thegoochking

my heater core is leaking coolant into my car, can i just disconnect it somehow to stop it from functioning instead of fixing it? i dont need heat in my car since its hot as heck here in florida.

Zepher

iTrader: (1)

yes, connect the 2 hoses together.

bonesbrakr

iTrader: (3)

I presume you have the plastic valve that connects to the TPI throttle body. Just take out the plastic valve, cap the vacuum line attached to the top, and run a hose from the throttle body to the radiator. At least thats one way to do it and give it a cleaner look.

thegoochking

do any of you have any pics or diagrams on which hoses to connect where? and besides wetting the inside of my car with coolant and making it smell will the leaking core cause performance problems?

Zepher

iTrader: (1)

I don't have any clear shots of my TPI motor in a stock configuration so I can't make you a diagram.

I'll look around this evening and see if I can find one and show you both ways to do it.

on my old 86, I cut the hose at "A" and attached it to the radiator at "B".
the "A" line on my 86 was attached to my Waterpump, and I can't remember where it would be on a stock TPI motor. Is it on the Throttlebody?

thegoochking

ok thanks

LAFireboyd

iTrader: (3)

Here's a link to "My Garage." I have an engine pic in there that shows you how to run the hose. Send the hose coming off the throttle body right to the radiator. That will bypass your heater core.

https://www.thirdgen.org/forums/vbga...ber-26799.html

And if you do a throttle body coolant bypass later, then all you'll have to do is cap the radiator nipple, and plug the hole in the intake manifold where the coolant comes out to the throttle body, getting rid of all those hoses.

Chevy86 IROC-Z

iTrader: (17)

Took made your engine bay look super clean with no heater hoses running here and there, Do what I did. You may have trouble though doing what I did because I performed the mod while the engine was out and the radiator on the work bench. But if your seriously up for the challenge of doing it with the engine in, then continue. You'll need an Allen Wrench set. You'll also need a threader set. I had to try different sizes of threading tools to get the proper fitting to make a good seal. Next you need some thread sealant with teflon ( http://store.qualitydist.net/per-80632.html ). You can use teflon tape but I recommend the liquid type. Now your ready. Drain some radiator fluid from petcock. Remove hoses and other items but remember to plug the vacuum line that is connected to the coolant diverter thingy. Yes I said thingy, my 86 IROC doesnt have that part. Now you can either go 1 of 2 routes. You can unscrew the male fitting that sticks out of the front of the intake manifold, or simply thread the inside of the fitting and plug it with a pipe plug (look at picture). I had to thread the inside because mine was too tight to take off and I didnt want to crack the fragile aluminum intake. So I just threaded and inserted a plug. Pluging this male fitting on the intake will stop the coolant from exiting the intake. Now thread the inside of the male fitting that is found just below the radiator cap. Insert a plug here too. Remmember to put on a light coat of teflon on the plugs because if you apply too much, it'll be pushed out while you insert the plug and it'll look not too pleasing. I used stainless steal plugs. The choice is yours. Good luck bro.

Chevy86 IROC-Z

iTrader: (17)

While your at it, you can delete the coolant that goes into the throttlebody too. https://www.thirdgen.org/coolantbypass

thegoochking

this is how my engine was setup when i got it.



this is now



what needs to be done on the new setup to bypass the heater core?
also if i bypass the heater core will my ac no longer be usable when i get it to work?

thegoochking

also can bypassing it cause overheating issues?

thegoochking

can i just disconnect and plug these 2 line and be done with it?

LAFireboyd

iTrader: (3)

Bypassing the heater core won't cause overheating. In fact, you'll have less things that can breakdown.

But this is taking a lot of figuring out because I'm not sure what you've done. The hoses in your "this is how is was before" pics look like the heater core is bypassed. Then in your "this is now" pics, everything looks connected the way it was supposed to be originally. Are you sure titled the "before" and "now" pics correctly in your post? Or have you put everything back the way it was supposed to be?

