Dex Cool Issues
 

On a 1999 Boxster, I wanted to use Prestone brand Dex-Cool. I have done a lot of searching and I've found that Havoline and Texaco DexCool are acceptable, but I can't find an answer on Prestone's version of DexCool.

Is it alright to use? Is there a better alternative? I can't imagine the two brands being that different, but I would rather be safe than sorry. I already purchased some Prestone Dex Cool, but I can take it back if necessary. All I seem to be able to find in the stores in my area is Prestone's version.

Thanks for the help!

If you'd rather be safe than sorry... go with Havoline or Texaco Dex Cool... I don't understand ... where's the problem ??

Dex Cool
 

My problem is finding the Havoline brand of Dex Cool, it doesn't seem as if the stores in my area carry it, but they all carry Prestone's version.

Also, if the Prestone Dex Cool formulation is indeed different, or has the ability to ruin my cooling system, it would probably be a good issue to clarify for other Boxster owners who may be in the same boat I'm in.

If I really wanted to err on the side of being safe, I would just buy the Porsche brand of coolant for $50 a jug (which is absurd). I was hoping someone on the board would have some extensive knowledge about what coolant brands would be compatible.

ok, I know coolant flavours have been beaten to death on this and other forums. But I gotta ask yet another time.

I have been to every single auto parts store in my area. No one has any of the brands listed on Mike Focke's page or the various other threads.

I can find Prestone Dex Cool. I can not find Havoline or Texaco Dex Cool. Is Prestone Dex Cool the same? Any issue with using it if i do a through flush first?

My local Porsche dealer claims that the *only* time they use Porsche coolant is when they're refilling entire system under warranty work. Else they top it or fill it with generic Prestone. This comment has made me even more leery about taking the boxster in to them. I may have to drive to another dealer that's 2.5 hours away.

I recently flushed and re-filled my coolant when I changed to the LN low temp thermostat. Purchased two gallons of "official" Porsche coolant from Pelican for $33 a piece; not worth risking anything else for pennies, IMO.

Next time, try Sunset Porsche, recent purchases of coolant was in the $24/gal range...........

If you could see the nightmares we have had to deal with that were caused by mixing the OEM coolant with aftermarket stuff (gelled lumps in the cooling system, plugged radiators, etc.), as well as the service bills they caused, you would view the use of the OEM coolant as cheap insurance…………

Prestone web site...
 

They claim to be Porsche approved and when I called they claimed to be the OEM provider. Said Dex Cool is fine and all the same formulations.

In any event, I would just do the flush and refill procedure and not sweat it that much. The problems, as far as I can tell come from mixing different coolant types, having the wrong proportions, or not using distilled water.

And I can tell you, from a direct conversation with a Porsche zone rep, that Porsche “due to well know issues, does not approve, recommend or condone the use of any coolant other than their own.”

Basically, using any aftermarket coolant is a bit of gamble; you may be fine, or you may not. In the end, it is your car to do with as you please…………..

A little clarification may be needed here.

The issue is mainly one of mixing the various types of coolant out there. It is here where compatibility problems pop up.

Porsche doesn't make anti-freeze, it's made by someone else. Nor is there any special proprietary voo-doo in their formula. It is basically phosphate and silicone free and the reason for this is that the phosphates attack the aluminum in the system and the silicone will mess up the oxygen sensors causing performance issues.

The chemistry is subtle though and that's where some of the incompatibilties happen, especially if you're mixing different fluids (formulations) even though they too may be phosphate/silicone free.

But, if you did a really thorough job of flushing the system, then most any phosphate/silicone free coolant would do the job. But, that could well be the rub.

In order to do such a thorough job, you'd likely have to drain, then fill with distilled water and run the car some miles to pick-up any errant coolant still in the system (obviously this would need to be in non-freezing conditions). In fact, you may need to repeat the process in order be certain all the old coolant was removed. Running for any length of time on pure distilled water would likely take a toll on the waterpump bearing as it uses the coolant as a lubricant between the impeller shaft and the bearing.

So while you could probably get away with it if you prepped the system as described above, it's probably better to simply go with the oem coolant - cheap insurance as someone put it.

But, many of you have used cars, and as such cannot be certain what the PO or PO's dealer may have used in the past. You may have gel forming in the system right now and not even know it. And, be aware that the coolant isn't really 'lifetime' - the 'best' coolants out there are currently 5yr./150k mi. (whichever comes first).

If I were to buy a used Boxster, one of the first things I'd do would be to flush the system and replace the fluid with oem coolant and distilled water, especially if the car were 5 yrs. or older.

One thing I'd like to see coming from Flat 6, LN Eng. or Pedro would be an in-line sleeve with a petcock that could be spliced into the lower radiator hose to make fluid changes easier for DIYers. It could be produced and sold cheaply and I suspect there's a market for it, maybe even rivalling oil filter adapters and mag plugs.

