NO HEAT - 0 degrees out!!

[BOOMERHD]

I may have gotten away with the headgasketinjectioncup problem until now, but the dealer thaught the problem with noheat was the heater core. They replaced it, and halfway home cold air started comming out the vents, and the temp guage showed a drop down to 160 degrees. Any thaughts on this? 2001 HD D/A, 47,000 miles.

[Kennedy]

UH-OHHHH....

Heater cores typically either leak or don't, and typically don't get blocked on the water side. The air side shoule be able to be visibly inspected.

Pushing water through a garden hose will prove the flow capability...

[mackin]

Originally posted by BOOMERHD:
I may have gotten away with the headgasketinjectioncup problem until now, but the dealer thaught the problem with noheat was the heater core. They replaced it, and halfway home cold air started comming out the vents, and the temp guage showed a drop down to 160 degrees. Any thaughts on this? 2001 HD D/A, 47,000 miles. No mention of thermostats
....??

Mac

[More Power]

Crack open the air bleed on top of the thermostat housing to see if any air is trapped in the engine. If there's a lot, and it keeps coming back whenever you drive the truck, you may have a gasket/cup leak.

MP

[BOOMERHD]

Mackin,
Sorry I did not mention that both thermostats were replace two weeks before. They were thaught to be the problem until it flaired up again a few days ago.

When I ran the truck hard after a good warm-up period this a.m., the temp guage did come up to 180-200 mark, and the heat did work. At a stop the temp went back down as-well-as the heat. Even while running at speed this afternoon the temp fell for a bit, and then came back up again.

?????BOOMERHD

[Kennedy]

You can also run up to temp w/o cap on, then put a cap or better yet psi gauge on to see if it builds pressure after the expansion is done.

Hoping this ends at 2001 early production...

[mackin]

Originally posted by BOOMERHD:
Mackin,
Sorry I did not mention that both thermostats were replace two weeks before. They were thaught to be the problem until it flaired up again a few days ago.

When I ran the truck hard after a good warm-up period this a.m., the temp guage did come up to 180-200 mark, and the heat did work. At a stop the temp went back down as-well-as the heat. Even while running at speed this afternoon the temp fell for a bit, and then came back up again.

?????BOOMERHD I know of someone who had a very similiar problem ...

Mac

[BOOMERHD]

DO TELL.

[SoCalDMAX]

Hoot just recently had his head gaskets replaced, maybe that's who he's referring to.


At any rate, my theory is much less costly. Do you have your cold front on? I'm just guessing here, but you live in an area that rivals the coldest climate in the US. Considering how much air is moved by the stock fan and how efficient the huge radiator is at shedding heat in Death Valley towing 15,000lbs, I'm guessing the cold front is a necessity to stay in normal temp range in your climate. GM wouldn't include it (even in sunny socal) if they didn't find a real need for it. At 0*, I'd think it might help a bit.

OTOH, is there some other symptoms you have that might indicate head gasket problems?

Regards, Steve

[BOOMERHD]

I have pretty much listed any and all symptoms of my sick rig. All else running well. She is much perkier and less noisy when the temp guage shows anything but cold.

[Onebigcanuck]

I've had both thermostates replaced twice, both times the rear one had opened and slipped off the pin leaving it cracked open.

When replaced I has heat again. :D

[mackin]

Boomer

Hoot had continual temperature swings along with an overflow tank that kept pressurizing .... He had no real lose of coolant, his truck also ran well right up to driving 700 miles to have it repaired last week ... He has PICS on his site ...

Best of luck

Mac

[SoCalDMAX]

So the only real symptom is it won't warm up?

Again I ask, do you have the bra on it? It sounds to me like the cooling system is working just fine and just needs to block some of that cold air.

Regards, Steve

[JMJORDAN]

Put on the grill cover. If you already have it on than I still would not get to worried. It is about 5 degrees here right now even with the cold front on my temp hardly gets above 170 just driving around empty. Driving on interstate my truck will loose heat so I drive in 5th gear instead of 6th to bring up the engine temps. Driving at 65mph in 5th gear raises my EGT about 200 degrees over 65mph in 6th. Makes all the difference in the world. These trucks have very efficient cooling. When its this cold out maybe a litte to efficient. :D