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The heater in my 86 na is really weak. It blows barely warm air even when the temp guage is in the middle. It has been below 40 this week, but I have noticed the same problem when its 60. Any thoughts?
 

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You might have something blocking the heater core hoses. Flush the cooling system (while doing that, connect a garden hose to the small heater hose going to the core on the engine side and see how the flow is from the other small hose.)

As for the vent not working, take off the dash cover under the steering wheel and make sure that the plastic pipe is connected correctly to the vent.
 

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huh,. that's weird.. Mine is the same way. If my temp gauge is halfway it still only blows out like a warm air...(typically cool by the time it gets to you). Also on the notches you turn to determine how fast you want it coming out.. Mine doesn't even start working until I get to the 3rd click.. That's gets annoying fast.
 

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I've got the same problem too.. I flushed the heater core untill the water came out clean with a hose, and flushed the entire cooling system untill it was crystal clear and re-filled it properly and put a new thermostat in.. with the temp gauge sitting at 1/2, its barely warm.. I always play around with the fan setting and where it blows, try closing certain vents, try recirulation and outside air settings, nothing is very warm..

Brando
 

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I've got the same problem after flushing my system twice. Maybe its just never that warm.. I can't remember. Does anyone have a mk1 that DOES blow nice and hot?
 

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My 88 blows super hot when the motor is warmed up.

For the guys experiencing the blower only operating on switch position 3-4, you have a bad heater relay. It is mounted on the heater venting under the glove box. Easiest way to get to it is to take the cardboard glovebox out.

If your heat will not get warm, but the coolant/engine does heat up properly, check:
*Control cables broken/binding
*Servo motor faulty
*Water valve faulty/misadjusted
*Air dampers broken
*Air ducts clogged
*Last but not least, Heater control unit faulty(this will probably be the last possible thing to break)
 

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My '86 has a new heater core and a new radiator and it still doesn't run you out of the car. If there is a little chill in the air it does fine. But if the temperature drops in the 40's or colder it takes a while till I can get it warm enough to take my jacket off.

~C.C.~
 

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GreeBo said:
I've got the same problem after flushing my system twice. Maybe its just never that warm.. I can't remember. Does anyone have a mk1 that DOES blow nice and hot?
My 86 will melt your feet off and I currently have a stuck open thermostat so it never really warms up. The 85 I had in 1985 was the same way.the only reason I can think that it would not be hot is that the heater core or lines are clogged.

Mark
 

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I have the same issue....i went throught the whole cooling system, i have 190 degree temps at the core and 160 at the valve, the system has been thourougly flushed and it hasnt gotten any better.

one of my good friends(Lime on the board) 85 blows really hot.
 

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I had the same problems and it turned out to be the blower motor. It was not blowing out enough hot air to warm up the car.
 

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My '88 S/C will run you out of the car. If your coolant temps are normal and the heater's not, you have a problem. The easiest thing to check is the heater control valve. If it's opening all the way, then you get into all the dampers and diverters in the duct work. That's a PITA. The '87 and later had vacuum motors on everything, so a vacuum problem could cause things not to work properly. The '85-'86 cars had more archaic, but more reliable, cable linkages.
 

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ive learned on mine (87) that if its below 40 have it going full blast at the hot setting b4 u start it and it will be fine, but if its not set that way it will always blow out warm.
 

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ITA-MR2 said:
My '88 S/C will run you out of the car. If your coolant temps are normal and the heater's not, you have a problem. The easiest thing to check is the heater control valve. If it's opening all the way, then you get into all the dampers and diverters in the duct work. That's a PITA. The '87 and later had vacuum motors on everything, so a vacuum problem could cause things not to work properly. The '85-'86 cars had more archaic, but more reliable, cable linkages.
I thought 87+ were servo motor controlled? There were no vacuum actuators on the ductwork that I pulled out of my 88SC.

In response to the original question, my heater seems to take a few minutes to warm up, but once it does it cranks. I've had a few passengers ask me to turn it off because it was too hot for them. So I just roll down their window and then hit the window lock switch. ;)
 

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Hmmm, so possibly, if I have a vacuum leak somewhere in the engine compartment, could that cause my heater to be weak? Ive checked everything else possible.
 

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Sounds like a common problem. Mine gets plenty warm but it barely blows out of the vents so it takes a while to heat the whole car.

How hard is it to replace the blower?
 

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I've got the opposite problem - blower works great, and so do the controls for the various vent settings. I just get almost no heat, even though the engine temp is OK.
 
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