Is dexcool fully synthetic? If not, are there any other coolants that are synthetic besides amsoil?

 

ttt

 

Dexcool is a manufactured OAT, or organic acid technology based coolant. In the strictest sense you could consider it a synthetic. There is much more info about OAT based coolants on the net then you are going to get here. Supposedly Dex does not form the scaling and is not as prone to corrosion with aluminum components as conventional coolant and it is silicate free prolonging pump seal life. It does have one drawback, if mixed in the wrong proportion or if the system is low and the vehicle is run for a prolonged period it will form a muddy residue the requires a chemical flush to eliminate. GM addresses this in a technical bulletin. Another benefit is that it is 100% biodegradeable, so it is more environmentally safe. It has the same toxicity as EG so don't stick it in a used orange juice container. Texaco invented it for GM, they have a lot of material data sheets for reprint.

 

Thanks for the info. Are there any other synthetic coolants?

 

Also, is regular Prestone synthetic?

 

Dexcool eats away at gaskets. I don't have any info to back this statement up other than my own personal observations in the automotive repair industry...but I have seen it many times.

 

thanks, I'll keep that in mind, but all I wanna know is what coolants are synthetic? I'm gonna flush my system out and was looking at replacing it with prestone, but was just wondering if it's synthetic, or if any coolants are synthetic?

 

Also don't overheat it with dexcool. I replaced the coolant in my mom's v-8 jeep with dex-cool. The lower hose failed and she overheated the hell out of it. Ever since I have to flush the system once every 6 mos to get the hard deposits out of it. I can tell when its due because the hoses sound crunchy. The dried up dex-cool crunching inside the hoses

 

Prestone has 2 coolants, the standard ethelyne glycol(green) or they also market a Dexcool replacement. Any fluid whether it's oil or coolant has a strong synthetic additive package so its a tough question. The advantage of Dexcool over standard was length of service and the fact it is silicate free. Unless all of the old stuff is out you still need to change Dexcool every 2 yrs. I changed out my block in the 89 and everything was new including hoses so I can safely go the long haul with Dexcool but unless you have no more than 10% of the old stuff left in the system it's 2 yr service intervals. There are some field reports of gasket contamination and sludge but upon investigating it I have found it's only when there has been some sort of cooling system problem. It's in all my cars and liquid cooled motorcycles and I have never had any problem. On a properly maintained system I think it's a good choice to eliminate the aggravation of draining and disposal issues.

 

if you're thinking of switching, be aware that if the older style "green" coolent mixes with dex-cool it forms a brown scale that cloggs up the whole cooling system..

 

I was looking at that Peak pre mixed stuff last time I was at Kragen. It comes pre mixed, 50/50 with distilled water. It says right on the bottle, DO NOT MIX WITH WATER. Seems kind of convenient if you ask me. The lady said it sells really good. Opinions on this stuff? And does anybody recommend using that prestone coolant system flush before I fill up the radiator? Oh and, how much coolant does my system take? Like two or three of those big jugs of coolant? Not sure if those are gallon sized or larger. Thanks.

 

you are paying for someone to add water to half the bottle. lol...
not worth it to me, but im not THAT lazy.

anyhoo, yea, that coolent flush works real well, esp if you use their reverse flush system thing too..

 

I know what you're saying but it was the same price as all the other stuff on the shelf, and it had distilled water in it, which would save me a trip to the store. So if it was the same price, exactly 50/50 mixed, I don't see how it wouldn't be worth it.

 

if it was half the price of the non premixed it would. But at the same price, it will take 2x the number of bottles to fill the cooling system. I just buy the non-mixed and get distilled water from the local grocery store in the center of town. its only like 50 cents a gallon or so.

 

How many jugs coolant/water will my system require? I now see what you mean that you would need to buy 2x So I am assuming the system will take one jug coolant and one jug distilled water. Is that right?

 

So two gallons (jugs) total? Or will I have to buy two gallons of antifreeze just in case I don't have enough?

 

Not true, DC only gets that way if the water/coolant ratio is too low or the system is constantly topped off with water again changing the ratio. Mixing DC with more than 10% of EG will cause it to turn almost black and reduce or eliminate any long term properties that make it desireable.

 

I just think I'm gonna stay away from the dexcool. I don't know much about what coolant is made of, and I would like to have the best for my car. Is the regular green coolant from Prestone synthetic? If not, are there any synthetic coolants available that won't cause the adverse effects of dexcool? I really do appreciate all this info guys. I dunno what I would do without it.

 

25- If I were you I'd just stick to the normal green prestone. I don't think that is synthetic...just the glycose stuff (forget the entire name.) That's what I'm going to do, but can anyone please tell me about how many gallons of coolant my system will hold? Also, when flushing my system and filling it with fresh coolant, is it important to have the engine running with the cap off? Thanks.

 

17.2 quarts in your system. I would leave the cap off for a little bit to let all the air out.

