Anybody clean their engine compartment / undercarriage?

[JacobFerguson]

I'm getting ready to do some maintenance to my 2003 Thomas Saf-T-Liner HDX with CAT 3126 and wouldn't mind finishing off with a nice little engine detail so I feel like I've accomplished something at the end. Anyone ever clean your engine bay and/or undercarriage? Any advice: steam clean, power wash, nothing fancy?

I've got lots of normal rust and dirt/grime, paint chipping off, and an oily mess under the pan from a leak, etc. Average filth.

[ewo1]

Originally Posted by JacobFerguson

I'm getting ready to do some maintenance to my 2003 Thomas Saf-T-Liner HDX with CAT 3126 and wouldn't mind finishing off with a nice little engine detail so I feel like I've accomplished something at the end. Anyone ever clean your engine bay and/or undercarriage? Any advice: steam clean, power wash, nothing fancy?

I've got lots of normal rust and dirt/grime, paint chipping off, and an oily mess under the pan from a leak, etc. Average filth.

Attachment 64950

Take a look at dry ice bLasting! Won’t harm any wires or connectors, no dry abrasive media to cleanup, only the small amount of dirt and grease that falls off when it freezes, no water waste!

I do dry sandblasting and also wet slurry blasting for a living now. Both these methods, I would never do in the engine compartment. Pressure washing is not good for the connectors or alternator. Abrasive blasting will remove paint and leave you with unprotected metal that will begin to rust in a very short amount of time.

Dry ice is the safest and most efficient way to go, but it does not come cheap!

If you got extra time on your hand and want to make the engine compartment look nice, I would suggest removing all the metal tubing, clean and repaint with Cerakote.
I would use high temp cerakote on the turbo housing and exhaust manifold!

It is really easy to apply, you could use a cheap HF airbrush kit to apply!

[fo4imtippin]

I have power washed mine 3 times. I stayed away from the ECU areas and plug connectors. I had years of oil leaks that I was fixing and wanted to track them all down. After power washing and driving I found my transmission hoses leaked, my steering box and oil pan gasket.


Also, since I was unbolting seat tracks, replacing wires/hoses, figured I might as well start clean. Pluto plastic bag over any electronics (and controller, transmission plugs, etc). I bought a short wand, so I could get close and accurate. I blasted my greasy brakes, air dryer, fuel tank. Don't use high pressure on wire looms or near plugs. If you think you might damage something, scrub with a wire brush and blow it off.


For stubborn stains, I used purple power and let it work for 15 minutes. It can etc aluminum, so rinse it off within 60 minutes.. anyway, good luck to you! Hope yours isn't parked in gravel like mine.

[Albatross]

I've cleaned the engines/bays on a number of vehicles, but I'd never take a power washer to them unless the bay is empty and I'm prepping for a repaint, or I'm getting ready to spend a lot of money and do some major overhauls.

Using a regular degreaser (Purple Power!) spray bottle and a regular hose spray attachment should get you looking pretty enough if you're not ready to pull a motor and rebuild. Grab some tooth brushes, nylon bristles, and rags if you really want to do some light detail work.

Obviously be careful around your hoses, hose connections, and especially electronics. And pull your batteries if you can.

[fo4imtippin]

Originally Posted by Albatross

I've cleaned the engines/bays on a number of vehicles, but I'd never take a power washer to them unless the bay is empty and I'm prepping for a repaint, or I'm getting ready to spend a lot of money and do some major overhauls.

Using a regular degreaser (Purple Power!) spray bottle and a regular hose spray attachment should get you looking pretty enough if you're not ready to pull a motor and rebuild. Grab some tooth brushes, nylon bristles, and rags if you really want to do some light detail work.

Obviously be careful around your hoses, hose connections, and especially electronics. And pull your batteries if you can.

I agree. I wouldn't touch the topside of the engine with pressure. Stay below the oil pan from the bottom.

[Booyah45828]

Yup.

We do it yearly before annual maintenance/inspection.

Superclean(concentrated) in a foam cannon applied and left sitting for half an hour. Then a hot pressure washer to hose it off. Grime and oil will melt off, mostly due to the hot pressure washer. Keep a foot plus away from all connectors and stuff and you won't have to worry about damaging anything.

We do this bumper to bumper underneath, cleaning the frame, axles, transmissions, engines, fuel tanks, essentially everything. Makes the inspection a lot easier, but anything that is bare metal afterwards will rust quickly. So be prepared to treat/spray paint stuff.

