idle raising when hot

[Epiphone]

Hi, on my SS 2.1i engine, as posted in my recent Prag trip thread. When sat in traffic for only 15 mins maybe (after 6 hour long drive) and the engine began to get hot, the idle started to raise from its normal 1000rpm to 3000rpm. I proceeded to park up and go for a beer while it cooled down and then it was fine again.

Last week in Italy, I was in traffic again and the cooling seemed to work better this time as for almost 45 mins, the fan was coming on at regular intervals etc, but then I saw the idle rising to 1500rpm, so proceeded to forget the traffic and drive back to the campsite I saw before.

So is this normal for any type of engine when it gets too hot? or just WBXs?

Yes I do have a cooling problem, after a breaking coolant junction a few months ago, which I need to investigate more. But I always try to keep the airflow over the radiator, on the Motorway for example its fine.

[KINGPRAWN]

have you bled the air from the system properly..(nose up)...have you seen the rad properly...replaced one on mine before that didn't leak but nearly all the cooling fins/webbs or whatever the proper term is has gone! so cooling on a fraction of the rad surface...don't know if this would make it idle fast but WILL make it run hot!!!
also my stablization valve was an incorrect one for my engine, had another wrong one, both had a different effect on idle speed(too fast) but different speeds..could poss be a duff/stuck valve?? east to test if its stuck by just putting 12v across the two pins where the connector fits,if it works it will "kick off"...???

[kevtherev]

The cooling system is designed to cope with most temps the rad is big enough to deal with quite extreme temps without the need for extra care to keep it in the wind

if it isn't then there is air in it

[Epiphone]

well anyway, I had the Bus back in a garage to change a couple of pipes and they bled the system and it looks better now.

Takes longer to get to running temperature, so before it was getting warm pretty fast and the needle is in the middle now too.

I dont think I will ever master the bleeding!

[Epiphone]

happened again today and at the start of my trip too. Got caught up in some traffic driving through the city. Temperature rose up and then the idle did too. I was able to crawl a little futher to the Motorway entrance and then get some wind over the radiator and then was ok.

Since the last time its been in the garage and had some pipes changed too. Ive also had the heater matrix out, but I bled the system a little and it seemed ok.

As said previously, at high speeds 110 kmh, it runs like a dream. Temperature needle dead centre. Only when im in traffic, it seems to play up.

Will try to narrow down the symptoms and bleed some more. Then try some other things like new idle stabiliser or something.

[big red bus]

HAd very similar prob on one of my old vans. 2.1 dj though. Eventually traced fault to idle unit bewhind o/s/r lamp. Swapped it for a known good one and sorted it out.

Does the ss have an idle switch on the throttle housing?
Clean out idle stab valve with carb cleaner.