2000 Dakota 3.9v6 250000km. still runs good but when it's hot outside, my temp gauge starts climbing and will almost hit red until the fan kicks in and temp goes down to almost normal. I don't think the fan comes on at all until almost in the red. Any ideas??

 

Just asking the obvious. Have you checked your coolant level?

 

Also, a 2000 would be OBDII. It may be a good idea to invest in a OBDII reader that can read a live data stream.

What I did on my old Malibu (alas, the 88 is NOT OBDII, nor is my Cougar!) was I bought a bluetooth ELM327 adapter, and used Torque (Free at first, then Pro for about $5) on my Android phone. Total OOP with Torque Free was about $45.

Monitor what temp the ECU thinks the truck is. If it's not quite 220 when the fan kicks on, there's a fair chance that it's operating like it should ... it's just higher than your comfort level on the gauge.

RwP

 

I use UltraGage

 

That's about 155k miles. The cooling system is working if the electric fan is bringing the temp down.

When does it get hot? Idling or slow traffic OR heading down the highway?

Are you still running a clutch fan? Is it working?

When's the last time you serviced the cooling system? Has the water pump been changed? Thermostat?

 

Same thing was happening to me, but I didn't have my clutch fan on. Ended up realizing my efan wasn't working as well (motor going bad?) So I put my clutch fan back on and it is working great.

If your clutch fan is still on I would look into it. Sounds like it may be failing.

 

Water pump changed last year still has clutch fan and it gets hot usually when idling and slow traffic. lots of coolant

 

You should be hearing the fan ROAR if it's getting hot. If you don't, your clutch fan isn't working correctly.

 

Yes the fan roars but why does it take so long to come on now?

 

It could be failing the clutch can wear out (leak).

Have you ever changed the thermostat?