No Heat - Possible No Vacuum Line

[Terbro]

I bought my '87 TR last year and it doesn't have heat. I've inspected the lever for the hot/cold adjustment, and it is working. It is opening/closing the door in the box near the firewall. There is another box close to the passenger fender with a vacuum line hooked up to it, and I don't think it's working. If there was no vacuum supply, would that prevent heat to the cabin?

I normally hear the "hiss" in most cars when adjusting temp. I don't in my car...so maybe that's it? And I've noticed this severed line in the engine bay...don't know where it's supposed to go, other than it's cut and open. Is this (at least part of) the problem? See pic.

 

[SHADOWII]

if you have a mighty vac, apply it to that line and see if it actuates the vacuum diaphragm.

 

[TurboBuRick]

It's a normally open valve. The valve actually closes when vacuum is applied.

 

[Terbro]

if you have a mighty vac, apply it to that line and see if it actuates the vacuum diaphragm.

Don't have a mighty vac.

 

[TurboBuRick]

That line either feeds the vacuum to the heater control or it's the signal for the heater valve. Is there a vacuum line on the heater valve under the hood? There should be another plastic line with the one in the pic. Locate that line and trace it out. That will help determine what the broken one is.

Take note that heater valve is a normally open. So in actuality it should not affect heat if the vacuum line to the actuator is missing. The spring can break leaving the valve closed. In that case you would need a new valve.

I've wired open a bad valve before to get heat in a jam.

 

[Terbro]

That line either feeds the vacuum to the heater control or it's the signal for the heater valve. Is there a vacuum line on the heater valve under the hood? There should be another plastic line with the one in the pic. Locate that line and trace it out. That will help determine what the broken one is.

Take note that heater valve is a normally open. So in actuality it should not affect heat if the vacuum line to the actuator is missing. The spring can break leaving the valve closed. In that case you would need a new valve.

I've wired open a bad valve before to get heat in a jam.

Okay, you've really helped me start to understand. I now see that that A) a heater valve exists!, and B) where the other vac line was connected to. Yes, the heater valve line is connected. I've attached a pic of the heater valve. Is it in the position that would allow heat?

I've also just discovered something else. Don't know it's exact name...I'll just call it one of the heater core lines - one of the two metal pipes that route the coolant to the heater core. Attached is a pic of the one that I just noticed as a pretty substantial kink right at the bend to the intake manifold. I think it may also be contributing, preventing coolant flow to the heater core. You can't see the kink in the pic (blocked by the rubber TB bypass tubing)

Anyway, I'm fairly confident I'm not getting vacuum to the dash. I don't hear hissing when trying to adjust anything. But if I can rig it to just get heat, that'd be great. Temps have dropped dramatically within the last week. Lows here in Colorado in the 30's...highs in the 50's.

Rick - Let me know about the heater valve...if I need to rig it, I won't hesitate.

 

[TurboBuRick]

The valve appears to be open. The metal line being kinked will definitely restrict your flow. How bad is it? I can't tell from the pic.

The vacuum line that feeds the heater control hooks to this check valve on the open port. The plastic line will have a rubber 90* fitting. Trace the platsic line. It's prolly broke.

 

[Terbro]

As you can see, the heater core line looks to be good an' kinked. So that's got to be one of the problems. And the vac line is another.

Okay, so I need to connect the vac line in the first photo I posted (that's open) to the check valve? One more problem...I don't have a check valve! See pic of my engine bay in that area.

I bought the car with a bad motor, immediately had it shipped to Nick Micale to rebuild the motor and this is the way it came back. Not Nick's fault. One thing that was obvious upon initial inspection when I bought it, was how it was jerry-rigged. Mixed-matched bolts all over. Looked like some high school kid on dope r&r'ed it in the dark at some point. I actually commend Nick for putting it back together as well as he did.

 

[John Larkin]

The tiny kinked line is the hot water source for the throttle body. Nothing to do with cabin heat. Leave the little kinked hose alone and concentrate on the heater valve back by the heater core.

 

[Terbro]

The tiny kinked line is the hot water source for the throttle body. Nothing to do with cabin heat. Leave the little kinked hose alone and concentrate on the heater valve back by the heater core.

You're looking at the wrong kink. I'm familiar with the rubber TB bypass in place there. Right in between the rubber bypass TB tubing, you will see that the metal heater core line is severely kinked. There's a red arrow pointing directly at it.

 

[John Larkin]

Ok I stand corrected. I didn't have my glasses on. Now I do. Yeah, you need to buy a hard heater line and replace that. I'm surprised it doesn't leak.

 

[Terbro]

Ok I stand corrected. I didn't have my glasses on. Now I do. Yeah, you need to buy a hard heater line and replace that. I'm surprised it doesn't leak.

Right. I've already got someone who's got one for sale...just waiting to get a pic to confirm it's in good shape, which I'm sure it is. But I'll still need to hook up the vac line for the heater control. Replacing that water line might get me heat...my guess is that I won't have my choice of zone control? Might just come out the upper vents or lower, or wherever it's been at when it was disconnected.

 

[aminga]

If the heater core is plugged up it can also reduce the heat into the cabin.