If your car has at least 100,000 miles on it, change the heater control valve (sometimes called diverter valve). They tend to get brittle over time and can break without warning, causing you to get stranded in the middle of nowhere with coolant spewing out.
$16.00 from Autozone.


:hail:IROC-Z

 

it ****ing took me like 3 months to find out why the hell my heat wasnt work,, yes yes,, i replaced it and it was damaged and falling apart, and it was just near 100k... good call rocky!

 

Can it be true that an 85 T/A didn't come from the factory with one? Mine never had one, and the parts stores don't list it. I'd really like to have one, anyone know what is involved in adding one on? TYIA

 

im not to aware about your situation... oh yeah, might i add mine went out during the end of the winter so it wasnt that bad. except for those cold days where my ffrend had to drive my *** to school.

 

VERY TRUE, I replaced 3 in a matter of 3 months on 3 different IROCs..

 

I saw a small leak coming from one of the outlets on mine, I picked the thing up and it just disintegrated in my hand. If that happens on the road you are lost!

I got one to the UK in 2 days for the princely sum of $60!!!

 

Thanks. My brother's fell apart on me yesterday and I wanted to kind of warn people. It's one of those VERY important parts you don't realize is even there 90% of the time, ya know?

:hail:IROC-Z

 

Yep. Mine busted on me a few weeks back. Had me on the side of the interstate for about an hour waiting on water and giving things time to cool off.

 

i have gone through two....r these things even needed?

 

If i understand correctly, they divert coolant around the heater core when the air conditioning is running. This makes the a/c work more effectively.

By the way, for future reference, you can find them at napa under P/N BK6601232 (Balkamp) for TPI engines..

 

Bah. I removed it on both of my cars. No hassles now.

 

About a month after I got my car, engine started to overheat and I had NO idea why. Everything looked ok. Took it to a shop for a tune up and mechanic said I really needed to have my heater control valve replaced. He asked if I wanted to wait while they ordered it and installed it.

I'm in school (broke alot), so I figured I'd run the car to the dealership, get the part, and do it myself. On the way to the dealership, on the highway, my temp guage red-lined. Walked a mile to where 3 GM dealerships were. NONE of them had it in stock.

100 degree summer day mind you.

Walked 3miles down to an autozone. Got the part and on the way back to my car grabbed a jug of water from 7-eleven. So I hauled a gallon jug + part 4 miles back. Did a little road-side surgery and was back on the road.

Moral of story: Change your HCV today if you have any doubt when it was replaced.

 

I had mine break on me too, but lucky for me a friend was on his way to a location close to where I was, and he brought me one. Takes about 5 mins to change with a pair of pliers. I was still stranded for an extra hour at the dog show with my girlfriend though......

 

Would a broken one cause water to leak from under the car when its parked (after you've used the A/C)? My 92 B4C has been leaking water lately .... but only after I use the A/C. And it has 91k miles. A/C still blows cold. Thanks!!

 

it's called condensation, it's supposed to do that. look under a brand new car that has the ac running or was running. you'll see little drips..or if it has been parked...a puddle

 

grrr..double post, damn 56k

 

Thats what I figgured .... but since it has been making alot more water than normal lately and reaching near 100k miles I am kinda concerned. Thanks.

 

just cracked enuf to start spewing coolant out,by time i got where i was going,she about blew all the coolant out,watched the gauge so it didn't overheat,got one from AZ,think i'll go buy a NAPA for the IROC,why didn't i think when i just went thru the sensors and rad end cap a couple months ago?????

 

You sure its JUST water. After you run it around for a while, park it, crack the hood, and inspect the hoses while its still running. Look for the source of leak around the t-stat, manifold gasket, and HC valve first...then check all other hose attachments just to be sure

 

i believe this to be the thing i pulled off last year.
I removed some diverter valve when i did my T/B BYPASS.
I only ask because the car doesn't get warm inside lately, and some were saying it had to do with heat...
PLease post a picture of the offender!!!
SHAGGY

 

hah....my jus broke bout 5,000 miles ago tearing up a civic..pooor civic.. then after the run it started smelling like fresh pancakes in my car. it turned out to be a broken heater control valve leaking coolant on the header.

 

This is the baby. If anyone notices the valve cover paint is getting a bit flakey, buy one of these before you think about lifting it up "to have a little check for leaks"!

 

yep yanked mine long ago.
No leaky leaky, yet the defroster still doesn't seem very warm.
May just be the 180* thermostat.
shaggy

 

lasher_350, yeah, you don't have one. The heater diverter valve started in '87. I dont' have one either- but if I did, I'd do what Jim did, and get rid of the damn thing altogether. On my '86 Firebird, which never had the diverter valve, before I took the a/c out, the a/c still blew nice and cold on a hot day.

