Overheating and no heat ??

Radiator, thermostat, water pump, antifreeze, etc.
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Topic author
blacknome
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Overheating and no heat ??

Post by blacknome »

Temps here have been -20 - -25 C range for the past few days.

Coming home last night ( 10 min commute ) I had no heat in the van ( front or rear ) but the engine temp was normal. When I got home I felt the heater core hoses and they were both cold. Checked the Antifreeze level and it was normal. I went out after supper ( 30 mins later ) to check again for a problem ( thinking the heater control valve ) and after 2 mins run time the heater was working fine.....WTF ?!? For giggles I checked the coolant ( new in july ) and it tests out at between -40 - -45 so it wasn't a frozen or blocked heater core.

Scratching my head I plugged the van knowing it was going to be cold this morning.

Running late today so only 2 mins warmup before I left for work. I got about a block from home before the temp climbed high enough that I had to turn around ( no heat in the van BTW ). By the time I got it back home it was overheated.

So as I sit here waiting for a cab ( not driving my 84 monte to work in this stuff ), what do you all think ??

I am leaning towards a water pump ( weep hole is dry ) and will swap out the thermostat while I am in there.

Topic author
blacknome
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Re: Overheating and no heat ??

Post by blacknome »

thermostat, serp belt , water pump, 2 gallons of coolant have been ordered from the local parts jobber.

Rocking an F150 ( with heat ) from Uhaul to get me around until I can sort this out.

Wish I had a garage to do this instead of the driveway. I would also like to flush out the heater core again ( I did it last summer when the lines rotted out to the rear heater ) but its too cold.

Teardown tonight and hopefully rebuild tomorrow. Will update if I figure this out.

astrozam
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Re: Overheating and no heat ??

Post by astrozam »

I would have figured the t-stat was partially blocked or you had very low coolant if you were getting little to no heat in the van. I don't think a 10 min drive in the crazy cold should have spiked your engine temps necessarily but then you mention the next day the engine getting too hot after only 2 min, something weird...anyhoo best of luck with the work it totally sucks in this weather :cheers:

Topic author
blacknome
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Re: Overheating and no heat ??

Post by blacknome »

astrozam wrote:I would have figured the t-stat was partially blocked or you had very low coolant if you were getting little to no heat in the van. I don't think a 10 min drive in the crazy cold should have spiked your engine temps necessarily but then you mention the next day the engine getting too hot after only 2 min, something weird...anyhoo best of luck with the work it totally sucks in this weather :cheers:
I am thinking the thermostat as well but wouldn't I still have interior heat ?? Rad was full and the overflow just past hot level when I changed the oil last weekend and again last night when I got home.

Meh, at least it happened on a Friday and I was able to limp it home saving me a tow and the cost of a rental car for the week. :)

LiftedAWDAstro
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Re: Overheating and no heat ??

Post by LiftedAWDAstro »

I would say the problem is the t-stat. The reason you don't get hot fluid through the heater core is that the t-stat never opens so the antifreeze never warms up. This is also why the engine got so hot in such a short time.
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Topic author
blacknome
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Re: Overheating and no heat ??

Post by blacknome »

fought the cold and got it stripped down to the 'stat. Tested the old one and the new one 3 times. Both open at appx 200 deg ( according to wifeys thermometer ). I don't have a wrench big enough to pull the fan so I will buy one in the AM and continue.

Forcast is for heavy wet snow sunday so I got to get this buttoned up Saturday
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1Gary
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Re: Overheating and no heat ??

Post by 1Gary »

I give tons of credit to work out that cold =D> =D> .When I was younger I could,but no more [-( .Even back then it would take some thinking about the job I was going to do before I could out to do it.
1979 Malibu drag race only car
1999 Sonoma 4.3 5 speed-Rufus
1989 Astro-Ole Yellar cancelled-still selling off parts
1985 Astro-shop van R.I.P. my friend
1994 Astro LT RWD W4.3 rod knock RIP
1982 Winnebago single rear wheel-Chevy 350 Scraped 1/28/13-broken dreams......


Rochester,NY

Topic author
blacknome
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Re: Overheating and no heat ??

Post by blacknome »

Thx Gary. I need the van for work otherwise it would be parked until it got warmer :)

Today I found the vacuum line ( which is fine at the top of the motor next to the firewall ) to be totally rotted appx 8" down and broke off at bottom into the vacuum canister. In my rush to get my arm and wrist into totally un-natural positions while replacing the rotted line I pulled the 3x 10mm bolts and still managed to crack the 6 nippled heat distribution valve ( I blame 50% on the cold and the other 50% to brute force carelessness ). I called around the local shops and NAPA will have one for me by Noon Monday for $53 vs the dealer can have on for 7am Monday for $85 ( the $30 saving from NAPA pays for a 1 day truck rental again from Uhaul )

So far the thermostat tested fine. The waterpump feels fine when you turn it with a little resistance.

I happened to have a new Rear Heat Valve on the shelf to swap in, and I swapped out about 10' of dry-rotted vacuum line.

Temps warmed up today and the forecasted snow will be heavy snow / rain mixture. This has got to be the longest waterpump swap in my life LOL. The only 2 times this van has broke in 7 years of ownership have both been in the bitter cold ( it must be from Florida :) )

Topic author
blacknome
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Re: Overheating and no heat ??

Post by blacknome »

Almost there! The van is back together, no overheating, better interior heat than in recent memory, no leaks, but I know I have air in the system to work out over the next few days when it warms up a little.

Betcha the rotten vacuum line was the culprit for the interior heat issue. It just crumbled in my hand when I took it off

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astrozam
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Re: Overheating and no heat ??

Post by astrozam »

Good to see you got it repaired. IIRC you should get some heat as a default thru the defrost if you lose a vacuum line but none thru the vents especially if your line looks like yours...lol :cheers:
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CaptSquid
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Re: Overheating and no heat ??

Post by CaptSquid »

Seems that I have almost the same problem. Right now, I'm letting the van cool down so I can get home. But the T-stat and the water pump are brand new (relatively speaking, only a few months old). Everything worked just peachy until today. I saw the temp gage climb into the stratosphere and yet I had icicles coming out of the vents. This happened once before, only to "reset" itself after a few hours in the coffee shop. Apparently, the hot coolant thawed whatever blockage there might be. Right now, it's -12ºF with a wind chill of -36º. It's bad enough that the "ignition" switch on my power scooter is iced up, but that wouldn't amount to much, as the silly thing has NO traction in this weather. (I've poured isopropyl into the switch to thaw it out.)

It does concern me that the coolant system will show obscenely high temps with ice coming out of the vents. Thinking back, I've had this type of problem once before in a 73 MB250 Sedan. Rapping on the t-stat housing opened the system and I wasn't plagued with it ever again.
Mike, Billings, MT, 'MERICA!
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