Hello Guys,

I'm a new member here. I just bought a 91 LS 4D. It have 133000 mile on it. After 2 days driving it and I found out a few thing I noted and I hope you guys can help me out.

1. Temp gauge acting up. If I park or driving slow speed the gauge point at normal Temp, but when the speed pass 50 mile per hours the gauge slowly drop all the way down and stay there.
2. RPM gauge it still go up and down but it stuck at 1750RPM won't go all the way down to 0.

If anyone know or have a same problem and all ready got it fix. Please help me out.


Thanks

 

replace you t stat but check your colant 1st the rmp thing seems like your vss might be going out.

 

Thank you L3GDKANG/JDM-KA for your reply. I will check the coolant before I change the thermostat.

About the RPM. Could you tell me what is VSS I don't know anything about mechanical term and could show me how to fix it?


Thanks

 

its the speed sensor if you speedo is working ill have to check something else out.

 

also dont forget to bleed the system after you open the radiator cap once you put it back on. the bleeder is located on the water neck ontop of the block.

 

The gauge for Mile/HRS working fine, only the RPM Gauge it just stuck at 1750RPM but when the car pick up speed to 45 the gauge start move up.

 

may need to be recalibraded. but if you get 1 from a junk yard you can swop it out easy.

 

Check to see if you have any vac leaks and dose your heat blow hot?

 

Thank you L3GDKANG/JDM-KA for your help. Your posts help me a lot.

Before there is no Heat. I just flushed the radiator and changed the thermostat(Thermostat is bad). Now I got heat but the Temp Gauge don't show any movement after I let the car run about 10min, maybe I didn't let run long enough the get it hot. I will make a long run today see what happen.

Thanks

 

keep me posted and glad i can help!