Prize for the right answer ....Whats this .
Discussion
That's the air inlet gasket from a 4.0/4.2 litres S/C.
It fits between the throttle body/inlet elbow and the S/C body.
When I fixed the S/C on my old 4.0 XKR refitting that gasket was possbily the most difficult and frustrating thing to achieve as you needed 3 hands to hold everything in the right place!
Other cars may use it of course.
Just seen that you have the XJR... if that bits fallen out, it's because someone dropped it whilst refitting the S/C. Question is... did they fit the S/C with another one?
If all is well I'd assume that one dropped off the S/C when it was removed, and they refitted a new one when putting everything back together. That one has just fallen off whatever bit of the engine bay it's been resting on since.
ETA: NCC7754BA - GASKET - INLET SIDE - 4.0L SUPERCHARGED - JAGUAR - XK8 - XJ
It fits between the throttle body/inlet elbow and the S/C body.
When I fixed the S/C on my old 4.0 XKR refitting that gasket was possbily the most difficult and frustrating thing to achieve as you needed 3 hands to hold everything in the right place!
Other cars may use it of course.
Just seen that you have the XJR... if that bits fallen out, it's because someone dropped it whilst refitting the S/C. Question is... did they fit the S/C with another one?
If all is well I'd assume that one dropped off the S/C when it was removed, and they refitted a new one when putting everything back together. That one has just fallen off whatever bit of the engine bay it's been resting on since.
ETA: NCC7754BA - GASKET - INLET SIDE - 4.0L SUPERCHARGED - JAGUAR - XK8 - XJ
Edited by Piersman2 on Sunday 5th August 10:52
Piersman2 said:
That's the air inlet gasket from a 4.0/4.2 litres S/C.
It fits between the throttle body/inlet elbow and the S/C body.
When I fixed the S/C on my old 4.0 XKR refitting that gasket was possbily the most difficult and frustrating thing to achieve as you needed 3 hands to hold everything in the right place!
Other cars may use it of course.
Just seen that you have the XJR... if that bits fallen out, it's because someone dropped it whilst refitting the S/C. Question is... did they fit the S/C with another one?
If all is well I'd assume that one dropped off the S/C when it was removed, and they refitted a new one when putting everything back together. That one has just fallen off whatever bit of the engine bay it's been resting on since.
ETA: NCC7754BA - GASKET - INLET SIDE - 4.0L SUPERCHARGED - JAGUAR - XK8 - XJ
You know your stuff ! The throttle body was replaced by Jaguar on the recall, years ago, must be 6 at least. The SC was replaced prior.It fits between the throttle body/inlet elbow and the S/C body.
When I fixed the S/C on my old 4.0 XKR refitting that gasket was possbily the most difficult and frustrating thing to achieve as you needed 3 hands to hold everything in the right place!
Other cars may use it of course.
Just seen that you have the XJR... if that bits fallen out, it's because someone dropped it whilst refitting the S/C. Question is... did they fit the S/C with another one?
If all is well I'd assume that one dropped off the S/C when it was removed, and they refitted a new one when putting everything back together. That one has just fallen off whatever bit of the engine bay it's been resting on since.
ETA: NCC7754BA - GASKET - INLET SIDE - 4.0L SUPERCHARGED - JAGUAR - XK8 - XJ
Edited by Piersman2 on Sunday 5th August 10:52
Do you think its possible to see if one is on there without much effort ?
Like you say, if its worked so long since, it must have been replaced. Probably good practice at Jaguar to replace....I hope.
Thankyou for your helpful response.
To be honest, if it's been that long and all is well I wouldn't be worrying about it. Believe me, replacing that gasket was the single biggest PITA of refitting the S/C as you have to hold the inlet elbow, the gasket and the two S/C bypass pipes in place whilst moving the elbow into position to engage all those bits all at the same time.
I was almost in tears the first time after having been sat on top of the engine for two hours.
You'll notice that the gasket has two holes 'rubberised'. This is supposed to hold the gasket on two of the 4 bolts you also have to be holding in place whilst refitting the inlet elbow. It doesn't.
By the 3rd time I'd removed and refitted the S/C I'd sussed out where to use tape to hold that gasket against the S/C body whilst I was holding all the other bits and pieces.
Someone will have just dropped that down the engine bay at some point, and not been able to find it. They'll have just used another to finish the refit.
I was almost in tears the first time after having been sat on top of the engine for two hours.
You'll notice that the gasket has two holes 'rubberised'. This is supposed to hold the gasket on two of the 4 bolts you also have to be holding in place whilst refitting the inlet elbow. It doesn't.
By the 3rd time I'd removed and refitted the S/C I'd sussed out where to use tape to hold that gasket against the S/C body whilst I was holding all the other bits and pieces.
Someone will have just dropped that down the engine bay at some point, and not been able to find it. They'll have just used another to finish the refit.