The bottom hose from the throttle body is the one that goes to the diverter valve, but will need to be routed directly to the radiator to bypass the valve and heater core. And in the "before" pics, it looks like it was already bypassing the valve and going... somewhere. That's why I asked if you titled the pics correctly. But once bypassed, then you can remove the valve and all the other heater hoses completely.

And where is the hose going that comes off the top of the throttle body? That's a port for the oil breather, so that hose(though originally it should've been a metal tube) should go to the breather in the valve cover. Is it? I can't see it back there.

But you could go another step further and delete the coolant flow through the throttle body, a procedure known as the "throttle body coolant bypass." And if you do that, then you can remove the hose from the throttle body to the radiator too; cap the radiator nipple; remove the U-shaped hose that goes from the front of the intake manifold up to the bottom of the throttle body; then remove the nipple from the front of the intake manifold, and plug the threaded hole with a 3/8" npt pipe plug. That will eliminate all of those hoses, and your cooling system will be simplified to just the large upper and lower radiator hoses.

Chevy86 IROC-Z

iTrader: (17)

, aswell as what I said.When I get a chance, Ill snap a pic of my TB Coolant Bypass. I didnt bypass my heater core though. I do plan on plugging the male fitting in front of the intake manifold agian until winter.

thegoochking

yes the hose is going to the breather valve. And i ended up disconnecting the hose from the throttle body to the diverter and the hose at the bottom left that connects to the second part that goes to the core and connected them together which i think is how they originaly had it. When i got it i didnt know they had bypassed the heater core so i put it back the way it was supposed to be. Since the car needed a fuel pump when i got it i had to just go by their word on what was wrong with it. Seems now that more and more needs to be fixed. Motor mounts are clunking durring accel, tranny is clunky going into first from park. suspention seems off and the wheel squeeking is annoying. And now she runs realy rich.

LAFireboyd

iTrader: (3)

Here's a diagram showing the direction of the coolant flow.

Connect the hose from the throttle body(the one with the red arrow running between the throttle body and diverter) to the hose that's connected to the radiator(the one with the blue arrow). The hose from the throttle body is 5/8", and the hose to the radiator is 3/4", so you'll need an appropriately-sized coupler to connect them together. And that's it... the heater core will be completely bypassed.

Then completely remove everything else: all the other associated hoses, the metal tube that's bolted to the body(marked with both blue and red arrows), and the diverter valve. Get rid of all of it; take it all out. Otherwise, from here on out, it will just be clutter that will keep things looking very confusing in the engine compartment.

Then I'd suggest putting rubber caps(3/4") on the two heater core nipples that protrude through the firewall, just to keep it sealed-up(and it'll look nicer than leaving them open).

And not that this matters for this topic, but your air plenum has been removed at one time or another, because that top/front runner bolt with the post sticking out of it is supposed to be the top/middle runner bolt on the driver's side. That post used to have a wire loom on it that clamped over the throttle cables to keep them nicely positioned. Obviously, the loom is gone from it, so it really doesn't matter. But I just happened to notice it. A correct torx bolt would look nicer there.

thegoochking

yea i thought that looked out of place

thegoochking

my hose from the radiator doesnt connect where it is in the diagram look at my pics see where its going. The one to the left of where that goes is going to where it is in the diagram. i disconnected that one and connected it where the heater core valve was connected

LAFireboyd

iTrader: (3)

And I forgot to mention, when you remove the diverter, be sure to put a small cap on that vacuum line after you unplug it from the top of the diverter.

Regarding the hoses providing flow back to the radiator, beginning from the firewall: the small S-shaped hose is sending coolant to the radiator from the heater core; that hose connects to a metal tube that's bolted to the body next to the fenderwell(your tube is probably still down there, though it might've been removed already); that metal tube has a nipple on its topside where the hose coming from the diverter(top nipple) curved downward and connected to the tube, joining-up with the flow from the heater core to head back to the radiator(that's what the diverter is there for: to provide flow back to the radiator, but also to divert some flow to the heater core when vacuum-activated); then the tube carries the joined-flow toward the radiator, and a hose connects it the rest of the way to the radiator.

