High Idle Speed

[Guest CR1]

Help guys

1.8 Petrol Manual 1996 mondeo Zetec

 

Just took car in to have engine steam cleaned, only to find out that the stupid muppet JETWASHED it instead! :)

 

Engine started and ran ok afterwards much to my surprise and relief, but on the way home, it wouldn't idle below 2250. Gradually it lowered to just below 2000. If I turn the steering wheel, the revs go up (as expected) but don't come down again and stick at 2500-3000. Turning the engine off and restarting has it idling at 2000 again.

 

I've taken the plug caps off, and not surprising there was a nice little puddle of water simmering away around each plug. I soaked that up so they were dry and left the caps off for a bit. I squirted carb cleaner in the air inlet just in case water/steam was sucked in (engine was running whilst it was subjected to this abuse). Neither made any difference.

 

Obviously this is something to do with water being blasted in somewhere. Where do I start?

 

I'm hoping that during the day heat will evaporate the water from where ever it is causing a propblem, but I'm not hopeful.

 

car is difficult to drive as it is - it drives at 30 MPH without my foot on the throttle! Need it for forthcoming holiday so a bit panicky.

 

The engine and bay are VERY clean, but I wouldn't recommend this process

[Andrew T]

As the idle speed is controlled by the ECU it's worth rebooting it by disconnecting the battery for half an hour. The ECU will then go through a re-learning process. May not help but it costs nothing to try.

 

Make sure you have your radio security code though.

[Guest CR1]

Thanks for your commets, I may have to try that. It occurs to me that if waters got in somewhere, only getting it out will cure the problem. When I've dried it out Imay try that but don't have any tools with me so can't try it yet anywaay.

[gregers]

take it back and stamp your feet and tell them to rectifiy any problems that have occured

[Guest CR1]

Took the connector off the temp sensor that feeds the ECU - on top of themostat housing. I changed that sensor at the weekend and the connector was a bit tight on the new one and one of the connecting grips has snapped :headshake: stupid design. There was a bit of water in that conenctor so i dried it, whilst it was off the engine was idling at 3500!

 

anyway, I took it for a drive along the motorway in the afternoon to keep the engine bay hot and get lots of air through the bay, and it seemed to work. The idle speed slowly came down though it was a bit sluggish to drop to its normal level when coming to a stop or changing gear. Took it out again last night and I think its sorted. Ran ok this morning so I think everythings ok, but maybe a bit lucky.

[Masked Marauder]

As you are probably now aware it was nothing but water that had got into a connector somewhere. Once dry it should be fine, and it seems it is.

 

I would only ever jetwash an engine if I knew every connector was sound.

[Andrew T]

I don't think I would either jet wash or steam clean a modern engine. I've never had a problem caused by a dirty engine but I've had loads of problems with electronics.

 

I recall a guy with an elderly Citroen XM on a website I used to frequent. His car was rendered undrivable and subsequently scrapped after steam cleaning the engine...............!