I recently drove my car back from Texas to SC and noticed that the temperature gauge went to 'C' cold whenever I exceeded 40mph+ ... Mostly when I got on the HWY. However, at idle/stop the temperature guage reached it's normal standing point.

I've searched common problems, and they all seem to point to a bad thermostat or faulty sensor. Before I go and change my TMS I wanted to get your guys second opinion because from my understanding a bad TMS either stays 'open' or 'closed'. In my case it fluctuates on how fast I am driving.

In other words, I'm running cold.

Any help appreciated.

 

Replace the thermostat.

 

+1. It will get your ECU out of open loop and you will have more power and better fuel eco also!

 

X2 cheapest thing to start with and most likely could be your problem.GL

 

Did someone put a 160 degree 'stat in there? That kinda sounds like the way those damn things behave.

But yeah, spend the $20 and get a new OEM 'stat first.

 

how quickly did it drop to C?

if it went slowly, like something cooling down, agree with the thermostat.
if it went quickly (middle to C in around 5 sec) then you have a connection or sensor problem.

 

Thermostat. The Honda thermostat fails open.

 

^^ 99% of the time.

 

Its not fluctuating based on how fast your driving, its fluctuating based on the amount of airflow that is passing through the radiator. It is your T stat almost always. Had the same issue on mine 6 months ago. Swap T stat and hoses and went right away. I bought the car with it messed up, my gas mileage drastically improved.

 

Hopefully it's just the T stat.. and Relic1 it drops slowly as I begin to drive past 40mph. I'll be taking it to the local dealer here Friday for a T stat replacement. I'll update you guys if that solved the issue. Thanks for everyones input/help.

 

Just do it yourself. It's like 12 bucks. Remove rad hose and these 3 bolts on the thermostat housing

 

I would, but I stay in apartments and really don't have any room or tools to do my own work. I'm on the waiting list to get a garage, hopefully I get one by the end of next month!

 

Thermostat Change it immediately.

 

thermostat is stuck open.

I do everything to my car in a parkinglot. Clutch, headgasket, waterpump/timing belt, adjust valves, you name it I've done it. A garage is nice, but not required if the weather cooperates.

swapping a thermostat requires VERY minimal tools.
drain coolant, 10mm to pull off the thermostat ground, 12mm to pull the mounting bolts, pull thermostat housing, spill coolant all over the back of the block and trans, pull out thermostat with rubber gasket, drop in new thermostat with new gasket, reinstall housing and bolts. Be sure to clean the ground wire connection point. Fill with coolant.
30-60 minute job depending on how many times you take a sip/gulp of what every you're drinking at the time.

 

Same happen with me, ended up being bad thermostat.

 

sorry to be off topic man..but I hope you have every form of security possible!!

 

Test the coolant sending unit on the block.

 

Change the thermostat. $40 and 30 mins. of your time.

 

So I got the thermostat changed and it solved the issue... BUT my heater doesn't work for some reason. I'm thinking it could be a bad wire/sensor behind the dash?

Car warms up good now though.

 

Did you bleed the cooling system?

 

I had the Honda dealer do the work. I'm not sure if they did that or not.

 

Brother man, going to the dealership for T stat? Unless you got a few dollars or seriously no time you could have don't it yourself in under two hours easy. Most of us can in 30min.

Anyway, they should have bleed it properly. At this point I would take it back just on priniciple.
To fix it yourself.
1.Jack up you front end a couple inches.
2.Get in the car and turn the key to the second postion, turn the temp gauge all the way to Heat.
3. Pop the hood, and undo that radiator cap.
4. Jump back in start the car, let it run till the fans kick on. During this time, add coolant to the radiator until it starts to overflow. It helps to squeeze the radiator hoses to push any air out.
5. Once it wont take any more coolant, put cap back on and turn car off.

 

I know, I don't want to talk about what they charged me. lol

I really don't have the time, working 12hrs shifts is killing me right now. Thanks for tip I will find some time to do this, hopefully it works.

 

they better have bled the system after im sure raping you on the price

 

You drive the rhd pheonix yellow r? Think I saw it on base today. Pm me next time Id help you out next time to change that T-stat.