Wierd idle when stopped

[djschick88]

I have a 2.3 5-speed and i replaced the water pump recently and now when i drive and stop at a light the trucks idle rpm drops significantly the throttles back up.

Also the temperature gauge doesnt work properly.
It raises to a certain degree but never levels out to normal.
The heater also does not work all the time. The heater will work now and then but slowly gets cold.

Any Ideas?

 

[Earl43P]

I'd try a new thermostat.

 

[modelageek]

It sounds to me like you are low on coolant or have air in the system. I would check your coolant level and burp out all of the air out of the coolant systems.this seems to work for me.take the cap off Run the truck till it is warmed up squeeze the upper rad hose trying to get the bubbles out. Also you can park on as steep of a hill as you can find and sit with engine running

 

[modelageek]

On your truck are the tenp gauge sensor and coolant temp semsor right next to each other on the tstat outlet housing

 

[hartwrenches]

coolant

On your truck are the tenp gauge sensor and coolant temp semsor right next to each other on the tstat outlet housing

if the coolant is low or has air in it there's nothing to heat the sensors.
First this will tell the computer your engine is cold, and mess with the idle.
Second it will enventually burn out the sensor.
Make sure the coolant is all the way full, and like mentioned before, make sure the thermostat is working.

 

[Bryan22]

I'm with model a geek. you probably didn't get all of the air out of the system when you replaced the water pump that would explain the intermitent heat and the wonky temp guage. just make sure you've got the coolant topped off and all the air out of the system.

 

[hartwrenches]

coolant

I'd try a new thermostat.

Purge all the air out, top up the coolant, and if its still a little screwy consider a thermostat.

 

[djschick88]

I replaced the thermostat over the past summer so that should be good.

I found a vacuum hose too the valve that opens when you turn on the heater was unplugged and now the heater works. So thats good the surging seems to have stopped also.

But the temp gauge is still not working properly ill take a pic of the gauge when the truck should be at normal operating temperature so yall can see what it looks like.

And the air bubbles were a problem thanks to everyone that posted so far.

 

[hartwrenches]

Temp gauge

If your gauge is just reading lower than it did before you changed the pump I wouldn't worry about it. Its just running cooler with the good pump. You can check it with a temp gun, if the temp is the same as the t-stat rating then everything is fine.

 

[djschick88]

it has always been lower than normal. For what ever reason.

 

[hartwrenches]

Mines allways ran at the first line in the gauge, not even to the n. Until the fan clutch crapped out then it ran warmer. But never more than halfway up the gauge.

 

[Resurrection Ranger]

I ran without the clutch fan for a winter once. Worked GREAT to build up heat considering it never really gets hot enough to lock up.

That was UNTIL i got stuck in the snow!!
Clutch fan back in place now