Seeking advice on cleaning grime from suspension and underbody

2004 C2, 67k miles when I bought it. All things considered it's a fairly clean car, but normal grime on suspension and motor. Being in the North East I have a few month layup period right around the corner to toil away. Is there any better method to clean this grime off than hand scrubbing with a harsh cleaner. Anyone have any experience with steam? Any particular cleaner that works like "magic" simple green and purple power seem to eventually cut it. On the aluminum parts that are exposed to my normal wash Sonax wheel cleaner seems to have worked well. I am unsure about how Sonax will effect rubber and plastic parts so have held off from going wild with that.

Check out the 928 forum. The answer you seek resides there. They are experts at exactly that. When I bought my 928 a couple of years ago, I spent about 20 hours cleaning 25+ years of grime off the engine and undercarriage. And it is still filthy. You'll want several wire brushes of various sizes and a lift. Be sure to wear goggles.

Search for a Cryo Detailing service in your area. They use dry ice to blast road gunk off suspension, engine, underbody. A bit costly, in my area TuneRS has the equipment and has brought many cars back to newish standards. Safe on all parts even rubber.

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If you have the $$ to spend, this is absolutely the ticket. Note that it IS more abrasive than the YouTube videos (where the guy blasts the fender on a Ferrari for a while *shudder*) suggest, but the results are amazing.

for aluminium suspension and enging you can start with mineral spirits, tar and grease remover, parts cleaning brushes, scotch brite pads, light metal brishes, hard brushes will make scratch marks. after that you can use engine degreaser, after that, simple green/ soaps

I'd caution about Simple Green - the regular green stuff. While it probably won't be an issue other than appearance, Simple Green has been proven to be corrosive to aluminum. As a result, there is now an Aviation Simple Green that is safe for aluminum. Like I inferred, there is a difference between an aluminum control arm vs relatively thin (.025-.032") airplane skins, there will probably be some affect. It may just be an appearance issue, but unless you know where and how thick any aluminum may be on our chassis, I'd say to not use the regular stuff.

The crud on my 928 was so bad I really felt like it had its own soul. A very evil one. I got to the point where I was ready to use a flamethrower. But then I thought it might leave a mark on my 4 post lift.

Do not use purple power. It's highly alkaline and will ruin the aluminum parts. Just use this with a hand brush and lots of elbow grease. https://www.amazon.com/Simple-Green-.../dp/B001VXU7OE "Product Description: water‐based formula for use of cleaning and degreasing engines, aircraft, vehicles, metals, plastics, high‐tech alloys, rubber, vinyl, hoses, gaskets, paint finishes and parts. Rinses residue‐free for ease of use and protection of structures and finishes. Oil and grease break back out of solution for easy disposal in clarifiers and Oil Water. - Safe on metal - Safe on plastic - Safe on rubber - Meets BOEING D6-17487P - Readily biodegradable - Rinses residue free - Additional aviation spec data available - No added color or fragrance - VOC compliant"

This is on my wish list as well, but I believe they are in FL which too far for me. Videos of the process are remarkable, but it is not cheap. Curious if there are shops elsewhere who provide this service.

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The guys at TuneRs always joke that they can remove 20 lbs of gunk from underneath your car. Sounds like you could've dropped 30?

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No cheap at all, 1000-1500 depending on vehicle. Time consuming im sure. Prices may have changed since I inquired. That machine makes A LOT of noise but the results are outstanding. Take a look on cryodetail.com

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I don't have a dog in this fight, but it looks to me like fairly simple (albeit labor-intensive) media blasting using dry ice as the abrasive medium.

It is labor-intensive and you can burn through a CRAPLOAD of medium. There's a gent in Off Topic who was evaluating the system and was floored by how much dry ice he was consuming.

The works toilet bowl cleaner is excellent t stuff, just make sure you wash it down. Don't get it on rubber or plastic parts though.

I dont know about simple green doing any harm, ive used it on everything since it was invented

I just did this last week. I put the car up on ramps and shot the bottom with Gunk Engine Degreaser Gel and then put on gloves and scrubbed with a stiff nylon brush. It did a great job of removing grease, dirt, and cosmolene. You Tube Just make sure that you put it on a cold motor, avoid getting it on the paint, and then rinse really well. It makes a mess but the grease is suspended in the cleaner and will rinse off of the driveway.

Thank you all. I googled and the only dry ice business in my area seems to specialize in the oil &a gas industry. Really looking for it to be my project rather than a money outlay. Simple green I have been using forever, I agree with some aluminum being sensitive, but I have only had issue if aluminum has a long constant exposure to it. Really simple green is not making a dent of what is gunked up one the car. I had some reservation with purple power as it has a longer and bolder list of warnings. I contemplated purchasing a steam cleaner, thought if it was a solid solution for this it could be a good long term tool to own. I'll follow up with results and pictures, will be another few weeks before the salt is spread on roads. I had good luckk with gunk on an old Audi 90 years ago, may go that route. I just remember the smell of it lingering in the garage and on the car forever.

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I'm on another forum where a 928 owner had his own steam cleaner. Here is the before: And here is the after: He says that he used Simple Green in conjunction with the steam cleaner. Actually, there's a thread here on Rennlist by the owner. He says the unit is a Daimer 200.

You Tube

GOOGONE https://rennlist.com/forums/996-foru...-eng-tran.html

I very carefully use a degreaser and a pressure washer.Works on engine and undercarriage.