just picked up a 1991 xjs v12, has a idle issue im trying to work out,i realized it is getting to much air, secondly i looke under the car and looked down from the topside and realized there were no gaskets where the down pipes hook up to the manifolds so,,,, shouldnt there be gaskets there and would that cure my idle issue? third while driving it on the brakes or acceleration between 30 40 miles p/h up or down i hear a rattling underneath the car and dont know where to look, could it be a heat shield or something rattling, any help or where to look would be greatly appreciated

 

I've renamed your post from HELP HELP & MORE HELP to Help XJS V12 issues.


HELP, HELP HELP is too non specific and unlikely to get the response you're looking for

Good luck

 

Please describe the idle issue





Most commonly the AAV is stuck





Not gaskets, exactly, but sealing rings...."exhaust donuts" as they're somtimes called in the USA. Jaguar calls them "olives".




Lots of "could be" items. Heatshield, yes, possibly. Get under there and do some banging around....might get lucky and fight the noise fairly easily

Cheers
DD