Random Heat
#1
Random Heat
It's getting cold and I've been running the heater in my 63 almost every morning. Lately, though the heat is intermittent. The fan blows, but it'll go between blowing hot and cold air. Seems that it blows warm and first and then starts to blow cold after a bit of driving. Not always, but usually sometime before I make it to work it'll start blowing cold. Sometimes it'll kick back to hot for a mile or so.
The core is not leaking from what I can see. I've checked the hoses in the engine bay and they are hot, so I think it's circulating. Maybe there is some sort of clog somewhere? Before I start tearing anything apart does anyone have suggestions as to where to start?
The core is not leaking from what I can see. I've checked the hoses in the engine bay and they are hot, so I think it's circulating. Maybe there is some sort of clog somewhere? Before I start tearing anything apart does anyone have suggestions as to where to start?
#2
I'd start with the basics.
A few things to check:
- coolant level
- maybe a blockage in the heater core?
- thermostat
- hvac controls
When I first bought my 75, upon inspection I noticed there was a vacuum line off near the blower motor. Once that was connected, it started blowing hot air as expected.
A few things to check:
- coolant level
- maybe a blockage in the heater core?
- thermostat
- hvac controls
When I first bought my 75, upon inspection I noticed there was a vacuum line off near the blower motor. Once that was connected, it started blowing hot air as expected.
#6
I'd start with the basics.
A few things to check:
- coolant level
- maybe a blockage in the heater core?
- thermostat
- hvac controls
When I first bought my 75, upon inspection I noticed there was a vacuum line off near the blower motor. Once that was connected, it started blowing hot air as expected.
A few things to check:
- coolant level
- maybe a blockage in the heater core?
- thermostat
- hvac controls
When I first bought my 75, upon inspection I noticed there was a vacuum line off near the blower motor. Once that was connected, it started blowing hot air as expected.
The second thing I thought of was the thermostat and water pump, but I've had no cooling issues and I can tell there is water flowing through the radiator. So not the water pump or the thermostat.
The havc controls work as it will blow hot sometimes. It will even go cold and then hot at random times throughout the drive.
I am leaning toward the core being blocked up or dirty as well.
I am definitely going to triple-check all of the mentioned, though.
Thanks for the advice.
I have no clue what thermostat I'm running, my guess is the original based on everything else on the car. It's worth cracking it open to double-check, though. Easier than pulling the core and checking it.
#7
The water pump isn't the issue. If the water pump is failing, the puddle of coolant under the car would be the tip-off. And as you noted, the car isn't overheating, so t-stat isn't an issue either. If you are SURE there are no air pockets (and I sometimes run the car with the nose elevated to force air bubbles to the radiator fill point), then check for blockage in the heater core or a broken cable controlling the temperature blend door. And just so we're all on the same page, a 1963 WHAT? Full size? F85? With or without A/C?
#8
I had a 88 acura integra for a few years. At the beginning of every winter i hade to back flush the heater core. Other wise the heater would work exactly as you described. I would just back flush it with a garden hose a few times and it was good all winter.
#9
The water pump isn't the issue. If the water pump is failing, the puddle of coolant under the car would be the tip-off. And as you noted, the car isn't overheating, so t-stat isn't an issue either. If you are SURE there are no air pockets (and I sometimes run the car with the nose elevated to force air bubbles to the radiator fill point), then check for blockage in the heater core or a broken cable controlling the temperature blend door. And just so we're all on the same page, a 1963 WHAT? Full size? F85? With or without A/C?
This is a 63 ninety-eight custom sport. 394 ultra-high compression with A/C.
#10
right from the hose in the engine bay or how did you get to it?
#12
You can get a flush kit for your radiator/heater core at any parts store.
Right next to it on the shelf should be a large funnel with various fittings that connects it to multiple radiators. This allows you to belch the coolant system an ensure there aren't any air pockets.
Right next to it on the shelf should be a large funnel with various fittings that connects it to multiple radiators. This allows you to belch the coolant system an ensure there aren't any air pockets.
#13
Does the car have a heater control valve? I should know since I have a 1964. My 1959 98 has one and it is vacuum controlled by the temperature lever on the dash. Maybe if there is a heater control valve a vacuum line which opens it and allows coolant into the heater core is loosing vacuum at times and then it closes.
In a 1959 394 V8 the heater control valve is on the passenger side on the rear of the engine and it has vacuum lines going to it.
Other than that I agree with air pockets in the coolant. Also the thermostat temp just means that's when it opens and allows coolant to flow freely. So the temp is not limited to that rating. I get tired of hearing people thinking that keeps the car cooler.
Also I am assuming full size Olds, this is a 98 forum.
In a 1959 394 V8 the heater control valve is on the passenger side on the rear of the engine and it has vacuum lines going to it.
Other than that I agree with air pockets in the coolant. Also the thermostat temp just means that's when it opens and allows coolant to flow freely. So the temp is not limited to that rating. I get tired of hearing people thinking that keeps the car cooler.
Also I am assuming full size Olds, this is a 98 forum.
#15
#16
You can get a flush kit for your radiator/heater core at any parts store.
Prestone Flush Kit
Right next to it on the shelf should be a large funnel with various fittings that connects it to multiple radiators. This allows you to belch the coolant system an ensure there aren't any air pockets.
Radiator kit
Prestone Flush Kit
Right next to it on the shelf should be a large funnel with various fittings that connects it to multiple radiators. This allows you to belch the coolant system an ensure there aren't any air pockets.
Radiator kit
Does the car have a heater control valve? I should know since I have a 1964. My 1959 98 has one and it is vacuum controlled by the temperature lever on the dash. Maybe if there is a heater control valve a vacuum line which opens it and allows coolant into the heater core is loosing vacuum at times and then it closes.
In a 1959 394 V8 the heater control valve is on the passenger side on the rear of the engine and it has vacuum lines going to it.
Other than that I agree with air pockets in the coolant. Also the thermostat temp just means that's when it opens and allows coolant to flow freely. So the temp is not limited to that rating. I get tired of hearing people thinking that keeps the car cooler.
Also I am assuming full size Olds, this is a 98 forum.
In a 1959 394 V8 the heater control valve is on the passenger side on the rear of the engine and it has vacuum lines going to it.
Other than that I agree with air pockets in the coolant. Also the thermostat temp just means that's when it opens and allows coolant to flow freely. So the temp is not limited to that rating. I get tired of hearing people thinking that keeps the car cooler.
Also I am assuming full size Olds, this is a 98 forum.
It's got 59,000 original miles and everything I am finding on it is original. It looks like someone found it in a garage or barn and did a Craigslist rebuild to it. But it is evident by the leaves that were painted red right along with the intake and how everything else is painted black under the hood. Including the belts, washer fluid container, etc.
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August 15th, 2015 09:18 AM