.)

Thanks again for thinking through this problem with me!

 

When you say you did not see any misfire codes - did you look just for codes or did you look at the actual counters? As I understand it, the codes don't appear especially readily, even if the counters are non-zero.

If you can read codes can you not also read the O2 sensor waveforms and then do that again after changing coils and/or plugs? You'd hope to see a real improvement if they're causing trouble.

 

Thanks. That helps.

 

There have been issues about needing to change the chain tensioners (from the earlier plastic ones to metal, I think) and guides but the general view seems to be that the chains last well. How well is a good question as not many cars seem to have 150K+ on them.

I should say I know much more about the V8 engine (as it's the one I have) so I could be mistaken - be sure to check.

I'd say the coils and plugs are a much more likely cause so it's good you're doing them.

 

We are thinking on the same lines. I was not certain if the originals were 'platinum' or 'iridium' plugs.

I was going to go back in with the iridiums. If it costs $70-80 just to get to them, I do not want to have to get in there for a long time. Iridiums in the correct length and heat range are ok, right?

I can usually get 100k on them in cars/trucks and such. I still usually change them out on my bikes in less than 20K if the bike lasts that long. Based on the condition of other parts I have replaced on the S-type the P.O. did not treat her very nicely. (I want to give her a better life!)

 

Bug, I've never used coils from ebay. I get them from the parts dept. at work......for installation on customer cars.

You are right about the 0420 code, but incomplete combustion (defective coil, valve, valve seal, broken ring, etc.) causes the catalyst to be ineffecient and the PCM uses the rear 02 sensor as a monitor for catalyst effeciency. BUT the 0420 could also be caused by a defective catalyst by itself, which I've seen a bazillion times.

The timing chains and tensioners on the 3.0L have been really, really reliable. I've never changed a tensioner or chain on a 3.0L. I've done one engine in the decade or so the engine has been outfitted in Jags. If you had a chain stretch issue, like you described, you'd probably have some noise, and a very rough, loping idle. She'd be very unhappy.

Glad I could help in some way. Good luck to you, Bug.

P.S. When I see JTIS written on this forum, I want to laugh. I haven't used JTIS in probably a good 6 years or so. It just sits out back collecting dust, if it's even still there! This wasn't directed at you, Bug. I'm just sayin' is all.

 

Most of us don't work for Jaguar and given how damn proprietary Jaguar is with their maintenance documentation, what other source do you suggest that would be better and more up-to-date than these JTIS CDs ?

 

I'm sorry, Jon. I know most of you don't work for Jag. I didn't mean it as a ha ha type of thing, hope you didn't take it as such. I just haven't heard about JTIS in so long.....just made me laugh is all.

I don't know what other source you would use aside from buying the service manuals, I guess. Some TSBs are on All Data, some are free, some aren't, but don't know for sure. Not all TSBs are on those type of sites, I do know that. You can call a dealer and request where you can buy wiring diagrams, manuals, and even ask if there is a website for customer use. That's about all I'm allowed to give. I have to try to protect myself and my job. Although I will try to help as much as I can.

I'm in the same boat as you, Jon, when it comes to my cars. I don't drive Jags, and have to buy my service manuals and such in order to repair them. I don't get much "inside" help if you know what I mean.