Okay....as I had posted here before, my heater core was nearly completely plugged from a couple of rounds of the block-seal-in-a-can deal. I hooked a Little Giant submersible pump up to the heater core lines and I was getting just a trickle....like an old man with prostate trouble!
So I decided..."what the hell"....and started off with a stong mixture of CASTROL SUPER CLEAN and boiling water and got a **** load of crap and gunk out of it. Then I reversed the flow and did it again....and got even more stuff out. My flow had improved to about twice what it was, but even this was just a pencil stream or less of flow.
So I got some PRESTONE RADIATOR FLUSH and put two bottles into about a half a gallon of boiling water and let it circulate all night long. I went out a little while ago and have a full stream of fluid coming out! And the bucket had a whole lot more of just **** in the bottom of it....nasty stuff! I am so ******* stoked! I REALLY wasn't looking forward to pulling the heater core (first step in the manual says, "Remove the dash...." ) and now it looks like I won't have to!
I got more PRESTONE RADIATOR FLUSH a while ago and am going to do it all over again, with the flow reversed once more.
This makes me happy!

 

Congrats... love it when things work out!

 

does that fix your heat not being very hot at all? mines warm sometimes, but mostly its just air coming out even with the heat all the way up and it on full blast. it sucks man, especially with 30 degree weather here.

 

It would certainly help. Fouling is a major issue with heat transfer, and anything that helps clean out gunk will improve it.

Dave

 

I would say that if your core is somehow plugged, it would definitely help with having good heat.

I always had one of the (seeming few) FDs that had a heater of nuclear capability. Man that thing would get hot! But after a couple of treatments to seal leaky water O-rings, I suffered a plugged up core. I would BARELY get even marginally lukewarm heat.

So I hope this gets me back to full heat again.

 

Congratulations!!

However, even tho I'm reluctant to throw a wet blanket on your success, watch for heater-core leakage.

It's not unusual for serious flushing to expose leaks.

 

hmmm... maybe thats why my heat doesnt work so well. is there a 'how to' on this?

 

I think that flushing the core is a worthwhile endeavor, especially if you are experiencing lack of heat. As we all know, replacing the core is a REAL P.I.T.A.! And really...it is pretty easy to do. Of course, I have it REAL easy with my engine out right now, but the inlet and outlet hoses are pretty easily accessible even with the engine in.
All it takes is a small submersible pump like a Little Giant, I bought 6 feet of 5/8" heater hose and spliced right into where the hoses go into the firewall, hooked one end up to the pump and let the other drain into my bucket where the pump was. Make a mixture of hot water and PRESTONE SUPER FLUSH and let it circulate for a few hours or couple of days.....I mean, it can't hurt.
The improvement I noticed was incredible. To go from near total blockage to near-full flow...very well worth it.

 

any update for us??????

thanks eddie

 

Are you asking if his heater core ever started to leak?

 

I am wondering two questions:

Did your heater work after this?

and

Did it ever start leaking?

 

Right on Baja, this is on my list of things to do.

 

Sorry for the delay guys....just got back from Las Vegas.

My heater core is seemingly (knocks wood) perfect now, I have nuclear heat and no leaks.

 

times like this I am kind of glad it never gets cold here. The coldest it gets is in the low 60's. If my heater gets plugged or leaks, just disconnect it and loop the coolant lines.

 

Sweet work and even sweeter result. worth a million bucks in experience. good job dude.

 

i did this with a water hose last fall, and black stuff literally shot out at me.


also, i now have air in my heater core a few months later. i can hear the water circulating when i start the car cold

 

Good deal! Creating a leak was a possibility, but, considering what you started with and now have, it was certainly worth the risk!

Dave

 

That is what I wanted to hear.

thanks Eddie

 

I think my heater core may be clogged...

 

this interests me, my heater core warms only very little.
any "how to" there?

 

Keep in mind the valve has to be open for coolant to flow thru the core. I am assuming you've already got the car's HVAC turned to max hot?

 

Somewhere in the annals of Forum history there is my complete write up. Crib Notes version is this: You'll need a submersible pump of some sort, (I used a Little Giant unit), a 5 gallon bucket, about 8 - 10' of heater hose, a few bottles of PRESTONE SUPERFLUSH, and some time.

Basically you get the hottest water you can and mix in a bottle of the SUPERFLUSH, hook your hoses up - one from the pump to the inlet or outlet (reverse flushing seems to be a little more effective so hook up to the outlet) of the heater core, and one from the other outlet/inlet of the core back to your bucket. You've of course made sure that you had the HVAC switched to heat and maxed the thermostat to the hottest setting before you shut the car off...
Run the pump, and see what you get coming out. When I first started, it was just barely a trickle, like about what you could pee. Within a short while it had increased substantially and the bucket was full of crap. So I emptied it out and replaced with new fresh hot water and another bottle of SUPERFLUSH and repeated the process until I had no restriction in the flow.

Where to buy Little Giant Utility and Transfer Pumps

I used the 505176 model.

 

Nope! FD doesnt have a valve. It has a blend door that controls air flow through the heater core. The heater core in an fd ALWAYS has coolant flowing through it.

 

Ah! That is why I love this forum...ALWAYS learning something!

 

Yeah, I took my heater core out and there's nothing to restrict flow.