Engine will not warm up

DAVE MACE

MEMBER
1994 CHEVROLET CAPRICE
4.3L
V8
2WD
AUTOMATIC
210,000 MILES

With the engine running for about forty minutes the heat gauge doesn't even make it to the middle, I was able to get some heat until I took it for a ride, about three miles it is blowing cold air. I changed the thermostat again because I thought I bought a bad one. I flushed heater core, the radiator and cleaned out fill tank and still nothing changed.

9 Replies

JOHNNYT73

MECHANIC
924 POSTS

First check to make sure you have the thermostat installed facing the correct direction. Are you sure that your burped all the air out of the system? Was the coolant full of rust? If it was then you may want to check your water pump to see if the fins have rusted away.

SPONSORED LINKS

Was this

answer

helpful?

Yes

Tuesday, February 16th, 2016 AT 1:17 PM

DAVE MACE

MEMBER
6 POSTS

I installed a new water pump, thermostat and flushed about three months ago. I just changed thermostat and flushed again. I cleaned the hoses and flushed the heater core seperatley. I got the whole radiator covered with cardboard and it still runs just a bit above cold.

Was this

answer

helpful?

Yes

Tuesday, February 16th, 2016 AT 1:39 PM

DAVE MACE

MEMBER
6 POSTS

My heater hoses are about 143 to 147 degrees just sitting at idle for forty minutes.

Was this

answer

helpful?

Yes

Tuesday, February 16th, 2016 AT 1:42 PM

JOHNNYT73

MECHANIC
924 POSTS

I am willing to bet there is still air in the system. It is really the only option left (unless you have blend door issue). Start the engine and turn on the heat, let it idle until you think it is where it should be warmed up, raise the rpm to 2500 and hold for about 5 seconds (you may need to do this quite a bit), keep looking for bubble at the filler until they are gone and you have heat at idle, both radiator hoses should also feel hot.

Was this

answer

helpful?

Yes

Tuesday, February 16th, 2016 AT 1:54 PM

DAVE MACE

MEMBER
6 POSTS

I burped the system for about three hours two days ago and I drove it to work twice for a total of 112 miles and the coolant level is fine I did not need to add any. It is difficult to get all the air out, but I am sure I got it.