So yank it out and bypass the lines! I've even dumped my steel heater lines; I've got heater hose running from the water pump back to the heater core. I fought for one long cold winter night trying to replace one of those lame *** question-mark shaped hoses against the firewall, and caught the flu. I vowed never to go through that again- and I haven't! It's so easy to change a heater hose now. Tip; they're not the same size, one heater core pipe takes 5/8" hose, the other pipe takes 3/4" hose. Be sure to use a wire tie (or similar) to keep the hoses from getting burned on the exhaust.

 

Wow! 140,000 and mines never been touched.

In the above pic...Is the round thing with the plastic line coming out the back and the hoses going in at the bottom? See since mine has not given me a problem, I have not had to learn about it yet.

If that is it.... Mine seems fine. Not aged or cracked. Hoses are good too. I checked all that when I replaced the old nasty vacuum lines. I even added hose covers to it and it was fine. But to be safe I may get a spare or just swap it anyway.

 

mine blew up just as i was leaving a drive in MAC machine at the bank. Replaced it, now i just removed it ..
https://www.thirdgen.org/rides/rideimages/acdeleted.jpg

 

Yeah, I wished someone had told me this stuff long along,My valve control went out on me right after work last winter and I had to wait 2 weeks to get it replaced and it was just $67.00 with professional install included!...better that than the heat core
that exploded on my caddy I looked like Cheech&Chong in "UP IN SMOKE "....flying down the I-5 at 6:00pm at night!

 

That was a funny movie. Nice Dreams is good too.

:hail:IROC-Z
:hail:BUD

 

When I first got my car I had to do somehting with my friend, he had to lift it up and SNAP one of the hose pieces broke right off, I was 11 miles from ANY auto store, so I had to do some fabrictaion and plugging to drive myself to the friggin autozone.

Long story short, spent 16 bucks on it, a few weeks later I removed my A/C so there was no need for it anymore

 

And like I said, 82-86 didn't come with the valve, and those 82-86's had a/c. My a/c always blew cold air at me.

So you don't need to pull your a/c to get rid of the heater diverter valve. Cut the valve out, run new hoses from the front of the engine straight back to the heater core, and plug the vaccuum line that was on top of the valve with a golf tee.

 

This would of been soo helpful a month ago...this guy isnt kidding when he says to replace it.. i was on the highway when mine exploded. its a good idea to replace it i only paid 10 bucks for it at AutoZone.

 

oh yeah, mine broke about a year ago. Had to replace radiator hose drove about 2 miles twords town and that thing broke. lucky my dad was folowing me, cause it was 60 miles to the closest OPEN auto parts store. No where to get one in a town with less than 1,000 on a saturday afternoon. had about 110,000 miles.
ryan

 

So if I don't have AC I don't have anything to worry about? Seems like I have that piece in the pic. in my car or something simular, but I don't have A/C, just T tops.

 

no you still probably have it, it really isnt related to the air conditioner it is related to the heat. it opens a valve to let coolant flow through the heater core.. i think so dont quote me.

 

If I understand right, 82-86 cars dont have the valve. Why wouldnt you want to have one on these cars to stop the hot water entering the heater core when not in use?

 

mine still blows cold air when i put it on vent. i didnt notice a difference when i took it out

 

If this is bad will the heater sometimes go to a high blower when on the low position? And when you dont have the heat on or the ac on will the vents blow hot air through?

 

your first problem sound sliek a blower motor resister( i dunno if 3rd gens have them but i did in my cavalier and thats exactly what happened and i had to fix it) as for it blowing hot air with nothing on, mine does that as well...

 

Does anybody know where that vacuum line on the top of the valve leads to and where I can get a replacement vacuum line? My valve broke too (along with the vac. line) before it got cold outside so I just threw it out; I noticed I don't get much heat in the car, is this the reason? Anyways, if anyone knows where to get that vac. line it would be most appreciated.

 

The vac line can be got at Murrays, autozone. it goes from the diverter to the back of your HVAC you have to run it through your firewall.

 

Thanks, that helps a lot

 

yes replace it asap, mine didnt go when driving mine went wile i was under the hood trying to to find another problem i pulled this hose becouse i was shaking wires and the H.C.V blew off the bottom hose and sprayed antifreeze on my forehead, i had
2nd and 1st degree burns all over my face.

 

This post is cursed
Right after I read this post the damn thing broke on me
Curses

 

it isnt cursed its a fact

CHANGE YOUR HEATER DIVERTER VALVE

at least you were aware of it

 

Changed it and it runs better than it did before or is it just my imagination.

 

i tprobably runs better now that you have a better cirrculation of coolant going through your engine...or maybe i hav eno idea what im talking about???

 

thats a good idea.

 

If coolant leaking on the header smells like pancakes to you... I'm never eating any of YOUR pancakes.

 

hes kinda right... if you are in teh car and have your heater going it somewhat smells like pancakes.......

ever tasted coolant(dont give me any bull about this cause if youve worked on yuor car enough you somehow have tasted{not drank} any fluid that goes in it)

 

HA! if that isnt the truth. nothing like getting a face-full of coolant and oil working on my friends '95 Z28. ahh the things we go through....