I have been reading several posts about my problem (no heat) and have came to the conclusion that my heater core is clogged or not functioning properly. I am not very experienced with cars, but am begining to get better with them. Bascially i was wondering if someone could detail the process of cleaning the core? Would i have to drain the coolant since the core is the highest point?

I also read something about a possible air pocket in my system. I recently changed my thermostat (still no heat before) and when i refilled the system i followed the procedure of bleeding and burping the system. My heat is midly warm, but makes you colder in low temperatures and my thermostat is functioning properly (car sits at roughly 180/185 w/ 180 t-stat).

Also what pieces/parts did you remove while flushing the core.

 

lol anyone?

 

We unclogged my heater core this summer, I had absolutely NO heat, and now it works like a charm! granted I have a 19 thermo in the car, it prob would pump out hotter air if it was a stock thermostat though.

here's instructions on how to fluch the core, pretty simple, but you can end up getting the driveway pretty wet...lol, oppps! for the summer I ran distilled H20 and water wetter, then switched to antifreeze for the winter.

****Flush the Heater Core****




Remove the heater hoses at the water pump. This allows flushing of the hoses and the core.
Orient the hoses to keep all moisture off the optispark.
Using a garden hose, flush into one heater hose allowing the water to come out the other.
Do not use high pressure. The cooling system is only rated for 18 psi. Full hose pressure can be over 50 psi.
When the water looks clear, swap hoses, flushing into the other one.
Reverse a couple of times to help ensure a good flush.
Re-connect the hoses and refill/bleed the system.

 

Sometimes it helps to get answers by including basic info about your car - year, model, engine, tranny and any major mods. That's useful info to include in your "signature" (click on "User CP" on the red task bar on the top of every page).

Not much of that is required with a question about the heater core... we can guess you have a 4th Gen, and you mentioned bleeding the system, so we can guess its an LT1. But you will probably get more responses if you include as much info a possible in your signature.

 

On the V6 its very easy. The hoses are on the passenger side and easy to remove and replace.

 

I just did what was already mentioned above.

I used this tool here:

http://shop.oreillyauto.com:80/Produ...egoryCode=3051

I think Maverick997 posted this earlier. It made it MUCH easier. Use the 5/8" adapter, and just put your finger on the side of the " T " and another finger over the small hose that goes to the throttle body (i think). Worked like a charm and am enjoying heat again.

Very easy.

You can get it at O'reillys or Advanced. It was like $4 and very worth it IMHO

 

Instead of making a new thread I figured that I would post in here.

My heater isn't blowing very hot. The larger hose, which I believe is the inlet on the heater core, feels hotter than the smaller hose. I'm assuming that indicates that hot coolant is getting to the core, but that it's not circulating correctly.

Obviously, trying to flush the heater core is the first course of action. I attempted to do that last night, but ran short on daylight and I don't think I did a very thorough job(air is still sort of lukewarm).

Is there a way to go about flushing the core without having a ton of coolant pour out of the bottom of the water pump? When I pulled that bottom hose coolant gushed out(that's to be expected), and I really don't feel like hassling with that again. The only other option I see is buying two lengths of hose(one 3/4 and one 5/8), pulling the connections at the firewall, hooking up the extra hose and flushing the core that way. Any other suggestions?

 

http://shbox.com/1/4th_gen_tech2.html#heaterflush

 

Shoebox, I actually followed your instructions the first time I tried this. Though, I obviously did not flush the core thoroughly enough because the air is not getting hot.

However, if I'm going to attempt this again I want to do it with the least amount of coolant loss possible. Pulling the top hose is fine for this, but pulling the bottom hose isn't really conducive to keeping coolant from pouring out of the water pump while you're flushing the heater core.

The reason I asked about the firewall method is because I read a few posts where people had flushed at those points, and they didn't seem to have too much coolant pour out when they disconnected them(one person used vice grips to keep the hoses clamped shut). Though, then you're dealing with the pain of working underneath the cowl to do all of this.

 

I just did mine today, do it at the waterpump its not that hard. I now have heat. Be prepared to get wet I got water everywhere.

One thing though, if I took both lines off the water pump and flushed no water came out the other hose just the waterpump. I had to keep one line hooked to the water pump and blow water throught the other to get it to finally blow out. I think it was so clogged is why.

 

Hi all, new here, working on my GF's 96 LT1 v8.
She has owned it since it was new.

Complaint, no heat.

Checked thermostat yesterday using pan on stove method. worked fine
Today:
Pulled hoses coming off water pump where one hose hooked to radiator on one side and there was coupler on the other hose on the side and i took it apart there.
Left both hoses attached to water pump and flushed from both sides of dangling hoses.
Getting clear water.
Reattached, filled system, bled system, fan blows fine, no heat still.

Any ideas?
me and my gf appreciate the help.

 

what bites about the heater cores is, there are several TSB's on LT1's not to use Dexron and if you do, you need to flush it every 3 years max due to a clogging agent in it.

 

I would not use Dexron, either (since it is transmission fluid). Please post a link to these particular TSBs.
Heater core clogging is not confined to those that use Dexcool. I find it absurd that there would be a "clogging agent" in any engine coolant. Dexcool does coagulate in a poorly maintained cooling system, but only when it is exposed to air (which it should never be).

 

The other issue with Dexcool that I have read about was the fact that the factory used clay pellets as an anti-leak sealant in the LT1 powered Impalas- back in '94-'96. There is lots of anecdotal evidence about it being the clay pellets, and not the Dexcool, that was causing the problems-

I have used whatever the Manufacturer specified- having owned and maintained a '95 Caprice LT1 to 248,000 miles, still running strong, but rusty, when sold for my 2001 Z28-now at 108,000 mi and still running a '97 Blazer- at about 122,000 miles. I change the antifreeze at either 50,000 miles or 3 years, and flush everything when I do- maintenance is cheap compared with replacing parts- my $.02

 

not only did it ( Dex-cool) goo up, it eats at the gaskets. There was a huge lawsuit over this about a year ago. If you had head gasket, raditor, water pump, heater core problems/ repairs this may have been the problem. see link, http://www.consumeraffairs.com/news0...m_dexcool.html


(note-I mistakely posted Dexrol, not Dex-cool earlier, my bad, it was late, sorry)