Hello,

I have had my 1999 jaguar xj8l v8 4.0 for about two weeks now and she is already giving me problems, yesterday when a coworker and I were coming back from a clients office the check engine light came on and the restricted performance light flashed a few times but did not stay on.

This morning I took it into autozone and they checked the codes for me and the codes are P0174 P1111 and P0171. I read that cleaning the MAF sensor may fix the problem but if anyone has any suggestions on anything else that may cause this that would be great!

 

I would also look at the intake going between the air box and the throttlebody. If you have a leak there, it can cause the same sort of issues. After that, look at the intake and check the vacuum lines for any cracked lines.

 

The error messages went away Friday night and have not come back on, i didn't do anything to the car yet. I think tonight I will try and clean the MAF sensor just to see if that helps the cars performance.

 

The P1111 code is a Jaguar code that does not mean anything.

The P0171 and P0174 codes tell you that the air fuel mixture is to lean.

You are on the right trail with cleaning the MAF. Like Thermo said from there it's a search for air getting in the system that has not been metered by the MAF.

On my 99 the o-ring on the oil dipstick was gone and both the part and full load crankcase breather tubes were cracked.

You really should consider purchasing the PDF version of the full service manual on ebay to compliment the info here on this forum. I bought one from the seller iGuide and it was the best $30 I've spent on the car to date.

Good luck, Ken

 

The JTIS is available for free download here:

https://www.jaguarforums.com/forum/x...uctions-54640/

The accordion section of the air filter to throttle body duct is famous for developing cracks due to the heat of the exhaust headers directly below. You have to flex the section to see the splits. Quick fix is electrical tape but the entire duct is only about $100.

 

Thanks for all of your advice you guys I am going to have to try some more of your suggestions and see where that takes me.

Last night I took the box that houses the air filter apart to clean the MAF sensor and the had some oil in it.... not sure what that means but I cleaned out and cleaned the MAF sensor. The air filter was black so I ordered another air filter which should be here tomorrow. The car ran like new this morning on the way to work, it always felt sluggish and slow before but this morning I felt like I actually had a V8 under the hood. the only problem I had was (I probably shouldnt have done this) when I was driving down a back country road on the way to work I got my foot in the throttle a bit and at about 90 it started to slip but it runs fine from not to about 70.....

Tomorrow when the air filter comes in I am going to see if there is more oil in the air filter housing, I am praying that there isn't but we will see.

Do you guys know what may cause the slipping and the oil in the filter housing? Could they be related?

 

I found this manual for free at the link below, is this the manual you guys were referring to?

Jaguarmanual

 

No, Jaguar Technical Information System (JTIS) v. 21 is, or was, the full dealer maintenance and repair manual and included electrical schematics and OBDII codes for all models and model years '96 - '03. At that time Jaguar went to an online system. JTIS v.21 has been sold on eBay as a CD for years for anywhere from $3 to $30 . . . whatever the seller could get for them. JTIS has been on the General Technical forum for years as a download to burn a CD. Then one of our wonderful forum friends, Jim Lombardi, converted the CD to a down load format for storage on your hard drive so you don't have to fool with a CD.

Anytime you see a post by Jim how about hitting the 'thanks' button.

 

Here's the one I'm referring to:

1998-2003 JAGUAR XJ XJ8 XJR (X308) Workshop Service Repair Manual | eBay

The best part is that it's a PDF so you can read it on any computer (Mac or PC), smartphone, Kindle, iPad, etc. No messing with the JTIS software which only runs on a PC. This makes working on the car and having the manual right there with you very easy.

I bought this manual for my 1999 and also bought the version for the later model XJ8's also since I plan on owning one of those real soon. The download takes about 15 minutes and I backed up my copies just in case my laptop crashes.

Good luck, Ken

 

oil in the kazoo could be a couple of things, there's a 'part load breather' tube clipped to the cam cover (looking from the front of the engine it's rhs) this could be blocked with crud.

The clip is a pita to get off, there's a technique of using two slim nails to open the clip up to pull it off. Next is to clear the breather hole usually with a fine drill. There's a how to document here,
DiY_Document_Clean_MAFS.pdf
Carry out the cleaning and see if it cures the issue.

How much oil are you seeing, a fine coating, or can you pour it out?
The other issue that can cause this, is a bit more serious, as it's a classic symptom of blowby caused by the nikasil bores breaking up. To see if the engine exhibits this, you need to carry out a blowby test.

I recall a thread on the ZF gearbox slipping due to A drum failure, but usually at low speed, until there's a bang into top gear and gearbox fault on the instrument pack, maybe early signs this part is failing. I hate to be highlighting these issues for you, but the great thing about this forum is the fact it's been discussed, the answers, cost of fixing, parts etc are all here.

 

Jaguar99 if you're getting oil in the air filter housing it might just be a breather problem as Sean mentioned above. Of course we're not really expecting your Nikasil bores to be breaking up like an arctic berg, but keep us in the loop.

 

There was quite a lot of oil in the kazoo, you could have poured it out. I ordered a new air filter and it should be here today so I was going to see how much oil was in the kazoo today (hopefully none), I just bought the car about 2 weeks ago and I have no idea when this thing was serviced last or what had been done to it. I am going to also try the cleaning steps that Sean B recommended in his post and see if that helps.

I will keep you guys posted on what happens after that. I really appreciate all of your help!

 

Hey guys,

I installed the new air filter last night and took apart the tube that connects the air filter housing to the throttle and cleaned it all up. There was a lot of oil standing in the crevices and open areas around the throttle but there didnt appear to be any oil in the throttle. I cleaned all of it up and cleaned the throttle and replaced the old air filter, I have a feeling though when I get home there will be more oil. I couldnt tell where the oil was coming from but I am hoping that since I cleaned it all up there will be a trail from somewhere.

Hopefully you guys have some ideas of what could be causing this! I appreciate all of your help!

 

Could this be caused by the PVC Valve? Does my jag have a PVC Valve?

 

Sorry I mean PCV valve

 

No PCV or PVC valve. Crankcase venting is done by the full load breather tube from the right valve cover to the air filter to throttle body duct. Excess oil can be caused by worn ring blow by or a clogged part load breather tube. The part load breather tube is the smaller one on the left valve cover. Down inside the plastic connector is an orifice that is subject to closing up with hard coke like deposits.

Be careful removing the plastic connector as 12 year plastic can be very brittle. Clean the orifice with a 3/32" drill bit held in a pair of vice grips. The actual small hole is at least 3/4" down inside the connector.

A compression test will tell the tale about the ring blow by.

Also check the O ring seal on the oil dip stick. Less than a good seal there can also cause problems.

 

I would clean up the breathers and see what happens -- all that oil does not sound good.

How many miles in this car ... who did you buy it from?

The transmission should not slip -- you should check the fluid level

 

I've currently got a customer's '99 XJ8 in my shop with the same codes. We have replaced the flexible tube to the intake tube, the seal under the intake tube at the throttle body, the intake tube itself (that runs from the airbox to the throttle body, amazing how much better a new one fits), and resealed the vacuum line at the bottom of the throttle body.

Last night, I drove the customer's car home and, sure enough, the problem repeated itself under mildly hard acceleration. Cleared the codes last night at the house, then drove it work this morning in Sport mode with no problems. Going to check the other load lines to the MAF today, as well as the MAF itself. Hope to post an update before I go home tonight.

Also heard the intermittent growling noise from the left rear last night, but that's another subject for another thread...

 

I bought the car from a very small car lot in columbus ohio, it has 88k miles on it.