: very little heat. Dealer results...?



catera00
10-18-07, 03:23 PM
ok, so basically my heater doesnt blow hot air. Only luke warm. No matter how long I drive. It worked last winter. Since then I've had a new head installed, a valve cover gasket replaced, a new a/c compressor installed and replaced both auxilliary water pumps. I took it into the dealer this week and they say the heater core isnt getting warm. They think it could be blockage of some sort and wanted to flush the system for $250. I didnt have them do it though. Any thoughts? Could something actually plug up the heater core?

Heres my previous post about this: http://www.cadillacforums.com/forums/cadillac-catera-cimarron-forum/115155-how-warm-should-heater-get.html?highlight=heat

Cadi Cat
10-18-07, 11:08 PM
What's the temp guage on the dash say? Is the car heating up to at least the halfway point? Mine doesn't and it blows very little heat when it's cooler out. Pointing to the thermostat. I didn't see anything in your posts about you replacing the thermostat.

catera00
10-19-07, 01:48 AM
What's the temp guage on the dash say? Is the car heating up to at least the halfway point? Mine doesn't and it blows very little heat when it's cooler out. Pointing to the thermostat. I didn't see anything in your posts about you replacing the thermostat.

It heats up quick to its proper operating temp ( almost half way up on the guage) even on rewal cold days, and never overheats.


I dont get it. I gotta be missing something. Every hose related to the cooling system is hot to the touch. How am I not getting warm air? Is there some hidden valve that isnt allowing water into the heater core? Its almost likr the heater bypass valve thing isnt working.

Warez
10-19-07, 06:55 AM
I bet is the the heater circulation pump.

It is located below the coolant reservoir.

catera00
10-20-07, 03:18 AM
I bet is the the heater circulation pump.

It is located below the coolant reservoir.

I actually just replaced that part. because it started leaking shortly after I replaced the aux. water pump on the radiator. I noticed the heater wasnt working and after poking around the engine bay, I saw the heater circ. pump leaking. I replaced it but the heater still didnt work.

Is there a way to test to see if the pump is working? Both hoses get hot. Infact, the only hose that doesnt get hot is the one coming from the heater bypass valve (Is that the right name) going into the heater core. So it seems that the coolant is getting to that valve but the valve isnt directing it to the heater core. Is there a way to manually operate the valve?

Warez
10-20-07, 04:53 AM
The valve is vacuum operated, if you disconnect that little line on it and connect it to a vacuum source, you will be able to open it.

If you then get heat, it will either mean that the valve is bad, or worse, something in the HVAC unit is not working.

Also why did you have a cylinder head replaced?

catera00
10-20-07, 02:24 PM
The valve is vacuum operated, if you disconnect that little line on it and connect it to a vacuum source, you will be able to open it.

If you then get heat, it will either mean that the valve is bad, or worse, something in the HVAC unit is not working.

Also why did you have a cylinder head replaced?

The head was replaced when I had the leaking head gasket replaced. It must have overheated at some point enough to warp the head.(It happened before I bought it) The machine shop couldnt resurface it because it was too warped. It was coverd by a warranty so I diddnt have to pay for it.

TitanCTS
10-20-07, 07:45 PM
Either the vacuum line to your heater valve is leaking,not connected, thermostat not opening fully, actuator for heater core not operating properly... eliminate as many possibilities as possible.

catera00
10-20-07, 08:50 PM
Either the vacuum line to your heater valve is leaking,not connected, thermostat not opening fully, actuator for heater core not operating properly... eliminate as many possibilities as possible.

Well I was wondering about the thermostat and even asked the dealer to change it but they said the cost would be astronomical and that since the car was getting to operating temp, it wasnt bad. I assume its expensive because the thermo. is under the intake somewhere. where is the actuator for the heater core?

investor74
10-21-07, 11:46 PM
As mentioned in several other threads, the heater control valve on these cars is a weak spot. :helpless: I have had mine replaced numerous times in the almost 11 years I have had my 97, most recently last week. Usually coolant leaks or heater not working.:crying:

Barry

TitanCTS
10-23-07, 12:14 AM
The heater control valve is probably 99% at fault... have that checked out :)

catera00
10-23-07, 12:18 AM
As mentioned in several other threads, the heater control valve on these cars is a weak spot. :helpless: I have had mine replaced numerous times in the almost 11 years I have had my 97, most recently last week. Usually coolant leaks or heater not working.:crying:

Barry

Oh, so they can go bad with out leaking? Hmm, might be worth just changing for the sake of trouble shooting. Thanks for the info

catera00
10-30-07, 12:53 AM
Ordered a heater control valve today. Usually $90 got it for $63 w/ my bros shop discount. I am cautiously optimistic. Should be fairly simple to replace. Do you have to drain the coolant or can I just kink the hoses? I'll let you guys know if that was the prob.

catera00
10-31-07, 01:27 PM
I replaced the heater control valve and still low heat. As before, it will get to 100 after about 10 miles of driving. Which is should be getting hotter much faster. I tested the old valve and it functioned properly. I hooked a vacuum hose to it and the plunger raised. I hooked the vacuum line that goes to the heater control valve and the plunger raised when I set the climate control to 60. And then it went back down when I set it to 90. Which confuses me because I would have thought it should do the opposite. But I hooked a constant vacuum line to the new valve and it still didnt get hot

