Power washing engine bay

Hi guys,

I have to clear ALOT of oil out of my engine bay and around the engine. I have been considering power washing the bay and covering electronics. What's the general opinion on this? Is it safer to do it all by hand with brake cleaner?

This is how I would clean an engine bay. Ensure major electrical items, open air filters etc are covered up. Just use common sense. Lightly spray the bay in a little water, this can be done with the jetwash off, you do not need water going all over the engine at full pelt from a powerful jetwash. Then use a selection of brushes and either an All Purpose Cleaner or something like Autoglym Engine & Machine cleaner and carefully clean everything. Do a section and then rinse again with the jetwash off. You cannot get away from the fact that some good old fashioned elbow grease is what’s needed here. Once everything has been cleaned, apply Aerospace 303 (designed to protect rubbers and plastics) to everything whilst it is all still wet. Do not follow the instructions on the bottle as it tells you to apply it dry and then buff off the residue. This is wrong! It is a water based product, there is absolutely no point in applying it and then buffing half of it off, it’s a waste. Just apply it to a wet bay and it will slowly fall over all surfaces and leave a lovely finish. Shut the bonnet and leave for 4-5 hours. Once dry just wipe off any paintwork or metals, don’t touch the rubbers or plastics.

This is how I would clean an engine bay. Ensure major electrical items, open air filters etc are covered up. Just use common sense. Lightly spray the bay in a little water, this can be done with the jetwash off, you do not need water going all over the engine at full pelt from a powerful jetwash. Then use a selection of brushes and either an All Purpose Cleaner or something like Autoglym Engine & Machine cleaner and carefully clean everything. Do a section and then rinse again with the jetwash off. You cannot get away from the fact that some good old fashioned elbow grease is what’s needed here. Once everything has been cleaned, apply Aerospace 303 (designed to protect rubbers and plastics) to everything whilst it is all still wet. Do not follow the instructions on the bottle as it tells you to apply it dry and then buff off the residue. This is wrong! It is a water based product, there is absolutely no point in applying it and then buffing half of it off, it’s a waste. Just apply it to a wet bay and it will slowly fall over all surfaces and leave a lovely finish. Shut the bonnet and leave for 4-5 hours. Once dry just wipe off any paintwork or metals, don’t touch the rubbers or plastics.

Is that 303 stuff the same as ACF50? I just purchased some of that to do the underside of the car

No, totally different product.

No, totally different product.

Ah ok good thing I checked haha . Thanks for the tips though

Your welcome

I've never bothered covering any parts other than exposed air filters on some cars or carburettor intakes when doing an engine wash down. I've just warmed the engine (not hot but hand warm) then sprayed away. Always done on a warm day and left bonnet up to dry which usually only takes no more than an hour or so with a good breeze. For serious grime around the sump or leaking oil gaskets I spray on some diesel an hour or so before spray washing and that tends to soften up most oil or grease derived deposits. Never had any issues with starting after doing things this way.

Its not something I'd ever contemplate doing in the middle of Winter.

I take my time covering all electrical connectors with masking tape and putting bags over the air filter and battery etc .. then I cover the engine in engine degreaser using a brush to work it in. Then I steam wash the engine from a distance

This is how I would clean an engine bay. Ensure major electrical items, open air filters etc are covered up. Just use common sense. Lightly spray the bay in a little water, this can be done with the jetwash off, you do not need water going all over the engine at full pelt from a powerful jetwash. Then use a selection of brushes and either an All Purpose Cleaner or something like Autoglym Engine & Machine cleaner and carefully clean everything. Do a section and then rinse again with the jetwash off. You cannot get away from the fact that some good old fashioned elbow grease is what’s needed here. Once everything has been cleaned, apply Aerospace 303 (designed to protect rubbers and plastics) to everything whilst it is all still wet. Do not follow the instructions on the bottle as it tells you to apply it dry and then buff off the residue. This is wrong! It is a water based product, there is absolutely no point in applying it and then buffing half of it off, it’s a waste. Just apply it to a wet bay and it will slowly fall over all surfaces and leave a lovely finish. Shut the bonnet and leave for 4-5 hours. Once dry just wipe off any paintwork or metals, don’t touch the rubbers or plastics.

Great advice. Thank you

For the guys with the NA engines, don't spray too much on the intake/valve covers. The water drips onto the cilinder head and will damage the sparkplugs and leads over time.

What Id do is - Power wash the engine bay. Done it hundreds of times with zero issues, only thing I was wary of was blasting the alternator