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What's the best way to clean off under-gunk?

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M

MGNoir

Jedi Hopeful
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I've got a fair buildup of road grime and oil around the suspension and other areas. I'd like to really clean it all off to get a better sense of how things are. Any advice on how best to do this, or perhaps even how NOT to do this? For example, garden hose with spray nozzle. Good move or bad?
 
I use a $100 pressure washer to clean the bottom of my cars.

Gently around any wires, fuel lines, brakes hoses, steering-rack bellows, etc.

But the rest of it, I hold the pressure wand close so it gets full force. I always re-grease any grease fittings afterwards. It can help if you apply some spray de-greaser first and let it sit for a while.
 
I took a can of Gunk engine cleaner to the engine recently and the wheel wells and anywhere I could think of - worked pretty good.
 
Second to Nial's cheap pressure washer and JPS' Gunk. You can usually find some new or rebuilt bottom-end electric pressure washers at Harbor Freight, Northern Tool, and other discount outlets. Often name brand type stuff, and some others. Not an expensive investment ($60-100) and the lower pressure models (1200 -1400) are great for general underside and engine bay cleaning. I keep one hooked up to the shop hot water line and wash the car mechanicals and engine bay with it after a race. Do the wheels and tires as well. Use Gunk, Wal-mart brand or generic auto-parts store brand degreaser. A CAUTION!!!! Ran into some cans of Wal-Mart Tech brand degreaser that had a high percentage of Naptha in them. Obviously from China. The same place that brought you the quality gypsum board and lead painted toys. Anyway, it works really good at removing paint. Took a good bit of it off the bottom of the car and the axle housing. So, now I use the Advance brand or Gunk for anything painted.

Anyway, what I would do is to jack the car up in the sun, remove the wheels and let it sit and get warm. Not too much of a problem in South Carolina in July. After about an hour, spray everything down with the degreaser and let sit for about 30 minutes. Then take the pressure washer connected to a hot water source and spray it all off. I've used the laundry room hot water line and the hot water heater drain valve before, depending upon my location. If you can't stand the smell of Gunk or the degreasers, then full strength 409, Purple Power, Greased Lightning or Simple Green will work almost as good. May take a couple of treatments. I use Oven cleaner on dis-assembled engine parts. Do the same thing, sit them in the sun or place in the shop oven and warm up. Spray with oven cleaner. Let sit for 15 -30 minutes, then brush/scrub with an old toothbrush or the like and then wash and dry. Nice and clean!!!

Use proper protective equipment when doing this. Filter masks with the oven cleaner and nitrile gloves. Don't forget the safety glasses as well. After this fun, don't be upset if the wife asks you to take your clothes off outside or in the laundry room.

HTH
Mike Miller
 
I look at the underside of my LBC as a living organism that manages itself, as old oil & gunk drips off new oil & gunk is there to replace it!, almost self healing in a way...
 
Sometimes the grease and gunk can be a good thing. In the process of doing the clutch in my MG, EVERYTHING was covered in oil/grease/grime....SUPER messy BUT nothing was frozen or rusted and all nuts/bolts came out without a fuss! :smile:
 
Hap:

Now-Now, you know I do too clean it! I just don't put any new paint on it other than what comes out of a spray can. And, only on the sand/grit blasted front. Black racer's tape can fix a lot of busted fiberglass and cover a lot of chipped/missing paint. 50 feet away and 100 mph, no one can see the difference. I figure if I strip off all the coats of paint on the car and the cracked Bondo, it would lose about 35 pounds. Then, I'd just be adding lead back to meet minimum weight.

I would have fit right in with the Team Turtle guys up in the DC area. Never did end up on my roof, but sure bounced one off the roll bar at Sebring back in '81. Almost have a black version of their blue cars.

Take care!
Mike
 
I used Dawn Power Degreaser with good results. Only place I could consistently find the product was at an Ace Hardware store. Spray it on and let it sit for about 15 minutes. Wear gloves and protective eye-gear and go to it with a paint scraper and tooth brush to get the first amount of crud off, then use the green scuff pads with a bucket of water to remove the final residue. My choice was to use the bed liner product as an undercoat. It was a messy job but I was happy with the results.
 
Silverghost said:
Sometimes the grease and gunk can be a good thing. In the process of doing the clutch in my MG, EVERYTHING was covered in oil/grease/grime....SUPER messy BUT nothing was frozen or rusted and all nuts/bolts came out without a fuss! :smile:
Click to expand...

Really agree with this thinking, unless you are prepping to paint.

free rust prevention
 
I use a scrapper and removed the bulk of the stuff without cleaner. Then I use super-clean, warm water and a bunch of chip brushes to get into nooks and crannies. I stay away from power washers as they tend to push water into places I don't want it. This is time consuming but it comes out like new and can be painted after a quick towel dry.
 
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