Hi Guys,

I'm back....well no I have no heat. I've changed the thermostat, new radiator 2 years ago, power flushed the system (2) different times, verified the control valve is working correctly on the firewall. The odd thing is after the Thermostat a 1st power flush I had heat. Till I replaced a leaking water pump and installed a new timing belt. So I power flushed her again. No heat. Are ther temp sensors anywhere that could be the issue??? the intake hose to the heater is HOT!!

Any ideas guys???

Thanks for the help!!
Dan

 

Feel the heater hoses going into and out of the heater core, both should be hot.

 

Thanks for the lead!!!!!!!!!!!!!

Anyways the intake hose was hot the outlet not as hot. Power flushed it again.....more gunk came out. Tested heat 82 degrees...should be around 130. Pulled intake hose off on firewall control valve, dumped in a can of NAPA flush....more gunk......repeated process again...more gunk. Still 82 degrees. OK now I'm getting pissed...I've spent 2 1/2 days flushing this thing and it won't clear up. So I go searching through my wifes cleaning supplies. Lime-away!!!!!!!!!!!!! Pulled hose off controller again...added 4 ounces, reattached hose and filled radiator...added 4 more ounces to radiator. More gunk but now heat is at 94 degrees. Did it again but doubled ounces...more heat 99 degrees and less gunk. Ran out of Lime-away. Will test temp. when fresh tomorrow and buy more Lime-away, have CLR but its much stronger....may end up trying it if its still not right. Has anyone else tried this??? Both products are diluted well below the recomended usages. But both have issues with Aluminum.

Thanks
Dan

 

If you can make up an adapter to attach a garden hose to the heater core inlet, then power flush.

 

Thanks Toyomoho,

Well I hooked up the garden hose and flushed the system it sure helped. Now the weird thing; Took it for a test drive and stopped to get some gas. Went to start it and it stalled (first time it did that) and NO Heat once it started again. Drove it about another 30 minutes and moved the control valve from cold to hot several times to get heat.

Flow rate coming out of the hose was very good when flushing the core. Is there a built in bypass valve when the core is clogged up?? Is there a bad sensor somewhere????

Thanks
Dan

 

What year and engine do you have?

 

Its a 1990 LE with the 2.5. When the car sits and idles, the heat is great. The fans seem to working OK, I've watched them come on religiously over the last week.

 

No bypass valve but a bypass system of hoses. These are the small pipes and hoses running off the rear of the water pump cover.

When you put the T-stat back in did you place any hole or loose rivet in its flange in the upright position? Is the T-stat working OK?

Are the climate controls manual or automatic? Is there a round **** you turn to adjust hot and cold? If so this **** system physically opens and closes the heater coolant valve via a push pull cable. Make sure the heater valve is opening.

Other then the heater coolant valve there is nothing else that turns the flow of coolant on or off.

 

[quote]ORIGINAL: toyomoho

No bypass valve but a bypass system of hoses. These are the small pipes and hoses running off the rear of the water pump cover.

When you put the T-stat back in did you place any hole or loose rivet in its flange in the upright position? Is the T-stat working OK?

Are the climate controls manual or automatic? Is there a round **** you turn to adjust hot and cold? If so this **** system physically opens and closes the heater coolant valve via a push pull cable. Make sure the heater valve is opening.

Other then the heater coolant valve there is nothing else that turns the flow of coolant on or off.

Check coolant level, it can drop once the air bleeds out of the system.

 

Thanks Toyomoho,

The Thermostat did not have any holes or rivets. Yes the Thermostat is functioning correctly.The dash controls are manual. You slide the lever over to the right for heat (while sitting in the drivers seat), left for cold. this operates the valve on the firewall. This valve is working correctly. this is also were the intake hose comes from the block and goes into the heater core. This is the same hose I disconnected from the valve, added the hose fitting, attached the garden hose to flush the system. I disconnected the heater core return hose from the block, attached another fitting to drain the system and watch for contaminates, the volume of flow out of this hose was excellent. The intake hose to the heater core becomes Very Hot, the return hose also is very hot but a little bit cooler.....probably due to the fan pushing air over the heater core and transferring some of the heat.

Test drive scenario: Last Night after flushing system, adding anti-freeze and setting to -20 degrees, the cabin heat was at 120 degrees. Took the car out to get gas and test it. Turned car off, when restarted no heat. But 2 minutes later full heat.... when I got on the Expressway and up to 70mph it started blowing cold air??? I stopped at a friends house for 4hours, and never got any heat on the return trip home????


I'm baffled....????

Is there a hot water hose that goes through or somewhere close to the throttle body for cold starts and idle quality???