VW Golf Mk III - Idle is erratic (600-800RPM) when engine is warm

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Tue 25 May 2010 21:10
VW Golf Mk III - Idle is erratic (600-800RPM) when engine is warm - s lyle

Ladies and Gents,

I have a 1996 1.6 Mk3 Golf CL that when the engine is cold the idle is fine (about 1200 RPM), but when the engine warms up to normal temperature the idle is hunting between 600 - 800 RPM. Normally when the engine is warm the idle is steady at about 650 RPM.

I have already taken the throttle body apart and given it a good clean, but to no avail.

Any ideas would be greatly appreciated.

Rgds.

S.

Reply | Report as offensive | Link
Wed 26 May 2010 09:20
VW Golf Mk III - Idle is erratic (600-800RPM) when engine is warm - Peter D

Chech all vacuum and breather pipes carefully, I suspect you will find an air leak. Regards Peter

Reply | Report as offensive | Link
Sun 30 May 2010 13:57
VW Golf Mk III - Idle is erratic (600-800RPM) when engine is warm - s lyle

Thanks Peter D for the reply.

I took the breather pipe off and it had some "mayonnaise like" residue inside it. I am hoping that it is due to condensation only . I changed the oil only about 3 months ago and there was no sign of any water in it. The breather hose otherwise looked okay .

When you say check vacuum hoses I presume you mean hoses connected to the throttle body ?

There was only one vacuum hose to the throttle body ( coming from a throttle control valve ) and that also looked okay. What I have noticed is that the top of the throttle body itself was very oily. And the gasket that fits between the base of the air filter housing and the thottle body was in poor condition. So I am going to replace that first and see what happens.

Any further ideas / suggestions would be much appreciated.

Thanks.

Reply | Report as offensive | Link
Mon 31 May 2010 13:11
VW Golf Mk III - Idle is erratic (600-800RPM) when engine is warm - s lyle

Looks like I'm going to have to wait a day or two for a new gasket.

Can anybody confirm that there is just the one vacuum hose on my car to check ?

And am I right in saying that it is the braided one that connects to a small pipe on the throttle body and is also connected to the throttle control valve ?

I should have said earlier that the engine code is AEE.

As I posted before, all ideas are gratefully accepted.

Rgds.

S.

Reply | Report as offensive | Link

Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.

The Good Garage Guide

If you cover no more than 100 miles per day and have easy access to a charging point at home or work, then an EV is ideal for you.

Is an electric car right for me?