I flushed my heater core on my 97 T/A for the third time back in mid-December. After I did it that time I was getting great heat for about 3-3.5 weeks. Now all of a sudden it is back to putting out lukewarm air. The same thing has happened the other two times I flushed the heater core as well. I am stumped as to what is going on here. I flushed it by removing the hoses from the water pump, so they should be cleared out as well. The coolant level is fine and I have tried to bleed the the system, although the upper bleeder is not being very productive. I am not really getting anything out of it. Any ideas as to what might be going on here? It is going to be warm here again this week and I want to get this fixed once and for all while the weather is decent.

Matt

 

I've got the same problem. It'd be nice to know the solution.

 

Since you say you are not getting anything out of one bleeder, I would say you have air in it.

 

yeah there's definatly something clogging up your system...could be air, could be you need to flush your entire cooling system, maybe you need a new heater core, doesn't sound like the thermostat...other than that i dunno

 

I will try and bleed the higher bleeder again in the morning. After bleeding some of the air out of the one bleeder screw today it seems to be a bit warmer, though it is definitely not near as hot as it was. I am hoping there is just air in it.

Matt

 

You might just need to flush your entire system. It might be glogging back up again after the 3-4 weeks. Might have a ton of junk in there.

 

Well, I tried to bleed the upper bleeder and still nothing is coming out of it. Today I took it and had the whole system flushed and I am still not getting any more heat than I was. Also, when I got home, just for laughs I tried the upper bleeder again and there is still nothing coming out of it. Anymore ideas? It is going to get cold again here in Ohio and I am surely going to want my heat. Thanks

Matt

 

Have you checked the level in the radiator when the engine is cold?

 

have you tried removing the entire upper bleeder (engine cold) and seeing it the bleeder itself is clogged?

 

The fluid level is fine and is right where it needs to be both hot and cold. I have taken the bleeder screw completely out, but I am not sure if that is what you are talking about or not. I am not exactly sure how to get the bleeder out to see if it is clogged. That could be an option I suppose. Thanks for the replies so far.

Matt

 

The 97 has two bleeders one on the hose and one on the thermostat housing. You need to bleed these until water come out of both. And this usually needs to be done several time over a period of hours or days.
If, as you say, this keeps re-occurring you may have a small water leak.

 

Z28SORR, I think you missed what I have been saying so far. The lower bleeder is fine, I am getting plenty of antifreeze out of it. The upper bleeder is not prducing anything. I open it up and can sit there for 10 minutes and not a drop will be produced. I am not convinced now that it is air trapped in the system. I am thinking there must be some other reason, but I don't know what. As always, open to suggestions.

Matt

 

Well, I thought I had read everything, but your right I missed that. You should be able to remove the bleeder and poke a piece of safety wire in the holes to see if they are clear.

 

Is the flow restrictor plugged up?