: Looks like I'm having Dexcool problems



M.A.C
07-23-11, 10:15 AM
About a month ago I noticed that my Dexcool looked like it had a jelly-like quality to it. So I stuck a paper towel in the surge tank to soak up some coolant to see if there is anything unusual. It looked okay, but I was still suspicious that something was going on because I could see what looked to be a jelly substance floating around. A week past when I noticed a jelly-like substance on the coolant cap. The reason why I've been so interested in the coolant is because I also have what I thought was an coolant leak but couldn't find what was leaking. The location of the leak is on the driver's side in close proximity to where the jack is placed. On Thursday I decided to pull the expansion tank overflow hose out and sure enough coolant was leaking/bubbling from it. When I loosened the cap, coolant came bubbling up and overflowed. I do not neglect coolant and in fact the Dexcool was no more than a year old. Also, since I've been having problems with losing coolant, it was even fresher because I would top it off with Prestone's GM approved Dexcool.

About a year ago I went to a Jiffy Lube and asked them to replace the Dexcool with fresh Dexcool. I told them not less than 3 times to make sure they replace my coolant with Dexcool only. When I was given the bill it stated that they used the universal coolant instead. Needless to say, I was infuriated because I told them specifically to make sure they used Dexcool. I ended up disputing the credit card charge for the flush and refill and about 3 days later had the cooling system flushed again and this time made sure the universal coolant was replaced with Dexcool. I was fairly confident that all would be okay since I didn't let the universal stuff linger in the system very long. Now, I don't know if what is happening now with what appears to be Dexcool problems is related to this incident.

However, I'm about to make a decision as to whether I should say goodby to Dexcool.

My question is, is it time to use another coolant, such as Prestone's Extended Life Antifreeze, which is yellow in color?

M.A.C
07-23-11, 02:03 PM
I made a decision to flush the Dexcool and replace it with the silicate based 5-year/150,000 miles antifreeze. I first flushed the system with Prestone Super Flush. What I saw was white cloudy water, which is the remnants of the apparent breakdown of the Dexcool into a white pasty or jelly-like substance. Luckily the heater core is working.

This wasn't an easy decision because I would have liked to continue using Dexcool. But I'm all too aware of the allegations surrounding Dexcool, including a clogged heater core, radiator, and intake manifold gasket failure. I didn't want to take a chance that I may have to deal with any of the above. At this time, it looks like there is no surge tank overflow problem that I was experiencing before flushing the Dexcool.

Subsailor613
07-23-11, 02:06 PM
Hi, NOT once did you say you were using a 50/50 diluted solution of Dexcool !
That is the recommended concentration, and it you have been putting straight
dexcool in your radiator, that is part of your problem.
the Cadillac dealer has a machine to push out the old and bring in the new.
That is what you need. somehow get the old out, and bring in the new.
Good Luck ! :cool2::cool2::cool2:

M.A.C
07-23-11, 02:45 PM
Hi, NOT once did you say you were using a 50/50 diluted solution of Dexcool !
That is the recommended concentration, and it you have been putting straight
dexcool in your radiator, that is part of your problem.
the Cadillac dealer has a machine to push out the old and bring in the new.
That is what you need. somehow get the old out, and bring in the new.
Good Luck ! :cool2::cool2::cool2:

I put 50/50 Dexcool. I know enough not to fill up with full strength antifreeze.

My view is that somehow it appears the Dexcool went bad. Why would I want to risk a similar situation in the future and end up running into even bigger problems. The 5-year/150,000 miles antifreeze I replaced the Dexcool with has added rust and corrosion inhibitors. It's not the green antifreeze, though many are using it to replace Dexcool and claim all is well after years of using it.

KRSTS
07-23-11, 03:36 PM
DEXCOOL does not play well with other antifreezes. Likely there was some of the previous antifreeze left in the system when you replaced it with DEXCOOL the last time. It is very hard to remove all the coolant from a system, even with flushing.

M.A.C
07-24-11, 11:05 AM
DEXCOOL does not play well with other antifreezes. Likely there was some of the previous antifreeze left in the system when you replaced it with DEXCOOL the last time. It is very hard to remove all the coolant from a system, even with flushing.

I'm not sure and doubt the universal antifreeze was a factor in causing Dexcool to brakedown as far as the white paste/jelly-like substance. After all, universal antifreeze is supposed to be compatible with Dexcool. There is one more possibility which I tend to think is the culprit, being a faulty surge tank cap. From what I understand, if air infiltrates a Dexcool cooling system it will likely cause Dexcool to breakdown. Dexcool apparently does not mix with air. This is not a problem with other types of antifreeze, such as the traditional green and universal. My STS has been leaking for some time but I wasn't sure where from until I pulled the overflow hose and noticed it was leaking. It was not until the hot weather did it become such a problem that I felt compelled to address it. So obviously it appears a faulty cap allowed air to infiltrate which, in turn, was likely the reason why the white pasty substance formed due to Dexcool not mixing with air. The white paste is likely all the evidence need to show air infiltrated since it looks to be Dexcool emulsifying, which happens when air is present. I don't know if GM has issued a warning about air infiltration causing Dexcool to emulsify and/or form a white paste, but I tend to believe the answer to my situation is a faulty cap.

EChas3
07-27-11, 10:42 PM
I agree. Air is very likely the culprit.

I did a lot of checking and I'm convinced Dexcool is fine when used according to instructons.

M.A.C
07-29-11, 01:02 PM
I bought a new surge tank cap and no more leaking. But I'm not going to flush the Prestone 5-year/150,000 miles coolant and reintroduce Dexcool. The Prestone is a OAT (or organic) forumula coolant like Dexcool. I believe it's actually a HOAT coolant. Anyway, the Prestone is very close to Dexcool and has been around a while with no reports of the kinds of problems associate with Dexcool.