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Topic: Heater core or vacuum hose? (Read 7275 times) previous topic - next topic

Heater core or vacuum hose?

When the heat was on this morning, I could swear I smelled antifreeze a little bit but just want to make sure it isn't my imagination.

While fighting odd cooling system issues, I want to rule out the heater core as being the culprit so I'm picking one up from Ford, along with a new blower motor. For over a year now when I have "heat" its kinda like its radiated heat - like the flap isn't moving over to the heater core side or whatever. The heat is a little "warm" but thats it. Both hoses on the firewall are hot to the touch and I can hear bubbles rushing through the dash when the thermostat opens. Does this sound more like a pinched vacuum line rather than a bad heater core? Also, looking at the water pump and heater tubes on the intake, isn't water always supposed to be flowing through the heater core, thermostat open or closed?

I'm not looking forward to this, but I'm sure my best bet for knowing is to unhook the hoses on the firewall and try blowing air through the heater core. Those hoses are a pain to put on/off.
1988 Thunderbird Sport

Heater core or vacuum hose?

Reply #1 –
Quote
Also, looking at the water pump and heater tubes on the intake, isn't water always supposed to be flowing through the heater core, thermostat open or closed?


Yes.


Quote
When the heat was on this morning, I could swear I smelled antifreeze a little bit but just want to make sure it isn't my imagination.



Turn the heat to the vent position.  Let the car run with it off for a couple of minutes then turn the heat on.  A slow leak will show itself as the smell being present for a few seconds and then it will seem to disappear.  Shut the heat off again for a few.  Repeat.  It should happen again if there is a leak...
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

Heater core or vacuum hose?

Reply #2 –
...Ford wanted $165 for a new blower motor. I figure while I'm in there it'd be a good time to replace that as wall but $160?!. Of course, for giggles, at the dealership its $750 in labor to replace the heater core.

Picked up a new radiator cap and going to replace the thermostat with a 180 degree one until I can figure out exactly whats up with the cooling system.
1988 Thunderbird Sport

Heater core or vacuum hose?

Reply #3 –
Quote from: V8Demon;200474
Yes.


The heater core guide on Coolcats states otherwise, which is why I ask. It mentions heat when the tstat opens.
1988 Thunderbird Sport

Heater core or vacuum hose?

Reply #4 –
I've had heat with a t-stat stuck closed.....:dunno:
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

Heater core or vacuum hose?

Reply #5 –
Well yeah...you're supposed to get GOOD heat when the thermostat opens. :)

The way the heater core is hooked up to the engine, there is always coolant going through, regardless of whether the thermostat is open or closed. The feed line to the core comes directly from the water pump via a coolant rail or a long hose, depending on the engine. Technically you can have a bad thermostat (stuck closed or open) and still get heat through the core, as Paul mentioned. But in a lot of instances it's not good heat when that happens. The core works much more efficiently when the thermostat is working correctly. Here is why.

Think of the water pump as sort of a "heart". It feeds two arteries at the same time: one to the heater core, one to the block. The amount of "blood" (coolant) remains the same; both systems pull from the same volume of coolant. So if one side is blocked (i.e. clogged core or bad thermostat), you lose some of the efficiency because the same amount of coolant is going to one "artery", not two like it's designed to do. When both are operating normally, then you get the correct amount of coolant to both the heater core and the block and efficiency is at its maximum. Plus, when the thermostat opens, it's letting the warmed-up coolant into the core...that's why you get the sudden burst of heat right after the thermostat opens when you watch your temp gauge.

Since the greater volume of coolant goes through the block, it's much more important that the thermostat works correctly, rather than the heater core. But it's better that both work as intended.
 

Heater core or vacuum hose?

Reply #6 –
Does this car have ATC or manual MVAC?

Heater core or vacuum hose?

Reply #7 –
Manual

Weird thing - on the drive back today, after the temp stayed at the top of the N for 15 miles, it suddenly dropped to over the M for 10 miles or so before the thermostat closed and the temperature shot back up. Top of radiator and hose was hot to the touch when I got back and the lower hose was "warm" with the temperature reading "O".

I took my temperature gauge back to the store last week since I know my problem isn't a faulty gauge - the thermostat, heat, and warmth of the radiator all act funny so need need to hold onto that $45 gauge at the moment. Just saying this so I don't get the "the factory gauge is far from accurate" speech - I know its only a reference, as are all the other gauges.

