Help! No Heat in my 84 xfire

[Janice]

Well i have been through every post i can find on this problem and after replacing the thermostat, coolant, and hoses. as well as blowing out the heater core with air, ensuring my air control flap is working "it is a manual link", burping the cooling sys, radiator flushed, water control valve to the heater core checked. I still have the same problem i started with.

It warms up to 241 then drops quickly to 181 then bounces between 220 and 184. i get luke warm air as it warms up but cold after its warm. I am at a loss as to what to do next. ive even asked a couple of repair places in springfield mo but i was given the same procedures that i had already completed.

 

[XLR8]

Hiya Janice!
I'm sorry I can't help with your issue but I'm sure some of our more knowledgeable folks will be checking in soon. I just wanted to say hello and

Jane Ann

 

[boomdriver]

Well i have been through every post i can find on this problem and after replacing the thermostat, coolant, and hoses. as well as blowing out the heater core with air, ensuring my air control flap is working "it is a manual link", burping the cooling sys, radiator flushed, water control valve to the heater core checked. I still have the same problem i started with.

It warms up to 241 then drops quickly to 181 then bounces between 220 and 184. i get luke warm air as it warms up but cold after its warm. I am at a loss as to what to do next. ive even asked a couple of repair places in springfield mo but i was given the same procedures that i had already completed.

Sounds to me like there is a circulation problem...241 is WAY too high for initial warm up...
If the pump were not moving water, then that would be expected as the HOTTEST water would be stuck in the block, not getting to the T-Stat to open it as it should.
As the water in the block hits boiling...there is finally some water at the t-stat thats hot enough to open it....around 240 degrees on the temp sensor for the block water temp....
The stat opens, some water is now moving and the cool water from the radiator causes the block temp to drop.
The cooling fan operation is thrown off due to the lack of circulation. The fans super cool whats in the radiator but thats not the hottest water...:W
The pump is either plugged up at the heater hose fittings, the intake manifold fitting could be plugged, and/or the pump is just worn out internally. For whatever reason, its not moving water. I've seen the pipe fitting screwed into the pump almost closed from corrosion and rusty crud from a dirty system. Same goes for the orifice usually screwed in the intake manifold heater line.

The Lower radiator hose can also collapse and stop the pump from sucking water out of the radiator. If the pump cannot get water it cannot pump water. The lower hose often comes with a steel spring inside to prevent collapse, but those eventually rust and corrode and break apart. People often do not use a lower hose with a spring/coil because they do not want to risk that junk circulating in the system and plugging everything else. New hoses are fine, but after a few years they get soft and as soon as the engine starts the hose flattens from suction and water cannot flow. Everybody assumes the lower hose is good because you can;t easily see all of it..:ugh

Hope this give you somewhere to start.
Good Luck !

 

[Janice]

Thanks

Thanks allot i will look into that. may take a couple of days but ill post my results.
Again thank you.

 

[vetteboy86]

If the cooling system coolant level is topped off, you should be able to bring it up to temp with the cap off the radiator. Once the T stat opens, and the pump starts circulating, the flow should be evident.

Welcome to the Forums!!

 

[boomdriver]

Thanks allot i will look into that. may take a couple of days but ill post my results.
Again thank you.

Do you know what size thermostat is in there? a 190 or 180 maybe?

Vetteboy has a good point...you should be able to start up COLD with the cap off and idle up to the normal or at least T-Stat temp with the and see the coolant flowing out of the cross-flow vents into the tank.. As it warms the coolant level should rise with temp...overflowing out of the neck. When the t-stat opens the level should drop slightly as coolant then circulates and fills any voids in the system. The return flow should be seen coming from the vents. Once warm, carefully bump the throttle up and look for the coolant to drop in the radiator as rpm increase. That shows that the pump is trying to move coolant. If the t-stat is open the coolant stays down when rpm go up IF the pump is able to move the liquid. If it just gets hot and nothing much happens in the radiator thats pretty good proof that coolant is not circulating for whatever reason.

Use gloves and protect your face when looking in a hot radiator...every once in a while the thing will burp and splash hot coolant:ugh without warning.

 

[John Robinson]

Since you have replaced the thermostat and flushed the system you have pretty much eliminated the blockage in the system or the T-state not opening. Do the cold start radiator test already described and I will bet you will find the water pump is not producing a good flow of water. But also feel the hoses to see if they are soft and mushy and if they are several years old you may have to replace them.

 

[Janice]

Thermostat

The thermostat is a 195. I was able to check the hoses last night and their all good. It builds allot of pressure in the hoses as it warms up. So the last time i was to check water flow i got nervous when it seemed like all my water was rolling out of the neck of the radiator, so i put the cap back on and stopped the test. ill try it again today.

on a side note

when it warms up i get some heat as it hits hi temp. If i keep the fan on low and stay moving on the highway it will stay a little warm. But as you all know the air in these gems normally will cook eggs in front of the vents.
It seems from what everyone is saying that a water flow issue is the problem be it a pump, or a clog. I think ill change out the rest of the hoses and rebuild the pump, after i re-conduct the water flow test.

