Ok I have no clue, the heater core is fine and none of the coolent lines are kinked or blocked. The valve that contols the heat is new. So I have no Idea.. It started after I changed my timing chain. Any Idea's?

 

Water pump is shot / on it way out. First sign of one going is no heat.

 

At 1st I was thinking that but its only 6 months old.

 

That or its froze up??? Got a good coolant mix?

Could be clogged up. Few time I made one work better by taking it to the U-do-it car wash and using the pressure wand to blow out the heater core in reverse of the flow.

Thermostat could be stuck?

take the radiator cap off , start it and let it run for a bit.
If its flowing you should see movement. Or even pull on or both of the heater core lines lose and check to see it coolant flow out of either well.

I use eco safe 50/50 coolant so its no big deal to make a mess.

 

Its not frozen everything with the coolant system exept the radiator is only 6 months or less old. I belive its flowing when you open the radiator cap its been about 2 weeks since I ran it anywhere... I will check that tomorrow again.

 

Is your blower motor working, and blowing air over the coil?

 

could be that you have a big air pocket in it from pulling the waterpump. if that hasnt bled out properly, that will cause no heat.

 

good point dave, I just skimmed thru.

If it happend during timing chain replacement, you have an air lock in the system somewhere. You will need to FULLY drain the system, and refill.

I got an air lock, and somehow managed to remove my CTS and backfill the system, and fixed it.

 

I didn't think about a air pocket. My temp light will sometimes light up but if I hit the gas or turn the car off then on it goes away.. Do you know how much coolant goes into these cars... I think I only put about 1 and a half jugs of coolant in and then it was full. I was thinking thats not enough.

 

its the vacuum control heater valve on the pass side of the engine on the heater hoses.
the valve has either lost vacuum source, of broken the referance internally.
easy fix, since the switch is vacuum closed, unplug the line from the top. then start the car, and unless the internal blade is jammed, the water pressure will force the valve open circulating the hot water to the heater core.

Mine went out about 15 months ago. I still have heat, just cannot stop the flow. I think the valave is like 20-30 at a parts store, but I still have heat, so why replace it?

If your resivoir is empty, you have air in the system.
to purge air, let car warm up NOT HOT just warm.
open the rad cap with a rag. Hot steam!
then fill the system WITH THE CAR STILL RUNNING, stop when it will no longer take water.
wait a few minutes, and do it again, and again and again. Should only take 5-10 minutes once started.

 

That was going to be my suggestion; low coolant. When coolant's low, it doesn't heat up the heater core as well. Think of a big 3" pipe FILLED with water.... that's full coolant. Then think of the same 3" pipe with a trickle of water in the bottom... that's low coolant.

As long as the rad is filled up to the neck, and the overflow bottle has a/f in it, you're okay.

I drill one or two small holes in the outer edge of the thermostat to prevent air bubbles from forming under the 'stat. I'll attach a pic to show what I mean.

 

Start filling the suppplied resivour tank, to the top. IF your RADIATOR CAP IS GOOD & THE SYSTEM IS FUNCTIONING CORRECTLY, you'll fill up engine cooling system that way. The overflow tank will empty & allow air to escape, removing the air bubble.
Other way to check is easy, too.
Drive car, for a bit, go to the grocery store & go shopping. When returned from shopping, open radiator cap, see water level.
IF RADIATOR LEVEL IS LOW, ya found the no heat cause. Just top off rad with fluid. BUT find out why your resivour tank is not empty. It could be a bad rad. cap, too.
On my 1985 I do not have that valve. Why did GM add it?

 

probly to keep the heater core from heating up the A/C air.

 

Ok. I got the air bubble out. It was about 2 liters low. Also I let it warm up plenty enough for the thermostat to open but it didn't. The lower radiator hose was hot and pressurized and the top radiator hose was cold and limp... I believe it's now the thermostat also. I got one so I'm going to change it anyway. Wish me luck!

 

ALSO try to run some water thru radiator to "flush it out".
Put hand over bottom and let rad fill up w/water, then release hand. IF ya can do it, try again.
10mm, 13mm, 15mm, maybe a 17mm wrench, box end wrench & long short sockets with attachemnts will do the thermostat dance trick.

 

Sounds like it may be the wrong water pump. Was it recently replaced? There are two different pumps, one for regular 'ole v-belts and another for serpentine setups. They rotate in opposite directions. Incorrect pump would attempt to {lamely} move the water the other way.

Even if the thermostat didn't open you should still have heat.

RBob.

 

Ok. I got the old thermostat out and I tested it and its fine. Let me try to explain this again, I had heat.... I changed the Timing chain.... Then I had no heat.... I had to remove the water pump and the timing chain cover I changed the cover also, I took the 3.4 timing cover off and put the 2.8 timing cover. The water pump was new 6 months ago right before I changed engines. It was originally purchased for the 2.8. I had heat for 6 months and now that I did that I have no heat now... Both engines where on a serp system. And at one time with both engines I had heat with the same water pump. I have no Idea whats wrong...

 

try pulling the two hoses to the heater core and flush it out w/ a garden hose or something. see if any junk comes out or just what. leave the hoses attached to the core, pull them from the engine. that way, if theres any blockage in the hoses, youll get that out too.

 

i dont no if anyone said thins did not read all post but did u check your thurmostat

 

Seems like the cover is the only thing that changed. I'd be tempted to put the 3.4 cover back on. And while both are off compare them, sounds like something changed between the 2.8 block/cover and the 3.4 block/cover.

RBob.

 

I'd take your top radiator hose lose from the radiator, and run your car till you see water start coming out of it, although if you did the relief holes like TomP said, then a small amount of water will come through. If no water comes through it, something's clogging the line somewhere. Most likely it's the water pump gasket.

Do this too....take your radiator cap off (everything else still hooked up). Rev your engine a lil bit and see if the water level drops at all when you do so. See if it raises back up when you let off. It's not a sure fire way to tell if your water pump is working, but it'll give you an idea.

 

ME?
I'd run a loop thru the ENGINE cooling & then touch the hoses.
IF it's hot, that'll show the water pump works & circulates heated water.
For when I "bypassed my old leaky heater core", I used the heater core hoses by firewall for my "loop location".
Then somehow figure out how to "flush" out/BACK flush the heater core.

NOW your heater core MAY NOT take the abuse.

The diff between a 3.4 & earlier T Cover is the mounting for the factor DIS set up & extra accessory mounting locations.

Truly not much else, beside (in my 1985 vehicle platform) the T cvover will mate to the oil pan (1985 has a angled lip that bolts to T Cover & oil pan).

Try bypassing the core for a more simple experiment, testing what is already "there" & proving water flow thru the current (pump) set up.

"I" think something is clogging the heater core it self.

PS When attempting the "core bypass set up" be prepared for "cutting current water hoses" for a "loop" fitment. Choose the best & easiest replaced hose section, for least work after. Those heater hoses really give a fight if ya try to disturb them. One can make a "loop from plumbing section or Lawn hose patch kit" stuff at hardware stores. Make sure your "loop" provides "heater hose kink free flow". Kink free water flow is an important detail.

I think ya clogged the heater core & it floats/flows out then clogs back up again. Heater cores are "only" tiny water radiators!

 

pocket warmers!:lala: :lala: