Thermostat problem or no?

[0r1landoDSM]

so my car randomly started to overheat, i pop the hood and noticed that the lower radiator hose was warm and the upper was really hot.

the next morning i started the car up and the upper radiator hose got really hot and the lower hose felt ice cold and again i started to overheat.

i did a lil research and the thermostat was most likely the problem, i went to advance auto and bought a "stan" brand OEM style thermostat. i replace it and still the same symptoms ice cold lower radiator hose and really hot upper radiator hose

i then decided to test it with out a thermostat to see if i have the same symptoms. i started the car up and my overheating problem was fixed and my car ran a lil colder, both the upper and lower radiator hose was hot.

can it just be that i bought a faulty thermostat or just is there something else wrong?

***my headgasket was replaced a few months ago along with arp headstuds was installed along with new waterpump**

**7 bolt 4g63 engine***

[92PandaTalonTSI]

I always hear that non OEM thermostats have a great chance of failing even when brand new. It definitely is a symptom of a thermostat and the autozone ones work about 75% of the time from what I heard. This is what I've heard and by no means have anything to back my statements. Guess you can call it my two cents, but sounds like you're on the right path.

[0r1landoDSM]

Originally Posted by 92PandaTalonTSI

I always hear that non OEM thermostats have a great chance of failing even when brand new. It definitely is a symptom of a thermostat and the autozone ones work about 75% of the time from what I heard. This is what I've heard and by no means have anything to back my statements. Guess you can call it my two cents, but sounds like you're on the right path.

if removing the thermostat still caused those symptoms it would've led me to question if the radiator is clogged or my water pump failed but my water pump is new but you never know lol

[iugrad92turbo]

do a compression test to rule that out, i had a hg done and shortly something was wrong ill but ver know what but the car began to over heat, are the fans coming on.

[0r1landoDSM]

Originally Posted by iugrad92turbo

do a compression test to rule that out, i had a hg done and shortly something was wrong ill but ver know what but the car began to over heat, are the fans coming on.

how would i know if i have a bad headgasket doing a compression test? what numbers would i get if my headgasket is bad?

UPDATE: i ripped it up an down the highway and still no overheating. the temp gauge only goes a lil bit below the middle line to the middle line, so i guess in fact the thermostat is the culperate. smelled the exhaust gas and checked the oil for coolant and none present in both

[colemoney1]

Ive had this problem before, 100% thermostat. You might want to flush the system while your at it.

[volcakid8787]

I just replaced my radiator because there was an obvious crack right at the top. Before, I was driving around replacing the coolant fluid with water just to keep it running until had time to replace it. Replaced it and drove it for about ten minutes and it overheated again. I go to look under the car and its coming out of the tube that is the overflow tube for the overflow reservoir. So I think its probably just the radiator cap. Replaced that and replaced the thermostat for good measure and its still doing it. Also I've "burped" it as well, or waited with the radiator cap off while it idled for roughly thirty minutes. Any ideas?

[98and01eclipse]

check you raditor sounds like a clog to me flush it and run wated though it to see if it flows fine though

[volcakid8787]

I just replaced the radiator though...would it already be clogged?

[bduran1220]

Originally Posted by volcakid8787

I just replaced the radiator though...would it already be clogged?

Some times they come faulty & theres nothing u can do about it but replace it again it sucks but thats where LLT Warranty comes in to play


Dang!!! i just started to have this problem to driving from work at night(11pm) white steam come out from the lines of my hood my stomach hardened i looked at the gauge it was normal!!! and stayed there the whole time driving, when i got home i heard bubbling like boiling water i thought it was from the Rad. but no it was coming from the over flow tank(not low) so i pulled it out. the tube that goes into the tank was blowing steam out and burnt me a bit. So i was like "Oh Hell NO" i just did a Rad. flush back in Aug. 2011 when i had a striaght on "short circuit". rad cooled fine back then and better after i did that. So NOW i just bought a Low temp Racing Theromstat along with Silcone lower and upper Rad. hoses courtesy of Mishimoto lets see what happens next

Dear Stock Radiator:
ive been waiting for u to give me any reason to replace u with a Mishimoto Radiator. i dont like u in my engine bay. You look to nasty and green and thats the truth im sorry if u broke. But it wasnt my fault

Love Brian

[nickk90]

Originally Posted by bduran1220

Some times they come faulty & theres nothing u can do about it but replace it again it sucks but thats where LLT Warranty comes in to play


Dang!!! i just started to have this problem to driving from work at night(11pm) white steam come out from the lines of my hood my stomach hardened i looked at the gauge it was normal!!! and stayed there the whole time driving, when i got home i heard bubbling like boiling water i thought it was from the Rad. but no it was coming from the over flow tank(not low) so i pulled it out. the tube that goes into the tank was blowing steam out and burnt me a bit. So i was like "Oh Hell NO" i just did a Rad. flush back in Aug. 2011 when i had a striaght on "short circuit". rad cooled fine back then and better after i did that. So NOW i just bought a Low temp Racing Theromstat along with Silcone lower and upper Rad. hoses courtesy of Mishimoto lets see what happens next

Dear Stock Radiator:
ive been waiting for u to give me any reason to replace u with a Mishimoto Radiator. i dont like u in my engine bay. You look to nasty and green and thats the truth im sorry if u broke. But it wasnt my fault

Love Brian

You might wanna try a new Radiator Cap. If it goes bad it wont hold pressure and will push all your coolant out the overflow and lowers the boiling point and your coolant will boil away

[volcakid8787]

The boiling in the overflow resevoir was what I am experiencing right now as well. A logical conclusion is the radiator cap but I replaced that and its still doing the same thing. The only thing I can think is that the radiator IS bad. The next test I will do is drive without the thermostat and see if it does the same thing. After that I guess I could see if the radiator is working properly by feeling both in/out houses?
I burped the system already which requires leaving the radiator cap off to allow pressure locked air bubbles to escape...water was seen to be flowing so that makes me think the pump is working fine but I could be mistaken?

[bduran1220]

U right i guess i forgot all about the rad. cap all my parts arent here yet but now i can imma buy that too while im at it Long Live the DSM Spyders in the summer

[volcakid8787]

Turns out that either my cylinder head or head gasket is cracked. Did a simple CO gas check and came back positive. Looks like the old DSM is going to have to sit for a bit until I get some time & money for a new head!

[boost97gst]

I just replaced my radiator. With this insane drought/heat here i noticed at 100* ambient temps sitting at idle with ac on(or off) max temp was 213. On the highway cruising at 75 temps are 219 to 223, a bit hot for my taste. Ducting is necessary obviously.
Funny thing is, from about 160* to 223* the needle stays right in the middle. Its really a non linear temp gauge. I use link to accurately read it. I would assume the gauge will read fine til its around 230 then spike up to hot. My system is completely full, new engine, water pump, pretty much everything is new.
I guess just having that big fmic and an ac condenser in front of my rad causes it to run hot. Its going to be 104 to 106 the next few days and i dont feel comfortable driving it on the highway. Good thing i have 2 other means of transportation