HMMM, so my Jag is an 03 but the valve cover gasket from Autozone that I posted in the previous thread isn't correct but this one for an 04 engine is correct. Now I'm wondering if the other stuff I got for it are ok.(ignition coils and some other things)


Felpro/Valve Cover Gasket (VS50612R) | 2004 Jaguar S-Type 6 Cylinders 3.0L SFI DOHC | AutoZone.com_

 

Got the plugs, ignition coils, valve cover gasket, plug gasket and intake manifold gaskets changed. I think I must have a vacuum leak. When I gas the car it feels like it's being held back and being choked as well as being louder than normal. I looked at the vacuum hoses but man on man I couldn't see or hear anything. Is there a trick to finding the leak if I do indeed have one?

 

Argh, I saw the how to on vacuum lines but didn't read to use water on it to see if it revs up or down.


Since I had misfires on 1, 3 and 5 I'm worried about my Catalytic converters. I have a scan tool on loan so I wanted to check them with the live data. I know the first one should be bouncing a round quite a bit but the second should be remaining stable. Is there a certain number is should be staying around?

 

The 2 LTFTs should be near zero, at idle & at 2500rpm.

 

No luck on water spray test to find vacuum leak. Is there anyway to use live data to figure out if I for sure have one? Could a bad MAF sensor give the same results to the car as a vacuum leak?(sluggish under load) Besides being sluggish under load it's just loud, like it's being choked kind of loud not like the sound of power. I hope that makes sense.

 

Post #24

 

1.8 and 16.8 at idle


-.8 and 14.8 at 2500


First number is long term trim 1(1.8 and -.8) and the other is trim 2

 

Doesn't look like an air leak but something odd's going on for the banks to be so different.

Hard for it to be anything there's only one of that's shared/common to both banks (such as MAF) else it would affect both banks.

 

JagV8, for it to be ltft2 it would mean the side with 2,4 and 6 is that correct?

 

Yes. Bank 1 always contains cyl 1.

 

I went for a drive and monitored the LTFTs and STFTs. Both ST and LT1 were all over the place under load but the LTFT2 would go from around 14.8 to 19.5 and from there wouldn't move. As long as it was under some load no matter if it was 1500rpm or I was flooring it, it stayed at 19.5.

 

Jag, any other ideas on what I should be looking at? It sounds like absolute crap and when I floor it is totally cutting out. It seems like it would throw some codes but I guess I haven't driven it far enough. I'm at a loss.

 

You know a number of things it's not but that leaves plenty it might be and so you're going to need either more data or someone who knows what to get and can get it.

I'd check next for a problem cat using an IR gun or maybe a borescope but a jag tech might know much better what to do (exhaust back pressure? tail pipe gas analysis? etc) so it may well be worth finding someone competent who actually knows these cars. Bear in mind I do not have a 3.0 car I only have an STR.

Any recent work is a suspect, of course.

 

I decided to reset to fuel trims by unplugging the negative batt cable and touching it to the positive. I drove around some and then came back and did the same idle and 2500 test. Idle is the same but this time at 2500 it was a little different.


Bank one went to -5.3 and bank two went 3.7. It didn't stop at 3.7 though. I held the 2500rpm steady but every few seconds it went up. Every time it went up it was by .8. When it finally got to the teens it started going up by .7. I have no clue if this matters but it was different.

 

Clearly it was or still is relearning.

 

After reading around I've come up with two things to try. One is switching my o2 sensors so the bank 2 is on the other side to see if that will switch anything. The other is that I might have an exhaust leak. I think the easiest way to see that is with some Seafoam. Maybe I'm wrong but it seems like it would be an easy way to visually tell if there were any leaks in the exhaust. Any ideas?

 

Went back thru my work today, took off intake manifold and made sure my plugs looked good and all bolts tightened down to specs. Car still driving like crap. Sounds good at idle but when I got to drive it sounds horrible and cuts out at around 3k rpm. My codes are-


P1300
P1316
P0300
p0301
p0303
p0305


there is also one for my coolant temp. I used a temp sensor from Autozone so I think that might be giving me a bad code on it. Temp on coolant is ok when the car is warm.


So, I'm back to misfires on the same side that I had misfires on before I changed everything out. Strange to me that this would all be on bank 1 but my LTFT2 is the one out of whack.


I haven't done this with this car or my Rover in years but I may break down and take it in this week. I need this car to be working. Any ideas before I take it in? I've looked for vacuum leaks but have had no luck finding one.

 

Left one code off


P1313

 

per another thread where a guy was having similar issues, I unplugged the o2 sensor on the passenger side. I still picked up misfires but it didn't cut out on me at 3k rpm like it has been. I'm guessing I have a blocked cat due to having misfires for too long.




My ltft2 is still high though but never goes higher than 19.5. I think this car might just be too messed up for me at this point.

 

Also, I never ended up replacing my lower intake manifold gaskets. Could that be part of the problem with what's going on? I didn't end up pulling it off, maybe I should have.