Overheating Issue

[jtmeyer8719]

'05 with a 5.3.

Symptoms
Temp guage reads at the 3/4 mark within 5 minutes of startup. When left to sit at idle for 5 minutes, temp guage went down to normal. Start to drive and it goes back up.
Heater blows out cool air.
When running, squeezed the radiator hose, felt like nothing was passing through.
While it was hot and running, I watched the OEM electric fans for about 5 minutes, and they did not come on.
No visible leaks.
Will check coolant level when truck cools down.
I'm going insane trying to pinpoint exactly what part of the system is screwed.
Any thoughts?

 

[Sam Harris]

Have you done anything to it recently? Could just be a radiator cap causing problems. Sounds like there may be air in the system. Kinda sounds like a t-stat as well.

 

[jtmeyer8719]

See that's my problem is it sounds like 10 different problems.

Update - no coolant in the tank. Completely cooled off.

Now I'm remembering - a month ago we had some serious rain. The passenger side carpet was wet, with liquid coming from around the firewall.

Leaking or clogged heater core?

 

[Doubeleive]

See that's my problem is it sounds like 10 different problems.

Update - no coolant in the tank. Completely cooled off.

Now I'm remembering - a month ago we had some serious rain. The passenger side carpet was wet, with liquid coming from around the firewall.

Leaking or clogged heater core?

unless you had straight water in the radiator then you would know right away if coolant leaked inside, but I would fill it up and check for leaks, get a flashlight and go all the way under the front end and look around, also look down the sides of the radiator if it's leaking you will usually see it on the lower bracket that it sits in or under the water pump or at the t connectors for the heater hoses on the firewall passenger side.

 

[HiHoeSilver]

Agree with @Doubeleive Fill er up and start watching.

 

[jtmeyer8719]

Coming out of the water pump like a faucet. Weird thing is though - it just started pouring out, and the truck hasn't been started since I filled it last night.

 

[OneofFew]

Replacing the water pump is an easy job. Getting the fan off is probably the hardest. I highly recommend the special tool specifically for this engine (has pins that go into the pulley). This would be a good opportunity for replacing the idler pulleys and serpentine belt.

 

[OneofFew]

And you might also replace the A/c belt and idler pulley while in there.

 

[Kraig]

On a related note, I recently learned that you can pop the seals out of sealed bearings like those in our idler and tensioner pulleys, add grease, and snap the seals back down—no need to change them near as often and you might be surprised at how little grease they start out with.

 

[Doubeleive]

Replacing the water pump is an easy job. Getting the fan off is probably the hardest. I highly recommend the special tool specifically for this engine (has pins that go into the pulley). This would be a good opportunity for replacing the idler pulleys and serpentine belt.

it's on 05 should be electric fans

 

[SnowDrifter]

it's on 05 should be electric fans

It is. Without the belt driven one in place there is SO MUCH room to work

Pop the engine cover off with an 8mm, remove the intake pipe with an 8mm, pop the belts off, throw a baggie over the ac compressor, rrmovr your serp belt tensioner with a 15mm. It's 3 Bolts.


Un do the upper rad hose from the tstat housing, remove the 2 Bolts securing the thermostat with a 10mm. Remove the 6 Bolts holding in the water pump with a 10mm, then get annoyed at the mess of coolant.

Clean gasket surfaces, install new thermostat to new WP with new gasket. Mind the orientation of the tstat and gasket. It's pretty self explanatory. Torque to 11ftlbs.

Then grab the whole thing and install that, with new gaskets, to the block. Torque the 6 Bolt first pass to 11ftlbs. Them 22ftlbs second pass. I like to do a third pass at 22 just to be extra sure.

Hose down the front of it to get all the glycol off, Put your belts on, remove the bag from the ac compressor

Put upper rad hose back on, intake tube, and engine cover.


Grba your coolant, fill the reservoir until its brimmed. Go take a piss, then do it again. Curse at the mess of coolant, itch your upper lip, then start spitting the bad taste out of your mouth, then fill the reservoir again.

Hop in, start the car, go back and keep the reservoir topped up. Once the level stops going down, give it a few revs and go again.

Now go for a drive or hold the revs at 3k until it's warmed up. Doesn't really matter. You should have heat at this point. If not, something is air locked. Sit tight. It means you're air locked.

Once at operating temp, your tstat will open. Top up your reservoir, give it a few revs, then go for a drive to let the remainder of the bubbles work their way out.

If the level didn't drop, you're air locked. Give the thing 5 or 6 sharp revs up to redline then proceed to panic as the gauge makes a quick trip to 225 degrees before coming back down.

Top up your reservoir and go for a drive.


When ya get back, check for leaks and treat yourself to a beer. Give her one last coolant top up the next morning and you're good to go!