Cooling system

[quickdraw1]

I have 98 Caravan. 3.0 engine. 198,000 miles. Just changed water pump and timing belt. Engine runs fine. I am concerned that temperature gauge on dash shows higher temperature than what I recall before water pump change. The temperature gauge now hovers around the halfway point and the engine seems and smells hotter. At this point, I can not hear the cooling fan on. It seems the only time the cooling fan will come on is when I turn on the A/C, at which time both fans come on automatically.

1) At what temperature is the cooling fan supposed to come on?

2) Do I need to investigate further? I am concerned that since I had the water pump go out on me maybe the cooling fan not coming on or operating properly is a secondary problem.

Any comments?

[mfahey]

Sounds like you may still have air in the system. I've had good luck with jacking the front end up as high as I can and then run the engine with the cap off.

[Rick99]

x2 on the air. Run the engine with the cap of as stated above. You can also "burp" the system by squeezing the upper radiator hose, just do it when you first start (with a cool engine) and watch out for coolant coming out of the radiator fill hole. You could also check to see if the connector on the temperature sensor is tight (maybe you knocked it loose as you were working on the van).

[quickdraw1]

I tried to jack up van last week and run for a while. Temperature gage still hovers around half way point. I also tried to 'burp' upper radiator hose. We are using this van every day and have probably run it over 6 hours.

1) Again, at what temperature is the cooling fan supposed to come on? Is letting the temperature get to the 1/2 way point ok? Again, if my wife's and mine memory serves us right, the temperature gage never got over 1/2 way between 1/4 and 1/2 on the dash temperature gage.

I am tempted to replace the sensor. I have already unplugged the wire to the sensor and the 2 fans come on automatically. Also, as I said earlier, when a/c is on, both fans come on.

But the cooling fan does not come on on its own. Why?

And the temperature never gets over 1/2 on the dash gage.

Any more comments?

[quickdraw1]

One more thing....since I replaced the water pump and timing belt, I have noticed that the engine feels like it is hesitating and the miles per gallon has gone down. The engine only hesitates when gas peddle is first pushed down. It still has plenty of power and go after initial hesitation. To answer those who think timing is maybe off, I checked timing alignment at least 3 separate times before putting timing cover back on. A friend of mine thinks that the higher than normal operating temperature could be the cause of the engine hesitation and lower gas mileage.

[mfahey]

That sounds more like a vacuum leak. Check all of your connections to be sure one didn't get disturbed or broken.

[quickdraw1]

One more thing....the cooling fan is not coming on by itself. It only comes on when the a/c fan (2nd fan) comes on.

[BigBobbyO]

When the AC is on and the fan is on, does he temp run cooler? Maybe there is a problem with the fan relay or temp switch.

Next, and this is just a thought because I'm not good with the particulars of timing but, is it possible that the temp it is running at now is normal and the old timing belt caused the temp to run cooler than it should have?

My 94 runs just below the 1/2 way mark on the gauge and the fan rarely goes on (except for sitting in traffic on a really hot day)

And now that I think about it, you changed the pump because it was leaking, right? Or did you change the timing belt, and the pump because it was there? My point is, did you happen to throw any stop leak in the radiator at all? Because that crap will cause some problems.

[jslash]

The temperature gauge now hovers around the halfway point

Any comments?

Just an FYI... My '97 has ALWAYS hovered right at the halfway point. The only time it was lower than that was when I had a problem with the thermostat.

Jim