Has anyone else had issues with the OEM thermostat sticking open? I found only one or two threads that even mention it, yet I'm now going to have to get a second one replaced in less than 4 years.

My original one was replaced under warranty last July after 14338 miles with 18 track days, all at stock engine power. This weekend during a brief drive I got the SES light and P0128 code after the car not really coming up to temp within 15 min. Same symptom as last time, except now only 5800 miles, but 11 track days with the typical bolt-ons running 324 whp/315 tq.

Last track event was two weekends ago at Palmer which was hot and humid, 85-92 deg depending on session time. Logs show the max ECT never got above 221, which was only during one session briefly. Most other afternoon sessions max ECT was 213-217, avg was 200-207 over the span of 20 min sessions.

Is this typical and just something that needs to be replaced every year or two when tracking? Or is it time for a radiator upgrade?

 

Do you know what water temps you're running on track? If you're running 230* all day at the track, it could shorten the life of the tstat.

 

Yes, highest coolant temp hit was 221 deg F during one of the afternoon sessions. Still running with OEM coolant since she's not completely dedicated to the track. Temps can dip here in the northeast early spring and late fall, and I park it over the winter.

Here are some logs from the afternoon sessions at Palmer.

D1 S3


D1 S4



D2 S4



D3 S3

 

220, while not terrible for track conditions, is still hot. You can expect it to shorten the life of the tstat..