Arsalan, from the sounds of things, you have more of a vacuum leak than you do a misfire. You can stop by your local auto parts store (Advance, Autozone, etc) and ask them for 2 o-ring kits: Felpro 96485 and Felpro 96496. Both are fairly cheap and that will put new gaskets on the intake. Then, most likely you will need to stop by Checkered Jag there in VA Beach and get 2 IMT o-rings (they may come in the one o-ring kit). You might be able to also pick up these IMT o-rings at the European parts specialty shop there at the end of Military Hwy and LIttle Creek (1 block east towards the navy base on Little Creek).

From there, check the brake booster line running from the top of the intake to the brake booster. Specifically, you want to look at the plastic bulge in the center of this line. Rub it with your finger/thumb and see if you spot a crack in the plastic or if it is starting to crumble away. if in doubt, replace.

The last thing that I would tell you to check is the PCV hose. If you find the throttlebody, look just to the left of it and you will see a hose about the diameter of your thumb running from the front valve cover to the elbow in the intake. Is this hose smooth or does it have a mesh groove design to it? If smooth, you need to replace it. I would say to pull the smooth hose off to see if it is split on the back side. This is a common problem and can cause what you are seeing.

 

Arsalan, by the way, I used to live in Norfolk. So, I kinda know what stores are in your area and where you can find the parts that are normally pretty difficult to get your hands on. I am not able to find the shop name that I liked there on Little Creek Road, but it will be right in the same general area as the NAPA. The place really specializes in the VW parts and higher performance accessories, but they have access to the jag parts. I used them to get my rear calipers for fairly cheap and they were the only ones in the area that could get the caliper.

 

Arsalan: By now you hopefully realize this forum is unique in that the good folks here will stick with you until your cat's purring again. More than once when a problem with my X-Type had me discouraged, it was the support and advice from folks on this forum that kept me encouraged and determined. And usually what appeared to be a big problem, turned out to be a single issue that was small and obvious once I pinpointed and understood it.

To recap the situation:
+ We think cylinders 1, 3 & 5 are not firing; Cylinders 2, 4 & 6 we think are firing.
+ The reasons cylinders 1, 3 & 5 are not firing could be:
(a) No spark due to an electrical problem
(b) Too much air due to a vacuum leak (i.e., too lean)
(c) Not enough air flow due to a restriction, e.g., clogged catalytic converter (i.e., too rich)
(d) Not enough fuel, due to a problem with the injectors (i.e., too lean)
(e) Too much fuel, again due to a problem with the injectors (i.e., too rich)

And whatever the problem is, we think it's common to cylinders 1, 3, & 5, while cylinders 2, 4, & 6 seem unbothered by the problem.

At first I suspected (a), no spark in cylinders 1, 3 & 5 due to an electrical problem. You've ruled out most common cause: engine oil in the common spark plug well due to a leaking valve cover gasket. I'd guess that the former mechanic / owner suspected this and already installed new gaskets, because you found minimal oil in the wells, and oil on the spark plug threads (which likely got there from a leak in the old gasket). You also ruled out another common cause: a bad ground for the Bank 1 coils.

But let's do one last check to ensure the ground wires from Bank 1 are good. Try this:
(1) unplug the electrical connector to all 6 coils
(2) with a multimeter, check the resistance between the 6 black ground wires from pin #3 of the electrical connector for each coils to a good ground point on the engine. You should find less than 5 ohms resistance between the black wire to each coil and the engine ground. But if you find more than 5 ohms resistance for coils 1, 3 & 5, trace the black wires from these coil to the ground point, looking for damage to the wire.

Let us know what you find, and we'll help you from there.

 

Arsalan: In addition to confirming that all 6 coils have a good ground connection, with less than 5 ohms resistance from pin 3 of the coil plugs thru the black wire to the engine ground, here's another quick test....

With the ignition key in the run position, test the voltage at pin 1 of each coil plug. Pin 1 lines up with the red & white wire going to each coil, and you should detect at least 10.5 volts in pin 1 for all 6 coils, again with the ignition key in the run position.

