Bypassing Heater Core

[mosho93]

Well, i've done my searching and concluded that my constant window fogginw up when the temp gets below 45 is because of the heater core and i can also smell coolant. I read in a lot of searches that you can fix it temporarly by bypassing the heater core, but nobody had a link or a write up on how to do this. can anybody help me on how to bypass the heater core so i dont have to deal with the smell of coolant and hardly being able to drive at night.

TIA

 

[qiksho]

There is an in and out that goes through the firewall. This is where you want to bypass it (inside the engine bay). Its about in the center of the car IIRC, and I believe (its been about 4 years since I have replaced a heater core in a SHO) the metal lines stick out a few inches past the firewall and have molded hoses with clamps attached to them.

All you need to do is connect the two lines coming from the motor together.

 

[shofun93]

you have the correct location. There are two lines that go through the firewall, the one on the drivers side is the inlet to the heater core, the other is the outlet to the engine.

To do the bypass go to the local AZ or other parts mart and get some 3/4" id heater hose that is pretty flexable. 3' should do the trick.

Remove the clamps on both ends of each hose, try to save them. You will have to pry the old hoses off, but be very careful not to damage the metal lines on either end.

Cut one peice about 8-10" and shape into a U. This peice needs to go over the inlet and outlet attached to the firewall. This will keep the core from leaking out any more coolant. Clamp the ends down tight.

Next take the other peice and put one end over the metal heater line that went to the inlet for the heater core and clamp it down. Then snake the other end of the new line against the firewall and attach it to the last open coolant pipe. This is the most difficult one to reach that is why I like to leave the line long. The length will not hurt anything as long as it stays back against the firewall. The curve in the line should do that for you.

Check the coolant level, make sure all the clamps are tight and start it up. Make sure there are not any leaks and the coolant is topped off. Your good to go.

Just remember you now have no heat!

GL

 

[DHMag]

one ****** is 3/4", the other is 5/8". i used 3ft of each size and connected them with a reducing ****** (available at your local parts store). once everything was tightened and checked for leaks, the entire hose assembly was tucked between the engine and firewall.

following the bypass, i drove 1000 miles from Indiana to Texas. that was May of 03, the bypass was not removed until November of 03, when the heater core was replaced.

 

[platoribs]

one ****** is 3/4", the other is 5/8". i used 3ft of each size and connected them with a reducing ****** (available at your local parts store). once everything was tightened and checked for leaks, the entire hose assembly was tucked between the engine and firewall.

following the bypass, i drove 1000 miles from Indiana to Texas. that was May of 03, the bypass was not removed until November of 03, when the heater core was replaced.

Anybody ever try bars leak in the heater core?

Just thinkering out LOUD

 

[qiksho]

Anybody ever try bars leak in the heater core?

Just thinkering out LOUD

My dad bought a 88 Taurus LX back in 97 from the auction. Found out from the previous owner the heater core was leakin so he put that stop leak in there, well it lasted about 4 months before the heater core finally totally blew and coolant was all over the inside of the windshield.

 

[SHOtimer]

I personally don't like the idea of a 'stop leak' clogging up all the passages in my cooling system that I would like to remain open.

Doug

 

[Rockledge]

I personally don't like the idea of a 'stop leak' clogging up all the passages in my cooling system that I would like to remain open.

Doug

Me neither.

What some people tend to forget sometimes is that the cooling system runs throughout the engine too, it doesn't just start and end with a radiator or a heater core that happens to be leaking.