The heater core in my '88 decided to puke a gallon of antifreeze inside the car last month when it finally gave up the ghost.

Funny thing was I wasn't even using it at the time. It just took a dump out of the blue while I was in sitting in traffic.

Since money's been tight these past few month's, I wanted to hold off on getting a new one for as long as I could.

Well, the past 2 weeks I've been driving to work each morning in an ice cold car.

Being able to see my own breath inside the car lost it's novelity after the first 6 minutes of driving. The fact that I could't see squat out my windows didn't help things either.

I finally decided to fix the problem and read up on how to go about replacing the core - with the help of this wonderful forum of coarse - after I was quoted 4 hours labour by the dealer. - $90 x 4 = $360

Opinions seemed to vary greatly in regards to the complexity of the procedure with some claiming it was easly done within an hour whilst others claimed it was a complete pain in the @ss.

After just finishing my install, I can definetely say my opinion falls in the second group!

WHAT A PAIN IN THE @SS !!!

It took me well over 6 hours (on and off) to finish everything. Why so long?

The answer? one simple screw ( at the top of the plastic heater housing - if you've ever changed the core- you know which one I'm talking about))

That one single screw is in a position that makes it virtously IMPOSSIBLE to easily reach it from above (after removing the dash pad) or from below (through the footwell)

I was completely in the dark, not being able to even see this one screw. I must have arranged myself into 153 different positions trying to get at it.

It was ridiculous

Why would anybody at GM think putting a screw in that area be a good idea? My guess is so that they'd be able to charge you an arm and a leg on labour by having to remove the entire dashboard to get to it !!

My entire body is sore right now and I feel like I've been stampeeded on by a heard of wild horse's. I feel like jello.

I just want to sleep.

Good news is that I finally managed to get at it, pulled out the old core and replaced it with the new one ($65). Just got bach from a 2 hour test run and the heater blows hot enough the fray the eyebrows off anyone who gets too close to the vents.

Best "mod" I've done to the car so far

My advice to those thing of diving into this project themselves? DONT !!

Save your sanity and spend the cash. Let you're local GM dealer put up with the heartach.

Otherwise, if you still want to go ahead and do it yourself, my prediction? That one single screw will end up screwing you

Rant over.....

 

ummmm i changed mine and with the right tools it isnt that hard, sure it's difficult, and also i didnt take my dash apart just removed the bottom hush panel, no the fuel tank.... removing that is a pain.

 

I didn't remove the entire dash either, just the dashpad and hush panal. You must have some pretty small hands and x-ray vision if you though that job was easy. Clearly you have more patience than I do.


Funny your comment about the fuel tank, I found that job pretty easy actually

 

One flexible shaft 1/4" driver, a couple sockets (one for the screws, and one for the hose clamps), and 30 minutes is all it takes. You did it the hard way..

 

I've only ever replaced one. Didn't think it was that bad. Think it took about a half hour.

I think I need to do the one in my 85 soon tho. There isn't a big pool of coolant on the floor but the windows get a film on them in a short amount of time and I can smell coolant inside the car. Think there is a tiny leak in the heater core.

 

I've never heard of it taking 6 hours holy crap that sucks

 

Don't get me wrong, I'm not saying the job itself was really hard, it wasn't. Far from it actually. It was all straight forward.

Dissconect the two hoses running to the core from inside the engine compartment.

Remove the "hush" panel and pull aside the ECM. There are a total of 8 screws. 4 on the outside plastic casing and another 4 on the inside.

That's all straight forward enough. It was that ONE screw at the top of the housing assembly that I just couldn't reach !! That was the only difficult part of the job and the reason why it took me so long.

The trouble is you cant even see it ! Not from the top or from the bottom. You're basically just "feeling" your way around. Then when you find the screw with your finger tips, you have to try and mangle your hand up and around all the wires and ductwork behind the dash with a socket wrench and hope you can secure it - which as I said, is a total pain since you can't even see what you're doing.

