High revs when idling

[Andy]

Hi,

[Fiat Bravo 1.6SX 16v, 1999 S-reg, 83k]

I was on my way to work this morning and got to some heavy traffic. I'd been doing a steady 70mph for about 10 miles prior to that.

Once I'd stopped in the heavy stuff, I noticed that when I put the car in neutral, revs shot up to 4000 and stayed there - pretty noisy. Dipping the clutch had no effect on this. The only way to stop it was to turn the engine off when I had to stop. On restarting the car, revs went back up again. Once the gears were engaged and the car was moving, the problem was not so obvious, but it did feel as though the choke was engaging and pushing the revs up to 2000 when my foot was off the gas.

When changing gear, revs would again go up to 4000 until the gear was engaged. After a while, the problem eased a little, with revs fluctuating between 1000 and 1500 in 1 second intervals.

Has anyone had this before? Does it sound expensive to fix? The car was only serviced and MOT'd 6 weeks ago. A friend suggests that maybe a thermostat has died, or that the choke is playing up.

Thanks,

Andy

 

[Andy]

Possible causes?

Found some other posts referring to:

Idle air valve;
Throttle position sensor;
Resetting fault codes;

Are any of these the likely cause?

 

[Tom]

Re: Possible causes?

It will be the idle control valve thats sticking.

If you have a Mk1 (alloy manifold) then its a 10min job and is detailed in the haynes manual, if you have a Mk2 (black plastic manifold) then you need to go to fiat.

 

[Anonymous]

Re: Re: Possible causes?

Most probably the idle control valve...

Daz

 

[Anonymous]

Re: Re: Re: Possible causes?

grrr...

beat me again...lol

Daz

 

[Tom]

Re: Re: Re: Re: Possible causes?

 

[Andy]

Thanks Daz, Tom

I tried one garage who seemed to agree with you guys, but he can't look at it until next Monday. He also said he's the only guy in the area with the diagnostic kit for Fiats (other than Fiat).

I phoned Fiat, and I've booked in for Friday. They want £70 just to look at it, but they also seem to agree with what you said.

Should I just find a local garage who can look at it today?

How safe is it to drive in the meantime, as Friday is a while off, and I need my car? I don't want to kill it! How do I know if I have a Mk1 or Mk2? stupid question?

And how much is this likely to cost?

Questions, questions, questions...

 

[Tom]

Re: Re: High revs when idling

Mk1s mostly say 1.6 on the side although some later ones had Mk2 engines.

Mk2s have 100 on the side.

 

[Andy]

Cool - it says 1.6 on the side. Reg'd Feb 1999.

Likely cost?

 

[Tom]

Re: Re: High revs when idling

OK, it may still be a Mk2 engine

Open the bonnet, if the bit on top of the engine is black plastic its a Mk2.

 

[Andy]

Thanks,

I've just sold my Fiat and purchased a Kia Pride
I guess I'll bite the bullet and trust the Fiat guys. Hope it isn't the ECU...