spectra premium heater core issue ? / anyone recommend a good heater core ?
But more seriously, yeah, that core isn't flowing properly. Using 20psi of compressed air isn't going to tell you much about flow without a manometer at the inlet. I had a bad core that seemed to flow 'pretty good' with a garden hose but NEVER got hot. Finally had it cleaned out and fixed proper and it worked! Turns out it's tough to gauge things by touch/feel/eyeballs - a simple pressure gauge (manometer style) at the inlet would have told me a lot more than just staring at a stream of water...
Testing the core outside the dash is a good idea though. I'd swap it at the autozone for another and see if the next one is better. If not, it might be a case of 'consolidation' where a part number that isn't suited for your application has been substituted in order to reduce the # of core part numbers at the supplier - sometimes it works out in their favor - sometimes you get a piss poor substitution. It sucks, but that's just how it goes sometimes.
I also wouldn't rule out air in the core. Make sure it's at a low point of the system when refilling and that the stat opens a few times to clear the air out of the system prior to making any judgments.
But more seriously, yeah, that core isn't flowing properly. Using 20psi of compressed air isn't going to tell you much about flow without a manometer at the inlet. I had a bad core that seemed to flow 'pretty good' with a garden hose but NEVER got hot. Finally had it cleaned out and fixed proper and it worked! Turns out it's tough to gauge things by touch/feel/eyeballs - a simple pressure gauge (manometer style) at the inlet would have told me a lot more than just staring at a stream of water...
Testing the core outside the dash is a good idea though. I'd swap it at the autozone for another and see if the next one is better. If not, it might be a case of 'consolidation' where a part number that isn't suited for your application has been substituted in order to reduce the # of core part numbers at the supplier - sometimes it works out in their favor - sometimes you get a piss poor substitution. It sucks, but that's just how it goes sometimes.
I also wouldn't rule out air in the core. Make sure it's at a low point of the system when refilling and that the stat opens a few times to clear the air out of the system prior to making any judgments.
