Engine running cold
Thread Starter
Joined: May 2016
Posts: 13
Engine running cold
Howdy, I have only posted here a couple times (thankfully) but i have had a little bit of a problem this past week I am trying to get some input on.
I have a 2002 monte carlo, 3400 v6, just put new brakes, tires and a new radiator on last summer.
I live in Illinois and we have been having a string of near 20-30 degree days and 10 degree nights for a while now, anyways, about 3-4 days ago i was at Walmart (which is a 20 min drive from my house) when i noticed my engine temperature gauge was sitting real low after the trip, it was about a 8th of the way up, which i know is too low.
I am trying to get some input on what it might be before i send it to a mechanic, have them tell me 10 things i need fixed and drain my savings, I seen online it is more than likely the thermostat... The radiator has dex cool, the fans are not kicking on, i checked the hose and it was fairly warm but not hot and i hovered my hand above the engine and felt heat.
It seems to drive fine, I am just worried why all of a sudden it is running low and what damage it can cause until i diagnose the problem or how i might go about diagnosing the problem, Anyway ideas why the temp is that low? Thank in advance.
By the way, Is it safe to drive with the temp that low?
I have a 2002 monte carlo, 3400 v6, just put new brakes, tires and a new radiator on last summer.
I live in Illinois and we have been having a string of near 20-30 degree days and 10 degree nights for a while now, anyways, about 3-4 days ago i was at Walmart (which is a 20 min drive from my house) when i noticed my engine temperature gauge was sitting real low after the trip, it was about a 8th of the way up, which i know is too low.
I am trying to get some input on what it might be before i send it to a mechanic, have them tell me 10 things i need fixed and drain my savings, I seen online it is more than likely the thermostat... The radiator has dex cool, the fans are not kicking on, i checked the hose and it was fairly warm but not hot and i hovered my hand above the engine and felt heat.
It seems to drive fine, I am just worried why all of a sudden it is running low and what damage it can cause until i diagnose the problem or how i might go about diagnosing the problem, Anyway ideas why the temp is that low? Thank in advance.
By the way, Is it safe to drive with the temp that low?
Last edited by bigman3692002; Jan 26, 2017 at 09:42 AM.
Joined: Oct 2016
Posts: 333
Sticky t-stat, inaccurate gauge/stepper motor, just things that stand out to me. Shouldn't cause any damage but I imagine you'll have worse fuel economy. Just get it repaired asap as with anything on a car - the sooner you fix a minor problem the better so you don't fix a major one later.
Thread Starter
Joined: May 2016
Posts: 13
Thank you for the quick reply, I am going to pick up a thermostat and hope it helps, i might even test the current thermostat first, to be honest they look like a son of a gun to get off and back on, nothing like the old cars, but everything that i read online said it has to be something to do with the thermostat or housing or gauge, i appericate your input, the whole situation just got me worried that i can cause damage to the engine leaving it run low, Lord knows i cant afford a new car, i know running hot is by far worse but it will probably be about a week before i can get it changed and i already been driving this way for 3 or 4 days, it is my only car and my daily driver, i need it to get to work and back.
I will look into what you mentioned, any other input is welcome, once again, thank you.
I will look into what you mentioned, any other input is welcome, once again, thank you.
Joined: Oct 2016
Posts: 333
Well the t-stat for a 3800 is super easy, but the water pump and PS pump on the 3400 are much easier. Give and take I suppose.
I'd say just replace the thing while you're there and put a new gasket on. Yeah it is a PITA for sure; I've been able to do it with the cross over pipe on.
3400s are great engines. I bought 1 in a GA with 189k is ran fine till my wife got rear ended and totaled the car. I have 1 3400 in my Impala at 196k and it's still going strong; had the car since 60k still original everything save for a water pump and hoses.
I'd say just replace the thing while you're there and put a new gasket on. Yeah it is a PITA for sure; I've been able to do it with the cross over pipe on.
3400s are great engines. I bought 1 in a GA with 189k is ran fine till my wife got rear ended and totaled the car. I have 1 3400 in my Impala at 196k and it's still going strong; had the car since 60k still original everything save for a water pump and hoses.
Joined: Nov 2016
Posts: 7
From: Massachusetts
T-stat, unless your coolant sensor is bad.
It won't cause any major damage over a week if it is in fact your t-stat. but cars are not made to run cold and it will create larger problems over a longer period of time. also you won't have good heat so that's not ideal. keep in mind that no one can know for sure if it will cause damage or not and you are doing all of this at your own risk. T-stats for GM vehicles are typically cheaper then 20 bucks. I just replaced mine and it cost 9 dollars for the OEM AC delco one in my 3800 series 2. so it would be real silly not to do this as soon as possible. also you are going to need coolant and after the replacement you will need to bleed the air out of the system. Monte's are known for being a PITA for bleeding the coolant system, but really it's not hard, it just takes more time than other vehicles. just look up a youtube video for a 3400.
It won't cause any major damage over a week if it is in fact your t-stat. but cars are not made to run cold and it will create larger problems over a longer period of time. also you won't have good heat so that's not ideal. keep in mind that no one can know for sure if it will cause damage or not and you are doing all of this at your own risk. T-stats for GM vehicles are typically cheaper then 20 bucks. I just replaced mine and it cost 9 dollars for the OEM AC delco one in my 3800 series 2. so it would be real silly not to do this as soon as possible. also you are going to need coolant and after the replacement you will need to bleed the air out of the system. Monte's are known for being a PITA for bleeding the coolant system, but really it's not hard, it just takes more time than other vehicles. just look up a youtube video for a 3400.
Joined: Jan 2017
Posts: 57
Most likely your on the right track with the thermostadt, but a few things to check out while your at it.
Check your coolant level. I have worked on 2 v6 cylinder Fords in the past few years that suddenly were running cold. Both of them ended up being head gaskets. So, check your coolant level and make sure it is holding at capacity. Remember the temp gauge will only read water. If there is air around the temp sending unit then it will read cool.
Next I would verify the temperature reading. Once I worked on a suburban that the owner swore was overheating. We flushed the system, changed thermostadts, changed water pump, checked belts and hoses but he still claimed it was over heating. One day he came into the shop while it was running hot. Turns out his guage was bad. The engine was normal but was showing hot. It sounds like you already checked the running temp with your hands, so it sounds like it iss in fact running cool, but it is always possible.
My wifes work car always runs cold in the winter, so I jammed some cardboard in front of the radiator to block airflow. It runs warmer now, but takes 10 miles or more before it will warm up enough to keep the fog off of the windows.
Check your coolant level. I have worked on 2 v6 cylinder Fords in the past few years that suddenly were running cold. Both of them ended up being head gaskets. So, check your coolant level and make sure it is holding at capacity. Remember the temp gauge will only read water. If there is air around the temp sending unit then it will read cool.
Next I would verify the temperature reading. Once I worked on a suburban that the owner swore was overheating. We flushed the system, changed thermostadts, changed water pump, checked belts and hoses but he still claimed it was over heating. One day he came into the shop while it was running hot. Turns out his guage was bad. The engine was normal but was showing hot. It sounds like you already checked the running temp with your hands, so it sounds like it iss in fact running cool, but it is always possible.
My wifes work car always runs cold in the winter, so I jammed some cardboard in front of the radiator to block airflow. It runs warmer now, but takes 10 miles or more before it will warm up enough to keep the fog off of the windows.
