Heater-core flush?

[LUMINATOR]

Has anyone done a heater core flush on a 1990 lumina 3.1 multi-port? If so, how do you do it? Thanks.

[Schurkey]

The same way you do any other heater core flush. Figure out which is the inlet hose, and which is the outlet hose. Disconnect both hoses wherever it's most convenient--at the core, or at the engine, or at the radiator, depending on how the heater core is plumbed. Most folks prefer to reverse-flush the heater core, so you'd flow the flush water from outlet to inlet, backwards from the normal direction of flow.

 

Truth is, most folks don't flush the heater core separately from the rest of the cooling system. I install a Prestone flush 'n' fill kit, connect the garden hose, and start the engine along with opening the faucet the garden hose is connected to. When the radiator flows clean, rev the engine--the engine water pump can stir up settled crap in the water jacket, so after revving the engine, you may see additional dreck come out the radiator.

 

http://www.amazon.com/Prestone-AF-KIT-Flush-Fill-Kit/dp/B000CCFY5W/ref=sr_1_1?ie=UTF8&qid=1386487716&sr=8-1&keywords=Flush+and+fill+kit

 

When I'm done, I open the radiator drain cock, and the engine block drains. When the engine and the radiator are fully-drained, close the drains and add the antifreeze BEFORE adding the distilled water.

 

Don't buy "premix" anti-freeze, since the cost is almost as much as the pure stuff, but you only get half as much actual anti-freeze.

[Crazy K]

I have done a heater core flush as a stand alone procedure on many vehicles.

 

I disconnect lines going to the heater core at both ends and use a garden hose to flush. I use a few tools to assist:

a female (head of) hose end repair kit, such as: (figure out what size you need, maybe 5/8?)

http://www.ebay.com/itm/Orbit-Female-end-3-4-Brass-Water-Hose-Repair-Garden-Watering-Hoses-Mender-/400612809857?pt=LH_DefaultDomain_0&hash=item5d46625c81

 

an inline garden hose valve

http://www.ebay.com/itm/Camco-Mfg-Garden-Hose-Valve-Straight-Plastic-20003-/231092245175?_trksid=p2054897.l4276

 

add a large size worm gear type hose clamp(or two), as well as a little scrap hose of 5/8" or 3/4" size when needed, if I have to attach to a metal line.

 

stick the valve onto the end of the hose, stick the hose repair fitting on the end of the valve, and plug it into one of the hoses going to or from the heater core. The valve allows you to control the hose at the vehicle quickly turning it on or off. You should back flush and forward flush the heater core a few times each way, meaning switch the hose a few times.

 

On a 3.1mpfi:

you have the return line that runs on the passenger side and has a hose hooking up right above the water pump. This line can and will rust out, it may even be clogged by rust. You can patch it with 3/4 inch hose if you have to do a repair to it.

 

You have a feed line right below the T-stat, directly under a temp sensor. you basically need to find a clamped joint in that line to hook to.

Bbeing a 90 it might have a replaceable heater hose connector.

like this:

http://www.summitracing.com/parts/rnb-800-401?seid=srese1&gclid=CM_X84yKorsCFawRMwoddDAAqA

 

I suggest... REPLACING IT. I have seen them clogged, and if it is original, it is worn out. You might also be the last year prior to the fitting...

Edited December 9, 2013 by Crazy K

[LUMINATOR]

I found the two rubber hoses that go to the heater-core I will disconnect them and try flushing it out! Thanks for the help guys!

[bleearg]

I just had to flush my heater core out both directions. First the way it flows and then back flushing with a hose to the outlet side. I had flushed out the coolant filled with water and the flushing solution and ran it 170 miles and still had no heat. Flushing out the core did the trick. It's real hot again. Tonight I planned on draining the radiator to fill with new antifreeze and distilled water. I took the drain plug all the way out and NOTHING happened. I hate clamp style hose clamps You can never reach the damn things to squeeze them off. I guess I'll warm it up and see if some pressure will get things flowing. This has been some dumb shit.

[bleearg]

So what's my next move? I ran it up to temp and still nothing came out of the drain.

[bleearg]

poked it up from the bottom with weedeater string i have flow

[Schurkey]

Drain plug blocked with sediment? Or plastic drain plug broken and doesn't flow?

 

If you've got that much sediment in the radiator, you'd better yank it and tank it. Any local radiator shop should be able to take care of this.

 

Remember that draining the radiator doesn't drain the bottom half of the block, there's going to be a LOT of water in the block that won't come out unless you pull the block drains. (Strongly recommend pulling both block drains!!!)

 

If you don't pop the block drains, add ALL of your anti-freeze BEFORE installing any water. The owner's manual should list the coolant capacity, so you can estimate the amount of antifreeze needed.

Edited December 24, 2013 by Schurkey