[JacobFerguson]

Interesting stuff, thanks guys. What do you all use to polish up the rust / repaint?

[mmoore6856]

use a steam cleaner not a power washer then paint it. heat is the answer for tar,oil and grease not preasure

[Booyah45828]

I agree that the heat is the answer, but most steam cleaners won't have enough water volume to actually wash the crud away once it melts it. Then again, most hot pressure washers aren't cheap......

[Albatross]

Depends on how bad the rust is, and on what kind of steel/metal.

Repainting--especially on a skoolie, which is generally initially painted using stuff like 2-part epoxy utility paints--is a whole 'nother animal.

Tractor/implement enamel is generally a good choice, as is bedliner, a recent favorite. Otherwise, you generally have to take it all the way to bare metal to get a suitable primer on it, and then you're stuck with some kind of generic auto finish which tends to be a little soft and brittle for what most people want to use it for.

[Rwnielsen]

Get some good degreaser and a parts brush from Amazon. Hose it of. Pressure washers put water in places it should never be, bearings, connectors etc..

[JacobFerguson]

Ok, thanks everybody.

[Meathead]

Meh. Looks clean enf to me [emoji41]

Ain’t gonna make it run any better [emoji1743]

[emoji3522]Dave

[JacobFerguson]

That's consistently been one voice on my shoulder haha - like what's the point, I know. The other voice says, "Clean it, it *might* actually make things run better - or at least motivate you to keep the bus maintained and in good shape."

It's a diesel school bus, hmmm...

[JacobFerguson]

Well good news is I got it looking *slightly* better than it did before, bad news is the engine won't start now haha, which was basically my biggest fear going in.

Ay yai yai, I could've swore I took pains to cover stuff up and do it right, but apparently though I am incompetent or something. For one I forgot to disconnect the batteries because I had just done so to service the air dryer cartridge and then must have reconnected them. Also I forgot to cover the starter and ecm, but I did cover the other electronic components, control box, and alternator with tape and plastic but didn't do the greatest job apparently because some of the connectors were slightly wet.

Hmm, let's see... I liberally degreased a lot of stuff, also blow dried (with leaf blower) *gently* afterwards. Now it won't crank. Voltage reading fine at dash, not sure if starter is clicking because it's 40 feet away in my rear engine. Gonna check a lot of things tomorrow. I'm on Quora, Reddit, and JustAnswer trying to get someone to help me figure it out. Might as well post at the place where it all started from too, see if any skoolie people have ever been through this with theirs. I just wanted to clean the engine!

Thanks a lot for any help from anyone...

[mmoore6856]

The clicking is a loose or corroded connection if you had the cables off start there

[mmoore6856]

i drive a tractor trailer and every week or so i wash my truck. every time they raise the hood and wash the engine also. in the last 2 or 3 million miles the washing has had no ill effect on the engine. they wash all engines as a clean engine does run cooler. they do not wrap anything but they do stay a bit further from it with the wand. maybe they know how to do it

[JacobFerguson]

Originally Posted by mmoore6856

i drive a tractor trailer and every week or so i wash my truck. every time they raise the hood and wash the engine also. in the last 2 or 3 million miles the washing has had no ill effect on the engine. they wash all engines as a clean engine does run cooler. they do not wrap anything but they do stay a bit further from it with the wand. maybe they know how to do it

I've had so many people tell me this lately. I don't know how I messed it up haha. It might have something to do with the fact that I forgot to disconnect batteries before washing the engine, and I bet virtually everyone else does that.

[Booyah45828]

We don't disconnect the batteries, and have never had an issue. We also don't spray directly on electrical panels, ecms, or anything else sensitive like that.

Who knows what you did. It might have been caused by spraying, or it might just be your luck.

[JacobFerguson]

Well I've narrowed down the issue significantly. No power is getting to the starter signal wire when trying to crank, so I traced the starter signal wire to a small solenoid next to my control box in the engine bay where the fuses/relays are. Touched a pair of pliers to the top terminals of the solenoid to connect the circuit and it jumps the starter, engine runs fine. Not sure why all of a sudden no power is getting to the starter or to this solenoid though (I tested for power to the solenoid with multimeter).



Does anybody know of any other safety features that would prevent the engine from starting? My e-hatches are closed, engine bay closed, transmission in neutral, etc. Anything else I might not yet know of???

Again this is 2003 Thomas Saf-T-Liner HDX