Idle problem

[M4rk3y]

Hi everyone. im new here and new to Jaguars, i bought my 99 s-type today! on viewing the car the engine was fine, really smooth, it is definitely not misfiring. i have read a few post on the internet about idle problems but i thought id ask here...

when sat in park or at a junction with my foot on the break (for an extended period) the car will slowly start to idle oddly (revs drop and increase, drop and increase... it even cut out once).

i have had cars do this before and it was the IAC valve. a friend of my fathers said it could be an air leak in the intake (after the air mass sensor).

just wondering if anyone else has played around with a problem like this and if they could suggest the cheap fixes to start off with before changing coils and plugs etc..

the car as 100k miles and full service history

thanks

Mark :)

[Rayinpompey]

I had an S Type that used to do that too, in fact it used to cut out a lot more when idling. It was a 99 Model too.

When I took it to a garage, the chap told me he had to swap out an intake hose as it had a nick in it, not sure what hose he was talking about, but he did say it was a problem as the hose was lying over the radiator,and got so hot and made a hole in it causing it to cut out when idling.

Not very helpful I know but, check your (cheaper) hoses.

[M4rk3y]

Ray, you have helped more than you think... you have calmed my worries a little as i have two people who have suggested air leaks and a post else where that said they had a problem with an air leak in the gasket of the throttle body.

il get a better look tomorrow, i am loosing daylight now and its raining :(

thanks man