Thought I wouldn’t have to post another question so soon but Honda FTW.
Have a 08 3.5L accord, got a check engine for the coolant thermostat couple weeks ago. Bought an oem thermostat, installed it, check engine came back. Bought a new sensor, installed it, stayed off for a couple days then the check engine came back.
Check engine only comes on with highway driving, usually around 70mph. And my car has never overheated once even before installing everything. Temperature gauge always reads just below the middle mark
Any suggestions?
Thank you for any help given
The Check Engine Light means you have a code or codes that are stored. A basic scan tool will help you in this process. Stop throwing parts at it.
I’ve been using my basic scan tool from Amazon to clear the code every time it comes back til I get another solution. I only resorted to throwing parts at it because I can do it myself and get the parts relatively cheap, I also bought the car used and have little info on maintenance that was done prior.
You have to do the proper troubleshooting before condemning a part. Also, did you use OEM replacement parts? I would only stick to OEM replacements especially for sensors.
Anyways, possible causes:
- Leaking or stuck open thermostat
- Low engine coolant level
- Insufficient warm up time
- Faulty engine coolant temperature sensor
- Engine coolant temperature sensor harness is open or shorted
- Engine coolant temperature sensor circuit poor electrical connection
Here is a video describing troubleshooting of this.
got a check engine for the coolant thermostat
No, you didn't. Read the whole description. I don't know why, but people always fixate on the names of parts in these diagnostic messages, and immediately run out to the store to buy parts.
P0128: Coolant Temperature Below Thermostat Regulating Temperature
In other words, the engine is running cooler than it should.
The thermostat might be perfectly fine. What else can cause cold coolant.... Bad pump maybe? Low coolant or air pockets? malfunctioning temperature sensor? faulty fan?
