Wash it all you want BUT and it's a major, important BUT:
DO NOT GET ANY WATER INTO THE TOP OF THE HEAD!

If you spray water from the driver's side and get it into the hole where the plug wires disappear under the cover that says "20VALVE" you WILL get water down into the spark plug wells.
After a day or two, you'll get a check engine light, and find that there's all kinds of white corrosion around the plug wire boots. The plug wires start shorting out to the head causing misfires. You'll need new plugs, new wires, and to reset the bogus code.
We used to get all kinds of cars at the dealership where someone thoughtfully washed the engine, either to detail it or prep it for sale... always causes this problem when someone who doesn't know or care gets water in there.

Also, never wash a hot engine, you can crack manifolds and things equally unpleasant. Castrol Super Clean is a great cleaning product which doesn't attack paint like some other powerful cleaners.
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Rob Bareiss, New London, CT 86 244, 87 244, 88 744