Zippyworld said:
Just having a poke around, and I just cannot tell if there is one on there !
I can see a rubber gasket in place. Is it a massive job to check, and us it a simple job ?
Not the most mechanically minded person, but I’m not daft either.
As the previous poster suggested - leave well alone!I can see a rubber gasket in place. Is it a massive job to check, and us it a simple job ?
Not the most mechanically minded person, but I’m not daft either.
The car is working fine.
Zippyworld said:
Just having a poke around, and I just cannot tell if there is one on there !
I can see a rubber gasket in place. Is it a massive job to check, and us it a simple job ?
Not the most mechanically minded person, but I’m not daft either.
If there's a rubber gasket between inlet elbow and S/C it could be the newer version gasket from the 4.2 S/C, which has slightly bigger bearings at the rear of it. Gasket has same size opening, just slightly different shape to allow for bigger bearing shape on 4.2 S/C.I can see a rubber gasket in place. Is it a massive job to check, and us it a simple job ?
Not the most mechanically minded person, but I’m not daft either.
Edited by Zippyworld on Sunday 5th August 11:55
Or possibly someone fitted the 4.2 S/C to your car. I did to my old XKR, I upgraded the original 4.0 S/C to a 4.2 S/C. Only thing that was needed was to slightly re-shape the inlet elbow where it met the back of the S/C and use the 4.2 gasket.
ETA: Just to re-iterate. Leave well alone if the car is good.
You do NOT want to be spending either time or money just to check, it's NOT a simple job to strip that elbow out. Edited by Piersman2 on Sunday 5th August 12:17
Zippyworld said:
Oh I’d have used tape in the first because I am a mechanical genius !
I do have an issue that when I accelerate foot flat, I get a misfire. Just in the middle of plugs and coils. Wonder if the missing gasket, after all these years is causing this....
Do you mean you're in the middle of checking the plugs and coils because you have a slight misfire?I do have an issue that when I accelerate foot flat, I get a misfire. Just in the middle of plugs and coils. Wonder if the missing gasket, after all these years is causing this....
Is the misfire all the way up the rev range, can you hear any 'knocking' or 'pinking' from the engine at the same time?
Another problem I recall from mine as a split EGR pipe which caused the symptons above.
If you can see a gasket between elbow and S/C leave it, it's good.
Plugs are ten years old, and the coils are original so the misfire effect has promoted me to change them, whether or not it fixes the issue, that said it threw up an ambiguous code P1601 incorrect module fitted. Which is weird because no module has been changed.
The misfire feeling is only when I have the throttle flat down. It can sit at 5500 rpm and not miss a beat. This is the same right across the range. I canaccelerate with my foot 80% diwn on the throttle and its fine. Hope that makes sense.
You are right though, I am going to pretend I never found the gasket loitering around my engine bay. Good job I only clean the engine bay once a decade !
The misfire feeling is only when I have the throttle flat down. It can sit at 5500 rpm and not miss a beat. This is the same right across the range. I canaccelerate with my foot 80% diwn on the throttle and its fine. Hope that makes sense.
You are right though, I am going to pretend I never found the gasket loitering around my engine bay. Good job I only clean the engine bay once a decade !
Edited by Zippyworld on Sunday 5th August 18:28
Yep, that's the one I used when I finally gave up trying to get my original 4.0 S/C quiet and swapped it for a low mileage 4.2 S/C. It differs in that it's completely coated in rubber and those two big holes along the side are formed to go round the larger rear needle bearings that the 4.2 S/C has compared to the 4.0.
To get that newer gasket to fit correctly I had to file away a little metal from the original inlet elbow where it butts up against that newer gasket. But other than that you can replace a 4.0 S/C with a 4.2 S/C - direct fit.
That P-Code you have seems to be something to do with ECUs not communicating, probably just a transient error, Clear it and see if it comes back.
For a misfire at full throttle I'd be doing,,, plugs and coil/cables, clean up the MAF, check no air leaks, clean the thottle body, etc.. Could be an injector maybe.
Difficult to track for sure without it throwing a decent code, you'll have to go old school until it does!
Trying googling and see if anyone has had similar symptons before, lots of sites out there with good information on them for the Jags.
To get that newer gasket to fit correctly I had to file away a little metal from the original inlet elbow where it butts up against that newer gasket. But other than that you can replace a 4.0 S/C with a 4.2 S/C - direct fit.
That P-Code you have seems to be something to do with ECUs not communicating, probably just a transient error, Clear it and see if it comes back.
For a misfire at full throttle I'd be doing,,, plugs and coil/cables, clean up the MAF, check no air leaks, clean the thottle body, etc.. Could be an injector maybe.
Difficult to track for sure without it throwing a decent code, you'll have to go old school until it does!
Trying googling and see if anyone has had similar symptons before, lots of sites out there with good information on them for the Jags.
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