Rough Idling After Engine Wash

[iduck]

Hi, I'm new to this forum, have a 2005 Citroen C3 1.4 sx petrol auto, decided to clean the engine after having some oil leaks fixed recently. I bought an engine cleaner from Halfords and sprayed the engine with it following the instruction on the can, covering all the electrical parts. Then washed it off with a pressure washer. The next day the engine stalled a couple of times whilst idling. The next few days it didn't stall but the idling remained rough. Driving is ok, the engine management light doesn't come on, no loss of power, etc. 

A friend said it might be the lambda sensors around the catalytic converter are faulty. I just wonder if anyone had the same experience and more importantly what's causing the problem. Many thanks.

[paul.h]

Welcome to the forum.

 

It is never a good idea to wet an engine and its electrics as you have now found out. Wiping with a cloth/tissue is the best way to clean them. You could try using a hair dryer on all the electrics to help dry them and you may need to unplug all the electrical connectors to dry them, including the ones on the ecu and in the fuse box and to remove the ignition coil and dry the spark plugs but you would think the engine heat would dry these. It may be best to disconnect the battery before doing this.

 

It is also possible you have damaged or disconnected something with the pressure washer. I would also make sure there is no water in the air filter.

 

If you can not find anything then you may need to use a code reader with live data to see what is wrong. This will also allow the lambda sensors to be checked - the inlet one should constantly switch values around 1.0 but the outlet one should be steady unless the catalyst is faulty.

 

The 1.4 petrol C3 is prone to injector failure due to water and this is copied from the C3 Technical section Common Problems pinned topic:

 

2. Petrol injector failure.

Replaced free by our dealer under warranty. The engine had a very bad misfire and the engine management light came on. Caused by water dripping on the injector from the washer pipe connections and through the bonnet washer jet holes. Prevention is to put sealant under the washer jet and to change the plastic washer piping to flexible rubber to seal better and move any joints to the side of the bonnet. If the engine is only a bit juddery without the management light coming on, it may be worth replacing the spark plugs before condemning the injectors.

 

Also from the same topic is a procedure for disconnecting/reconnecting the battery:

20. Odd electrical problems caused by wrong battery disconnection procedure.

If you need to disconnect the battery and not do a BSI reset procedure, I have found the following has not given me any problems on a 2004 and 2007 C5 and a 2003 C3:

- remove the ignition key from the car

- open the bonnet

- wait a few minutes for the BSI to shut down

- disconnect the battery negative terminal

 

When reconnecting

- ignition key out of the car

- reconnect the battery

- wait a few minutes

- insert the key in the ignition and wait a minute

- turn the key to the first position and wait a minute

- turn the key so the dash lights come on and wait a minute

- start the engine

- take the windows down and up to reset the anti pinch

- reset the clock (and radio on the C3).

[iduck]

I did cover the fuel injector and the spark plugs and the alternator with plastic bags. I did not spray water over air filter or the battery. In fact I only spray water under the outlet manifold. I didn't put water over the top of the engine. I just wonder if there was any water in or around the electrical bits, they would have evaporated by now with the engine temperature. The wash was over a week ago and I have been using the car, I would have thought all the water should have gone by now. Well, I'll go to examine all the electrical bits, just in case. Thanks very much Paul for your reply, much appreciated.

[iduck]

Just feedback to the forum, I checked all the wire connections, no obvious signs of damage or water. Left it to run for a week or so, the idling gradually improved to my relief and it is running well now. I guess some water must have got in somewhere and have evaporated in time. Cheers.

[paul.h]

Thanks for getting back to us and I am pleased your car is now ok.