Heater core or vacuum hose?

Topic: Heater core or vacuum hose? (Read 5939 times) previous topic - next topic

Heater core or vacuum hose?

Reply #15 – January 29, 2008, 10:27:32 PM

Thats hard to tell but from the way it has acted over the last week, I would have to say on average, yes. In the morning the temperature gauge always seems to stay pegged at the top of "Norm" and no heat but later in the day the thermostat opens more and it seems to hang around the middle and I have some heat...and I can hear the water rushing. Either way, today's weather was cold and cold - it was snowing in the afternoon so I doubt temperature had much to do with it. When I parked it a few hours ago I topped the radiator off again and refilling the overflow bottle that was pretty much empty.

It really seems like I'm not getting any coolant flow through the heads until the tstat opens all the way. Both gaskets are on correctly though.

Heater core or vacuum hose?

Reply #16 – January 29, 2008, 10:49:31 PM

That motor is in the car?
and, do you only lose coolant when the car is driven, rather than at idle?

Heater core or vacuum hose?

Reply #17 – January 29, 2008, 10:58:31 PM

I haven't let it idle long enough to check that or even if its consuming coolant at all (all my gauges are up in Seattle at the moment). The motor's in the car and has a whopping 400 miles on it since rebuild (similar to '93 Cobra, compression and all, but with the cam from an '89 GT). When the head gasket on the drivers side blew from the fuel injector flooding the cylinder, it was the only cylinder that when compressed air was applied, the radiator began to bubble so I'm kinda hesitant to test them all again but likely will this weekend. Initial testing after the new head gasket and resurfacing of that head (up to .007 milled off now) showed that everything should be fine. We had a couple hours of burning coolant out the catalytic converter and it was clear afterwards.

Heater core or vacuum hose?

Reply #18 – January 29, 2008, 11:09:55 PM

I hope its not a HG, but it kinda sounds as if it may be.
My caddy did the same thing. it only lost coolant when driving at higher speeds, when the motor heated up.

Heater core or vacuum hose?

Reply #19 – January 29, 2008, 11:39:30 PM

Head gasket is just a weekend's worth of work and a few hours in the machine shop to resurface the head to verify its still perfectly smooth...a pain if we must do it but thats what a leak down test is for. If anything, I would hope theres a problem on the passenger side as we made sure everything was perfect on the driver's when we pulled the head - other than a horizontal line in one of the cylinders that had us worried but the block was checked for cracks long before we even had the thing machined and built (it is not the cylinder that had the bad fuel injector). Should have pulled the other side while we were at it but some of those things are a pain to unbolt! The other side's compression with nothing but idle time on the motor were all reading around 135psi though so we "thought" the bank was alright but I'm not sure now.

I'm looking at finding the problem before something gets worse. If that mark in the one cylinder IS actually a crack (unlikely, but I'm not ruling anything out), it'll be time to build up a Boss 302 or Dart block so I can start with a strong foundation for more than 6psi on some aluminum heads. The majority of the parts in the block now should be able to take 500-600hp if it weren't for the stock roller block and the rest of the drivetrain that I have waiting to install when it warms up.

I'm still seeing 17 traffic commute, 21-22mpg city, 30 highway in the car at the moment though. Apparently, after running a tank through the car, the gallons used thats shown on the tripminder is accurate. The engine's got a ton of vacuum which is nice to see as the valves appear to be adjusted properly.

Heater core or vacuum hose?

Reply #20 – January 29, 2008, 11:43:11 PM

I need an actual recent picture, but here's how the car sat after we finished bolting everything together and the car was running decent for once.

Here's what the old motor looked like...beautiful :p

Heater core or vacuum hose?

Reply #21 – January 29, 2008, 11:57:03 PM

I remember doing the HG on my cougar. ran it and the other side blew. Tried to save a couple bucks and the job took twice as much and twice as long in the end. what can you do.

Heater core or vacuum hose?

Reply #22 – January 30, 2008, 02:32:43 AM

If your adding coolant and you dont see drips/leaks, then best do a compression test.

do that first off.

next,
Check your fan clutch because if that is mostly defective but not yet completly broke, you just found the source of the coolant problem. With a bone cold motor, you should not be able to spin the fan a complete revolution with all your might.

To check if the heater core is busted, roll back the carpet on the pass side front and feel for moisture.

