Hey all,

I've recently started having an issue with my 2004 X-Type. Long story short, these issues began happening after pulling a stupid and using regular 87 grade fuel vs. the good stuff. Aside from the slightly reduced performance, I had a big misfire occur, flashing CEL and all. That went away and it seemed to be fine, no noticeable damage or issues aside from the continuing performance deficit. As soon as possible I replaced as much fuel as I could with premium. I've been driving it easy throughout the last week, got an oil change, fluids topped up, fuel cleaner, all the stuff. I took it on the highway once and noticed a really heavy rumble at highway speeds, and promptly got off and finished the journey off the highway at slower speeds. Problems persisted, and just today I went ahead and replaced all the spark plugs. The old plugs looked like just that, old. It seems that the high speed rumble is gone, which tells me I fixed part of the issue, but small misfires are still occuring. I noticed they are most likely to occur in situations towards the top of a gear, around 50-60mph, and only if I back off the throttle and get back on it. It has no issues with constant acceleration, regardless of how fast I accelerate, and no problems with idling or maintaining a certain speed. I am feeling a noticeable delay in acceleration, but not more than a quarter to a half a second at most. With all these symptoms, and spark plugs and vacuum being removed as a concern, are there any other ideas as to what the issue may be, and based on the symptoms, which is most likely?

Another point to mention, it has been really cold here.

ANOTHER event to mention, because of the cold, there was a moment where the car didn't want to cycle into reverse immediately when pulling out of the garage. Thinking it was just a snow drift behind me or something, I gave it some gas, and that was when I realized it hadn't sat into gear, and there was a little bit of grinding going on somewhere. That hasn't been an issue lately, and the temperatures are now above 10 degrees again. It's important to note this happened after I put regular gas in and before the misfires occured, so its stuck in the back of my mind that this may be a culprit, but I can't really figure how. Any insight into that being a possibility would be welcome as well.

If anyone wants to throw out other symptoms to look for to point one way or another, I'm all ears. There's a possibility there are other things occurring that I'm just not seeing.

Thank you!

 

What plugs did you replace them with and also did any of them have oil on them as in around the outside where the coils goes over them. I ask about the plugs because the xtypes are very picky and when they don’t like them the missing going on at those speeds and and rpm range usually points to the plugs.

 

Classic signs of a bad coil or poor power (failing battery / poor connection).

Could be an air leak - not very likely, but you could check fuel trims to be sure.

 

Jaden, like was said, a coil is most likely your problem. This is where I would say to take the car for a drive and then force the car to misfire, but stay in it. Force the check engine light to come on. This will give you a P030X code where X is the cylinder that is misfiring. If you get the P0300 code, then this is a random misfire.

The other thing I would be looking at is cleaning the throttle body. It could be that your throttlebody is sticking and that is causing what you are seeing (throttlebody is not moving fast enough). You can use some carb cleaner or throttle body cleaner and spray the throttle body to get rid of any brown that is there. You want to especially look on the edge of the butterfly valve (the silver disk in the center). Stuff loves to build up there and causes lots of drag. A rag with a bit of cleaner on it rubbed there will clean it up for you. Do not worry about flooding out the car (odds are, you are going to do it). When you go to start the car, simply depress the gas pedal as far as it will go, hold it there as you crank the car. Leave it like this for 3-4 seconds and then start easing off of the gas. This will bring the car up to idle. If the engine starts to race, simply back off the gas pedal faster.

 

I have some new coils and new injectors on order, along with a new knock sensor. I cleaned the throttle body, it did look a little messy, and after cleaning it it gets power a little better right away, but the slight delay remains, along with all the other issues. Although the misfires are predictable as far as the speed, rpm, and conditions are concerned, it’s still hard to make them occur purposefully, and when I do, I can’t get it to stick long enough to throw a code, which in itself is odd, especially considering it had thrown a blinking CEL early on.

I took it by O’Reilly’s and used their code reader, and looked at the live data. Fuel pressure is adequate at idle, sitting between 50-57 psi, so I didn’t see a reason to check it while moving. Everything else also seems to be within the expected areas, but I haven’t dug too much into what everything means or what all the numbers should read.