 

That seems like a lot. If that's the case, I would need about 2 gallons of antifreeze, and 2 gallons of water....is this about correct? Thanks.

 

A little more than that, but thats about it. 8.6 quarts each and there is 4 quarts in a gallon so you do the math, lol.

 

Isn't Dex-Cool a SPECIAL coolent? If the car is meant for Dex-cool then that's what you are supposed to use. If you use anything other than Dex then you will screw up everything in the coolent system. Plus it won't keep the car as cool as the coolent it was meant for. I've seen lots of people put Dex in a regular car and they sprout leaks all the time. Same thing with regular coolent, if you try to put dex in it then not only will you not keep your engine cool, you will also sprout leaks. Just use the coolent the car was made for and you will be fine.

Dex cool has a different BOIL point than regular green coolent. Thats something else to consider. Plus the coolent lubricates the water pump, lots of times i've seen a water pump go out cause it wasn't lubed properly, and those are the people that switched from green coolent to the Dex cool.

 

With a 50/50 mix DC has the same cooling characteristics as EG coolant. The leak thing is nonsense, I have done many conversions and never had any problem. More often than not it's the flush that dislodges crud that had plugged up small potential leaks. The water pump issue you mention has no basis in fact. OAT based coolant has none of the silicates that enhance bearing failure, even the newer EG coolants for a lot of imports feature a low silicate formula for that very reason. The proper way to convert is to replace all the hoses and do a good flush. I prefer a chemical flush after all is said and done then a refill with DC. I did a friends 95 Ford after it was due for it's first coolant service and with 135k it's still got the DC in it and it's fine, never a cooling system issue. You mention the car being "made for" a certain coolant, that's simply not true. The major system components are the same whether it's got DC or the green stuff. The issue is getting the old stuff out so as to have as little cross contamination as possible. That's why they say to stick with a normal 2 yr service interval with converted vehicles, because they know that most people will not do it correctly and they want to be protected from liability. I spent a lot of time talking with dealer techs and some mechanics with large fleets and in every case where they had a problem there was another issue present. The fact is that the cooling system is the most least likely to be serviced at recommended intervals. By the time a lot of vehicles are changed over they already have cooling system problems requireing proper service to correct. GM has a bucketful of cars running around in warranty using DC. If there were any real problems other than the mythical ones they would have changed back a long time ago. Most of what you posted has little basis in fact if you took the time to research it. It's amazing how one or two stories get through the food chain and all of a sudden become fact.

 

.

 

Prestone makes a decent chemical flush mix, I generally use thier flush kit they sell at the chain stores. The factory uses a sealing tablet in new vehicles, however GM in a TSB says it's not required and I have not done it with any vehicle. Texaco who formulated Dexcool for GM recommends you do 2 flushes approx 2 wks apart to reduce residual EG coolant cross contamination. Many dealers and drive through lube places can do a dripless flush and complete exchange of the coolant with Dexcool but it's pricey. I like it because it extends service intervals and I hate messing with anti-freeze.

 

I wasn't to sure about the coolent. I figured if the came originally came with Dex-cool or GO-5 then thats what you should use. Since his car didn't come with dex I figured you should stay with the Green coolent. As far as leaks, I've seen people mix the Dex and the Green and things screw up, like the cooling system.
Tell me what the difference is between the different coolents?

 

Mixing is a no-no and will create compatability issues, that's why they recommend 2 flushes 2 wks apart. Dexcool is an Organic Acid Technology based coolant and is 100% biodegradeable. It is low silicate and remains more stable than EG for much longer. All manufacturers are striving for lubricants and fluids that meet or exceed the warranty period and also for environmental concerns. Some areas of the country, local townships are trying to ban at home oil changes, coolant changes etc. Dexcool was an attempt to address these issues as well as providing a long term stable coolant for their engines which have more and more aluminum components. The 2 coolants work equally well as far as providing freeze protection and corrosion inhibitors.

 

My 96 GMC Sierra pickup came from GM with Dex-cool in it. The system was never touched & in less than 24,000 miles the overflow tank developed some nasty cystalization. The radiator, thermostat, recovery tank & hoses all had to be replaced at the Generals expense. I worked at the dealer at that time & we did countless similar repairs.

 

.

 

Did you ever find out why? I have a friend at a dealer and he had the same thing to say. Thats why I tried to talk with as many mechanics as possible. what I found out almost every time was either cross contamination or excessive water was the culprit. I am curious, anybody ever check the mix with a problem car with a test strip. Figuring every GM car since the mid 90's came with it, what do you think the actual percentage of problems vs total numbers of cars built? That's what I look at. Are the numbers the same or close to the rest running EG conventional. That's my dilemma, every time I tried to get more info there just wasn't any. The one guy who handled a municipal fleet of about 50-60 cars with it said he saw problems in about 3 vehicles(the muddy look). He was one of those guys who thought the greatest technological advance was when GM incorporated the points and the condensor on one mounting plate, amd even he admitted he could not fault the coolant as being the main issue. If you have any more info it would be appreciated.