I have a 1999 s-type auto 3 litre only 60k on it has been a great car and runner till the other day, went out for a drive and when i come to a stop at lights or in trafic the car idles realy rough and then some times just cuts out any sugestions please.

T o me it sounds like an air leek. try the breather pipe on top of the engine and to where it disappears at back of engine, it has a elbow joint that is a known fault on S Types, you may have to remove it to find fault, usually a small crack.

Stan

Welcome to the club, Steve.

 

Stan has given you some good advice [as always].

 

Regards,

 

Peter.

checked that one its ok some one has told me there is a breather pipe under neath the plennam that is known to split or collapse any one know if this is there or it is prown to collapse thanks

There is a pipe there as you suspect, I have read a number of comments on other forums about this, but, before you delve in too deeply to the engine bay have a look at the pipework at the front of the engine just past the air cleaner ssembly, the vac tube here on mine had a split underneath which was not at first glance obvious, only noticed when flexing the pipe and trying to hear any air leek or hiss As a temp fix i used insulation tape to bind the split,that was some time ago, the orange  performance light went off and it has been ok ever since, have you had any warning lights/ comments  come up on the dash?

Noel

no warning lights on, the revs just seem to drop slowley till about 5k then it cuts out., when car is running on revs its ok no loss of power just on idle the problem is there.

I am still positive it is an air leek. That beather pipe I mentioned is not blocked is it, it has a restricter at each end of only a few mm. so it will show same fault has a leek. I had same trouble. Have you had the codes read with obd2 tester.

Also it may have developed a inlet manifold gasket leek.

will have a good root about in the morning see if i can find any leeks its just annoying, if i cant find any thing will get garage to read fault codes for me early next week