Solution to diminished AC performance after evaporator core replacement - ZR-1 Net Registry Forums

GOLDCYLON · 05-15-2014

Many thanks to Vettemed, I have created this thread to be a standalone thread as a searchable solution. Folks take note of Andrews post #318 in his update of his hi miler ZR-1 project. If you are having dimished AC performance after replacing the evaporator core. Last summer my car in my opinion was not cooling down as much as it used to do in heavy AC load conditions in the 118-122 dog days of summer in Arizona. It always used to be a lot colder from my memory and since reparing the AC a year or so ago with all new parts I just could not figure out what was going on. I remembered this post up as Andrew was having the same problems. I put this on the long list of projects I wanted to complete this winter. I missed it.. however, and it didnt make it to the list last winter, Tuesday of this week was a uber rare Santa Ana winds fed blustery day here in AZ and the evening temps in the garage were in the 70s and I said well... now or never. I had my evaporator core replaced while I was TDY at work so I never saw the original unit that was removed. Long story short I had the exact same gap on the left side of the heater core that Andrew has pictured in picture #1 of post #318. So I fed gray foam material, the kind used used to protect guns and hard drives into that vertical slot. Walla.. in 100 degree temps yesterday the AC was spitting out 46 Degree air.

This view is what you might see if you pull the blower motor and look towards the evaporator core. See that vertical gap? it should not be there. As Andrew stated in his post either the replacement evaporator core is shorter than stock or it is factory foamed in on that side. Make sure you or your installer is aware of this issue so they can address it at time of replacement. Andrew was 100% correct with the gap hot air was bypassed into the system and mixing into the cooler air.

05-15-2014	#1
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,155	Solution to diminished AC performance after evaporator core replacement Many thanks to Vettemed, I have created this thread to be a standalone thread as a searchable solution. Folks take note of Andrews post #318 in his update of his hi miler ZR-1 project. If you are having dimished AC performance after replacing the evaporator core. Last summer my car in my opinion was not cooling down as much as it used to do in heavy AC load conditions in the 118-122 dog days of summer in Arizona. It always used to be a lot colder from my memory and since reparing the AC a year or so ago with all new parts I just could not figure out what was going on. I remembered this post up as Andrew was having the same problems. I put this on the long list of projects I wanted to complete this winter. I missed it.. however, and it didnt make it to the list last winter, Tuesday of this week was a uber rare Santa Ana winds fed blustery day here in AZ and the evening temps in the garage were in the 70s and I said well... now or never. I had my evaporator core replaced while I was TDY at work so I never saw the original unit that was removed. Long story short I had the exact same gap on the left side of the heater core that Andrew has pictured in picture #1 of post #318. So I fed gray foam material, the kind used used to protect guns and hard drives into that vertical slot. Walla.. in 100 degree temps yesterday the AC was spitting out 46 Degree air. This view is what you might see if you pull the blower motor and look towards the evaporator core. See that vertical gap? it should not be there. As Andrew stated in his post either the replacement evaporator core is shorter than stock or it is factory foamed in on that side. Make sure you or your installer is aware of this issue so they can address it at time of replacement. Andrew was 100% correct with the gap hot air was bypassed into the system and mixing into the cooler air. __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V Last edited by GOLDCYLON; 05-15-2014 at 11:15 PM.