FYI, oven cleaner and Purple Power are both sodium hydroxide. Both cause skin irritation and both will corrode metal if left on too long. Neither are really safe to use on rubber parts but I've never had an issue with plastic.

Thanx Rog! .

I found that ZEP Industrial Purple Degreaser from Home Depot is the exact same stuff. I have always used the coin-op car wash pressure washer, and never had a problem getting water where it was not supposed to be. Obviously don't spray it directly on electrical components or air intake, but everything else is not effected by the high pressure.

Sorry Nate, but I disagree. I have NEVER had a problem using high pressure on the MANY engines/engine bays that I have cleaned over the years.

I used a steam cleaner on a hot engine with good results. Drown the engine in purple power and let it rip. Dont hit the alternator or starter with degreaser and be careful around seals like the water pump shaft. Blowing dirt into rotational seals will hurt them.

I took pictures prior to make sure any vacuum lines blown loose could be reconnected.

Just curious, there are several nice steam cleaners on the market now, some specifically designed for use on cars. Would you mind sharing which brand/model steamer you used?

Best way to degrease engine, transmission?
 

https://m.northerntool.com/shop/tools/product_200921682_200921682

We have it at work. Drove in on a Saturday and used the wash bay. Really worked good on the tarry grease.

The 15 degree tip worked best.

OK, I have managed to locate a professional pressure washing service. They say they have a long handle wand to go under both the engine and the transmission for more thorough cleaning. I'm planning on telling them to stay off the valve cover area (oil cap) and to go easy around the water pump area although there is grease/grime on the front of the engine which I want removed.

If the oil cap, valve cover gasket, and other seals are keeping the oil in, there is no way for water, even at high pressure to get in. There is absolutely no risk in pressure washing every part of the entire engine, save the air intake or any other orifice that is left open. The water pump seal and bearing are behind the pulley, and it would be quite a magic trick to get enough water pressure there to even think about doing damage. I have cleaned MANY engines/engine bays with strong degreaser and the high pressure wand at my local coin-op car wash, and never had any problem after spraying directly at every part of the engine, transmission, engine bay, or suspension part......Rich

Thanks for the tip Rich! :) I actually have some of that stuff I bought for a totally different project. I had no idea it was Members Mark Degreaser.

My power washer is only 1800 psi. Pretty low but okay for a $70 washer.

Sorry Greg I missed this ?.

Let’s see I changed 1) valve cover & filed the stops, 2) front main seal, 3) turbo drain grommet and orings, 4) oil separator drain tube o-ring on air cleaner side, 5) turbo intake u tube seals, 6) vacuum pump gasket, 7) crankcase vent elbows, 8) seal in the oil cap (just cut one out of thick gasket material). I guess it’s more than six but those are typical leaks on these cars.

My oil filter leaked but I have never changed one of those on my cars. I just tighten the bolts and the leaking stops. My injection pump gasket weeps a bit so I rubbed some black silicone on it and it stopped. I also went under and tightened the umpteen screws on my oil pan. I bought a gasket but it’s still on the shelf because the pan gasket leak stopped. The last leak was the copper crush washer on my oil drain. I stopped using the copper and went to the metal ones with the bonded rubber seal inside - Dowty washer. And I rebuilt my oil cooler hoses with goodyear galaxy barrier hose.

After this I got the clean engine. So dry the scratches on the oil pan rust. The process took a couple of months. I just power washed and changed a seal. Then the leak would move and I’d change another seal and wash again. Rinse repeat till no more leaks.

Be warned that if you have any anodizing left on engine components, Purple Power will destroy it. It will also leave your aluminum prone to white corrosion deposits. I've had better luck with Simple Green, it doesn't seem to be as caustic.

L.A. Awesome at dollar stores works well and is cheap. Spray all over, brush, hose, repeat. I have also used diesel, as gasoline evaporates too fast, plus diesel is safer. I recently had the transmission out of our Chrysler minvan and used Awesome plus a little power washer. That is best for getting in crevasses like the webs on the upper oil pan. I've used purple stuff but doesn't seem to work any better.