Antifreeze question

pepi · September 21, 2015

My thermostat needs changed on my 2008 V6 work truck. The antifreeze in it looks good. Only has 30,000 miles on the truck LOL. I will probably lose a small about on antifreeze when I pull the thermostat out. Can I just replace it with any DexCool antifeeze?

Thanks!

txab · September 21, 2015

when was it last changed, the coolant that is

You don't go by "looks"

if it's the factory fill then definitely flush and replace with fresh DEXCOOL

fondupot · September 21, 2015

You honestly shouldn't lose much doing the t-stat.

But if you do have to add, make sure its the same as what's in there now. You never want to mix Dexcool with anything else. Because it will being to coagulate and clog the cooling system.

kstruckcountry · September 21, 2015

Coolant should be replaced every 3 yrs.

intheburbs · September 21, 2015

Coolant should be replaced every 3 yrs.

Really? Is that why both of my GMT900 owner's manuals say 5 years or 150,000 miles?

kstruckcountry · September 22, 2015

Really? Is that why both of my GMT900 owner's manuals say 5 years or 150,000 miles?

I have noticed coolant doing some congealing in 3 years, have to remember different climate and driving changes things. You can follow the manual on transmission, diffs, and oil if you want too.

I'd say on a 7 year old vehicle it's past due.

MikeInCtown · September 22, 2015

Given the cost of new coolant and how easy it is to pull a lower hose, I'd just replace the coolant with new stuff. If you have to remove any belts or hoses to get to the thermostat then just replace those too. Its is far easier to replace stuff when you already have it off than it is to do the work two or three times later.

intheburbs · September 22, 2015

I have noticed coolant doing some congealing in 3 years, have to remember different climate and driving changes things. You can follow the manual on transmission, diffs, and oil if you want too.

I'd say on a 7 year old vehicle it's past due.

I'm not disagreeing with you on 7 years. I am disagreeing with you on the 3 year thing.

And the only time I've seen Dexcool congeal is in a truck with a cracked block. I've driven in 110° heat for days at a time (engine and trans getting as hot as 230°), and I've always lived in areas where it goes well below zero during winter.

So, are you saying that GM's recommended intervals are BS? You're one of those guys? So, how often do you change your trans and axle fluids? 10k? 5k? And I guess you ignore the oil life monitor, too? Lemme guess, it's all a conspiracy by GM to decrease the life of their vehicles so people have to buy new ones sooner.

I've owned five trucks; all of them are/have been driven and worked hard. I've never had to replace an engine or transmission. That covers about 500,000 miles of driving. My highest-mileage truck is my '01, and it has the original engine and transmission and 210k on the odometer. Only reason the rear's been replaced is because I overloaded it towing a too-heavy trailer across the country. But, I guess I'm just lucky that none of my trucks break. I just follow the intervals in the manuals.

MikeInCtown · September 22, 2015

I'm not disagreeing with you on 7 years. I am disagreeing with you on the 3 year thing.

And the only time I've seen Dexcool congeal is in a truck with a cracked block. I've driven in 110° heat for days at a time (engine and trans getting as hot as 230°), and I've always lived in areas where it goes well below zero during winter.

So, are you saying that GM's recommended intervals are BS? You're one of those guys? So, how often do you change your trans and axle fluids? 10k? 5k? And I guess you ignore the oil life monitor, too? Lemme guess, it's all a conspiracy by GM to decrease the life of their vehicles so people have to buy new ones sooner.

I've owned five trucks; all of them are/have been driven and worked hard. I've never had to replace an engine or transmission. That covers about 500,000 miles of driving. My highest-mileage truck is my '01, and it has the original engine and transmission. Only reason the rear's been replaced is because I overloaded it towing a too-heavy trailer across the country. But, I guess I'm just lucky that none of my trucks break. I just follow the intervals in the manuals.

If I remember correctly, when Dexcool first came out, they did indeed have issues with it and it did not last as long as claimed. I'm not sure what has changed since then, however. I'd have no issues using it now or letting it go to 5 years or beyond. (had the original coolant in my 04 for 9+ years)

txab · September 22, 2015

OP. Opinions are like assholes, everyone has one. Do what you feel comfortable doing on the change interval

kstruckcountry · September 23, 2015

I'm not disagreeing with you on 7 years. I am disagreeing with you on the 3 year thing.

And the only time I've seen Dexcool congeal is in a truck with a cracked block. I've driven in 110° heat for days at a time (engine and trans getting as hot as 230°), and I've always lived in areas where it goes well below zero during winter.

So, are you saying that GM's recommended intervals are BS? You're one of those guys? So, how often do you change your trans and axle fluids? 10k? 5k? And I guess you ignore the oil life monitor, too? Lemme guess, it's all a conspiracy by GM to decrease the life of their vehicles so people have to buy new ones sooner.

I've owned five trucks; all of them are/have been driven and worked hard. I've never had to replace an engine or transmission. That covers about 500,000 miles of driving. My highest-mileage truck is my '01, and it has the original engine and transmission and 210k on the odometer. Only reason the rear's been replaced is because I overloaded it towing a too-heavy trailer across the country. But, I guess I'm just lucky that none of my trucks break. I just follow the intervals in the manuals.

Do what you want.

Yes, I ignore the oil life monitor, and run it longer than GM suggests. My oil is sent out and analyzed. The manual intervals are a one size fits all solution. For me, 3 years seems to be about right for coolant + thermostat. For you it's different.

pepi · September 23, 2015

Why is it I bring out the bad in everyone No need for a flame-war.

I changed the stat and antifreeze but I'm still having issues with low heat from my heater. Appears it maybe that dam control? I assume the control operates a vacuum or electric switching unit. Any ideas?

Thanks

MikeInCtown · September 23, 2015

Is the engine operating at normal temperature? If yes, then my guess would either be the blend door actuator (you may have more than one) or the controller itself. I'm not familiar with the 08 trucks enough to say any more. Also, double check any procedures you may have been required to do when you changed the coolant. For example, when I replaced my water pump, the instructions specifically said to hold the RPMs at 2k or 2500k for several minutes to make sure any air got bled out of the heating system.

txab · September 23, 2015

You may have a heater core that is plugged. Have you tried flushing through it?

pepi · September 23, 2015

Yep, I flushed the system out. I'm leaning towards a blend door actuator. I noticed this summer the AC was not cooling like it did last year. My temp is running in the middle on that cheap temp gauge. This is where it has always ran.

How hard is it to replace the blend door actuator? Have to tear out the dash? Probably a 500.00 dollar bill at the GM dealer