MudEye

When I bought this car the Old guy told Me there was a heater core in the trunk... And that the heater didn't work. So I finally had the one in the trunk put in. It was bypassed before this. The mechanic who put it in ( The one that was in the trunk ) said it wasn't blowing warm air and He didn't know why.
Which leads Me to believe it was not the heater core to begin with.( Sorry I forgot to mention that the heat is still not working ) The hose going into the radiator is very hot. The hose going into the heater core seems warm but not hot ( after a long drive in the country ) Is there a heater control valve solenoid in this Cutlass? The water level is up where it is supposed to be. Any suggestions.. I appreciate.

oldcutlass

What thermostat do you have installed? Does your car have A/C?

MDchanic

When heater cores fail, they leak, they don't stop making heat.

The heater circuit is pretty simple: Coolant flows out the passenger side rear of the engine, through the hose, through the heater core, through the other hose, and into the water pump.

In A/C cars, there will be a vacuum-operated valve screwed into the manifold where the hose comes out, in heat-only cars it's just a nipple.
The heat valve is generally closed in the full-A/C position only (there were a few different ways of doing this over the years, including some that used vacuum to turn the flow on, and some that used vacuum to turn the flow off).

Check to make sure that the coolant is flowing freely.

- Eric

Charlie Jones

Was the heater core that was in the trunk a used one?
If it was, there is a possibility that it was clogged.
Radiator stop-leak is notorious for this.

stan 65 cutlass

true, plugged the one one in my old truck, forgot to turn off the heat when i used it. stopped one hell of a leak tho

MudEye

Not sure about what kind of thermostat.Just picked it up from auto zone.

No A.C.

MDchanic

No A/C means no valve - it's just a straight shot from the back of the manifold through the core and into the water pump.

- Eric

oldcutlass

What temp rating was it?

RandyS

You likely need a new heater core. IMO, the first clue was that the heater core was in the trunk.........

MDchanic

Ha ha. Yeah. At the very least, any parts found in the trunk need to be fully tested.

For a heater core, running a garden hose through it is enough to test for blockages - it should flow freely.

For holes, put a piece of hose on each end, block one with a suitable bolt or a dowel (clamp everything tightly), fill with water, then adapt your air compressor blow gun into the other end (second piece of smaller hose, or whatever).
Put about 50psi into it and see if any water squirts (or trickles) out.

- Eric

MudEye

Are You thinking maybe they gave me a 200 instead of a 160( or whatever the norm is? )

The fella I bought The car from said the heater core in the trunk was new.
And that's what was just installed as the other was removed.

To check if coolant is flowing freely: So I remove the cap before starting and visually inspect the flow?

To check for a clog: Disconnect upper radiator hose , run water through hose going into the core , should flow out freely ?

oldcutlass

I'm thinking you have a 160 in there, and at that temp your not going to get much heat in very cold weather.

MudEye

Hmmm... I'll replace with a 192- 195... Not sure what this one is rated.

If that doesn't work , I'll try the flushing method.... I'll post....

oldcutlass

I'd use a 180 Stant Super stat.

rustyroger

If your core is clogged this might work;
I cleared out the heater core of my Nissan with domestic limescale remover, I was amazed at how much crap it shifted.
It was an aluminium core btw (not aluminum, it was made in the UK ), if I had left it in there indefinitely it may have reacted with the chemicals, if you have a copper core the same might apply to the solder used building it. Check for leaks afterwards.
I would have thought even a 160 thermostat would allow the heater to work, but I haven't experienced a Northern state or Canadian winter.


Roger.

MudEye

Ordered the 45358 Stant super stat... Which gasket ??? There are 3 different styles ( 2 holes , 2 holes with a smily face , 3 holes ..... Do they all work the same?
or do I need one? Thanks
Read a interesting thread... A guy said He drilled 2 additional holes in his thermostat to allow air to bleed. Even He said it may be an old wives tale... But worked just fine.

Wives tale? Just wondering..... You know the air bubble in the system thing... HeHe! I don't know!

RandyS

Get the one that matches your manifold & water neck. No need to drill any holes in the stat. Yes, old wives tale.............

oldcutlass

The 2ea 1/8 holes work on Chevy's. X2 on the gasket that matches your water neck.

rustyroger

How is your heater now?.

Roger.

oldcutlass

Wondering also?

Koda

Understood he hasn't gotten back, but I was reading through the comments on how a 160 stat will not yield much heat. I agree, but only in the cases where the thermostat is in a healthy cooling system. A healthy cooling system should have the operating temp be at the same range downhill idling in neutral and coasting at 30 mph in the freezing winter but also at WOT in the hot humid summer; in other words, all the time, because the thermostat will regulate the flow through the radiator. However, many old cars have a compromised radiator and they will run at some temp above the thermostat value because the radiator cannot keep up.

A high flow, low temp "superstat" style thermostat offers the engine the chance for a thermal reservoir of artificially keeping the engine at a lower cruising temp to mitigate periods of high cooling requirements and their temp spikes, and allows less flow restriction through the thermostat. It's not the intended design, but it can make it work.

Short version: a 160 stat with a gunked up radiator will put heat out the heater core.

MudEye

O.k. Replaced the thermostat with the 180 Stant super stat. And still no heat.

I did notice however that the hose going to the heater core is cold ( from waterpump to top part of core. The short lower hose coming out of bottom core to engine block is cold too. Rad hoses are hot. The thermostat is opening .The fluid drops a few inches.I filled it back up the fill mark. That fill mark is at least 4 inches below the top of Rad.While I know it will expand when hot,would this create any issues with heat? Bubbble in the system perhaps? Thanks

steverw

Did you replace all heater hoses too? If there old they can also build up a blockage. Pull them off the water pump and block, check the fittings to be sure there not blocked. It simply water passages that let hot water from the engine pass through the heater core. If its not getting through then something is likely blocked somewhere in the system. Also if the engine has not been rebuilt recently, perhaps you need to flush the entire cooling system, or have it done. Is it an A/C car? If so be sure the blend doors in the underdash unit are connected and moving freely. I believe there cable controlled. Use a 180 degree thermostat.

oldcutlass

Your going to have to determine if there is water flow through the heater core. You mentioned the hose back to the water pump is cold. Does the hose coming out of the rear of the manifold go directly into the firewall? My car does not throw a bunch of heat out there but it does get the inside comfortable.

MudEye

Yes the hose ( short one ) comes out from rear manifold into firewall ( the connector on the bottom ) While the connector on top has the hose going up to the waterpump.

MudEye

O.K. Sorry it took so long to respond. I did get The heat to work a couple months ago.
There was a whole lot of rusty debris clogging up the hose going into the water pump. The pump also had the debris in it. Explaining why there was no flow going into heater core.The pump was obviously to clogged to send proper water pressure to the heater core.
Heater core was fine. Replaced water pump and Timing chain ( original chain at 109,000 )
And the Heat was on! Sorry I made it sound so complicated. You guys were spot on.