Again thank you all for your invaluable insight.

 

[John Robinson]

Does the fan blow air really hard on high. Can you tell us if the fan (blower) speed changes when you set it on different speeds. Also you might want to pull the blower and check for a nest built by your friendly neighborhood rodent population. Your comment about getting some heat when moving sure sounds like a bad blower motor to me.

 

[Janice]

Blower motor

Actually yes it blows real good and I've checked the air flow components for contaminates when i checked the air flow control valve for movement. The system is real clean. Cleaner than i thought it would be. same with the heater core. when i blew it out with air i thought i would get some crud, but it was clean, real clean. even the inside of the radiator is real clean. No apparent build up of any kind.

water flow seems to be the culprit I'm just not sure where its not getting to. I thought since the engine cooled so much on warm-up that my water flow was good, but i have not checked it as of yet. tonight i should be able to.

 

[Schrade]

Welcome onto the boards there.

Since the coolant started to flow out with the cap off, you could have air in the system. Air expands MUCH more than fluid when heated.

No coolant leaks under the car?

 

[Janice]

Coolant leak

I did try to burp the coolant sys. but i guessed on how to do it, but there are NO leaks.
After it warmed up, and started pressuring up again. I removed the cap till there was water at the neck.
Im sure this is not how to burp the coolant sys.

 

[Schrade]

I did try to burp the coolant sys. but i guessed on how to do it, but there are NO leaks.
After it warmed up, and started pressuring up again. I removed the cap till there was water at the neck.
Im sure this is not how to burp the coolant sys.

All the air usually will work up to the radiator after a few drive cycles (fully warmed up).

Any white smoke at cold start? Is it running tip-top besides? No SES light? No work done lately?

 

[John Robinson]

All the air usually will work up to the radiator after a few drive cycles (fully warmed up).

Schrade just jogged my memory. Have you replaced the radiator cap? Take the car to an Advance Auto Parts store or a garage and have the radiator and the cap pressure tested. This will tell you if you have a leak somewhere or if the cap is not holding pressure. It just may be something as simple as low system pressure which would account for the higher temp of the engine and also it would allow the system to pull air into it on cool offs.

 

[English Guy]

Hi Janice , I had this problem on my 89 c4 and tried everything to fix it.
In the end I used a long flatblade screwdriver to reach the vent door through the hole left by removing the electical plugs at the top of the evap housing.If you carefully lever the door over to the right you will be able to see the heater core and with the door unstuck your heater/blower should give you no more problems.
Good luck with the fix.
See ya

 

[Janice]

Water

Well poop.

English guy, My air control door works great.
Thanks for the tip.

John Robinson, I did have it checked and it is working properly.
Thanks for the tip.

Schrade, The engine runs great, other than hi temp at first warm up, and the cooling sys holds pressure great. no leaks.

I am still at a loss but i have not rebuilt the water pump yet. Let hope this works.

 

[Schrade]

:confused

Ok, thermostat is in up-side-down.

?

ed.:
Exactly what do you mean by "hi temp at first warm up"? Chart this, by time and temp, and post up. At what temp does the radiator fan come on? Later C4 is supposed to be 228; earlier C4 I'm not sure here... Anybody?

 

[Janice]

Thermostat is upside down

You may be on to something on that i did not ensure that i got it in correctly. I do make mistakes from time to time.
Temp.....
First i have my fan set up for manual turn on.
Cold start at 50 outside temp.
Warms up slow and steady to 232 this takes 7 minutes
At 232 it then drops to 178 this takes 22 seconds.
At this point i have luke warm heat. enough heat to defrost.
then it heats up to 222 in about 5 min then drops again. this is how it stays it just keep bouncing back and fourth.

I had read on here that drilling a 1/8" hole in the thermostat is a good idea.
Anyone know any more about this?

 

[English Guy]

Hi Janice, glad to hear you got the vent fixed ok:bang See ya!
Bri

 

[Schrade]

You may be on to something on that i did not ensure that i got it in correctly. I do make mistakes from time to time.
Temp.....
First i have my fan set up for manual turn on.
Cold start at 50 outside temp.
Warms up slow and steady to 232 this takes 7 minutes
At 232 it then drops to 178 this takes 22 seconds.
At this point i have luke warm heat. enough heat to defrost.
then it heats up to 222 in about 5 min then drops again. this is how it stays it just keep bouncing back and fourth.

I had read on here that drilling a 1/8" hole in the thermostat is a good idea.
Anyone know any more about this?

Ok, if this is withOUT the manual fan getting turned on, then I stick with up-side-down thermostat.