Heater Core

[wdaly]

Anyone ever replace the heater core in an '88 coupe? Mine has 'finally' had it (used some stop leak last year but now I'm back to square one). I actually have some 'special instructions' for this car from a former Youngstown employee - looks as if the dash will have to be removed. Anyone got some 'tricks' they can share? I'm guessing the core is located just about in the middle on top of the trans tunnel under the dash. I'm FREEZING!!! (and breathing the antifrz vapor is not helping)........

[ernier]

I just did the heater hoses on mine and pray I don't ever have to do that job.

I have seen instances where a hose is leaking and spraying coolant backwards into the heater core cavity causing the same symptoms as a leaking core. I had to re-tighten the clamps on my hoses a couple of times. They leaked out not in but I have had it happen. Just something to check before you tear into the dash.

While I don't have any tips on doing the job I think if you document the task when you do it you will be the first to give us 87-89 owners a guide to do the job.

ErnieR

[wdaly]

I just did the heater hoses on mine and pray I don't ever have to do that job.

I have seen instances where a hose is leaking and spraying coolant backwards into the heater core cavity causing the same symptoms as a leaking core. I had to re-tighten the clamps on my hoses a couple of times. They leaked out not in but I have had it happen. Just something to check before you tear into the dash.

While I don't have any tips on doing the job I think if you document the task when you do it you will be the first to give us 87-89 owners a guide to do the job.

ErnieR

'87 & '88 owners - take a look under the hood at middle firewall where the in & out water heater hoses are located. The area has a square section with 4 bolts (one on each corner). Almost looks as if one might be able to remove the heater core from this area (after moving the distributer out of the way). If this is the case I'm thinking Small core and why it never heated good from day One. Also, if this is the case I'm thinking GREAT!!!

[wdaly]

'87 & '88 owners - take a look under the hood at middle firewall where the in & out water heater hoses are located. The area has a square section with 4 bolts (one on each corner). Almost looks as if one might be able to remove the heater core from this area (after moving the distributer out of the way). If this is the case I'm thinking Small core and why it never heated good from day One. Also, if this is the case I'm thinking GREAT!!!

Ummmmm - it wasn't the case. The core is back there somewhere.

Edited December 26, 2010 by wdaly

[ernier]

It has to be in the air box. It almost looks like they built the car around the heater box. Anyway, you wouldn't be able to see the core until you took out the air box. Not that I've done the job on this year Avanti but they are always enclosed never just hanging out for the world to see. The tubes aren't usually more than a few inches long so you know it's on the other side of the firewall from where the hoses go in and I'm pretty sure it's fastened inside the box so you would need to disconnect hoses to pull out the assembly.

ErnieR

[wdaly]

It has to be in the air box. It almost looks like they built the car around the heater box. Anyway, you wouldn't be able to see the core until you took out the air box. Not that I've done the job on this year Avanti but they are always enclosed never just hanging out for the world to see. The tubes aren't usually more than a few inches long so you know it's on the other side of the firewall from where the hoses go in and I'm pretty sure it's fastened inside the box so you would need to disconnect hoses to pull out the assembly.

ErnieR

Thanks Ernier - It looks like I'll be going from right to left: Remove fan and air intake housing / remove evaporator / hope to be able to reach core from there OR will need to remove entire system (which may have been installed before they installed the 'Z' Bar!!!)

[ernier]

Is the air box one piece?

Once the hoses are out of the way look to see if it's 2 pieces. One piece sliiding into the other is common. I would think that installation in one peice would be difficult. It could be riveted together or screwed. In fact, from what I've seen of the workmanship on these cars I wouldn't be shocked to see things riveted together that other manufacturers would design with screws or nuts and bolts. I don't think longevity or ease of service was ever a goal when these cars were built.

I bet you could touch the core with the air hoses off. There could also be screws or studs in the engine compartment that hold the air box.

ErnieR

[wdaly]

Is the air box one piece?

Once the hoses are out of the way look to see if it's 2 pieces. One piece sliiding into the other is common. I would think that installation in one peice would be difficult. It could be riveted together or screwed. In fact, from what I've seen of the workmanship on these cars I wouldn't be shocked to see things riveted together that other manufacturers would design with screws or nuts and bolts. I don't think longevity or ease of service was ever a goal when these cars were built.

I bet you could touch the core with the air hoses off. There could also be screws or studs in the engine compartment that hold the air box.

ErnieR

Patience - 1st I have to go and get someone to evacuate the AC so I can disconnect and remove the evaporator. Some rivets and some screws all around on this airbox. 4 screws at the firewall/engine compartment where the actual heater hoses connect.... Overall - very 'plastically'.

[ernier]

Were you told that the evaporator needed to be removed?

ErnieR

[wdaly]

Were you told that the evaporator needed to be removed?

ErnieR

No, I have instructions on how to remove it (evaporator) and the first thing you have to do is remove the blower and housing to the right of it. The way this whole thing is set-up it connects from right to left. If I attempted to remove the actual air box with the hoses and heater core inside I would need space in the front and to the left which looks 'iffy'. I may have to remove everything though. Right now I'm hoping to be able to gain access from the opening when the evaporator is removed.

[IndyJimW]

Well I'm trying to get my HVAC unit out now so that I can replace it with a Vintage Air unit, what a PITA!

Local dealer has ordered mock-up units for me to try. Will have directions and pictures soon.

1987 Avanti Coupe

Jim Wood

[wdaly]

Well I'm trying to get my HVAC unit out now so that I can replace it with a Vintage Air unit, what a PITA!

Local dealer has ordered mock-up units for me to try. Will have directions and pictures soon.

1987 Avanti Coupe

Jim Wood

Let me know if I can be of any assistance.

[IndyJimW]

Did you get yours out without removing the dash?

Jim Wood

[wdaly]

Did you get yours out without removing the dash?

Jim Wood

I have a 1988 Coupe. The Dash must be removed. Then the center console. To remove the center console you must remove the seats in order to reach 2 screws towards the rear of the console. The 4 fasteners on the top of the dashboard (underneath) are in the exact location as original Stued-Avanti's. The one most difficult to reach is located near the driver's side wiper. To remove the evaporator box just take a soldering iron and make an opening all the way to the right of the air door lever.

Do you have the one page 'Youngstown' instructions on removing the dash?