Washing the Engine Compartment

[Dirty Harry]

It's been a couple years and several thousand miles since I freshened the engine and cleaned up the engine bay. It's pretty dusty in there again, and I'd like to wash the engine and surrounding area for some hood-up time this summer.

Anybody got some good tips for products or procedures to use to get things looking good again?

[Bernica]

Well first, never spray water in there! Start with an air hose to blow off loose stuff. Then, just tedious hand work. No real easy way that I know of other than hiring a detailer and paying him/her to do the same thing.
My 2 c

[jhv48]

What he said times 10.

I thought I had covered all the electrics with plastic and proceeded to spray a degreaser all over the engine compartment and then proceeded to lightly spray water on the engine to rinse off the degreaser.

BAD MOVE! I must not have covered the starter solenoid well enough as water got on it and shorted out the solenoid causing the starter to engage and try and start the engine. Since it was parked and in first gear, as the starter turned, the car lurched forward and hit a cement planter that was in my drive way, and since the connection was still wet, it kept pushing the car into the planter until the solenoid finally gave out and the starter quit.

Result? $17,000 in fiberglass damage and a month in the body shop! Also, battery and solenoid were shot. So use a rag or, if you're going to use anything wet, disconnect the battery and don't even think of reconnecting it until the entire compartment is dry.

[patrickt]

I haven't washed an engine compartment in a long, long time... and I've never done it to my Cobra at all. But, any time I did it in the past I always had sensor or wiring/electrical problems after I did it. Plus, it would leave a stain on whatever was under the engine compartment (I would use the spray "Engine Brite" type grease cutter.) Now, when I "tidy up" the engine compartment in the Cobra, I use a rag and 409 spray cleaner and do it by hand. I love 409 -- it's my favorite cleaner for the car (I don't use it on the body though).

[1795]

I have seen someone use Dawn dish detergent on a rag. Same stuff they use to get oil off of waterfowl in an oil spill. What ever you use, spray it on a rag then apply. Tough and tedious work.

[Joe's Garage]

Originally Posted by jhv48

What he said times 10.

I thought I had covered all the electrics with plastic and proceeded to spray a degreaser all over the engine compartment and then proceeded to lightly spray water on the engine to rinse off the degreaser.

BAD MOVE! I must not have covered the starter solenoid well enough as water got on it and shorted out the solenoid causing the starter to engage and try and start the engine. Since it was parked and in first gear, as the starter turned, the car lurched forward and hit a cement planter that was in my drive way, and since the connection was still wet, it kept pushing the car into the planter until the solenoid finally gave out and the starter quit.

Result? $17,000 in fiberglass damage and a month in the body shop! Also, battery and solenoid were shot. So use a rag or, if you're going to use anything wet, disconnect the battery and don't even think of reconnecting it until the entire compartment is dry.

Wow, that's one helluva lesson. I have taken various classic cars to a motor steam clean service but the golden rule they followed was to let it sit in the sun with hood up for 4 hours before returning it back to you. I never had a problem, not even with cars still using points, condenser and much of the original wiring.

[Steve Gallegos]

I used brake cleaner. I put news paper under the car, spray close, it sprays in a stream not a wide spray,to the block from above and below, sometimes I put it on a lift to spray below. The dirt, oil and grease just drips off I then use a rag to clean off the rest.

[1795]

Just be careful with brake cleaner around rubber hoses and other things that may be rubber, such as spark plug wires and bushings. It will deteriorate them.

[CHANMADD]

I've used a pressure washer for years...

[Bernica]

Originally Posted by CHANMADD

I've used a pressure washer for years...

I have also used Gunk and a pressure washer on many cars over the years. I just won't do it on the Cobra!

[patrickt]

Originally Posted by jhv48

I must not have covered the starter solenoid well enough as water got on it and shorted out the solenoid causing the starter to engage and try and start the engine.

You know, I have, occasionally, when I was doing something with the engine, reached in to the cockpit from outside the car and started it up -- thinking afterwards, "damn, I'm glad it was in neutral." I have also, from time to time, absent mindedly left the ignition key in the car -- tempting someone to reach in and turn the key -- and I usually leave the car in gear. When I blew my clutch out years ago out in the middle of nowhere I drove the car up on to the flatbed using nothing more than the old stock Ford monster 50 lb. starter motor -- so I know that thing can power the Cobra with no problem whatsoever. I have toyed with the idea of making use of the TKO's neutral safety switch. But, I don't know if even a NSS would stop a water short to the solenoid.

[DanEC]

Originally Posted by CHANMADD

I've used a pressure washer for years...

