Heater Core replacement
 

I didn't make this video but it looks useful:

I haven't looked at it but if it's as good as you say - post the link in the DIY thread.

I already tried but it says that I do not have permission :(

That Vid was OK to show what a mess one has to get into,but was hardly a step-by-step! I noticed that individual missed a few things upon disassembly,and keep in mind that some of those electrical connectors may prove difficult to get apart! I also recall the ebrake cable had to be disconnected,and yes the radio & heater controls must come out early on. I have done this job twice:12 hours the first time,seven the second time. I have seen on this forum some who claim 4 HOURS! I don't see how that is possible! My advice:don't scatter your hardware all over the car,use cups with labels to identify where all those lil buggers go,and watch the contacts for the gauge cluster,easy to damage!

if you've done a dozen or so, you'd get good at it, but 4 hours is FAST!! Worst job ive had to do on my blazer yet!

I agree,but every vehicle I have ever owned the heater core job is the worst! My 66 truck has 1600 little screws that strip,a 78 GMC C-15 w/o air still took about three hours! My 91 Suburban (with air) was a similar nightmare! I've done these on Ford fox chassais as well! Difficult! This is why I question ones ability to do this job in 4 hours!
The LIM is a walk in the park compared to the core!

Heater core, heater core, Ai yi yi
 

I've only done this once. On an '88 Mustang GT. It took me and another guy 2 days to do it and I swore I'd never do it again. Well, never say never. I'm now on disability and my '02 4WD Blazer LS is blowing cold air. I don't have $500+ to pay to have it done.

I know the core is plugged because my mechanic unplugged it a couple of years ago. My neighbor and I discussed it and he suggested I try dumping some CLR in it to see if that would get us through the winter. My biggest problem is I'm recovering from a broken leg. Still can't put any pressure on it, but it's got to be done ASAP. We only have the one car and I have to try to get it done before my wife has to take off and run the roads again.

I've watched a few videos on blowing it out but I don't know which is the inlet and which is the outlet. My wife got home from driving all over Hell's half-acre and I checked both hoses trying to see which was hotter but they're both the same temp?!?

So my question is, which pipe is the inlet? The one towards the driver's side or the on towards the passenger's side as you look at the engine compartment facing the back of the truck? I guess it really doesn't matter to do what I'm goiing to do, but I'd like to know for future reference.

Thanks for the help and any additional advice you can share!!

Jack

HMMM! If both hoses arm the same temp than theoretically you have flow! It sounds like what would be called in an older vehicle:the heater control valve! On Blazers this is done by vacuum as in the old days,But is controlled by the blend door actuators! Do you feel any warmth at all after a 20 mile trip? This may be the issue. If I recall the return hose runs back to the water pump.

step66, thanks for the response. This core is beyond plugged! I cannot get any flow through it at all, which leads me to another concern. If no coolant will flow through the core, what is the long-term damage to the cooling system? I replaced the radiator and the water pump ~3 months ago. I've been told that the intake gasket is leaking, too.

I want to splice the heater core hoses temporarily so the coolant can at least circulate through the motor. I'm really worried about the pressure backing up since the water pump is trying to push water through a completely clogged channel. I figure I can use a small diameter PVC pipe to simply connect the two hoses together and clamp them. Any thoughts or ideas? What is the risk if I don't at least do that?

Also, can anyone recommend a good place online to find a reliable replacement heater core for <$100? AutoZone doesn't even list the item and Advance's parts all seem to have compatibility issues except for the one that's nearly a buck and a half. I don't want to rip the dash out only to find the replacement doesn't fit! :eek: Like I said, I have a broken leg and this is our only vehicle so I'd rather do this once and be done.

Thanks again!
Jack

Does anyone know whether this heater core is the exact OEM replacement for my truck?

I have no idea how the core is situated on the firewall but the pipes look right as far as the size of them compared to the ones in the engine compartment in my truck. I mean that the larger outlet (I think) is toward the passenger side and the smaller inlet (ditto) is towarde the driver side.

The guy in Car-Stuff.com's chat assistance recommended this product right off the bat when I gave him the info on my Blazer. I just have a horror of tearing my dash apart only to find that the replacement won't fit for some stupid reason. Like, for example, a review for a Spectra core on Advance's site: "The original core had rounded edges to fit in [whatever slot he was talking about] and the [replacement] has square edges and will not fit." All reviews, even for the high dollar AC/Delco part made reference to the included replacement foam that doesn't work, so I'm sweating that, too. :icon_eek:

Any ideas?

Thanks again!
Jack