Hello all, first time here. I have recently purchased a 98 XJ8 and of course it was great when I got it about 400 miles ago but not so much anymore. I'll start by saying my top radiator hose decided to come off one day, after cooling down and refilling, the car seemed great again until a couple days later it started running rough. I am getting a cylinder 5 misfire code and wanted to verify here what the cylinder numbers are. Seems to be the one thing that google don't know! All I want to do is try swapping 5 and another to see if the error changes. I saw elsewhere on these forums that people have posted a link to a pdf for the cylinder locations but I am not member enough yet to access these areas. So can anyone simply let me know the cylinder locations (numbers) for a 1998 xj8l . Thanks
Mike

 

Continuing confusing issue.

Jaguar lists the cylinders A bank (right side) 1 through 4, B bank 1 through 4.

Where does that leave your #5 code? The ODBII generic codes use the long standing standard of 1,3,5,7, on the right, 2,4,6,8 on the left.

Then Jaguar changed their numbering to the OBDII standard in Model Year 2002.5, yes 2002.5.

Welcome to the wonderful world of Jaguar!

Go to the new member area and make a few posts, or the girls on Jaguars forum for a contribution and you will very quickly be a full fledged member.

 

Hi mwade109,

As said... welcome to the wonderful world of jaguar! I had a similar problem on my XJ (intermittent misfire caused by a couple of duff coils) and have been through the fun of OBD numbers vs jag numbering.

According to the JTIS -

[if you don't have a copy GET ONE... they are the most useful things in the world after a socket set and a 'willing' volunteer to work on the car, and can be downloaded from this site/ bought for about a fiver.]

- It lists cylinder B1 as 5. The B bank is the one NOT on the air intake/brake fluid side, so it's the easy one to get to and cylinder 1 is at the front (radiator end).

Hope this helps, btw what codes did you get? You looking at a failed coil or sparks/injector?

Good luck

Alex

 

Just in case you havn't spotted it (easy to do with the number of new threads/odd directions forum threads can go - ending up having little to do with the title/original question) post #8 in

https://www.jaguarforums.com/forum/s...ad.php?t=38864

has the diagram you need.

Alex

{btw: would i be right in thinking your XJ is in the 8XXXXXXX vin series rather than the F0XXXXXX's. Just wondering as it will dictate the location of 'cylinder 5'}

 

Just a note that if the coil is bad to replace the plug as it may be fouled.

Also note to clean oil residue out of the bottom of the Sparkplug Hole. That is can be the cause of a coil failure. The oil allows the coil to arc to ground. You may want to pull the other coils and look down the holes for oil in those plug holes too. The time spent cleaning with a paper towel is worth the savings on the coils at $92 each from the dealer.

If oil is an issue in all holes consider replacing the valve cover gaskets to save the $800.00 worth of coils.

Ken

 

there sure are a lotta helpful folks here. After having the car towed to a kinda-local jag dealer and having them run their diagnostics on it, them came up with problems ranging from spark pluge to fron abs harneses, both sides and a 5000.00+ quote.

I towed it back and my mechanic replaces one coil & plug, valve cover gaskets & seals and it runs great.

BUT

We are smelling a 'overheat' smell after riding a while and he found a water leak at what looks to be between the thermostat housing and the engine. My mechanic took a quick look and is saying he may have to remove the manifold to replace the thermostat housing if the housing is cracked. Does anyone know if the manifold would need to be removed? He is really pressed for time and if I can tell him it don't have to be removed it may get done faster! Thanks
-Mike

 

Mike,

Welcome to the club. At the risk of being corrected by members with a whole lot more Jag experience than I have, I offer the following. I just looked at my 99xj8, and I would attempt to do this without removing the intake first. It may not work though, those back two bolts are just under the front lip of the intake and may be too long to allow removal. It'd be worth a shot though. As a side note, Welsh Enterprises has a nice looking machined aluminum thermostat housing in this months flyer for $65 PN# AJ8-2217-K, no gaskets though.

Good Luck
Ralph

 

The old 'removing the thermo housing' problem. The back two bolts are indeed difficult to get to but the manifold does not need to be removed. Since the plastic housing is trash anyway, just use a pair of pliers to break it apart till the bolts are exposed. A 'crows foot' wrench is all that is needed to remove the bolts. I ground down a 1/4" drive socket to fit and Gordo bent a cheap wrench to accomplish the same thing. Consider cutting a blade screwdriver slot into two of the bolts to assist in running them down when reassembling.

By all means replace the plastic housing with the aluminum one. Consider painting it black like Jaguar did with the plastic one as the bright aluminum looks a little out of place on the black engine.

 

Thanks Ralph, I googled and found that there was aluminum & plastic thermostat housings.... you know plastic will not be going back on!

test point, excellent instructions, they have been printed and I will bring them to work with me today to give to the mechanic who works next door. He did want me to bring up one thing, he said he would like to pressure test the system to make sure thats where the water is coming from, is there an adapter to changeover to connect to Jaguars radiator cap?

Mike

 

Sorry, no radiator cap!

There is a pressure cap on the overflow reservoir. I rented a huge pressure testing system from one of the auto parts stores. It had 21 special adapters for fit every auto on the planet . . . except Jaguar. Had to use the universal connector that just blows up like a balloon.

By all means do a pressure test. With all the aging plastic and clamps these cars find very creative places to leak. Specifically check the multiple port plastic manifold at the thermostat, the Norma connectors on each side of the engine rear connecting to the heater system, the hoses running under the intake manifold and the overflow reservoir. All reoccurring leak locations.

Good luck!

 

Mike,
Glad I could help and wasn't off base. I definitely concur with Test Point on various leak locations. Great "special tool" remedies also. I had one of the rear Norma fittings leaking, and plastic manifold up front was shot, old, soft, decaying. Dealer got my wallet good...

Enjoy your ride.
Ralph

 

Ralph, I would love to but as of now, it's official, the mechanic has had it more then I. I am hoping after these bugs are out that it will swing the other way at least for a bit. The car is beautiful and I can't wait to take it on some nice long drives, probably up into the Blue Ridge or Smoky Mountains. But.... it will have to gain my confidence a bit first!

Have a great weekend everyone.
-Mike

 

had my mechanic replace the thermostat housing with a nice shiny metal one (mechanic said is was a royal pain in the butt) and thought it would be good but he is now having a problem with the temp gauge going up to the top then if the car turned off for a few minutes, it goes back to normal. He said he bleed all air off it but is there anything he should be focusing on?

on another note, I had taken ill with a heart attack a couple weeks ago and then 3 days had a small stroke (i am 50) and can't really be stressing over this car a whole lot right now but would really like to get it going soon as I have to currently drive a conversion van, and it like driving a 'turd' down the street... help!
Mike

BTW, anyone know a Jag mechanic in the Va. Beach area that does not charge Jag dealer service costs? I just want my Jaguar fixed.

 

Your mechanic refers to the air supply manifold on passenger side of an engine. It is difficult to get to the bolts of the thermostat housing from this side. if I were you I would also think about replacing plastic (original) thermostat housing with one made of aluminum. Plastic housigs have a history of cracking due to age or temperature changes.
Burza

 

Hello Mike,

First off, I hope your health has improved and you're getting back to your old self. Don't stress over the car, it will still be there when you are feeling better. Here's to a speedy recovery.

Ralph