So by bypassing the heater core, connecting directly from the throttle body to the radiator, you can physically remove everything else.

thegoochking

this is what i did. The radiator hose doesnt connect to the rail it is going down by where the smog pump was and then there is one next to it that goes to the rain. I unhoked the one going to the rail and used an extention to connect it where the diverter was connecting to the throttle body. Now there are no hoses connected to any of the hoses for the hearer core.

thegoochking

sorry wrong pic

Chevy86 IROC-Z

iTrader: (17)

thegoochking, food for thought. Bro, checkout your picture, The bolt circled in yellow can be placed on the driverside of the plenum. Many use it to hold down the accel. pedal. Prevents it from vibrating on hood.

thegoochking

i dont see anything circled in yellow. Are you refering to the bolt that is the most to the front? i thought that looked out of place there

LAFireboyd

iTrader: (3)

So you've connected the two hoses down under, where we can't see in the pic? That's why it was difficult to know what you had going on there... because all the hoses disappear from view before we can see what's happening with them. Then that newly-coupled hose connects the radiator and the... what... throttle body or diverter? I suspect the throttle body, because you said nothing is connected to the heater core anymore. But...

According to your last pic with the white arrows, it still shows the diverter looking connected to something. However, it looks like you've drawn the arrow past the diverter, directly up to the throttle body, leading me to believe the pic is no longer representative of what you've done, and the diverter is no longer connected, right? Then ok, you've got it.

Now you can remove all the other hoses and the diverter, cap the vacuum line that formerly went to the diverter, and cap the heater core nipples at the firewall... done... and it will look a lot cleaner on that side of the engine bay. And if you ever replace your heater core, now you know how everything will go back together the right way.

By the way, the metal tube you have a red X through is not the metal tube I was talking about. That metal tube is part of the A/C system. The metal tube I was refering to is black, and it's underneath the A/C tube; it was the one that had the heater hoses connected to it. I suspect you know that, but I thought I should mention it, just in case...

thegoochking

the hose comming from the radiator goes down where the arrow is pointing then right next to that there was another tube that went where the diagram showed the radiator hose going. I just disconected that one that went to the heater core and conected it to the one that goes to the throttle body where the diverter was. There are no loose hoses only the ones that lead to the heater core. That would be the 2 that go to the firewall and the metal rail that leads there also has no more connected to it.

LAFireboyd

iTrader: (3)

Right... sounds like you've got it. The diverter is gone, now cap its vaccum line, pull out those disconnected hoses that go to the heater core, and cap the heater core nipples.

Eventually, you might want to bypass the coolant flow through the throttle body too. That will clean-up things even more, and it will bring your cooling system down to its simplest and most efficient form.

You'll remove the hose you just created that runs from the throttle body to the radiator; cap the radiator nipple; remove the U-shaped hose underneath the front of the throttle body that runs from the front of the intake manifold to the underside of the throttle body; remove the nipple it was connected to(unscrew it from the front of the intake manifold) and plug that hole with a 3/8" npt pipe plug. Or you may never want to do that.

But for this current operation, you're done.

thegoochking

which line is the vacume line

LAFireboyd

iTrader: (3)

It's the lone(oops, edit: long, not lone... although it is lone too lol), thin, black plastic hose(tube) coming from the back of the engine bay that connected to the top of the diverter valve. With the diverter gone, that will need to be capped-off, or you'll have a vacuum leak. Edit: You can cap it with a small rubber cap(purchased in the "help" section of auto stores), or some people just plug it with a small screw or nail.

Chevy86 IROC-Z

iTrader: (17)

Yup. The bolt that is close to the throttlebody on passengerside, you can remove it and put it on the otherside of the plenum to hold down the accel. pedal cable. It's really up to you though. If you dont have a rattling issue, then you can leave it like that. Well then,

thegoochking

im sure i do hear rattling so i may just do that. and i havent phisicaly removed the diverter valve and tubing yet. So with it being still there but not routed to the coolant system will i still have a vacume leak?

LAFireboyd

iTrader: (3)

A "hissing" sound coming from the valve while the engine is running would indicate there's a leak. But I doubt you're hearing that, because it shouldn't be leaking if it's still connected.