: Bypassing heater core


2Pontiacs1Cup
03-09-2012, 12:36 PM
Any harmful longterm effects from bypassing the heater core permanently?

I do not need it...car is in garage in winter...it's leaking and I don't see the point of fixing it since I never use it.

Beach Goat
03-09-2012, 12:59 PM
Seems pretty ghetto. What would you think of the previous owner of a car you bought that had that done?

yowzerman
03-09-2012, 07:48 PM
True on that...besides, even though you don't think you need any heat, your system will occasionally need heat (to some degree) to clear any fog or dampness from your windshield and inside the car. Do it right and get it fixed...

Tom.

HunterKiller89
03-09-2012, 08:44 PM
True on that...besides, even though you don't think you need any heat, your system will occasionally need heat (to some degree) to clear any fog or dampness from your windshield and inside the car. Do it right and get it fixed...

Tom.

to be fair, fog and dampness can be cleared with the AC, probably more effectively than with the heat. IMO fix it or remove it and bypass, but leaving it and bypassing, IE leaving a broken part on your car, is trashy

IBM05GTO
03-09-2012, 09:16 PM
Some people don't have the money to fix the hvac system, the heater core goes deeply involved into the dash, its not exactly a job that your average joe blow should usually do, that being said i'm sure it is probably a pretty expensive piece new or used (ESPECIALLY new) being that it is a GTO part and GM likes to bend over the owners of these cars and reem them for every part they sell for it. There is nothing wrong with bypassing it if you don't have the time or money or a combination of both to do it.

J Burna
03-09-2012, 11:26 PM
Some people don't have the money to fix the hvac system, the heater core goes deeply involved into the dash, its not exactly a job that your average joe blow should usually do, that being said i'm sure it is probably a pretty expensive piece new or used (ESPECIALLY new) being that it is a GTO part and GM likes to bend over the owners of these cars and reem them for every part they sell for it. There is nothing wrong with bypassing it if you don't have the time or money or a combination of both to do it.

+1. And thank for answering the op's question.

yowzerman
03-10-2012, 06:57 AM
OP, you may want to try the least expensive approach and put some GM stop leak pucks into your cooling system (crush them up first). If your leak isn't too bad, the stop leak may do the trick. Again, good luck.

Tom.

IBM05GTO
03-10-2012, 07:26 AM
OP, you may want to try the least expensive approach and put some GM stop leak pucks into your cooling system (crush them up first). If your leak isn't too bad, the stop leak may do the trick. Again, good luck.

Tom.

He doesn't use the heater at all because he doesn't need it, the fact it is leaking only gives him further incentive to bypass the heater core. This is just from my experience, but stop leak is detrimental to the cooling system, the stuff in time will just gum up in the cooling system which will cause further problems like overheating and will blow his head gasket sooner. I wouldn't go that route but that is just me.

I also believe his heater core has come to start leaking because he doesn't use it and since he doesn't the seals have gotten dry from lack of coolant lubrication and rotted out. It makes me really glad I daily drive my car and use the HVAC system daily.

ArthurJGuy
03-10-2012, 05:24 PM
This is overly common on Mustangs because the heater core is a PITA to replace.

As mentioned before, there is no critical function that you need the heat for, you can do it if you want.

Kernal
03-11-2012, 07:09 AM
Im from Australia, so prices may be a little different. But i bought a heater core for $130 and coolant for $40.

It took a mate and myself exactly 12hrs to replace it. And thats us just mucking around and talking shit lol.

I reckon you should fix it. You you wan i can post up a How To which i used.

Konnie the Goat
03-11-2012, 07:15 AM
If you dont need it, and dont care about future re-sale, by pass it.

IBM05GTO
03-11-2012, 10:37 AM
^^ exactly.

87LC2
03-12-2012, 02:57 AM
Any harmful longterm effects from bypassing the heater core permanently?

I do not need it...car is in garage in winter...it's leaking and I don't see the point of fixing it since I never use it.

I've read where if you do by-pass the heater, loop the two heater outlets on the water pump together with a section of hose, just plugging the two ports effects the system operation negatively. I read this in Carcraft or Hotrod somewhere, they plugged them and had overheating or something, I forget.

IBM05GTO
03-12-2012, 12:46 PM
That's the first time I have ever read about someone having cooling system issues just because they bypassed the heater core. It sounds to me like whichever car they did this modification on has a shoddy cooling system at best to begin with.