Lastly, this morning when I went to park the car, I popped the radiator cap off a couple times for a split second. Both times warm water sprayed out. The odd thing is after doing this, the temperature gauge dropped a few seconds later. What does relieving the pressure tell me? Lower radiator hose is collapsing?
1988 Thunderbird Sport

Heater core or vacuum hose?

Reply #8 –
...and when I went to lunch today, the gauge went up as the thermostat opened...stopped at "M". No going up to peak and dropping. Lots of bubbles being pushed through the system/heater core(sounds like thats where it is coming from anyways). Whats the hell is going on with this thing?

I'm thinking of bypassing the heater core and checking for exhaust gases in the coolant to pinpoint what the problem is. Semi easy way to test everything.
1988 Thunderbird Sport

Heater core or vacuum hose?

Reply #9 –
Quote
I'm thinking of bypassing the heater core and checking for exhaust gases in the coolant to pinpoint what the problem is. Semi easy way to test everything.



;)  Good place to start!
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

Heater core or vacuum hose?

Reply #10 –
yeah...its finding time though. Those hoses on the heater core tubes are VERY hard to get off - especially with them being new and firm. Then there's always the kink of trying to make a hose make a 180 degree bend with an inch and a half of space in between tubes/4" from firewall. Its too freaking cold to be without the heater too!
1988 Thunderbird Sport

Heater core or vacuum hose?

Reply #11 –
Omg, I swear the entire car is cursed with this new motor. With the heater WORKING (still not at actual full heat though, like it was years ago), I popped the radiator cap and dumped another 1/2 gallon in. You would think I would either be seeing leaks or see steam coming out the exhaust or under the hood.

My transmission will also randomly jump out of gear and back in, even if I have it set to stay in 1st. Then this morning one of my headlights wouldn't come on...its fine now.
1988 Thunderbird Sport

Heater core or vacuum hose?

Reply #12 –
Is the coolant level ever low?
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***** Project "EVOLUTION" 1987 Cougar LS  & 1985 Cougar Convertible *****
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5.0 HO 306 roller block, machined GT-40P heads, Wiseco dished forged pistons, Eagle forged floating I-beam connecting rods, Lunati pushrods, ARP bolts, Scorpion aluminum 1.6 rockers, Comp Cams Magnum 266HR, Explorer intake, 65mm TB, MAF Conversion, 19# injectors, Ford Racing stainless P-headers, 2-1/2" cat-less exhaust w/ Flowtech Afterburner lers , SC AOD with 2800 BDR torque converter, 3.73 T-Lok rear, CHE rear control arms, full 2-1/2" frame w/1" jacking rails & seat supports, Rear disk brakes, Turbine wheels, All original interior w/ floor shift upgrade .......
Pretty much every panel on my 87 is new, rebuilt, or re constructed. :D
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Heater core or vacuum hose?

Reply #13 –
I guess. The overflow bottle keeps going empty, yet I don't have any leaks I can see, nor do I have a ton of white exhaust (only steam on startup in the morning). Exhaust smells fine - rich when cold and just "hot" after its warmed up. I would think that with the amount of water I keep seeming to put into the radiator I would have a trail of white behind me going down the road. Fluids are all still good in terms of no cross contamination but there's still the possibility of combustion pushing past the gasket since we only pulled the head off the bank that had the bad fuel injector - the other one may have a slight problem. That or I have a crack in the block...

I'm going to have to park the car until I get this figured out, whether its a problem with the motor, a bad heater core, or just a ton of air in the system - or a combination of the above.
1988 Thunderbird Sport

Heater core or vacuum hose?

Reply #14 –
do you get more heat sitting at an idle than driving?
[SIGPIC][/SIGPIC]
***** Project "EVOLUTION" 1987 Cougar LS  & 1985 Cougar Convertible *****
[/COLOR]
5.0 HO 306 roller block, machined GT-40P heads, Wiseco dished forged pistons, Eagle forged floating I-beam connecting rods, Lunati pushrods, ARP bolts, Scorpion aluminum 1.6 rockers, Comp Cams Magnum 266HR, Explorer intake, 65mm TB, MAF Conversion, 19# injectors, Ford Racing stainless P-headers, 2-1/2" cat-less exhaust w/ Flowtech Afterburner lers , SC AOD with 2800 BDR torque converter, 3.73 T-Lok rear, CHE rear control arms, full 2-1/2" frame w/1" jacking rails & seat supports, Rear disk brakes, Turbine wheels, All original interior w/ floor shift upgrade .......
Pretty much every panel on my 87 is new, rebuilt, or re constructed. :D
Join us on Facebook
http://www.facebook.com/home.php?sk=group_137541156293768&ap=1