MY cars heat works but after about 8-15 min of hard driving. If i turn on the heat before the amount of time above. It will blow cold air. Is there something wrong with it? or is this the way our heaters work also. My condenser is not on Had problems during the summer. Will this also effect the problem?

 

I've been having the same problem with my '89, except mine NEVER heats up. I know, I'm in Arizona, so I should never need heat, right? But I do occasionally. When I slide my temp control lever back and forth, it works smoothly, and I can hear the door under the dash opening and closing. Heater cores and car heat systems have never been very complicated, but I'm at a loss!

Anyone help us out???

 

- Is your engine running cool. Change Thermostat. If that does not help getting more heating water into the cabin heatercell, somewhere is something blocking the cabin heater circ.
Thermostat change no big deal, 5$ half hour.
-If the engine runs cool -be it due to thermostat or no- the temp gauge shows it.
Is it working normally [cold engine zero, warm halway up?]

How it works: Engine water circulates always in cylinder heads and cabin cell tubings, if temp ctrl lever =valve open. This water is cold until engine really warms. Now you start to get hot water. Next the thermostat opens and engine water will be cooled in the front radiator. However, If the engine thermostat is stuck open, the engine stays always cool and cabin heater will never get hot (lukewarm, yes). Engine water circ heats the Cabin heatercell, and air blower sucks outside air through it and results in air cooling the cell. If the incoming waterflow from engine is insufficinet or temp is low, the air will never become hot. Revving engine revs the pump also, you get more excess heat and watercirc and so more warm air in.

Another possibility is the bypass coolair -door in the cabin heating block you mention. If it never truly closes [temp lever at right end], cool air will always come and bypass the cabin heater cell. (Something broken, seals worn or bad adjustment?)

- Is cooling water level ok?

- Air bubbles in the cooling system: vent the air bubbles out:
One peugeot piping system was like Chiraq himself - impossible and always cooking. The only way to get all air out, was to make a small leak on the highest part of the water system, drive one hour (cab heating on) while adding cooling liquid, and then close.

Somewhere the tubing might be blocked.
- somehow broken rubbertubing (inner ring of the tube ripped off, blocking flow intermittently)
- debris has formed a block
- some other external force pressing/bending tubing closed
- temp slider does not really open the water valve or valve stuck.
"I can hear the door under the dash opening and closing."...valve is connected but still separate.

Note: Heated water makes rubber hoses softer and easier to collapse.

- Open the in/out hoses connected to engine. Put garden hose running water in on one hose. Water should run out freely from the other exit hose. If not, smtg has blocked your system.

 

Thanks alot i have been looking into flushing the heater core will do that when i have a chance. Also cooling water? what is this ? My engine runs warm in the middle i dont ever see it rise above the center of meter. How do you check for bubbles in the cooling system?

 

"How do you check for bubbles in the cooling system?"
Hmm. who knows... but gas bubble in tubing, be it in my stomach or friends car, blocks circ, gives pain. cool.

Typically its never a problem in cars. On some, however:
The only way to get all air out, is to make a small leak on the highest part of the water system, drive one hour (cab heating on) while adding cooling liquid, and then close.

Once in three ? years it is recommended to change cooling fluid. Never done myself.

 

My car does the exact same. Last year, the heating was better.

I have 212k+ miles on my GXE 92. This summar, I got the timing belt and water pump replaced. After that, I noticed that the temperature guage maxs out with just 10 minutes of driving and then gradually cools down to the center of the meter without even stopping the car. Happened many many times. I took the car back to the mechanic and he added a lot of coolant with the car running. But I've noticed the same thing later too several times. Later when I checked once, the radiator was empty (but the reserse plastic "bottle" for coolant was full, I don't know what is its purpose then). I put almost half gallon of coolant and started the car and waited for air bubbles. Not one was found. After that, the temperature guage stays in the middle.

Now the heater blows cold air. I took my car to the mechanic (after driving for an hour). He pressed gas hard for 10 minutes with the heating on. Then warmer air started coming out. He told me that since there are too many miles, the engine is weak and I should start it at least for 10-15 minutes and then rev the engine. He also told me that the coil for the heater is bad and it is for $400.

Any comments?

 

Go to another mechanic. And get another option.

 

You need to jack the front end up in the air as high as you can get it,start engine,remove rad cap,start adding coolant as the car warms up to operating temperature...

 

In my case, cool air always comes through the vents unless I close them on the dash and yes, I push the lever down on the left side to see if the flow of air will stop, but it doesn't.

