Last week car started misfiring on cylinder 8. I swapped the existing coil from 8 with bank 6 and bank 6 began to misfire, so I ordered a new ignition coil.
After ordering a new ignition coil and the dealership sending it to Michigan instead, I finally got it after more than a week. I also replaced the sparkplug in 8, but I plan on doing the rest this weekend probably. The car is still misfiring on bank 8 and I'm not sure what else to check.

 

any codes after/or same the replacement coil?

 

Just to be straight, there are only 2 banks: 1 is R, 2 is L. On OBD, bank 1 has cylinder 1. On your car, bank 1 also has 3,5,7. Cyl 1 is at the front. Cyl 8 is in bank 2 at the rear. Is that the one you swapped? You had code P0308, right? You swapped with cyl6 so that was the cyl next to 8, also right?

Any signs of oil or water ingress around those cyls?

 

Yea sorry, and it was P0308. I swapped cyl8 with cyl6, cleared the codes and ran the car until I got the code again. It gave P0308 and P0306. Replaced the coil I put in 6 with the new one and it went away and also replaced the plug in 8 (which was using the good coil from 6), and I'm still getting P0308. That's the only code.

I checked for oil around the area (found none) as that was a problem I had last summer, but Jag replaced all the gaskets. I'd have to look for the paper work to see specifically what was all done, but I'm also no longer under warranty as of a few months ago.

I showed the sparkplug I pulled out to my dad and he said it looked like it was too hot or something.

Just to help me clarify, when you say bank 1 is on the right, would that be the driver side or passenger side?

 

In USA, usually cars are LHD so R is passenger. They're iridium plugs and tend to be good for a LOT of miles (100K+) but can of course still fail. How many miles on your car?

Sounds a bit like another dead coil or another problem that ends as a cyl8 misfire. Could be wiring, injector (not likely, but possible), and so on. Coil is #1 suspect. They get baked and they're a bit fragile.

Er, you did put in the right kind of new plug? (Just checking, no offence intended!)

 

I have about 96k miles on the car. I did swap the new coil with another, just to make sure the new one was DOA. It looks like the other new ones I bought last year, and Jaguar ordered it based on my VIN, so I'm pretty sure it's the correct one.

I've had this problem before, and it's always be due to a faulty coil.

 

Can you do OBD to check the monitors, fuel trims, O2s, etc?

I agree chances are the new coils/plugs would be the right ones.

Any chance you have an air (vacuum) leak? Not sure why it would only be #8 reported, though. Fuel trims will tell you, if you can do OBD.

 

I think if it were a lean condition, it would surely give you an entire bank code.

My mom's Lincoln LS just had a cyl 8 misfire, same code. Here's what happened to her car. Valve covers leaked, fouled her plug wells and the deteriorated the boots that connect to each coil pack. When the gaskets were changed, and all the plugs replaced, new boots were installed but coil packs remained.

As it turns out, Cyl8 pack didn't survive the inundation of the oil, and misfired. Replaced that single coil, and all is well again.

 

Depends how lean. He's changed the coil. But may be a marginal or dead one. We all think it's the coil LOL

Worse case, get one, swap with #8, keep the one just taken out, and end up with a spare. It'll be needed sooner or later.

And quit with the L-word.

 

What?
Lincoln LS
Lincoln LS
Lincoln LS

 

I just got misfire on Cyl5. I have a 2000 S-type 3.0. Do you know a rough estimate on what the cost might be for this work at the dealer? I changed the window regulator, but this one kind of scares me.

 

Well if your problem is just a bad coil, mine cost $58 from the dealership. When I first encountered the problem, they charged me for 2.5 hours of labor plus cost of parts. I think in total it was around 400-500 for the visit, that included diagnostics.

I'd suggest clearing the codes, swap the coil in cyl 5 with another one, then see if the other cylinder misfires like 5 did. If it turns out that was the problem, buy the coil yourself and replace it. It takes about a minute.

I'll go borrow the OBD scanner tomorrow afternoon, Advanced Auto lets you use theirs.

 

Thanks for the response. I've been looking for pictures out here on the website of how to switch it out. I did get a diagnostic check from Advance Auto yesterday. They gave me the code for the 5 cylinder misfire and it cleared. Its been a day since I had it checked and no new code. If I could see some pics and instructions I might take a try at it myself. Without that I'm not sure I want to risk it.

 

I replaced the rest of my spark plugs today, and in the process accidently put the old coil back in. Oddly enough, the car no longer has the misfire. Idles smoothly and I don't hear anything wrong.

I do have one problem, however, when I tried to remove the old coil again to put the new on in, the coil came out but the rubber around the end didn't. So now I have a piece of rubber stuck on the plug, and its the one in the far back on the driver side. Tried to grab it with some flexible "magic fingers" (spring-loaded claw thingy), but had no luck. I put the coil back in carefully until I find a better way to get it out. But the car is running fine now.

 

Shibajack, just in case you want to DIY, I believe your cylinders are numbered differently than the newer (03+) cars:

front
4.....1
5.....2
6.....3
rear

bank 1 (aka A) has 1,2,3 & bank 2 (aka B) has 4,5,6

IIRC the 3.0's layout, #5 is easier for you to get at

Have at a look at BugDoc's posts - he did a write-up of your era car with pics.

 

Thanks jagv8! I'll do some lookin' and maybe build up the nerve.

 

Car still feels like its running ok, but my engine light came back on last night. And occasionally it'll jump into restricted performance when I'm just sitting at a light. Tried to scan the codes, but the OBD is broken and the other Advanced Auto by me had theirs stolen.

 

use long needle nose pliers and pull the boot off

 

I got the boot out and swapped the coils, but the car runs worse now. Before it felt just fine, even though the check engine light would come on. Now the engine actually feels rough and acceleration isn't what it should be.

I believe the codes I got were P0171, P0174, P1111. The descriptions the scanner gave for the codes were the system was running lean on bank 1 and 2. The cylinder that had the broken coil isn't the one I replaced with a new coil, so maybe this one went bad too? It wouldn't be the first time I had one fail right after another, and it is 1 of few remaining old coils left. But without the codes throwing an error on a specific cylinder, I can't really swap it with another to see if the problem jumps.

I also want to point out that I've been having a lot of trouble lately reading the codes with multiple OBD scanners. It often takes me several attempts before it can read the computer.

 

In case you have a faulty coil the car may interpret misfires as lean running - because a misfire leaves extra O2 in the exhaust. I don't see how that would give lean on BOTH banks.

You may have air/vacuum leak(s). Did you make sure any gaskets you disturbed are still soft and springy and sealing properly - and replace any that were aged? Did you take any intake trunking apart and maybe not re-join it properly? Even a small leak can cause mayhem.