Q: Cleaning Engine and Engine Compartment

The other day I had to do some minor work on my 1997 Outback. While washing my hands from the work I began to wonder what it would take to clean my engine, engine compartment, and all the various things inside. I've heard of several ways to do this:

 

• Steam Cleaning: From what I've been able to determine steam cleaning is the tried and true way to cleaning the gunk off of an engine. However its use appears to have fallen out in favor due to an increased use of electronics
  
• Engine De-greasers: These tend to be spray on, wait a few minutes, and then wash off with low pressure water. Seems simple enough but there is still the risk of damage to electrical devices.
  
• Hand Cleaning: This one should need no explanation.
  

I've researched this on the Internet and it seems there's no consistent answer. Some people recommend steam cleaning, others are against it. I didn't see any real objection to engine de-greasers except by those who think hand cleaning is the only appropriate way. I've watched Youtube videos of both (especially the Gunk manufacturer videos) and everything seemed to work out fine. However what might the long term impact of spraying everything with water (even if low pressure)?

 

 

Should I even embark on this? Or should I take it to someone who has experience with this? If I were to steam clean I'd need to buy a steam cleaner...might be just as cost effective to pay someone. Then there's where to do this. I'd need to find a location with the appropriate resources to capture everything that comes off.

I detail my engine compartment at least every other Saturday. I only use degreaser about once a month but when I do, i spray it everywhere. Of course I don't spray directly on sensors, the alternator, or the fuse box but I don't concern myself with a little overspray. Same thing with the rinse. I hose it all down thoroughly so you don't leave any degreaser on. Before I start it, I'll blow as many connectors and sensors with compressed air that I can reach. Our H4's don't use a distributor so there shouldn't be too much concern about it not starting. As far as hurting something, the connectors should be water tight. So long as they're in good shape, you should be fine. You know your car better than anyone else so use your best judgment.

I've only done engine and engine bay cleaning four times and I've just used the degreaser method. Before spraying the degreaser though I put a plastic bag around any kind of electrical thingie, to include wrapping the battery and alternator. Spray degreaser, agitate where needed, let sit, then wash off with garden hose. Repeated as necessay. Worked fine each time. Done on cars of varying age and milage, the oldest being my Leggy, and cars turned out fine each time. Knock on wood.

Thanks for the feedback guys. Anyone have any comments on steam cleaning?

I did try my own steam cleaning...sort of. I have one of those Shark hand held steam cleaner things, so I tried using the "steam blaster" attachment to try to steam blast away the grime and oil and stuff. Was taking way too long, so I went with the degreaser method :-)

 

But then again, the Shark isn't a professional steam cleaning device.

Hello;

I generally let the motor warmup and use a foamy motor cleaner product. Let this set for a half hour and clean off with a pressure washer. Have used a steam cleaner in the past but can raise hell on paint and coatings that are in place for corrosion resistance, Steven.

Thanks everyone for your feedback. It appears the de-greaser is the preferred method.

Simply Green is my go to for engine cleaning. Spray on, let it sit for 5 minutes wash it off. Easy Peasy.

Use cheap brake cleaner! It's like a mini power washer that just eats grim away. And dries in seconds. Get a few cans.

A good steamer will blast off whatever you need it to, but most consumer ones won't have enough power. You'll be better off with engine degreaser and low pressure water. Warm engine, not hot. Avoid electronics, modern connectors/sensors are generally pretty well sealed but it's best to be safe. Presoak, apply product, agitate with brushes to break everything loose, flush off with low pressure water, dry.

Thanks guys. I just bought a 2005 Outback which required some troubleshooting. To start the troubleshooting I ended up cleaning part of the engine. Bought some Gunk Original, sprayed it one, waited 15 minutes, and washed it off with low pressure. Worked like a charm. If I were detailing the engine this would be a way to go.