TR2/3/3A Tr3a heater valve question

[ekamm]

I searched and didn't see a thread on heater valves. This may seem rudimentary but the valve screwed all the way down is closed right? I have mine all the way up or unscrewed and no heat what's up?

 

[tinman58]

there must be a blockage in the valve. Remove it and clean the insides. or the hoses are blocked You are right up is open down is closed.

 

[Deleted member 8987]

While you're at it, flush the core....use a spray nozzle on a garden hose, go back and forth until you don't dislodge any more crud (you'll see it coming out the other spout).

 

[TR3driver]

Most likely core clogged, IMO, tho of course it could be anywhere in the heater circuit. Another common place is the return tube on the LH side of the engine.

Also check the hoses where they go into the heater core, they tend to kink there.

Flushing the core is a good idea, but be careful how much pressure you put on it. Household water pressure is frequently enough to blow the core apart, if it's clogged enough to let the pressure build.

Of course, it's also possible the heater is working just fine and you didn't notice ... they don't exactly put out a lot of heat! One of the few ways an MGA is better than a TR3.

 

[angelfj1]

Eric: check out my article in the wiki section. Start the engine and after it is up to temp, open the heater valve. Touch the heater inlet hose. If it is hot there is coolant flowing to that point. Now touch the hose that returns the coolant to the engine. it should also be fairly warm. If not, you probably have a blocked core. This can be repaired (flushed) either by a radiator shop or you can do it yourself. Be careful when flushing the core and do not use more than 4 psi pressure. Otherwise you are likely to blow the core, which is very difficult and expensive to repair.

good luck

 

[prb51]

Mine blows pretty hot and I can feel the dif in winter with the aeroscreens and tonneau in place.
Just a thought but is your fan working properly, no fan, no heat.

 

[ekamm]

I'll flush when I get a chance I'm thinking that it is a blockage of crud some where. The fan blows icy air and not just not very warm but icy! The rad water appears to be great but I'm due to flush any way so I will.When I get a chance I'll check the hoses by the valve for temp. Any ideas on not over pressuring the flush of the heater core?

 

[Deleted member 8987]

Using a garden hose and a trigger spray nozzle, I have never had a failure in over 40 years of doing this.

That said, one of my moron employees....decided he was going to NOT follow directions, and used shop air and a suction hose to "blow" out a core.
He blew it out, alright....at 150PSI right out of the case!

I just hold the nozzle up to the heater hose nipple....not screwed into a hose on the nipple.
Back and forth, it will dislodge all the built-up garbage that has settled into the core.

I did my Jag....went from ZERO heat to quite comfortable for the lovely bride.


The 4PSI is cap release pressure.
Unless that core is toast, according to my radiator shop, cores and radiators handle MUCH more than that.
They generally test radiators (even my Flathead 4PSI ones) at something like 50 PSI.

I don't want to tell you what to do and have you blow it out....but, they will pressure flush it anyway, at a guaranteed higher than 4PSI.

The back-and-forth is what does the trick.
If you are concerned, keep the faucet cranked way down.

 

[Deleted member 8987]

One more thing......if this core really is plugged up, and has been for more than two millenium.....chances are good the "crud" residing therein has done it's thing on the inside of the core walls, and it may leak no matter what you do to it.

 

[martx-5]

When I redid my heater core, it was out of the car, and I was flushing the core out in the basement sink. Well, the crud flowing out of it never stopped, even after over a half an hour of flushing in both directions. I finally figured that there can't be too much good core left, so I finished restoring it, put it in the car, but bypassed the core altogether with a hose just looping around inside the car. I was just too afraid that the sucker was going to leak all over the new carpeting. :eeek:

One day I may get up enough nerve to hook it up. Until then, I'll do without the heat.

 

[Deleted member 8987]

The use of a trigger nozzle, allows you to "pulse" the water through.
Using a kitchen spout ain't gonna do it.

I have spent 10 minutes or even more "pulsing" back and forth, and it always comes reasonably clean.

Every 2 years I try to flush my cores like that.

You'll notice, towards the end of a winter, it sure is cold in the cockpit.....flush it in spring and it'll drive you out.

 

[bgbassplyr]

Open the fresh air vent on the cowl ahead of the windshield in order to push air through the heater core.

 

[TR3driver]

Open the fresh air vent on the cowl ahead of the windshield in order to push air through the heater core.

On a TR3, the two are not linked. In fact, there is a deflector so the incoming cold air doesn't blow onto the heater!