Had it not been for that one screw, yeah, it would be a 45min- 1 hour's job.

 

Could you leave that screw out so if it goes bad again you dont have to F with hit?

 

i have 3 flexable extensions that came with a multi tip style ratched screwdriver set. (i got 2 extras sets from a christmas goof) and i have done plenty of core swaps for the same reason the dealer gave ya. i did one last week for a friend and he said the dealer quoted him 6 hrs. i rolled my eyes and said bring it by, we'll knock it right out.
if i stayed on it and we didnt BS i coulda done it well within an hr and thats pulling and putting the tools back up.
the panel thats under the dash pouch, pull that to access that top screw. i reach under the dash and guide the extension to the screw. noooooooo sweat. after i got done with my friends heater core i loked at him and said "ok, what are they doing for the rest of the 5 hrs on this fix?" and he laughed.

 

As I said earlier, there a 4 small screw's which hold together the 2 parts of plastic heater core housing. It's very important that heater core is completely sealed inside the housing with no air leaks escaping otherwise the air pressure coming out the vent's won't be as strong.

That was my biggest worry when putting everthing back in place. I knew having to put that particular screw BACK would be just as hard if not more so, then pulling it out.

Good news is that with just the remaining 3 screws put in place, the box was air tight with no leaks at all, even with the fan speed turned to the max,

Apparently, there isn't even a need for that 4th screw. That just made me even more frustrated at all the BS I had to put up with to take it out to begin with.

However, because I like things to be done properly, I spent the time to install back the 4th screw (even though it didn't need one)


I made the install a bit easier by shaving down the lenghth of the screw itself so that there wouldn't be so much of it to put back in.

 

Could you have used duct tape to seal the screw hole? You wouldn't have a leak and would get screwed in the butt next time you go to replace...just trying to run some ideas by you guys for making it easier.

 

I never did find that upper screw on mine!

Just got fed up, grabbed the panel, and pulled, lol

It now has mucho duct tape on it so it doesn't leak, lol

Works just fine, and after you stick the under-dash cover back on, you can't see any silver :P Heater is hot enough to boil you alive too!

 

Thats what I'd do, if you get the screw out then seems like duct tape would work just fine.

 

Finally, someone who isn't posting "yeah I replaced my heater core in 10 minutes.. it was super easy."

I knew I wasn't the only person who's had trouble with that screw.

That makes me feel a whole lot better

 

Did mine about a month ago took me about an hour. Like others here have said a flexible shaft screw driver makes all the difference. The hardest part of the whole deal was gettin the new core lined up properly, the bracket kept falling off.

 

i had a friend on the other side with a screwdriver and a standard extension guiding the pipes to the hole.
what bracket did you have probs with falling off?

 

The bracket that the core mounts in, the one with the four screws. the metal strap kept slipping off. I thought about soldering it direct to the core but didn't want to take the chance that the solder joints on the pipes would overheat.

 

well i'll jump in by saying its a pain in the **** too ! mines been leaking for a few weeks and ive never been able to get the cover off either, i didnt know about that hidden screw, so my dad pokes his head under the dash and just ripped the panel off, lol, so its all snapped now but at least i can see the core now.

What i didnt get is even though the heaters were turned off all the time when you run the car it starts dripping.

Scott

 

Am i doing this right, me and my dad have come in defeated today with trying to get the heater core out. we got that cover off, unfortunatly it just totally snapped off coz we didnt know about that screw at the time,

now my whole dash is in pieces from trying to figure out how to get the bloody thing out. My dad was trying to remove the hoses in the engine bay going to the heater, is that right first of all ? i cant see anymore screws holding the dash in and it still wont come out, however i was under the impression you didnt have to take the dash out at all, i thought you take the plastic cover off the heater, and it comes out quite easliy ????? my car is an 87 GTA by the way, any help much appreciated because im so p***ed off with the car right now, and not knowing much about them doesnt help when this sort of thing happens.

