sagjohnson

ENGINE CLEANING: Protective Coating or not...

When cleaning my engine, here are the steps that I take:
1- Spray on Simple Green (or other multi-purpose cleaner, degreaser)
2- Let sit for 5 minutes or so
3- Spray off with medium-powered water hose
4- Let drip-dry for 5 minutes or so
5- Spray entire engine compartment thoroughly with WD40

My question is mainly on the last step. Is it good, or necessary to put a protective coating on the engine, or should I just stop after spraying on water?

If protective coating is good, what should be used other than WD40?

Any other critiques to the steps above?

Dwight V.

Let it dry. Haven't had a problem on any of the cars I do this to.

MikTip

Depends greatly on where you live and the corrosive nature of the climate, where you live! ;O)

When I lived in Arizona, I never sprayed any sort of "protective coating" let alone WD-40 all over my engine!

WD-40 is probably not very good for plastic & rubber bits? "Petrolium Distillates".

What is it your trying to protect the engine from? Rust?

In the UK they "wax" coat the engine compartments on certain cars.

AudiSport4000

And personally, I did a bad job of it. I did the simple green then rinse maybe 3 times. Some parts looked really good, perhaps I didnt try hard enough. I got some different degreaser (orange clean I think), and am told its a bit better, and it leaves the bay smelling like oranges (not that it matters).

squidix9

There's some serious science trying to get the right blend. You need the right gunk to apply.

You want protection, but not a gooey mess.

WD-40 is way too volatile anyway, it'll evaporate before you say boo.

Best experiment so far, was a mix of rubberized undercoating/CRC-556(WD40 lookalike)& a touch of lacquer thinner. This is applied to the underbody only.

I've seen a few wax blends for the under hood area, I'll have to look around again. They're generally not for the block though. You want to keep the insulation down, it's hot enough. If you're doing a rebuild, a good coat of Rustoleum works best. It handles the heat, and grease pretty well. I've heard of a few guys doing the inside of the block with it for oil runoff, but I'm chicken, I'm afraid of what'll happen if it comes off.

furiousgeorge

good to dry electrical connections, but not for coating. and for degreaser, dont most degreasers say NOT to use on aluminum?

JeromeS.

Its cheap, and works great. Spray on, hose off..

CGTBrad

I never spray anything directly on the engine. What I do is get a rag damp with hot water and just a little degreaser too. I just wipe down what I can see is dirty...

I know a guy that was religious about doing the whole spray on 'Gunk' and hose it off. After going through 2 ECUs's on his car he finally listened to the Chrysler dealer who told him that both times they found water in many places it should not be.

My advice to you guy who do the whole spray it on thing is be VERY careful where you spray... like only your block...

sagjohnson

WD40 displaces water and when it evaporates leaves a parafin wax-type coating. It's a little gooey and attracts dust, but it does protect the metals, and I've read that it is not very corrosive to modern rubber and plastic. (could be wrong on this, though)

I live in Utah and drive the car in all types of weather, so yes, the reasoning behind WD40, or any protective coating, is to prevent corrosion.

Case in point, I bought a 1989 100q from Ohio. Great car, and well-maintained, but lots of corrosion in the engine compartment that could have been prevented, at least to some degree, if it had been treated regularly with a protective coating.

I have had my engines in the past professionally steam-cleaned and coated. Don't know what the coating was, but it sure acted like WD40.

Anyway, I posted this subject to find out your opinions and I thank you for them. So far, it looks like I'll have to try Foamy Engine Bright next time.

But I'd still like to know what the best protective coating is that can be liberally sprayed over the entire compartment. It is a good idea for those of us in the 4-seasons states.

sagjohnson

sprayed without protection. I spray with medium-force, then apply the WD40, which serves to displace water and coat engine.