87LC2
03-12-2012, 03:38 PM
It was on an engine dyno not in a car, they mentioned plugging the hose fittings vs hooking it up to the dyno cooling system. If I can find the article I post up what they actually wrote.

I personally don't see how plugging the heater fittings would cause an issue.

Konnie the Goat
03-12-2012, 04:10 PM
That's the first time I have ever read about someone having cooling system issues just because they bypassed the heater core. It sounds to me like whichever car they did this modification on has a shoddy cooling system at best to begin with.

Its actually not that uncommon. Cooling systems can go wonky for some silly reasons. Best practice when by-passing a heater core is to maintain the cooling flow instead of dead-ending it.

IBM05GTO
03-12-2012, 04:54 PM
I've read where if you do by-pass the heater, loop the two heater outlets on the water pump together with a section of hose, just plugging the two ports effects the system operation negatively. I read this in Carcraft or Hotrod somewhere, they plugged them and had overheating or something, I forget.

It was on an engine dyno not in a car, they mentioned plugging the hose fittings vs hooking it up to the dyno cooling system. If I can find the article I post up what they actually wrote.

I personally don't see how plugging the heater fittings would cause an issue.

Its actually not that uncommon. Cooling systems can go wonky for some silly reasons. Best practice when by-passing a heater core is to maintain the cooling flow instead of dead-ending it.

My mistake, I read it wrong. All I ever learned doing heater core bypasses was to take a hose and loop it around from the inlet to the outlet. I had no idea they had plugs for inlets/outlets but it has always made sense to do the loop method because it maintains the system pressure still while removing the heater core out of the equation.

87LC2 I was reading your post so fast I read over the fact they plugged it and I took it as the loop around bypass mod.

MuhThugga
03-12-2012, 06:29 PM
Yeah, you always loop the ports when bypassing.

Heater cores are a royal pain in the ass. I remember my cousin calling me one time about his 88 Firebird, "Hey, tell me if this makes sense: my car is leaking coolant...inside the cabin."
FUUUUUUUUUUUUUUUUUUU........

I wound up having to pull up the carpeting because it got so stained with coolant. Luckily I found a used carpet for $25. It had some worn spots. Nothing a black Sharpie didn't fix.

Stoopalini
03-13-2012, 06:37 AM
Bypassing the heater core used to be extremely common. Just get 3 valves, two tees, and a small section of hose, and plumb a bypass into the 2 existing lines.

Basically, you cut the lines, connect the Tees to each hose coming from the water pump, install one valve on the end of each Tee (between the Tees and the hoses going to the heater core), then install the 3rd valve between the 2 Tees.

This way, you can redirect the flow back to the heater core in the future of you need to.

HunterKiller89
03-13-2012, 10:37 AM
Bypassing the heater core used to be extremely common. Just get 3 valves, two tees, and a small section of hose, and plumb a bypass into the 2 existing lines.

Basically, you cut the lines, connect the Tees to each hose coming from the water pump, install one valve on the end of each Tee (between the Tees and the hoses going to the heater core), then install the 3rd valve between the 2 Tees.

This way, you can redirect the flow back to the heater core in the future of you need to.

disconnect hoses and connect them to a U joint or double elbow joints? why all the unnecessary steps?

Stoopalini
03-13-2012, 11:20 AM
disconnect hoses and connect them to a U joint or double elbow joints? why all the unnecessary steps?

This way, you can redirect the flow back to the heater core in the future of you need to.

Installing the valves allows you to bypass the heater core during the summer, then un-bypass it for winter months. In the "old days", seals around the heater core boxes weren't so great and heat would make it's way into the cabin even when the heat was off.

for the OP, having the valves would give the option to replace the faulty heater core in the future, and simply switch the valves to redirect flow back to it.

Yes, it's completely unnecessary, but it's what I would do if I planned on bypassing the heater core in my car.

rsparso
03-13-2012, 02:00 PM
Installing the valves allows you to bypass the heater core during the summer, then un-bypass it for winter months. In the "old days", seals around the heater core boxes weren't so great and heat would make it's way into the cabin even when the heat was off.

for the OP, having the valves would give the option to replace the faulty heater core in the future, and simply switch the valves to redirect flow back to it.

Yes, it's completely unnecessary, but it's what I would do if I planned on bypassing the heater core in my car.

If the core's leaking you won't be wanting to turn it on and off. Just disconnect and loop back with a piece of pipe.

If I was doing it I wouldn't cut the original hoses and clutter everything up with valves. Just me.