Gradual Overheating

[nflo555]

Sorry to post but I have read several threads and can't find one related to my problem.

Background:
2000 Blazer V6 4x4 w/ 103k miles.

New fan clutch (Hayden severe duty), tstat replaced last year and coolant is the green kind and at the correct level. Heater core inlet and outlet hoses are both hot to the touch. MotorRAD rad cap, probably replaced 2 or 3 years ago.
I am not losing coolant.

I live in Oklahoma and it has finally gotten over 100 degrees.

Problem:
When leaving work (5:00) and the temp outside is 100 plus, it stays a tick left or less of 210. Then about 10 minutes or so into the ride (highway) it's begins to move a tick or two right of 210 and then when I get off the highway it stays between 1/2 and 3/4 and can't seem to cool down to a tick left of 210.
I've also noticed in the mornings (before 8:00) when I arrive at work (20 minute drive via all highway) it is just a tick or two right of 210. The outside temp at this point is between 80 and 90 degrees.

Only a couple of times has it gone to the 3/4 mark but that has usually been when I shut the truck off and start it again and then it goes between 1/2 and 3/4.

It has never gone to the 260 mark.

Is this normal with such high outside temps?
Will a flush really help?
Could it be the water pump? If so, it doesn't leak. How do check if it is going bad?
Any thoughts would be great.

Thank you for your time.

[Rick Norwood]

Welcome to the Forum. Don't apologise for posting, that's what were here for.

Start here: http://www.automotiveforums.com/vbul...d.php?t=729213

It sounds like you may need a good flush to start. I had the same exact problem with my 2001, and I live in Phoenix, mine only overheated above 210° when the Air Cond was on. A good flush will help. A Reverse power flush at your favorite garage or dealer is best and well worth the money, Usually around $75 USD. Otherwise, use a good cleaner like Prestone heavy duty Radiator Flush. Follow the directions on the Bottle. Don't put it off, I lost a Radiator over it. When you shut the truck off and start it up again it is normal to see the temp go up for a minute, then go back down.

it doesn't sound like a water pump to me, it sounds like a dirty Radiator.

[MT-2500]

If your system is dirty a flush will help.
I would also make sure the gauge is reading the right temp.
And always go another stat.

If the stat and gauge is right at about 195-200 the tempt should stop raising and level off in that area.

Dash gauges can be off so verify the actual running temp.

You can read the engine running temt with a scanner.
Or use one of these.

http://www.calright.com/_coreModules...FRieWAodkzhWpA

[BlazerBoyLT98]

I had the same issue and it was a plugged radiator do to some moron mechanics putting in a new radiator and mixing green with red. A good reverse power flush with a new rad cap, t-stat and a few new hoses and have not had a problems since, even running the ac while towing.

[nflo555]

Thank you for the assistance.

I did leave one item out.

About a year and half ago, one of the plastic tanks cracked. I drained the radiator (did not flush or drain the block) and removed it so a local radiator shop could replace the tanks ($75 with a 1 year warranty) and just refilled the system with the green stuff. It had green stuff in it before.

Probably should have flushed it prior to the re-installation.

Do any of you remove the drain plugs (located below the exhaust manifolds on V6's) on the block to remove the fluid before the flush?

The Haynes manual I have lists that as one of their steps when flushing the engine. They just seem hard to get to but may not be if I remove the front tires.

Thanks!