Scott

 

Once you get the cover off there are 4 more screws one at each corner of the bracket, the two on the right shouldn't be a problem but the two on the left are kinda deep down in there.

Also on the front of the housing just to the left of the opening there is one more screw on the bottom, take that out so the cover can flex alittle. This will help clear the core bracket.

 

haha - the inside part was fairly easy for me - cover, screws, etc. what took most of my time was under the hood - getting all that crap out of the way just to get to the heater lines... i think that was more of a patience thing, tho...

 

I replaced my core the same time I did the A/C Delete heater box.
Took me about 3 hours total.
I didn't feel like wasting too much time on the inside box working on the top screw so I just grabbed it and yanked.

I was told that on the birds, you can drill a hole behind the dash pouch so that you can get a straight shot at that top bolt. I didn't feel like doing it.

 

Im no further forward with getting the heater out, can anyone tell me where to go from, from this pic, the plastic cover is off but i cant see how the core actually comes out, i cant see anymore screws holding it in or anything like that

 

There is one more screw it looks like, look at the top left corner of the box.

 

here, I circled where 2 of the screws are,

 

ah well there you go, hopefully thats all it is, thanks guys, im gonna try again in the morning so i'll let you's know if that done the trick or if i failed miserably !

 

Man, I almost feel bad for posting. I just changed mine today and did it in less than 2 hours...and that was including walking back and forth to the garage for tools and going to the parts store again because the first one was cracked at the seams...However, I must admit that I am a smaller guy and can get up there with no problems. That one bolt up top was a PITA at first and the most time consuming part of the entire thing. A simple 1/4" ratchet and a deep 7mm 1/4" socket held at the right angle worked perfectly. Also, remove your coil if you have a remote mount to get to the hose clamps in the engine bay. Just use one rule of thumb whenever you work on a car and especially something like this. PATIENCE. If it doesn't come out easily, there's something holding it in, don't yank. Take your time, walk away, punch a wall, etc. you'll break less and be happier with the results.



Oh yeah, I left that top screw out of the box when I put it back together. 4 screws holding it in will suffice for me, and it works perfectly so what the hell....


Also, where the hell do you live LT1fun? $90 an hour for labor...I want to work in that shop. However, $65 for a heater core...that's rediculous! I got mine for under $20 from O'Reily's

 

Canada. Scarborough, Ontario to be exact. The $90/hour rate was at a local GM dealer. That's about $75/hour US.

The core is a new (not rebuilt) genuine GM replacement from the dealer. The $65 it cost is about $54 US.

Yeah, the hardest part of the job was the one screw. All else was straight forward and pretty easy to do. The screw was what made things so difficult. Glad it's all finally over with.

 

hey thanks a lot guys, as soon as i got those two screws out i missed it came out straight away, thanks a lot

Scott

 

GTA, when you go to put the new unit in have a friend help ya to aim the tubes. use a screwdriver to pull them over once ya get close. i do this and it cuts down time.
also there is a arm inside that you can see. the core bracket will hang on this when going in so just take a sec to get it past the plastic core frame and all will be good. aim the tubes and then deal with the arm in that order.

 

That makes all the difference in the world.

I'm 6'3" and about 250 lbs. My hands don't "fit" anywhere.

AAMOF, the srew that's on the upper right (the car's right) wasn't on tight enough and the flapper door wouldn't move because the "tit" on the door wouldn't pop back into the groove it's supposed to.

I had to get my wife's narrow hands in there to get to it to tighten it for me. But even she said there was no way in hell she could get to the other top screw. And she's ~5' 9" and only 135 lbs.

I don't know how some of you did it.

 

I took the ecm out of the way, in fact I unplugged it and put it out of harms way.
I was able to get my whole arm in there and put my fingers right on the screw.

 

Yeah, that's key as well. Take the ECM out and the bracket that holds it in. There's a TON more room after that.

Also, I'm 5'6" and about 135 so working in tight places is a cinch for me.