Thermostat OEM Volkswagen or OEM Honda

It has been two weeks since the repair without issues, so I am going to call this one solved. If I was paying for this out of pocket in the future, I would only replace the thermostat and not the pump as that is what was closing and causing the issue.

After getting a P0128 code and replacing the Tstat with an OEM equivalent from a parts house and my code coming back and then actually buying the OEM straight from the dealer fixing my code, I’m hesitant on what I should really put in my car since it seems to be sensitive to parts as well. I remember buying Tstats from AutoZone and never being a problem before.

I did the timing belt water pump thing on my MK4 last year, and shortly after the test drive with fresh genuine VW antifreeze and while patting myself on the back for a job well done it occurred to me that I hadn't changed the thermostat. Sure enough a month or so ago when the first of the really cold whether started around here the temp gauge would only get to about halfway to normal during a trip to town and back. I tried the ol' cardboard in the grill routine for a couple of days until I got a chance to change the thermostat and that brought things back to normal.

I've got a 13 sport with 135k miles on it. Only ever done oil changes, spark plugs, 12v battery and a thermostat. Other than that it’s been stupid reliable.

I work at a Honda dealership in the mechanic field, and I would recommend the OEM thermostat, unless you have a rebuilt engine.

Stop using cheap thermostats. Get an oem honda unit and it will last and work correctly.

I have owned my B6 since new and had the thermostat replaced under Warranty around 36,000 miles, at that point the slow warm up was causing the MIL to illuminate with a error that basically said warm up outside specification.

Car takes forever to warm up and seems to always be running rich, so I'm guessing either the thermostat or ECT, or both, is/are bad.

I have a 2015 sedan and I’ve got 192,000 km and owned it since brand new and I’ve had that happen and changed the thermostat twice, just make sure you get OEM Honda thermostat and coolant as it takes a certain type. Make sure you

Burp the cooling system of all air and make sure you add enough coolant to the radiator and overflow, it’s fairly common for the thermostats to fail

mine is also a problem an my car is 1.5 yrs old. Sometimes the temp gauge acts as if it is -40C outside even if it is a couple degrees above freezing. Often the car will take 4-5minutes to get near base idle when it is cool outside, but when it's really cold, sometimes it takes 30seconds and there is no way it's warmed up. Can also smell coolant anytime I open the hood. Sad.