Tony, the plugs I got were Bosch Platinums, #6747. This was one of the ones recommended from Autozone, and I don’t know anything about what’s best, so hopefully those are adequate.

I’m fairly certain the battery is satisfactory, I’ve noticed no other symptoms of a bad or failing battery. All electronics seem to function fine, no flickering, normal ignition startup, etc.

I can rule out with almost 99% certainty that it has nothing to do with a vacuum or air leak. The idle is steady, and spraying starter fluid around the vacuum lines, intakes, and seams all around the engine compartment didn’t touch the RPM’s.

Tomorrow I’ll be getting a new fuel filter from the local shop and putting it in, just because and just incase, and the other parts are expected on or before March 5th, so we’ll see what that does for the car around that time.

Any other suggestions or inquires for specific data are welcome while I try to figure this out a little better in the mean time. Thanks for the help so far everyone!

 

Pull and clean your MAF/IAT with MAF cleaner only (not carb cleaner that leaves a residue). You have a problem somewhere as using lower octane gas will NOT cause what you are seeing. Remember, Octane has no relationship to power output from combustion. Big misconception of most drivers.

There's a couple of explanations from me in this thread on octane vs power combustion output (free energy).

https://www.jaguarforums.com/forum/x...st-car-217174/

 

I will do that tomorrow along with the fuel filter replacement.

My thoughts are the lower octane gas is not the cause of what is happening directly, because I have 100% 91 Premium in it now, but I think it may have contributed to aggravating the issues I’m seeing now. The timing just seems too coincidental to me. Won’t early detonation create a lot of muck and grime in the engine? If so that would point to issues in the injectors, and possible issues in the plugs which have either been addressed or proven not the culprit. My guess is it’s either the injectors exclusively, or the coils exclusively now. With 131k miles both could use a replacement anyway.

If you’re right on the MAF I owe you a beer!

 

Just remember the MAF is down inside the "tube" & don't stick anything down there to clean it (you'll bugger it up). The little visible "bulb" when you pull it out is the IAT. I chased an intermittent (that became constant) code for months that is 99.9% ALWAYS an air leak cause and finally replaced my MAF and cured it.

https://www.jaguarforums.com/forum/x...sensor-206354/

This is more of a c.y.a. like replacing the fuel filter. My guess is coil or MAYBE a weak/failing knock sensor. If you do replace the knock sensor search this forum for a member's easy repositioning of the sensor that's WAY easier than the old one.

 

The 87 gas is not the culprit. That is all I use in mine. It sounds like a sensor or coil pack. I have noticed that if there is a little problem on these cars, the cold will amplify it lol.

 

The 6747’s plugs is what I had in mine and mine didn’t like them and had the miss like you have almost like clockwork and your right getting it to keep missing to throw a code is about impossible because once the car misses for so long it’ll automatically downshift which raises the rpms above the range that it normally misses at. I took mine out and after 6 months they still looked new so I put them in my truck and it doesn’t skip a beat with them. Bosch 8103 is what I put in the cat and it’s never ran as smooth as it does now for as long as I’ve owned the car.

 

I've had my 2002 X-Type for four years. Never used any thing other than 87 octane. No problems.

 

Sounds like my 02 xtype, a great drive but the winter seems to affect the carburation, chugging on 4 or 5 cylinders, and a hefty tune-up in the spring.
How do beamers handle the winter? I drive junk in the winter and the x is just fine in April.

 

I don't drive it much in the winter. It is clean, not "cream puff" but almost, with 54,000 original miles. With kids and grand kids, and snow-salt-slush, I try to keep it clean. Dive my 2015 T & C Van instead. By the way, I have been to Kamloops BC. Rev., Dr., Duane Beals

 

The BMW’s I’ve driven haven’t had a problem. I had an ‘03 325xi that was a dream to drive, probably my favorite car I’ve owned, and then it sprang a quick and effective oil leak and the engine seized within the same drive. The next was a ‘90 735i that despite being 30 years old held fast in the winter. It just ended up getting to be too old that annoying issues were prevalent so I ditched it for the cat. The X type is by far the best on the snow so I’m very happy with it this time of year, despite the issues I’m having now.

 

I’ll keep this in mind for after I change the incoming parts. If the problem persists and we don’t notice anything dire during the full tear down this will be my next move.