Let us know what you find.

 

hello about 3 days ago my jaguar x type 2.5 litre v6 started misfiring but was working fine prior now it will go into limp mode but will also come out of just in and out the whole time im driving when it first started happening it seemed as if it just needed to idle for about 5 minutes and then it was fine now its constantly back and forth while im driving 5 minutes in limp mode 5 minutes back to normal when in limp mode wont rev over 3000 rpms obviously to be completely honest this is my first car and im only 17 so any help would be greatly appreciated many people have said sparks or coils but i figured if that was the case it wouldnt come in and out of limp mode correct any help would be very much appreciated im reading the codes tonight so i will let you know what the codes are so you guys can further your help my guess if faulty wiring or such im really not sure as well people said maf sensor so im really lost not trying to spend a fortune fixing it it also only has 147 if that helps at all and prior to me starting to drive it last Wednesday was sitting for 2 years if that helps at all
Any help would be much appreciated thanks in advance ​

 

I am guessing you have the check engine icon lit up on the dash, correct? When it goes into limp mode is any lighting FLASHING on the dash?

Do you have a code reader or acess to one, maybe through a friend? If so, have the car scanned to see what numbers pop up. If not, maybe you could go to one of the auto parts cahin stores, like Autozone and have the codes read. Then do a search on here and post them and we can get a better idea of what might be happening.

Seeing as it sounds like an intermittent kind of thing, my first guess would be a vacuum leak. Do you hear any sucking or hissing sounds coming from under the hood? First places to check on that are the brake booster hose, the IMT O-Rings and the PCV hose. If you do a search for "Big Three" you will see plenty of threads about them.

Without having the specific codes it is hard to say with any certainty where to start. There are plenty of friendly helpful people here willing to help out on here. YOu have come to the right place. best car forum on the web.

 

Engine light has never flashed once just been stuck on for a while getting my codes read in 10 minutes here in a sec up il update as a I go car was sitting 2 years prior to me driving it starting last Wednesday was working fine till 4 days ago already did all regular maintenance i Just popped the hood thought and I hear a hissing on the left side just above the belts ?

 

Was hard to hear with the engine misfiring couldn’t really hear it until I got close

 

These are my codes
P0174

P0171

B1165

B1175

P1000

B1165

so only the first two apply to the engine from what I’ve gathered is it’s running too lean which would conclude what would this make it misfire like so really want to pin the root of the problem before I go and buy parts for it thanks in advance for any input guys

 

https://www.justanswer.com/jaguar/68...165-b1175.html

https://www.autocodes.com/qa/39632/0...r-x-code-b1165

A p0171 & p0174 together are almost ALWAYS a vacuum leak from one or more of the "big 3" =




P1000 says codes were cleared at some point and the drive cycle(s) have not been (or allowed) to complete. It will turn to p1111 when completed.

 

Well, there you go. Definitely looks like a vacuum leak. Check those areas we recommended and also double check the accoridan hose going to the throttle body to make sure it is in good shape and not split or loose. To replace all of "The Big Three" will take you maybe 1/2 total time and less than $100 in parts. Start with that and see where you are at.

You list the B1165 and B1175. The B codes on an X-Type start at B12XX. Are you sure they are not C1165 and C1175? If so, that looks like there is an issue with the rear wheel speed sensors. You have any message saying cruise control not available on the dash? If not, maybe those were taken care of a while ago.

You might also want to clear all the codes and see what comes back to make sure what you are seeing is recent and not something stored from a long time ago.

 

the codes definitely looked like a B not exactly sure then cruise inst available and just replaced the abs sensors on the back wheels honestly not too worried about anything other then the engine right now as i just need it to stop misfiring then go from there
Thanks let me know

 

If you just replaced the sensors in the back then those probably are old codes. Erase and see if they don't come back. Like you said, don't worry about those right now.

Good luck.