Firstly please let me say hello to all on the forum, I am a new member and wonder if I anyone could offer me some assistance with a problem I have with my x type.

Car is a 2004, x type, petrol, manual, 2.0L.
The problem is the car is ticking over reasonably ok (not juping around like its missfiring) but it it making a noise like a washing machine and I can feel a very slight vibration/missfire throuch the pedals.
On accelleration (which is ok but not great) it is ok until I reach 3000rpms, at which point it jerks violently (like a massive missfire), if I drop revs below 3000, it drives ok.
I have had it in a couple of back street garages but they could not diagnose the problem ( tried new coil packs, one even started messing around with the wiring loom) but both garages gave up and returned it to me just as bad as it was when they got it.
Finally went to an independent jaguar specialist, who diagnosed it as needing two lambda sensors and also possible a new cat. He wrote everything down as follows:

P031 - Cylinder 1 missfire.
P1313 - Missfire rate exceeded
Bank 1 vat damage
P1646 - EMC Ho2 sensor malfunction
Bank 1, sensor 1 (grey plug)
P1646 - EMC Ho2 sensor malfunction
Bank 2, sensor 2 (grey plug)
No heater circuit

Requires:
2 lambda sensors part number, denso dox-0-0430
1 cat bank 1.

Just wondered if this makes sense to any experts on here as the price he quoted for repairs is quite hefty (well to my pocket anyway)
Any help or advice would be greatly appreciated.

 

Sounds to me like you may have a vacuum leak.

First, check the 2 hoses shown in the included photo. The front (with the arrow) is the Purge and the rear is the brake booster. I had a problem with the Purge line, but most seem to have the Brake Booster line around the white "bubble."

Start your car, open the hood and take a listen to see if you hear any air flow coming from either of these locations.

 

Thanks,
Just had a look and both hoses seem fine.

 

Good. Another spot to check is the PCV ribbed hose that departs the windshield side of the airbox. Place your ear near this hose as well to listen for air escaping. Also feel the underside to see if there is rot. This hose is also shown in the picture above...it's on the left side...now, your hose may not look like this one though.

If it is none of those 3 "hoses", the next thing to check is the IMT valve O-rings. I have not had to deal with this issue, so please search the forum for IMT valve/ring or something of the sort for more information, or wait for someone else to chime in.

If it is one of the 3 "hoses," it's an easy fix you can perform yourself. If it's the IMT valve o-rings, it's more labor intensive, but you can do it yourself as well.

 

What is happening is your car is going into Limp Mode. It will not allow the revs to go above 3000 RPMs to protect the engine. One of the codes is not complete. Instead of P031 could it be P0301? That would be a misfire in cylinder 1 which is in the back bank closest to the firewall on the left side as you face the firewall from the front of the car. If that is the case you might have a fouled plug or possibly the coil is bad. Try swapping out that coil to another cylinder, clearing the codes and see if the code changes to the cylinder you just put it in.

If the code is actually P0301 then clean or replace your MAF sensor.

I have to guess you have a check engine light on. Is it on constantly? Are there any lights that are flashing on your dash when you drive? If so, how long have they been like that? If you have had a misfire for quite a while and continued to drive with it you could damage your catalytic converters.

It could be the O2 sensor, but if the car is misfiring it could be something else that is causing the issue. I would start with the coil and plug first. How much did they quote you for the work they are going to do?

Good luck. Hope they sort you out quickly and cheaply.

 

Thanks for your replies guys. I should have said beforehand that I am a total novice and have no idea about codes etc.

The garages it was previously in fitted new plugs, coil packs etc and even 'fiddled' about with the wiring loom before both garages admitted defeat and advised I take the car to a jaguar dealer.

I took it to an independant jag specialist who checked it over and diagnosed it as per my first post-needing 2 lambda sensors and possibly also a cat.
The mechanic checked both lambda sensors with a hand held meter and said neither were showing any readings at all so both must be replaced. He also said that changing both sensors might fix the problem but there was a good chance the problem would still be there and that I would also have to replace the cat, but the sensors would have to be replaced anyway.

I forgot to mention in my first post that the engine management light is on. Occassionally it stays solid but most of the time it flashes on and off. When it is solid, I can drive ovef 3000 rpm without the missfire, but when its flashing it missfires as soon as I hit 3000rpm.

******* UPDATE********

Just had the two lambda sensors replaced and the car is still the same...I suppose this means it needs a new Cat?

 

When you say it is the same do you mean the codes coming up are the same or the performance of the car is the same? Can you find out if they cleared the previous codes? If they did not, have them do that and report here what code numbers you are seeing.

If the light is flashing that could be a bad coil, but could be the catalytic converter. Whenever something is flashing like that you do not want to drive the car. You will be doing damage to it. If you have driven it for a while with the light flashing you could have damaged the catalytic converter. If that is the case then you will have to bite the bullet to get it replaced. How long have you been driving it with this condition?

 

I would not replace so many items as many will be fine.

Flashing MIL = catalyst damage occurring due to misfires.

If you have P0301 you could swap coil as posted or just buy a known good one (avoid cheap and nasty ones!) and replace. Much cheaper than the long list suggested. Vital to check if you did mean P0301.

 

Agreed. This sounds like a misfire issue. Either the shop used generic coils (price would be an indicator) and one of them failed, or your plug(s) are fouled or not gaped. Did the shop that did the plugs just put them in out of the box, or did they gap them (adjusting the tong closer or farther from the electrode tip)? Out of the box plugs usually aren't properly gaped which can lead to misfire issues or the feeling of a slight sputter/miss upon acceleration. I had an issue where one of my new coils (Airtex and Wells) was faulty out of the box and caused similar symptoms. It was on my #2 cylinder so I eventually put an old stock coil back on and the issue went away. Then I bought OEM Denso coils and haven't had an issue.

As it was stated above, a misfire on a cylinder will also throw an indicator that the lambda or cat may be the issue when it could simply be fixing the cause of the misfire. A P1313 basically means that at every revolution the system is recognizing a misfire occurring. As a result, if gone unrepaired, this would cause damage to the cats and the lambda sensors requiring their eventual replacement as well.

Are you just getting a severe misfire at 3000rpms or is your dash lighting up and you are getting a gearbox fault message causing you to have to turn the car off and restart after 30+ seconds?