In an attempt to have the car super clean for a 'show and shine' in my town, I washed the engine and I got the "Restricted Performance" and idling very rough when I started it up. It does drive under load normally... just at idle. I used a regular hose and soap/water as I was attempting to be cautious... guess I wasn't careful enough. I'm going to let the engine dry for a bit.

So, any suggestions as to what I need to check? Ignition coils? And I read somewhere about the knock sensor - where is that? How do I check if I ruined it? (sigh).

 

oh..no ...remember cats dont like water...

you want to make sure water is all dried up and start checking the spark plugs and move on

 

From TSB 600-02 (Jaguar warned.......)

"Whenever possible, do NOT use high pressure washing equipment or steam cleaners."

 

Generally water gets under the spark plug cover and fills the cavities round the plugs if you flush the engine with water. Take off the spark plug covers and remove the coil packs and blow out the spark plug holes. Might need to dry the coil packs too.

 

Last time I washd my xjr engine I got code from knock sensors, misfires and cracked left exhaust manifold. Haven't washed this car engine since. It sure looks like it... Manifolds were not even that warm. Nowhere near hot.

For me basic thought is that engine bay is supposed to withstand water and temperatures greatly. So washing should not do anything. If it does then there is not great sealing somewhere. Flooding alternator is not wise.

 

As a general rule, H2O and anything electronic do not play well together. I remember when you could spray off an engine in the car wash bay and
think absolutely nothing about it. The Jaguars of our era are so sophisticated and have so many electrical checks and dependencies, the harm of doing
such a thing could prove disheartening to say the least, In most cases the Jaguar engineers provided protection for everyday driving in the rain and
puddles but age can cause these safeguards to become less than effective, especially under a pressurized flow. The best thing for these is an air
compressor with a hose equipped with a long nozzle. You can blow most of the dust and loose dirt off, and then use a damp rag to finish the job.

 

Check the plugs for water, blow it out; check the MAF sensor leads for water, let it dry or clean with electrical connection cleaner; check along the air tube for water. Let it dry for a few days. Per the Tech Bulletin Bob sent: don't do it again. It ain't like the old days where you could SARAN wrap the distributor, coil and carb and steam clean it . . . And in spite of the good work TRW, Denso, and Ford did to cleanup the electrics from the bad old Lucas days , there are still tons of electrical connections.