tveltman

What has everyone used to get their engine bays shiny and bright? My covers and intake are due for a refinish, but I like driving the car too much to tear her down now, plus I'm driving x-country in a few days anyway. Before I set off, I'd like to clean up the engine bay to match the shiny rims/exterior. Anyone have recommended products/techniques? I thought about taking it to one of those DY carwash bays and just powerwashing the crap out of it, but I was concerned about electrical components and sensitive old wiring being subjected to high-pressure water. Thanks!

ammonman

Power wash at your own risk. Most strongly advise against it. There is a pretty good article in the latest Panorama about engine cleaning. The recommendation from the article is to cover everything water-sensitive (14 pin connector for example) with foil and/or plastic, then use a pump-up garden sprayer to apply HOT water, then apply detergent (the milder the better) and allow to sit and work. After the working time, rinse using the pump-up sprayer and again, HOT water. After the first go 'round removes the loose surface dirt, repeat and use soft brushes and wooden dowels wrapped in rag to get the stubborn spots. Repeat the rinse with HOT water from the garden sprayer. Continue this process as many times as necessary or until you are satisfied.

I have used many cans of brake cleaner to remove VERY stubborn grease/grime build-up. The hot water and Simple Green type de-greaser from a pump up sprayer combined with some elbow grease has worked pretty well for me so far.

Good Luck.

Mike

Richter12x2

I do a lot of detailed cleaning for painting and restoration, and I've tried Simple Green, spray-on engine degreaser, and others, probably a half-dozen different products designed to degrease engines.

. . . So far the best thing I've found is cheap liquid dishsoap, an old toothbrush, and a rinse with cold water. My wife was cleaning the inside of my wheels for fifteen minutes and not making any progress until I showed her how you take a couple Tablespoons of dishsoap and coat the entire wheel with it, give it 30 seconds, and then wipe it off with a wet rag. Other than the mounting scratches, looks like the day it came out of the showroom.

namasgt

Do not power wash, All the water is going to stay in the valley, and you have sensors there.

No HTwo O

There is a great engine cleaning write-up in the August 2009 Panorama, "The Nitty-Gritty of Engine Cleaning", page #40.

Landseer

I use a lot of WD 40 from a pump sprayer on engine parts, esp. alloy ones.

Also, Gain in hot water, from an insect sprayer. It cuts grease well.

But I'm doing rough cleaning usually, not detailing.

Marine Blue

Do a search under my screen name. I've documented this at least twice I believe including pictures. Probably a couple of years old now but the technique remains the same. Some newer products on the market will make it easier like P21S Total Auto Wash

JWise

As Afshin mentioned, P21S products are good. I've also used Simple Green and gentle brushes with good success. Just make sure you rinse real good, and no power wash.

dr bob

There are some critical connections and sensors/switches that will punish you for getting them wet. Simply, anything that has a wire attached to itt will hate you if you get it wet.

The current Panorama, as mentioned above, has a nice writeup on engine bay cleaning. It's pointed towards the air-cooled crowd for concours when it comes to techniques, but the core ideas are sound. The author suggests that you use P21S auto wash, weak mixture, in a garden sprayer, to do the basic washing. The low velocity from the sprayer minimizes chances of pushing water into sensors and wire connectors. The pH-neutral detergent reduces the risk of later corrosion if in fact some water does get where it shouldn't. Use a garden sprayer with clean water for a rinse too, for the same reasons.

I do a lot of wiping and a relatively tiny amount of washing in the engine bay. Did one wet wash early in my stewardship period and replaced a few sensors as a result. Learned my lesson. Now the harshest chem that gets used in there is an alcohol-based window cleaner (Airway in the blue spraycan from Costco). I sometimes get out a little brake cleaner and spray it on a paper towel for grease/oil, but tend not to use the blast-and-rinse with the spray can as most do. The top of the oil sump on my car seems to catch stuff, so it might get a little Simple Green and a weak garden-hose rinse once in a blue moon. The bottom half of the engine, accessed from below only, gets a similar treatment. Oil sender, starter and alternator get bagged before ay of this process starts.

I use a little of the spray tire foam stuff, on a sponge, for dressing up the black rubber and plastic bits ib the engine bay. Stuff that hides in cavities in the top of thefan support gets a spray of window cleaner at the same time the shop vac is used to pick up the dissolved emulsified crud before it can run someplace else and leave a stain.

Remember that anything that's far from pH neutral will eventually remove tegold-colored cad or zinc plating from hardware. Use ONLY plastic detailing brushes on painted or plated surfaces. It's OK to rinse after any spot treatments. I have distilled water in a spray bottle, used concurrently with the shop vac, to make sure the rinse water doesn't get loose where it shouldn't.

Compressed air can be a helper if it's used at low velocities, so long as you don't end up just redistributing any mess with it. Blowing stuff from where you can see it to where you can't isn't a valid solution IMHO.

Good luck with your project!

nsantolick

RE: Sensors - Assuming the battery is disconnected, and the car will sit in the sun for a few months afterwards, can sensors STILL be damaged from an intensive cleaning, under those conditions?

I couldn't find much on this a while back, and did just that to my Maserati Biturbo. It's known to be very sensitive to water-damaged sensors, and they're not in good places to begin with...

The car was filthy enough though, that I thought I'd try it. The water has been visibly gone for 3-4 months now, at least. I'm about to start tinkering with it again soon. I'll post my results, BUT, if anyone cares to speculate, I'd love to hear what you have to say...

With that car, I used a whole case of spray degreaser and spent the whole day with a pressure washer and even a steam gun that jewelers use to clean jewelery. (~70PSI steam)

I love that this thread came up. I washed the bejesus out of my S4 a few weeks back, but haven't yet done the engine/undercarriage. I was actually searching for this subject recently. : )










Nick - 89S4

nsantolick

Whoopsie - last message came in while I was posting mine... Thanks... : )

tveltman

This is great advice. I will try to do this tomorrow and post before/after pics (assuming my camera will hold a charge). Thanks!

dr bob

Nick--

Two concerns on your technique.

First is that there is/was residue from cleaner forced into sensors and connectors. Most degreasers are mildly caustic, some are mild acids. Purple is caustic, orange is acid, for instance. Labels will tell you a lot. If they say don't get it in your eyes, it's a sign that electrical connectors will suffer. Most solvent-based engine cleaners, like Gunk, leave a film of grease until they are somehow degreased with something else. Anyway, the water and the acid or caustic get washed INTO wire connector and sensors. In your case with the BiTurbo, they've been in there at work for months now, adding an oxide layer between the connector elements. In the sensors, same thing if the solution made it inside. Many cleaners tell you to start with a warm engine. Add cold water to the wash mix and the solution wil be drawn into warm connectors and components. Should you panic? No. Be concerned? probably. Be cautious with this kind of thing? Definitely. Corrosion works in many ways, beyond the direct damage to connectors and sensors. Anything that finds its way into wire, for instance, will eventually haunt you. Nice protected environmnet with nice clean reactive copper sealed ina plastic sleeve. Wire! Haven for the green devils of chloride contamination.

Tony

Pull the motor.

FBIII

I guess ignorance is bliss. I have been using power washing since the days of the twenty-five cent car wash. Now I have a pretty serious pressure washer. Have used it on every 928 and Land Rover I have owned while most have cautioned against it. On occassion something gets wet that may take a couple hours to dry, but I still haven't had any form of electronic catastrophe.