Lanos Running Cold

[chefrza]

I am a noob to this forum. I love it and it has been a huge help to me so far. I do have a problem that I am wondering if anyone has come across with their woo. I live in NY and it was time for my yearly inspection. Anyway the CEL is on stating that the engine is running too cool. I have replaced the T-Stat 2 times in the past week with no help. See the problem that I noticed is the car at idle runs a good temp. As soon as I drive the temp gauge goes way down and I even lose heat. I am at wits end here. I just bought the Temp Sensor and will be replacing that tomorrow. I was also looking at the air temp sensor to replace also. I am just real iffy about the problem being the T- Stat. I just don't see getting 2 bad stats in a row. Can somebody please help?? I love my car and hate to call it quits on her for something soo petty.

[Trey05Woo]

Is the coolant mixture correct? You can check it with a 5 dollar tool available most places even walmart. I would also check to see if the fan is always on even with the AC off.

BUUUT MOST IMPORTANT what is the code?

[chefrza]

The mixture is correct. I had a T-Stat blowout in November on the road. So the the stat was recently replaced and the coolant was flushed. The fan is running correct I let her run this morning and she heats up correctly and the fan kicks on when needed. Its just when driving the temp drops all the way. This is the second stat since I replaced the blowout in November. I just find it hard to believe its bad yet again. As far as the code I will get that for ya ASAP.

[MMamdouh]

your t stat is stuck open

MMamdouh

[chefrza]

Would it be easier to replace with a metal t-stat housing? What do you guys think? Whats better? I see the metal has some advantages but why did they do away with them? I mean wouldn't you think its because something was wrong with them?

[Daniel]

Hi chefrza,

Metal or plastic housing only makes difference in durability.
Now maybe a stupid question: Are you sure you have the (correct) item #3 in place in you new tstat housing? You must be able to feel a suddent temp increase on the lower radiator hose when tsat opens.

Tstat lanos.jpg

Daniel

[chefrza]

The thermostat that I have is a 1 piece unit. You cannot remove the actual stat. But yes it is installed correctly (spring towards the block). And I just don't understand why it would be the third t-stat in a row that is bad. The car warms up to a nice spot on the needle then the fan kicks in like it should. When I drive it the needle shoots to the bottom. I know it points to a stuck stat but why? How possible is it to have 3 bad stats in a row? I did order the Metal Housing today BTW. I am sick of having to order the plastic one from California and waiting a week. As it is I have to pay for shipping to send these things back. At least I can buy a T-stat from my local parts store for $10 with the metal housing.

[Daniel]

Weird problem. Try pouring water in a removed thermostat and check if it leaks.

[Trey05Woo]

I don't think its your thermostat, though it could be... you can do a physical check and touch the hoses... but the simple fact you have a C E L makes me believe you have an electrical issues with the temperature sensor or circuit...

GET THE CODE...

probably your fan is coming on but not turning off

[chefrza]

Well I got the metal housing today and hope it works. I will put it in later. As for the CEL code it is PO128 Which it says Coolant below normal running teperature. I have no clue as to what that could be besides the t-stat. Any input would be greatly appreciated.

[Trey05Woo]

Well many things can affect coolant temperature. The coolant system is composed of a temperature sensor, dual speed cooling fans, and the thermostat and coolant. You can check the thermostat by boiling some water and dropping it in and verifying that it opens, and then closes once it cools down.

You can also have a lazy or slow responding temperature sensor fooling the computer ans making it think the coolant is cooler/hotter than it real is...

Put in the new thero and see what happens...

[wolfsreign]

im with trey, either stuck t-stat or thermo sens. basically.
you did say the fans turn ON, but what about OFF? we need to know these things to help >.<
if they don't turn off, then there's you #1 problem...
and if i could, i would roll with the metal, i already had one blow apart, plus like u said, u can take it apart and change the t-stat, if u wanna run hotter or cooler engine
~wolf

[chefrza]

Ok guys here is what I have so far. I am starting to get boggled. I installed the new temp sensor. The CEL kicked back on with the same code. So I got the metal housing and went to install that yesterday. While tightening the bolts the housing snapped in half. With that said it has now put me into the red with the loss of a $63 part. I found that a local auto parts store can order a t-stat straight from daewoo in south korea. The fan does operate normally. Turns on and off. I really hope its the stat. I really dont know what else to look into. Thanks so far you guys have been great.

[wolfsreign]

didnt you say you bought a metal one?
if you did, just go down to autozone (or something like it) and match the inner diameter of a stat, say from a chevy....
but the plastic ones... they can't break while tightening them, b.c they should have a metal bushing in the screw holes.
unless you put the hose and hose clamp on and tightened it too much like i did and broke it @.@
but try try try again.
~wolf

[chefrza]

Looks like I have a problem solved. I ordered a t-stat from daewoo in south korea. It is on and the car is running good and keeping temp. Now to just let the computers run and see if it kicks the CEL on. Here's praying to a happy and inspected car. Thanks for the help guys. I will let you know about the inspection.