Well i had a leak in my old radiator so i got a new aluminum one and installed it with a new cap of course. All lines are good, nothing is leaking finally. However when i get on the road the temp rises to 220 REAL fast and stays there unless i start driving. I have enuff coolant and the mixture is mostly water in there. However i am not so sure about the coolant i bought. Its some high milage coolant with a red color, called Dex-Cool which it says is approved by GM, which is why i bought it. But i think this might not be the coolant i need and i might be hurting myself here. any tips? already checked water pump, cap, and radiator with a pressure tester and it all held up to 14 PSI. any help please?

 

I don't know how Dex-cool is but I do know that you can only use certain kinds of coolant with an aluminum radiator (it's what i've heard). It should say on the jug if it can be used with aluminum, I think. Also, some people hate Dex-cool but I am not sure why. Someone is bound to know more than me, though. Hope this helps some.

 

You dont want to use dexcool with regualar ethlene glycol(the green stuff). When the two mix they begin to form a solid so you want to flush your old stuff out really good before you switch.

Your overheating could also be caused by a sticking thermostat. Check to see what the temp is on your upper radiator hose and housing. It should be at least near 195. If its alot cooler than your stat is sticking closed.

 

its a brand new 160 stat i just got in october so i dont think thats it. How do i check the temp of the upper radiator hose? and i flushed the system before i put the dex cool in but i didnt do it too well. i think im just gonna flush this and get the good old green stuff, lol.

 

I thought DEX-COOL was only for cars made after like 2001 or somthing!?

 

You could use your hand to guess at the coolant temp. You could go by a cheap temp gun. Or you could go to the junkyard and get and old hose and temp sensor then just rig the two together.

Dexcool was used on some gm cars after about 96. Just becuase it wasnt originally there doesnt mean you cant use it. ie sythetic oil.

 

are you sure your fan is coming on? I had that problem before and it turns out the fan motor was bad. also (and I'm sure you know this already) you want to have a 50/50 mix of coolant&water. and as someone already said, don't mix the two. hope that helps

 

Is it running hot while idling/low speed, or while at higher speed while driving?

Running hot while idling and driving will be a coolant circulation problem (thermostat, collapsed hose, clogged something)

Running hot while driving only it will be an airflow problem (no nose ducting, missing or bent under chin spoiler)

Only at idle/low speed is probably the fan or missing fan shrouding. I hope this helps!

Good luck

Troy
So Cal

 

I had a similar problem since I got my car a few months ago, it ran cool on the highway but the needle would start climbing if I let it sit and idle. It turns out the cooling fan wires were switched around and the fan was running backwards, so it was actually sucking air from the engine bay and pushing it out the front. I didn't figure this out until I charged the A/C system the other day and was getting no cooling when the car was sitting still. I knew that the condensor wasn't getting enough airflow to do the job even though the fan was spinning away. ANyway since I fixed the the a/c is icy when moving or sitting still and the temp needle doesn't ever move once it's warmed up. It's something to check anyway...

 

well it isnt so bad now, however it seems to get hotter no matter what and likes to stay at about 220-235 all the time when its warm. which way should the fans be spinning so that it doesnt such in the air. Also i dont have the air dam underneath the car so im guessing thats a major factor. Also im not sure if this has anything to do with it but when the car is warmed up to about 220-235 and im cruising at about 45 or 50 the car jerks real hard like its choking and i mean hard. could this be a factor? heat soaking? or maybe a bad maf or fuel pressure? thanks!

 

you NEED that air dam underneath, that is a major part of how your radiator and engine get cool air. as far as you car acting up when you are crusing around, I'll bet that your engine bay gets hot which of course results in your fuel getting hot, and hot fuel dose not combust nearly as well as cool fuel. well thats pretty much my little spiel, good luck

 

What you need to do is get another thermostat gasket ..
-Take your thermostat out and take it to your kitchen.
-Place it in a pot of water and test it.
-If its a 160 it shouldnt take long for you to watch it open as soon as it hits temp..you can even put it over an open flame..
Most of the newer thermostats that look like a top are junk...
But I had confidence as you did thinking that a new thermostat wasnt my problem and I also bought a aluminum Be-Cool radiator for big bucks hoping it would help my heating problems but to say the least it was the 5 dollar thermosat sticking.. So I just removed it totally and let the water flow.Now I run between 150 to 175.. and I also bought a new temperature gauge from auto meter and found out how far off my factory gauge is.