Maybe customers were topping off with the green stuff (silicates precipitating.) Plus, I suggest that no formulations are static, things do change. Dexx is a standard (I believe by GM) and different brands may be and probably are slightly different formulations.:dance:

Pentofrost SE O'Reilly sells it
 

I bought pentofrost SF 1.5L at O'Reillys. Auto-Haus said OK for Boxster.

Here is a topic I have never seen discussed. Has anybody used a 'flush chemical' prior to refilling? I am going to guess the OEM fluid group hasn't. What about the Prestone faithful? Prestone makes a 'flush and cleaner.' Back in the day when the earth was flat, I always used a flush on my cast iron blocks before replacing the anti-freeze.

Most threads/videos speak to flushing once or twice with distilled only.

Yes Porsche coolant is expensive, but really do you want to risk problems for maybe less than $100 difference????

I know that Mercedes has a citric acid flush. If the directions are followed exactly, it works well for breaking down gunk. Some forum posters claim it's not as strong as the Prestone flush, for what it's worth.

Unless you want to replace your water pump, I would suggest against it. We only use flush chemicals in the case of an intermix, other wise just flush it with clear water.

The previous owner of my 01 had an ongoing relationship with a garden hose. When I pulled the engine, I noticed a lot of scale in the water pump housing and other coolant connections to the engine. I'm not going to use a flush chemical, but will (as finances permit) either buy new radiators or have them boiled out at a radiator shop. The replacement engine and new water pump have no scale--the previous owner of my engine did his/her due diligence in that regard.

You have to pull coolant hoses off the front of the engine anyway, it's a good time to evaluate the hard water deposits.

For that matter, one could use white vinegar & distilled water as a flush. Probably a 50/50 mix and drive it for a day would do. The stuff in a coolant system is water & acid soluble, shouldn't be any oily or greasy residue. :cheers:

Thanks for all of the input. Should've thought of vinegar myself. I use vinegar, once a year, on my tank-less water heater. Works great. I am over-due for a coolant flush and fill. I am going to drain the system and see how crusty it is inside and then decide.

Coolant is cheap. Engines are expensive.

You bought a Porsche. Pony up.

There are plenty of Miatas out there.

I replaced several years ago when I replaced my water pump, engine mount, and thermostate. Used the stuff at Walmart for Porsches/German cars. When I added a center S radiator the coolant was fine.

Pretty easy. Porsche uses Glysantin G30 (OAT) for the M96 engines Glysantin / BASF is the OEM supplier for Porsche coolant. So search for an OAT coolant that fits the ingredients of / compatility with Pentosin G30.

G30® | Glysantin®

Glysantin G40 (SiOAT) is not compatible with the engines and definetely not recommended.

If you haven't yet, then visit Pedro's site. Lot's of good info. The attached is specific to your question.

Coolant/Antifreeze

Some people on the other forums say this is the same as the Porsche Bottled product. I been using it for 5 years not issues. Also sold at Advanced Auto.

I've got the 100% certified P-car stuff in mine. Replaced at 95k miles and now have 134K. I'm pretty sure its kept my IMS from failing...it should at $30/gallon.

I used the P-car stuff and figured I'd never have to replace it again. I've kept my car way longer (10 years) than I thought I would as it has been bullet proof and a blast. I've got about 50k miles more to go before I have to address again. No idea what I'll do next time but I'll lean toward the P-car stuff as worring about the IMS is enough for me!

PS. I don't worry about the IMS...my car owes me nothing.