ps374

I decided to change my thermostat from a 160 to a 180 since my Corvette lived most of its life in Florida. The car was running bad. Idling at 1300 RPMs and the idle would fluctuate. I would seem to almost die at idles then speed up. It was crazy. I changed the thermostat today and its like a different Corvette. It idles at 600, when you stop it drops down in RPMs it even shifts different. I can drive the car at normal slow speeds without it speeding up.And so far no Check engine light. Is it possible a thermostat can do so much in my 1984?

RRT vette

No a thermostat can't perform miracles. All it does is control the warm up time and the minimum operating temperature. I'm thinking you might have fixed a vacuum leak by accident. But sounds good.

daca

aminnich

Put in a 187 1/2* t/stat and gain 50 hp and your MPG will increase to about 75mpg. Just not teling what a 195* would do.

Glad it worked out for you

runner140*

I put in a 160 tstat and it made me better looking.

ps374

Is it possible that the thermostat change which now makes the car run warmer (is never got past 164 on temp guage) would make the ECU operate differently?

RRT vette

Not likely. The 160* stat is why the engine ran cooler than stock. The temp stated is probably the temp when driving and in traffic the temp increased. The fan is controled by the ECM and doesn't come on until 228* stock. If the thermostat had anything to do with the ECM it was because the CTS was sending a higher resistance signal from the cooler engine to the ECM which contols the A/F ratio depending on engine temp, throttle %, ect. You probably stayed closer to open loop more. You should notice a difference in MPG now. Stock t-stat for a 84, I believe is 195*.

silver84

I really like a 180 t-stat.

coolant, oil, always at 190 to 200 degrees.

I can turn the fan on from inside.

180, strongly recommended.

Muffin

Food for thought: If the coolant sensors were correctly reporting both the incoming air and coolant temps were too low the ECM would be overfueling. Same logic as a xxx ohm resistor across the coolant sensor for more fuel at WOT. I really don't know but it is something to think about. BTW closed loop only requires a temp of 104, on the 85 that is, so I don't think that is a cause.

RRT vette

Interesting and does make sense.

I noticed on my 86E, from scanning, that the ECM went closed loop at around 140*f coolant temp (CTS and guage sender being equal). I am using stock exhaust manifolds and a one wire O2 sensor. I know the exhaust temp has to get to 600*F before the O2 sensors starts sending signal. Less temp for a 3 wire heated O2 sensor.

dc3plt

Just curious.

What is the stock T-stat temp for a 1995?? It's involved in my winter plans but I'm not sure what temp to buy. I want stock and nothing else.

Thanks ALL!!

RRT vette

180*, but make sure it's for the LT1 when you purchase and make sure it has the rubber gasket ring around it.

rick lambert

there's also a timer for going into closed loop. And...I could be wrong, but I thought stock for later C4s was a 190 stat. just look when you pull it...stamped on it.