I was waiting for someone to break the ice. I've washed engine bays down in most of my cars since probably 1969 - in car washes and with a hose. I haven't used my pressure washer but with a wide pattern I would not be afraid to. The worst thing that ever happened was a wet distributor cap. Learned to spray them inside with WD-40 at an early age. That being said I don't wash down either my ERA or my 66 Corvette engine bay since I restored it. Neither one gets enough miles to need to do more than wipe them down periodically - but if I did put a lot of miles on them I would tape plastic bags over the distributor and air cleaners, spray the area with a diluted mix of Simple Green and water, use a soft bristle paint brush on any especially grimy areas, rinse with water out of a garden hose and use compressed air or my leaf blower to blow it down before drying with towels. I then start the motor and let engine heat and fan air finish drying out all the crevices.

[Tim7139]

This is fairly straight forward with proper care.
First, cover obvious problem areas like bare electrical connections, carb intake, distributor and control box.
Get a container of S100 motorcycle wash and LIGHTLY spray it in a cool engine compartment, as per directions.
Follow up with a light spray to wash off.
This last part is a huge improvement......if you have access to a compressor, crank it up to 100 psi or so and with a blow gun, hopefully with an extension, blow all residual moisture out until dry.
Using this method will get it pretty clean without water spots.

[mdross1]

I must be one of the lucky ones have always washed all engine compartments using garden hose to rinse everything off then compressed air with 2' long 3/8" brake line extension to dry everything off. The last several years have changed to Pink Stuff it really works amazingly well.

[Buzz]

Originally Posted by jhv48

What he said times 10.

I thought I had covered all the electrics with plastic and proceeded to spray a degreaser all over the engine compartment and then proceeded to lightly spray water on the engine to rinse off the degreaser.

BAD MOVE! I must not have covered the starter solenoid well enough as water got on it and shorted out the solenoid causing the starter to engage and try and start the engine. Since it was parked and in first gear, as the starter turned, the car lurched forward and hit a cement planter that was in my drive way, and since the connection was still wet, it kept pushing the car into the planter until the solenoid finally gave out and the starter quit.

Result? $17,000 in fiberglass damage and a month in the body shop! Also, battery and solenoid were shot. So use a rag or, if you're going to use anything wet, disconnect the battery and don't even think of reconnecting it until the entire compartment is dry.

Wow - I feel for you, man! What a day that must've been - mishaps like that either make a man blow a gasket or just stand there shaking his head in disbelief.
I've always carefully used degreaser and a hose along with some elbow grease after covering the carb and distributor with plastic, but I never ever thought of something like that happening.

[twobjshelbys]

Originally Posted by jhv48

What he said times 10.

I thought I had covered all the electrics with plastic and proceeded to spray a degreaser all over the engine compartment and then proceeded to lightly spray water on the engine to rinse off the degreaser.

BAD MOVE! I must not have covered the starter solenoid well enough as water got on it and shorted out the solenoid causing the starter to engage and try and start the engine. Since it was parked and in first gear, as the starter turned, the car lurched forward and hit a cement planter that was in my drive way, and since the connection was still wet, it kept pushing the car into the planter until the solenoid finally gave out and the starter quit.

Result? $17,000 in fiberglass damage and a month in the body shop! Also, battery and solenoid were shot. So use a rag or, if you're going to use anything wet, disconnect the battery and don't even think of reconnecting it until the entire compartment is dry.

I was just catching up and saw this. My first comment was going to be:

Whatever you do, first, disconnect the battery.

I've never washed the compartment on my sports cars, but I did on my truck and Jeep. Again, first thing is to disconnect the battery. Then I used a lawn garden sprayer (exactly the one I use to spray fertilizer) filled with simple green. It's "no pressure" and gives a good spray. Let it sit for a while (not so long that the soap dries out) Then I rinse using the same sprayer and use a bottle brush on tight spots to try to loosen as much as I could. repeat the degreaser/rinse if needed. After that is all done, I used compressed air to get all of the remaining water off. Let it dry for a while (in Colorado/Nevada that is in the sun, so things warm up and dry quickly) and then reconnect the battery.

[DanEC]

Disconnecting the battery first is an excellent suggestion, although I've never before heard of washing an engine causing a starter motor short and operate. But, I guess it's happened at least once now.

[Bernica]

If it is a highly detailed engine and compartment, there are folks out there that do it for a living like these guys. Of course it's probably not cheap!...

Undercarriage Steamcleaning,Detailing - Doctor Detail, Costa Mesa,CA - About Doctor Detail

[BAsque1]

Originally Posted by Dirty Harry

It's been a couple years and several thousand miles since I freshened the engine and cleaned up the engine bay. It's pretty dusty in there again, and I'd like to wash the engine and surrounding area for some hood-up time this summer.

Anybody got some good tips for products or procedures to use to get things looking good again?

I was at a car show last year where a guy was demonstrating steam cleaning, it was great and without any harm to any electrical or electronics components, he did my Range Rover and I could not be happier. You might want to consider that avenue.

[Dirty Harry]

Thanks, everyone, for your responses. There seems to be a bit diversity of opinion as to the best way to rid oneself of a dusty engine compartment. When my electric fan kicks in and I'm on a gravel parking lot or some place like that, I seem to put a light layer of dust on everything. I appreciate your suggestions. Keep 'em coming!