Ah, how long is a piece of string? The process of engine cleaning depends on how many electricals are exposed. I suggest it is essential to cover the alternator in a plastic bag tied tightly with string to stop water penetration - computers likewise - and possibly the distributor. If HT leads are shielded where they meet the spark plugs, then they should be OK provided you pull off each after cleaning and dry the inside of the cap.
I use an ordinary spray degreaser, any brand, and after taping up electricals I get down and dirty with a set of small brushes - and then use the high-pressure cleaner on a low setting.
If you get the fan and alternator belts wet, then they will squeal so a little dab of Vaseline on the two faces of the belt when dry will ensure they are quiet.
Once your engine is clean a short mist with the hose will keep it that way unless you have an oil leak but that belongs on the Jaguar forum
Naturally you will want to wax exposed paintwork if you can get access - and perhaps a plastic reviver on plastic parts.
It usually takes me a full day to do a proper clean but then I have OCD.
Stand back with your sunglasses on and enjoy the sparkle
Regards,
Brian