So the only other thing I can think of is the heater core. All the hoses are hot so there must be a blockage at the heater core right? I am at a loss at this point. But I know I'm not paying $250 to have the heater core flushed like the dealer recommended.

frank moran
10-31-07, 06:46 PM
I replaced the heater control valve and still low heat. As before, it will get to 100 after about 10 miles of driving. Which is should be getting hotter much faster. I tested the old valve and it functioned properly. I hooked a vacuum hose to it and the plunger raised. I hooked the vacuum line that goes to the heater control valve and the plunger raised when I set the climate control to 60. And then it went back down when I set it to 90. Which confuses me because I would have thought it should do the opposite. But I hooked a constant vacuum line to the new valve and it still didnt get hot

So the only other thing I can think of is the heater core. All the hoses are hot so there must be a blockage at the heater core right? I am at a loss at this point. But I know I'm not paying $250 to have the heater core flushed like the dealer recommended.

Some thoughts, are the hoses on the contol valve in the correct position, is the elec. heater pump working (you replaced it)?, can you get the proper response when you move through the various HVAC modes, is air moving correctly?is there a temp deferential on the control valve hoses which would indicate flow, the vac line holds the valve closed to reduce coolent flow to the core... disconnect the CV hoses and blow some compressed air through the core, see what happens??? let us know.

Resilient
11-01-07, 07:20 AM
Well I was wondering about the thermostat and even asked the dealer to change it but they said the cost would be astronomical and that since the car was getting to operating temp, it wasnt bad. I assume its expensive because the thermo. is under the intake somewhere. where is the actuator for the heater core?

I had a thread on this... I had a similar problem, and yes it's expensive but... my T-Stat was actually stuck open, so engine temp was almost reaching mid-gauge, AND little to no heat (sound familiar)...

catera00
11-01-07, 12:50 PM
Some thoughts, are the hoses on the contol valve in the correct position, is the elec. heater pump working (you replaced it)?, can you get the proper response when you move through the various HVAC modes, is air moving correctly?is there a temp deferential on the control valve hoses which would indicate flow, the vac line holds the valve closed to reduce coolent flow to the core... disconnect the CV hoses and blow some compressed air through the core, see what happens??? let us know.

Well as for the hoses positions, I can only assume the ones on the drivers side are right. I put them back on the spots I removed them from. Obviously The one on the passenger side going to the heater core is correct.

As for the Auxilliary heater pump, the only way I know its working is that both hoses on it are hot. And yes , I replaced both auxiliary water pumps. I dont know any way to really test it.

As for temp differential on the control valve hoses, they are all hot when the heater is set to 90 degrees.

Are those some special connectors on the hoses going to the heater core?

Thanks

catera00
11-01-07, 12:55 PM
I had a thread on this... I had a similar problem, and yes it's expensive but... my T-Stat was actually stuck open, so engine temp was almost reaching mid-gauge, AND little to no heat (sound familiar)...

I really hope thats not the prob. Call me nieve but if it was stuck open, wouldnt it take a long time to warm the motor up? And it would still get warm eventually. I noticed after switching the dial from 60-90 degreesa couple times yesterday to test the new valve that I am getting zero heat again. It seems if I leave it at 90 with a/c off for a few days, it will get a little warm. (about 100 degrees after 10 miles.) But right now its gets no higher than 60 no matter how long I drive.

Resilient
11-02-07, 01:26 PM
"if it was stuck open, wouldnt it take a long time to warm the motor up? "

In my case it never went to half on the gauge, so yes it would take a long time depending on your definition or warm engine... Mid-gauge is supposed to be engine operating temp (about 180 F), mine got close but never to it...

essentially with the T-Stat open... coolant is continuously flowing through-out the rad...angine and heater core. Normally the T-Stat stays closed UNTIL the engine temp is right and requires cooling.... then it opens, regulates the engine temp...

Found my thread:
http://www.cadillacforums.com/forums/cadillac-catera-cimarron-forum/96106-low-non-existent-heat.html

Gsi209greg_UK
11-02-07, 08:19 PM
u made sure ur heater matrix is bled?

when the car is cold, take the filler cap off the header tank and set the fan settngsto blow on the hottest setting.

then start the car and let it tick over, watch the level of the coolent in the header tank and top up as necessary.

once the car hits normal opperateing temp (normally about 95degrees) chuck the cap back on and see if it warms up!

catera00
11-03-07, 12:51 AM
u made sure ur heater matrix is bled?

when the car is cold, take the filler cap off the header tank and set the fan settngsto blow on the hottest setting.

then start the car and let it tick over, watch the level of the coolent in the header tank and top up as necessary.

once the car hits normal opperateing temp (normally about 95degrees) chuck the cap back on and see if it warms up!

I diddnt do that. I will try it this weekend. Thanks. As for the engine temp mentioned above, it gets just a hair under the halfway point which is where it alway has gone to. It gets there within a a mile of driving on a 50 degree day.