Not sure why your pricing a blower motor unless yours does not "SOUND" like it changes speeds. If it has nothing but "HIGH" then the blower motor resistor is easy to repair and will be the fault.

If you think your HVAC is not deflecting the ductwork to direct heat inside the car, there is a vac line just to the right of the glovebox area that may be defective or the hvac vac connnections have a leak.

good luck on issue, looping back the heater core hoses together can be done easy enough with any 90deg tubing of a reasonable size.

Btw,, yes the core has coolant all the time ,, hense the reason for the water pump "BYPASS" hose.

To get the old hoses off, use a razor blade and cut along the tubing then peal off the hose from the tubing to insure you do not jack up the core incase it is good.

The core was repalced by a user here who claims that she cut three sides of a rectangle out on the HVAC box and was able to extract the core out this new "door" created. the core was inserted and the plastic was folded back and duct taped. This sounds like the best idea to me.

Heater core or vacuum hose?

Reply #23 – January 30, 2008, 09:06:57 AM

Radiator is cool when this all happens - its not a fan issue. This fan even cools better than the Mark VIII fan I had on there that ended up having a faulty motor.

My blower on high sounds like it has a bearing or something thats about toast. If I end up replacing the heater core, I figure it'd be best to replace the blower at the same time. As far as a vacuum leak, I haven't ruled that out as a possibility since the problem came out of nowhere one day - some time after messing with indash wiring. I think this was done in the summer though so it wasn't noticed until heat was needed again a short while later. I just need to convert the thing over to rotary controls.

As far as everything else - I don't want to buy a second compression gauge since I have one up in Seattle so I'll likely wait until the weekend to pick it up. If need be, I may also end up picking up a leak down tester since they can be a lot more useful is the the compression seems to hold fine.

Heater core or vacuum hose?

Reply #24 – January 30, 2008, 09:19:57 AM

Quote from: jcassity;200921

If you think your HVAC is not deflecting the ductwork to direct heat inside the car, there is a vac line just to the right of the glovebox area that may be defective or the hvac vac connnections have a leak.

Incorrect, if the vacuum line is broken the hvac box will default to the defrost. The blend door is cable operated.

Heater core or vacuum hose?

Reply #25 – January 30, 2008, 11:02:24 PM

Cable operated? I thought the only thing done to swap over rotary controls was to deal with vacuum hoses - that'd mean there are no cables?

Either way, this is on hold till this weekend when I'll take it back up to Seattle and likely leave it there for a week until we can test a few things and if need be, yank the head and have the machine shop go over it again. I tried adjusting the idle and it just won't go up - after many turns and yanking the IAC. I think I may have an issue with my TPS sensor too. The car's cursed I tell you! It keeps idling too low and surging/dying. Its time to sit until I can hook the compressor up to each cylinder.

Edit:
Fluids are still all clear though. Its kinda seeming like its running lean, or thinks it is, at low speeds though and richening the mixture. I would think this would have a good chance of burning coolant as the culprit - as long as the fuel pressure remains steady during all of this. Again, won't know anything until I can get some readings from the motor to see what its doing inside. I can hope for the best but I am assuming the worst - passenger side head gasket or a crack.

Heater core or vacuum hose?

Reply #26 – January 31, 2008, 12:02:05 AM

Nope. Mr. Seek you have to use the early Taurus hvac controls that are cable operated. I've done several heater core swaps and even converted one car from manual to ATC. Been there done that, got the T-Shirt.

Heater core or vacuum hose?

Reply #27 – January 31, 2008, 01:46:04 AM

So unless something is binding up or a something is in the way of the blend door, its 99% chance of a plugged heatercore. Thanks for the insight

Heater core or vacuum hose?

Reply #28 – January 31, 2008, 10:40:17 AM

Have you tried flushing it out? I take two 3ft long pieces of heater hose and stick one end in on of the slots in the hood along the side to hold it upright. I then poor CLR into the other hose and add water until I hear it coming up the other hose. Then I cram the other one up in another slot in the hood. Let soak :p

Heater core or vacuum hose?

Reply #29 – January 31, 2008, 10:43:25 AM

Quote from: Seek;200490

...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?!.

You can get a Siemens blower motor from partsamerica for $47.99 (PM251). Siemens is an OEM level supplier, so I'd trust it to be as good as a Motorcraft replacement.