Need more heat!

[Jim S]

My 87 heater takes a long time to heat up and never gets really hot.  The temp gauge only gets up to 140. I have a 195 thermostat. The core has good flow too and I have a new water pump.  I had the same 305 engine in an 89 Camaro and it got nice and toasty.  Any suggestions?

[Avanti83]

Are you sure the thermostat isn't faulty or missing. If it's closed the engine should heat up as essentially all the water flow is restricted?

Edited December 19, 2022 by Avanti83

[Jim S]

It has a 195 thermostat in it.  I don't know if it's stuck open though.  I'll have to pull it and see.

 

[Jim S]

I looked at the thermostat on a cold engine. Heck it was 28 degrees in the garage.  The themostat was closed.  I replaced it anyway with a new 195 degree thermostat.  I ran the engine until the temp gauge moved up to about 150 and that's when the thermostat opens. Then the temp drops again, and the cycle repeats.  Still just luke warm heater air.  This is the exact same thing the previous thermostat did.  Why is a 195 thermostat opening so early?  I'm indeed baffeled.  

[mfg]

1 hour ago, Jim S said:

I looked at the thermostat on a cold engine. Heck it was 28 degrees in the garage.  The themostat was closed.  I replaced it anyway with a new 195 degree thermostat.  I ran the engine until the temp gauge moved up to about 150 and that's when the thermostat opens. Then the temp drops again, and the cycle repeats.  Still just luke warm heater air.  This is the exact same thing the previous thermostat did.  Why is a 195 thermostat opening so early?  I'm indeed baffeled.  

Hmmm..that's a head scratcher!

As a band aid, you could try partially blocking the radiator from the front.

 

[wdaly]

18 hours ago, mfg said:

Hmmm..that's a head scratcher!

As a band aid, you could try partially blocking the radiator from the front.

 

Yep - nice piece of cardboard always works for me (when it's really cold).🥶

[Footer]

It would be nice if you could connect another temp gauge to make sure yours is accurate. Suppose it wasn’t and your engine temp was right but your heater core is restricted. Have you ever flushed your cooling system and back flushed the heater core?  Just a thought.   Mike

[pantera928]

You could check that the slider for the heater control opens the valve 100%. If it does, try disconnecting the heater hoses where that connect to the engine and flushing water through the heater core backwards and forwards using a water hose to make sure it is not partially plugged. Of course be sure that the water valve is wide open

[Avanti83]

On 12/24/2022 at 4:34 PM, Jim S said:

I looked at the thermostat on a cold engine. Heck it was 28 degrees in the garage.  The themostat was closed.  I replaced it anyway with a new 195 degree thermostat.  I ran the engine until the temp gauge moved up to about 150 and that's when the thermostat opens. Then the temp drops again, and the cycle repeats.  Still just luke warm heater air.  This is the exact same thing the previous thermostat did.  Why is a 195 thermostat opening so early?  I'm indeed baffeled.  

You can check both thermostats for opening temperature by putting them in a pan with a thermometer and heating the water. You'll be able to see when they start to open and at what temperature. If they open close to the 190 deg range then it's a circulation problem and you'll need to look at the suggestions above like flow through the heater including restrictions in a line and how the valve is working. Does it open all the way or restrict flow. You cannot rule out an air bubble in the heater circuit reducing flow so when you check for a restriction you should also look at air in the system.