Overhauling the m20

[oekundar]

Gents,

I am currently in the beginning stages of performing the first major tune up on the m20 including the following:

Water pump
T-stat
All belts
Timing Belt
Plugs
hoses

so as I'm taking things apart, I notice that there is a bunch of oil/dirt on the splash guards below, which I'm assuming is from years of neglect, although she does start up everything and runs great.
In any case is it wise to power wash the engine bay prior to swapping in the new belts/parts?

Thanks for any insight.

Ola

[jlevie]

I'd suggest that you include ignition wires and a valve adjustment in your list.

I don't recommend getting a power washer near the engine bay. That can force water into places that should remain dry. Periodic cleaning of the engine is a good idea. The process I use is:

1) Start with a hot engine and get front of the car up on jack stands. Several
large pieces of cardboard under the engine area will soak up the grunge and
help prevent stains.

2) Using a putty knife, screw driver, etc., scrape off any heavy
deposits. Most of that will be on the lower part of the engine and you'll have
to get to it from underneath.

3) Spray a mixture of Gunk and diesel on using a garden sprayer.

4) Scrub every thing you can reach using plastic bristle brushes on painted
surfaces and wire brushes on bare metal. Work heavily caked areas again with
the scrapers. Spray on more solvent mixture as needed.

5) Re-fill the sprayer with any concentrated detergent (Simple Green, pressure
washer detergent, etc) and spray everything down.

6) Using a garden hose set for a gentle spray, or better yet a plant watering
wand, wash down the engine and engine bay. You want to avoid any high pressure
spray as that may force water into places that you don't want it.

7) Spray on more detergent and go over everything with the brushes, then
repeat (6).

8) Leave the hood open and allow the engine bay to dry for at least 8 hours
before starting the engine.

Notes: Having the engine hot will make oil and grease easier to wash off and
the residual heat will help dry out any water that reaches electrical
parts. You won't get the cosmoline/oil stains off the valve cover as they are
baked on. The best way to clean up the valve cover is to have it bead blasted
or hot tanked, but you can get most of it off with paint remover (with the
cover off the engine).

[alpinaclone]

The way that jlevie said is prolly best,having said that,at every shop I have ever worked at a preassure washer was always used. This was more for speed than anything else though. If you decide to go this route be shure to pay attention to where you are spraying because you could cause seious damage. Also, if you do this, start with a cold engine, because no matter how hot the water is from the sprayer, it will still be cooler than a hot engine. The rapid cooling caused by the water, and resulting contraction of metal parts is no good for anybody. Just be carefull and keep away from electrical bits, dipstick tubes and the like.

Matt