engine idles like a diesel

[greendale65]

Ok. Yes I love my bx 16v what it is I don't know, something about these cars anyway
can someone tell me why the car idles like a diesel and sometimes when in traffic idles
high don't use no oil or water would it be filters need changing. Alan

[Way2go]

Idling like a diesel - don't know about that, could it be hydraulic pump clatter maybe because of a low accumulator sphere?

High idle is likely because of a sticking second throttle butterfly. This should close completely under it's independent spring pressure - if it doesn't, an application of 3in1 oil is a good place to start.

[rutter123]

ive been having idling probs with my gti 8v, best to start with the breathers and check every single one very carefully as i found out, any slight air leak after the airflow meter will upset pretty much everything moreso idle and low rpm's.

[Mike P]

These 16V engines are known for not being quiet at idle

You could have a noisy lifter that would make it sound tapperty like a diesel.

Regarding the idle, check the idle speed control valve / auxillary air valve. These do fail and are available from motor factors.

I would first of all check that the throttle position switch is making when the car is at idle and with no throttle applied. Do this by having the car running and the bonnet open, rev the car slightly by turning the cam on the throttle body where the cable connnects. Then turn it back to the idle position and you should hear an audible click from the TPS. Try a few times, if it doesn't click, try pushing the actuator a bit until it does click. This just means that you have to make a tiny adjustment on the throttle body, remember that these cars are over 20 years old now and parts will be starting to wear and clearances etc opening up.

I had to do this on one of my 16v's last year, it was driving me crazy with it's erratic idle and has been as good as gold since.

Otherwise, as others have already said, check all hoses and connections for air leaks and splits. All the hoses on the front of the engine are easy to take off and check, a main culprit can be the large hose between the airbox and the inlet manifold.

An oil and filter change is always a good think to do anyway.

Regards,

Mike P

[Defender110]

"Engine idles like a diesel" so it's ticking like a Cartier then