So I have a project day coming up on my pick up. Tappet cover gaskets need replaced as do the soft plugs (only 1 side leaking but if I'm gonna do one just as well do them both.) In order to replace the soft plugs the exhaust needs to be pulled from the manifold, and to do that I'm pretty sure will involve breaking and/or rounding off the nuts.

Anyway, there's a pretty good amount of grease/oil/dirt pile up on the engine. Not so much the topside as the bottom, but I'm trying to figure out the best way to go about removing it.

I have a few options-

First is the good old scraper method. It would probably be effective for the bulk of it, but not so good for the tighter spaces.

Then there's generic engine degreaser. Again probably effective for the bulk and would work better for tighter spaces, but there's something else I'm wondering about.

Years ago, when I rebuilt my first engine my older cousin was helping me pull it out of the car. It was an old 75 V8 with close to [no bullshit] 400,000 miles on it, so you can imagine how much dirt and grease was built up on the block and frame. After the job was done my cousin says [no expert mechanic but he knows his way around a car] "You know it doesn't hurt anything to pop the hood at the car wash and hit the engine with the power washer from time to time."

Now on an old V8 engine, I can see that- but how would a more modern engine react to that? Obviously they're built to withstand some water, but to take a power washer straight to it just kind of throws me. One reason I've never done it is because taking cold water to a hot engine makes me nervous about cracking an exhaust manifold or something else. But other than electrical shorts, if the engine was cold, what could result from straight power washing an engine?

If it's a modern engine with fuel injection, make plans to push it home .................

Seriously, shops like mine could make a fortune starting freshly washed engines. I've made that VERY clear to my customers, so they don't make that mistake. The Cap'n

That's just silly Cap'n. I've washed hundreds of engines without an issue. If you know what you're doing everything will be fine.

The biggest issue is that if you turn the engine off you get water in the distributor. Here is the best and easiest guide for the DIY engine clean.

1. pull into a car wash bay and leave the engine running.

2. Select the tire cleaner. It is some really strong degreaser that really works well on engine slime.

3. Soak the engine with about 5 minutes worth of tire cleaner. Avoid the distributor and electrical areas if you can but since the car is running you really won't have an issue. You just want to keep it away from them if you can. Also aviod the air cleaner for obvious reasons.

4. after it is all soaked rinse with the hot wax selected. It is heated and will not crack anything. Sure it will leave a little residue but not much.

5. Close hood and drive off.

You work on modern cars much? Maybe even not-so-modern? A local shop is replacing an ECU on a 72 MBZ right now because there was an engine washing induced ECU failure, and the water didn't even get into the ECU itself, just the injector plugs. I see things like this all the time, and I read about them often on the techs network to which I belong. Not only do you have to protect the distributor, but every electronic connector on the engine and trans. And not just from high pressure water, but also condensation. The jet doesn't even have to directly hit the affected component! If you choose to continue, I'm sure not gonna stand in your way, but telling others it's OK without a clear understanding of the real world issues involved is irresponsible, and could lead those advised into an expensive world of hurt. The Cap'n

For what it's worth...

When I had Babydoll's engine out (2.0 D-Jet), I decided that it would be a good idea to wash the engine, so when it went back in, everything would be nice and clean. I carefully wrapped the ECU and as many electrical connections as I could find, then soaked it in Gunk, then washed it with a hose (not a pressure washer).

The result of my ever so carefully conceived plan of washing the engine resulted in electrical gremlins that took weeks to sort out. If you do something like this, you should prepare to troubleshoot electrical connections that you didn't even know you had.

Neighbor is a dealership mechanic. He says at least 2 cars a week are towed in from someone cleaning it. I've never had a problem, but I DON"T USE HIGH PRESSURE!. Just degreaser and a hose.

The shop I worked at only had Japanese cars. Maybe those cars have better connections . We never had any cars towed in from someone washing their engines and we never had a problem from washing an engine. This was not a small shop either. So I guess it is going to depend on what kind of car you are going to wash.

Again, the reasons you mention are why it is important to keep the engine hot and running and use the hotwax as rinse. The shop was two miles away and by the time I got back the engine was dry again.

I have had issues pressure washing an old rocco, but just had to dry out the distributor after...
and often( carefully) pressure wash my jeep tj's engine
never had an issue with it
but i could easily see how this could be a expensive problem if something went wrong....

If you could pressure wash it with something non-conductive....

Thanks for the tips guys- I think I'll hit it with the scraper for the bulk of it, and then I'll run it thru an auto car wash with underblast. That should be more than enough to clean the areas I need for replacing the soft plugs. I'll just clean the tappet covers when I pull them off. I've got a two part intake so I have to pull basically the entire top half of the engine off to get to them anyway- that'll be a good time for cleaning.

I can also see where a problem could arise, but ... I've been blasting engines all my driving life. I do try to avoid blasting connectors on the top end and the wiring harness. With the exception of a few dizzy's that had to be dried out a bit, I've never had an issue.

Most Japanese cars do have much better connections than 914's. I don't think that they expected our cars to last so long. This was not too long after the time when American cars didn't usually last more than 100K if that.