Ok. So this is my first post. Recently. Ought my wife a 2008 alpha. Well the water pump started leaking so I did a water pump and thermostat job. Get it all back together, bled it with a snap on vacuum bleed kit. And the truck wants to run warmer than it did. It also seems to want to run warmer on the interstate rather than just around town. Hasn't gotten above the 3/4 mark. I also noticed they were running green coolant instead of the Dex so I flushed and changed it back. Any suggestions? Btw. The fan clutch is a pain in the *** on these unless you. Uh the air hammer style fan clutch kit.

 

Mine ran hotter after I replaced the thermostat . I was told that the new thermostats are a lil warmer than the factory one. The dealer said that GM changed the recommended temp.

 

Really? Because 3/4 on the temp gauge is pretty hot. And I can tell a difference in performance when it hot

 

And I put a *185 thermostat in it

 

Mine didn't go that high. It went from 1/2 to just under to just over. It was noticeable ,but didn't see any power change. Here in SoCal we hit 110 days and I would love to see it run cooler.

 

If you put in a new AC Delco T Stat, the replacements are 5 degrees F warmer than the old factory stats from 2006-08.

You can't tell chit from the dash temp gauge, it is like an idiot light with a needle. You would need a scan gauge to confirm actual temp. 3/4 on the dash gauge is normal.

If you think 5 degrees F is going to change your performance, buy a set of fuel magnets and a TB spacer to transform your truck into a sports car.

 

I'll hook it up to my scan tool tomorrow. And get a true temp reading. Still doesn't explain why it gets hotter at highway speeds that it does around town.

 

I removed my front skid plate and the temps went down a bit. I think it may be an air flow problem rather than an actual mechanical prob.

 

Not sure why these air flow problems would show up after I put a water pump and thermostat in the truck.

 

Yes I agree. The only thing I can think of is that the new stat being of a higher temp setting, creating a more direct better airflow may help. I don't have the right answer....wish I did. I'm trying to lower my temp also. I do know we have a feature that if the car gets too hot and the a/c is on, the computer will automatically kill the a/c to help bring the temp down.

I do know many have changed radiators, pumps, thermostats and they still have the same issue. The truck still runs warm.