Thermostat replacement

[Jasher20]

I took my truck to the dealer to get my transmission looked at. They told me I needed a rebuilt one or a new one, around $4500. I took it to a transmission shop and they just had the computer flashed and a flush with new filters, $354, runs like a champ. ANyways, the dealer did say my thermostats are bad. My temp on the truck seems low when it should be warm. Aound 175 and no higher than 180. Any ideas? I am just wondering if this is another thing the dealer has said that is wrong about. I heard I can take them out and soak them in soapy water. There is some coolant in my oil, but I had a head gasket test and injector test and they are both good to go.

[chevy_trux69]

My truck wouldn't heat above 160, and wouldn't blow warm air. I replaced my stats from napa ( $90 with a gallon of antifreeze ) and that took care of. I bled the system, it took a few times and it heats well now and my upper hose don't cave in on me anymore, as far as the coolant in the oil Id get another opinion, that can't be good.

[daddysLBZ]

Originally Posted by Jasher20

I took my truck to the dealer to get my transmission looked at. They told me I needed a rebuilt one or a new one, around $4500. I took it to a transmission shop and they just had the computer flashed and a flush with new filters, $354, runs like a champ. ANyways, the dealer did say my thermostats are bad. My temp on the truck seems low when it should be warm. Aound 175 and no higher than 180. Any ideas? I am just wondering if this is another thing the dealer has said that is wrong about. I heard I can take them out and soak them in soapy water. There is some coolant in my oil, but I had a head gasket test and injector test and they are both good to go.

Reflash and changed fluid..........Temporary fix if it was limped.What other details led up to the trans giving trouble???BTW each limp makes it WEAKER!
My rig runs at 185 idle all day long.........it is a diesel and temp rises accordingly,up to but never exceeding 210*
Soak what in soapy water???????
If there IS coolant in your oil it got there from somewhere,we'll all just hope no one poured that in!!How much coolant did you find in the oil,versus quamtity of oil[10 qts.]
Who determined that that temp was incorrect?If it never got hot then the thermostats aren't faulty,I know they fail open,but you said that the temp fluctuated a bit.......
Sounds like ya truck needs TLC from a competent mechanic

[Jasher20]

Well they ran a diagnostic with a computer hooked to it. They just said the thermos are bad. The heat does not come out hard at all, it is very weak. There is somethin in the oil that is green. I thought it was coolant because it didn't smell like diesel, but my coolant is not green I don't think. They did a pressure check on my injectors and they are fine. It could have been a clogged injector I guess that cleared out. I don't really know. The tranny's shifting patterns were off according to the technitian. He said the symptoms matched the code in the books requiring a flash. Now it shifts better than before. Either way I am in no position to spend 4000 on a new transmission

[chevy_trux69]

I didn't think the scanner could tell that the stats were bad, when you say the heat don't come out hard at all, are you talking about the volume of air that is coming out of the vent? If so, your evaporator could be plugged up. What year is your truck? Are you having to fill your truck with coolant? I know it is supposed to be red, but is there a chance that someone had the system flushed and filled it with green anti freeze? Is your engine oil level increasing? What does your truck run like? Is it smoking white? Does it start and idle ok? How many miles are on it? I wouldn't dought that your stats are bad, but i didn't think that a scanner could tell you that. Both of my stats were stuck open, so it is possible.

[LBZ_Duramax]

Fill out your sig. Coolant in your oil dosent sound good on any terms

[duratothemax]

it sounds like whatever "tech" worked on your truck doesnt have a clue what he is talking about, or how to work on a duramax...

[Jasher20]

Originally Posted by chevy_trux69

I didn't think the scanner could tell that the stats were bad, when you say the heat don't come out hard at all, are you talking about the volume of air that is coming out of the vent? If so, your evaporator could be plugged up. What year is your truck? Are you having to fill your truck with coolant? I know it is supposed to be red, but is there a chance that someone had the system flushed and filled it with green anti freeze? Is your engine oil level increasing? What does your truck run like? Is it smoking white? Does it start and idle ok? How many miles are on it? I wouldn't dought that your stats are bad, but i didn't think that a scanner could tell you that. Both of my stats were stuck open, so it is possible.

I ended up getting a tranny rebuild. As far as the heat goes, the volume coming out is weak. It is warm, but when I put it on high it sounds like it is coming out hard but the amount of warm air is hardly any and it goes for the same with a/c. The Engine oil level stays the same, there is just a greenish tint to the oil. One GM mechanic claimed that can be normal for those trucks. I dunno. It runs great, no smoke, cranks up great. Here is what my temperature maxes out at. It has 170,000 miles on it. It idles great. I don't really know if they saw anything on the scanner about the thermostats, or just observed. They said my truck didn't warm up fast enough. If my evaporator is clogged, how do i unclogg it and where is that at? Pics would be great if there is a link.

[jc1843]

The 01 trucks came with cabin filters, you may replace those and it may help. The cold outside air affects these trucks and many have to use a front cover to get the engine temperature up faster.

When the upper radiator hose collapses when cold-- that is caused by a sticky valve in the recovery cap-- washing in soapy water will usually correct that.

[Jasher20]

I changed the cabin air filter under the glove box, is that what you mean? Do you mean a grill cover to get the temperature up? It still blows weak when its summer and the a/c is on. So i dont' feel like it has to do with the engine temp, unless that is too low for efficiency's sake?