:cheers:

Perhaps it is because we change out coolant on a fair number of cars, but I really do not see the OEM prescribed drain method as all that difficult. Once you have the belly pan section off (about 2-3 min.), everything is out in the open; the engine drain plug, the hoses to the radiators, the thermostat housing, and heater hoses. As for flushing the system, we fabricated some bits from hardware store sourced plastic fittings that allow us to attach a garden hose to either the engine or radiators and back flush the entire system with hot (135F) water. Typically, however, unless the system shows signs of problems, we usually do not flush the system, preferring to thoroughly drain it and then refill under vacuum with a 50/50 premixed OEM coolant and distilled water. Been doing it this way for a lot of years and to date have not had one come back with problems……

All excellent points. But, you're not working on jackstands either...lol

:cheers:

Actually, we have done this on jack stands from time to time, a few times at Porsche gatherings where an "impromptu" tech session was held. We did it to demonstrate for the onlookers how it can be DIY'd. Only real difference was how long it took to get the car up on the stands and being on your back rather than your feet.......still, not that bad of a “backyard” project.

j/k... I have done it on stands and it's not that bad. Like many of the DIY tasks on the Boxster, the difficulty factor is often the product of actually getting to the work rather than the work itself.

But a handy, well placed petcock would make the job much easier, maybe even without having to raise the car at all.

:cheers:

I believe that is what the marketing folks call “mystique”……….

JFP - How do you fill the coolant under vacuum?
 

What tools do you use to refill under vacuum? Is there a DIY on that someplace?

Very simple, you use one of these and follow the directions; it is the same tool Porsche dealers use, only it comes with adaptors to fit any car and costs about 1/5 what Porsche sells them for................

http://www.uview.com/Media/Products/.../550000-Medium

Unit is made by Uview, and they have a great website.............

Great website? Where are the prices?

The sales site is on Amazon.com; unit costs about $100.....................

Is the Porsche coolant a guaranteed thing, that's guaranteed to not cause compatibility issues? Assuming that your car is currently filled with factory coolant, absolutely. As has been pointed out, the issue is not in the coolant meeting proper specs, but in being fully compatible with whatever is currently in the system.

I don't think you can even buy coolant anymore, even the cheapest stuff around, that is not phosphate and silicone free, so is Prestone Dex-Cool acceptable? Certainly more than likely. Is the cheapest Walmart brand stuff probably fine too? Yup. Am I going to try either of these in my car? Nope.

If you do a complete flush, you can virtually run whatever you want in there. The key word there is complete. It will likely take 3 drain and fill with distilled water cycles to get everything out. I recently had to do this on my newest BMW, as when I purchased the car it had "standard" green coolant of unknown origin, and it took me 3 full drain and fill cycles until the water came out clear, without hints of green. Keep in mind also, that when doing this, you'll likely have to add a bit more coolant than water when you re-fill, as there will always be residual fluid left (the reason for the fill and drain cycles in the first place), which is now just water, not 50/50 mix.

If you're just topping off the system, I would save the hassle and just get the factory stuff. If doing a full drain and re-fill, you can save a little bit of money not buying factory coolant. At the end of the day, is all that hassle worth saving $20? Not to me.

Choice is yours; however, the last car we had in the shop that made the mistake of not using the OEM coolant (which can be purchased for $24/gal), cost its owner one Hell of a lot of money for us to clean out and repair................ So use whatever you please, but be aware of the consequences if you are wrong.................

Have you ever seen the gloppy stuff when someone used dex cool?

We have to go on what we are told happened, and yes, we have been told that DexCool (and some other products) have been involved when the system "went oatmeal" on the owner............... That is why we keep telling people that the Porsche coolant is not all that expensive, so why do you even think about adding something else? If the system burps up and is low, just add water until you can get it properly cared for…………and don’t use “coolant additives” as they are unnecessary and you do not know what is going to happen when you put them in your cooling system……….

Just so I understand then, you've never had a customer state that they added only dex cool and had the coolant gel? You've only seen it when they added something else too?

No, that is not correct. We have had multiple clients tell us that the gelation happened just after they added DexCool; we have also been told that gelation occurred when other brands were used as well, and that the use of cooling system additives also led to the issue.

When I say that "we have to go on what we are told"; we were not standing there when it was done, we only have the client's word as to what actually happened and the evidence of the end result, but as we have been told the same thing more than once by different oweners (sometimes by the individual that actually did it), have no reason to suspect what we are being told.

I really don’t understand the apparent need to find a substitute coolant for these cars; the OEM stuff is actually quite good, long lived and seems to protect well, is readily available and not particularly expensive. Considering the potential consequences of guessing wrong on a replacement, I fail to see why anyone even bothers…………….

Porsche OEM Coolant
 

For me it is an easy choice. At $24.00 a Gal and no compatibility or gel issues....go with what Porsche recommends.

Yes, I will be flushing the system and THANKS!! JFP for the vacuum recommendation. At $100 from Amazon, it is just another tool in my Porsche tool collection (which is getting bigger and bigger.....).

I am buying a reman waterpump with the metal impeller and the 160 degree Tstat. If I am going to do it, I want to do it right!

Actually, the Uview tool, with all the adaptors that comes with it, will work on literally anything with a cooling system......

Why the 160 t'stat?
the ECM needs to see 180 to run the engine efficiently

I bought a metal impeller water pump awhile ago for another vehicle and it weeped since day one. On that vehicle it was a 3.5 hour job to change it out again. I got a refund and went with a factory reman for the replacement.
Plastic impellers are not a bad word. If the metal was superior I would think all the luxury car manufacturers would use metal. The difference in cost is minuscule

Nonsense........We have them in about 15 cars, all of them pass emissions testing and, in fact, dyno testing has shown slight HP and torque increases due to improved volumetric efficiencies...................the DME has more than enough range to adjust to changing to 160F stat.................

Already in work...