I warmed up my car today for around 15mins(temp outside around 35degrees) and when I got into the car,the air was luke warm at best, after the car runs awhile longer it gets hot. Anyway,I replaced the thermostat to start the cheapest route. I was told that it could be the heater core,but I don't see any fluid or smell anything. I won't know if it was the thermostat until tomorrow morning. I noticed that the hoses that attach to the heater core are a little soft(mainly the one that appears to go to the water pump),but I can't seem to find anybody that sells heater hose assemblies. anybody know what kind of price I'm looking at? They have part hose and part metal pips it appears. Could I just cut away the old hose and use the metal pipe? I am going to go ahead and replace the rdiator hoses as well.

 

sounds more like a partially clogged heater core, if it does the same thing in the morning

 

Flush the heater core. It won't cost you anything.

 

Well,
replacing the thermostat didn't work.Still no heat.I put in the 180 degree thermostat. I had the rediator and heater core flushed Saturday. I took it to a friend of mine who runs a repair shop and he found two of the front heater hose were in bad shape and he's going to replace them. Could this be my problem? I was thinking that if they were bad maybe they were collapsing and not letting the fluid to flow,then when the fluid warmed up the hoses expanded then I would get heat. Maybe a stretch,but I guess it could happen. He is replacing them tomorrow,so I guess I'll find out Thursday morning.

 

The heater hoses shouldn't collapse, especially after the engine is warmed up. There should be pressure in both.

Low coolant flow due to a blocked core could cause this, but if the system was flushed well that is not real likely. If you have put 'bars leak' or similar in to stop leaks, too much could block some of the heater core's small tubes. However, my splined water pump driveshaft coupler recently started slipping, because the splines had worn off. Looked like the part got a bad heat treat and was too soft. That caused overheating, initially at high rpm's only, since the pump wasn't turning fast enough. In cold weather it would have resulted in poor heater flow as well. I'd keep an eye on the temp gage in case that is happening to you.

Another possible cause is if the temperature door that varies the airflow through the heater core is not going all the way to full hot. My '95 temp door is cable operated, and those can become misadjusted. Does the temp **** feel like it is firmly controlling the door? If the cable is slipping, then turning the **** fast/hard towards cold, then gently back to hot, might cause the adjustment to slip the other way and let you get warmer air. Not a fix, but could indicate the problem. There is an actuator arm on the hvac module end of the cable (up under the IP) that you could move by hand, as well, if you can get to it. My cable was replaced under warranty, so I'm not sure how tough it is to access.

 

No bars leak. Didn't think to check the cable.The control **** seems to feel pretty accurate to me,same as always.

 

What you have is a clogged or partially clogged heater core. Probably a flake of rust or some foreign material is blocking the flow.
My symptoms were the same as yours. I flushed it twice with a cleaner and that didn't help.
Here's what fixed it. Remove the heater outlet hose from the engine. It is the one that has the bleeder valve on it. Just use some pliers to remove the clamp. You may have to remove the upper radiator hose from the engine to get at it. I took off the air intake elbow to have plenty of room. If you remove the elbow be sure to put a clean rag in the TB so nothing gets in.
Once I had the heater outlet hose off the engine I used my air compressor to shoot some air(I used the hose clamp to seal the air nozzle into the heater outlet hose)into the heater outlet hose. A small volcano of green goo shot out of the fitting that the hose came off of. I put everything together and flushed the cooling system one more time to get all of the crud out that was trapped in the heater core. I filled with water only to see if the heater now worked and was amazed at how well the heater works now. It hasn't been that efficient for a while so I must of had a slow buildup that finally clogged up. I drained the system again and filled up with a 50% mix of DexCool.
It's great to have the heater back.
Good Luck 97WS6

 

Just got my car back from the shop and he replaced all the heater hose/pipe from the radiator to the heater core. I will check it tomorrow morning to see if it works now. If not,I took off the glove compartment and lower kick panel,removed 4 screws and removed the cover over the heater core. There was the heater core. I was told that the whole dash had to be removed? I may have to replace the heater core myself,since it seems to be pretty straight forward process. What i don't understand is, if the heater core is bad/going bad,how can it get really hot when the car runs for 30-40 mins,but isn't doing anything when i first start the car?

 

Call the shop you left your car at and have them blow some air through the heater output hose as I described above. That will blow out your heater core. I doubt very much that you need a new heater core at about $190 or so bucks. Once it's done they should flush the system with water and then refill it with the antifreeze mix.
I doubt very much the hose was clogged. The passages in the core are much smaller and can easily clog. So if you get your car back before the core is blown out as I suggested and it is still messed up dont replace the core until you have it blown out.
If you have to replace the core you don't need to remove the entire dash. Do get a decent service manual and it will show you what to do to replace it.
Like I said I just went through this and did TWO flushes with a cleaner and it didn't work. What worked and took 20 minutes to complete was to blow out the core as I described in my earlier post. It's worth a try before spending the money for a core and the work involved.
Have fun.
Jim

 

The heater hoses were pretty bad,so I had them replaced. If I had an air compressor,I would blow it out my self. May go back to them to do it. Anyway, iahve a friend who works at the local parts store and he can get me a heater core with his discount for 65.00 w/ a 5 yr warranty. I assume that i would have to remove all the coolant to replace the heater core? I just hate to waste the new stuff they put in,unless I can reuse it?? My manual has pictures for the core install and it didn't show the dash removed. I was wondering as why everybody told me It had to be removed.Why would I get heat after the car runs awhile and not when the car has been running for 10-15 mins if the core was bad?? Seems that I wouldn't get any heat at all.