If it isn't the thermostat and the door is stuck in the open position, what is the procedure to have it repaired? I can't do my own work, so I'll end up taking it to a shop. But I want to have some knowledge when I go int there. I've had some difficulty with mechanics in the past because I'm young and not mechanically inclined.

 

Sissy,the switch that controls the vent air my be the culprit,have a j-yard pull a used one,bring it to your shop,have them swap it out..

 

i think my heater control valve is bad because I have bled my system. Sometimes I have hot air, sometimes I have cold air.

 

I elevated the front of the car and added some coolant as the radiator was empty. It burped several times.

Two Observations:

1) Since the radiator was empty, does it mean that the coolant is leaking from somewhere?

2) What is the role of the coolant container which is connected to the radiator with a small pipe. It was full and I thought it replenish the radiator when it's empty. But this was not happening.

Comments?

 

You might have a leak somewhere,so make sure the system is full and continue to monitor the coolant level,also look under the car periodically for puddles of coolant.


The coolant over fill reservoir tends to only work when the cooling system is full or almost full,if the system is too low,it can no longer replace the coolant due to all the air in the cooling system..

 

Many thanks for helping me MyGreenMax94.

I couldn't find puddles of coolant but after 2-3 weeks, the radiator is always empty and I've to fill it up. I took the car to a mechanic and he suggested me that the radiator is leaking and the thermostat is bad (so I should get replaced both, but I didn't because of his ridiculous estimate). He flushed the system.

I made the radiator burped (elevating the front of car) and still it blows out cold air. But when I revved up the engine around 2500 rpm, after a minute, hot airs comes out. The temperature needle does not go down. When I took my foot off the gas, the air becomes cold again.

 

I'm also having problems with my heat, whenever I'm driving around 40 mph, the temp needle goes down a little over C. When I put on the defroster for the front windshield, cold air blows out the vents that blow in your face. Also when I have it set to blow out to your face the passenger side vents blow out cold air. I already jacked up the car with the rad cap off to operating temp and didn't change anything.

 

you either
a: have a blown head gasket which would account for the constant coolant loss (it gets burned up in the combustion chamber)
b: need to bleed the system some more, they don't always bleed very well.

your lack of heat is indicative of low coolant, I went through it on one of my VEs I just had to add a bit every week or so for a little bit then it was all better.

 

I thought that too when I read a few things about head gasket. But the mechanic told me that if that's the case, the car won't run good. There will be many other problems too in such senario.

 

you can have a leaking head gasket and car still be running in good order thats just when you have a slight crack in the head somewhere or the gasket in the head is just starting to go. it will slowly drain your cooling system as i seen it happen on a ford explorer at college during driveabilty and found it to be a crack in the head after we did a compression test with the fuel cut and took the compression tool out from the plug and found green coolent on the tip of the tool. it can preform like nomral its just as time goes on it will get worse then not be preforming correctly.

 

That sounds like a stuck open T stat for sure. Driving at a decent speed results in over cooling, and no heat. Also it wears down the engine excessively and hurts MPG as well.

~Alex.

 

I have the same problem, but my temp gauge says its running hot.

 

have you checked the fluid level?
are you getting heat?
are your fans kicking on?
have you flushed the system?
is your water pump working?

 

heating systems are so annoying....i replaced mt t stat...and flushed my coolant...i only get heat when i have the rpms high....i flushed my coolant 3 more times, cause it was once green but wuickly turns a rank orange....then i got out the garden hose and flushe the radiator, heater core and engine until the water ran clear....my coolant is orange again after a day....heat a little better but still bad. not to mention i get warm air out of my top vent and floor vent, but cold out of the main vents, wtf.

 

1. you need to bleed the system by raising the front end of the car roughly 3ft off the ground
2. do you have the lever on the left in the up or the down position?

 

Between the engine compartment and dashboard, you will find two pipes going into the wall (i think it's called firewall). The top pipe is the intake of the coolant/antifreeze into the heater core. The bottom one is bringing the coolant out from the heater core, back to the radiator. Check both the pipes by grabbing with a finger and thumb firmly for 10 seconds or more.

If the top one is hotter than the bottom one, the problem is in heater core and was not fixed when you have blown it with hot water (if you have done so). In this case, you have to either replace the heater core or take it out and unclog it somehow.

If the top if is not hot enough, then the engine is not warmed up properly. I can't think of a good reason for this.

Check this and let us know what are your findings. I also replaced the thermostat and got the radiator flushed twice. But still no luck. Then my trusted mechanic put a hot water hose to the top pipe for heater core and bingo, I have heat.

 

free fix 4 u

 

DOH