Devil in My De Soto - over heat mystery

Gotta a stock 50 DeSoto flat heat six.

New thermostat, new re done radiator, checked out the stupid coolant tube that doesn't want to come out but a fishing expedition with a long *** threaded rod revealed no rust evidence - block was boiled at last rebuild a few thousand miles ago. Water pump seems happy, no pee hole drip. Timing is set . Ran nice last week when ambient air temp was about the same - watched aftermarket gauge rise and thermostat open at around 180 life is good it's cruise time. Car sat two weeks - started yesterday and let her idle. Look at driveway and she's puking water like an over hear - sure an be gora she is at 220 ! Gasp
So I'm guessing defective new thermostat - any other thoughts ?
Thx


Poverty leaves an impression

 

Have you checked to see if the water is actually circulating when the thermostat opens? Could be a defective thermostat and a water pump doen"t always leak out the weep hole. Pull the thermostat out and see if theres anychange.With the thermostat out water should circulate if the pump hasn"t taken a ****.

 

X2, water pump impeller may be spinning on the shaft

 

Thanks - will yank therm o stat
Also thought about an air pocket - any burp technique suggestions ?


Poverty leaves an impression

 

could be air.i have jacked the front of a car 2ft off the and let it run for 1/2 hour just to get the air out.you just have to make sure the top of the rad.is the highest part of the cooling system.on one car i put a flush valve it the heater hose just to bleed the air out.

 

Thank you

 

Those beauties have a hidden devil in them all that name don't start with De by mistake. Fix it and drive "the hell" out of it. ~sololobo~

 

sounds like it may be the ticket. but i would be checkin thermostat, they nearly always stick after they've overheated

 

A new one though - Oy well parts ain't what they used to be I guess.


Poverty leaves an impression

 

New these days don"t make it good. Had a buddy buy a new water pump for Mopar 440,he put it on and car instantly got hot. Pulled the water pump and one side of the water outlet to the head wasn"t machined. My oldman always checked his thermostats before installing.

 

When you buy new thermostat be sure to brush all of the rice off. It will stop up your radiator.

 

I always drill a 3/16 hole in the thermostat to allow air to go through. In a non critical area of course. It won't allow enough water flow to cause a problem but it prevents the stat from being airlocked and not heating up.

When I worked for a Ford dealer, the service manual advised heating the thermostat in water to open it and putting a piece of hard candy in it to hold it open to let air out.

 

Now that I read this I miss my old man - he told me the same thing and I forgot - thanks HAMBsters I'll give thermostat a test recheck the waterpump - say tuned


Poverty leaves an impression

 

Kind of forgotten about that tip. Also remember hearing about using an aspirin to temporarily hold the thermostat open. After the job is done then you can treat yourself to a piece of hard candy.

 

thermostat is not upside down ?
hoses collapsing?
bad rad cap ....

start cold without cap idleing look for water movement in top of rad .. after 5 minutes of running a bad pump will have not moved the water thru the system and it will get hot a bad stat will also show signs of excess heat.l
nothing?
install cap and watch for temp to rise
that car should have a low pressure cap below 10 lbs

 

New cap hoses fine and not quite dumb enough to install inverted

Thanks !


Poverty leaves an impression

 

Did your T stat come wrapped in the plastic stuff on a little piece of cardboard of a rack in the autoparts store?

Those stats are iffy at best. Pull the stat, throw it in a pot of boiling water and make sure it is opening. Or easier that that get the car up to heat then squeeze the top radiator hose and make the sure the stat is comming open.

A few years back I started using fast actiing T stats, they are a performance stat. Many companies make them I have had pretty good luck with MR Gasket. Stant also makes them as well as Wieand etc. I even sue them in stock engiones that I am responsable for any more.

They are a little pricey like up in the 7-10 buck range but they work and I haven't had any problems with one yet. Knock on wood.

 

Air in the system should not be a problem. Which byp*** system do you have internal or external??? This is externally evidenced by the thermostat housing. If it is a big cast iron piece with s ahort hose connecting it to the water pump it is an external system. If it has a pressed sheet metal outlet which only connects to the upper radiator hose it is an internal system. The gaskets and rear piece of the water pump must match the system.

With the internal there is a slot in the backing plate and gasket that meet up with p***ages in the block near the water distribution tube. so the water pump and gasket must match up. the external system doesn not communicate with these p***ages.

Also the water distribution tube does not really have a large effect on operating temp if its clear of crud. Its job is to direct coolant upwards to the valve seat area to provide cooling for the valves. Thats why the slots point up, and the tube is designed like a heating duct, in that it gets smaller as it gets further away from the pump. It keeps the velocity and quan***y of coolant equal alont th elenght of the tube.

Also did you test your stat by placing it in a pan on the stove to see if it opens at the correct temp.

See page 14 of the pamphlet in the attached link. Notice the gasket for the pump. it has a hole for the distribution tube, and a round hole. If you have the internal byp***, there needs to be a corresponding hole in the rear plate of the pump.

the pump shown in the illustration is the external style. If you new pump backing plate doesn't match the old one switch them.

http://www.imperialclub.com/Repair/Lit/Master/013/index.htm

 

This is a non pressurized system.

 

Based on the info above it's external
Cast monster and lil hose

It's a napa thermostat
They had the gasket too
As for water pump it was oe rebuilt a long time ago - I'll pull thermostat and boil it and I suspect the water pump could use an r/r - any suggestions on a rebuilder in SF bay Area ?


Poverty leaves an impression

 

my chevy 6 tried to cook itself. i had the dizzy va***e line on the wrong carb port.

 

Hang the stat froma wire so it is reading water temp not the"pan'temp

oh ya i was not saying anything bout you... But making sure that the inverted stat was not an issue

IS THERE A CHOKE STOVE ****ERFLY IN THE EXHAUST ?

 

There is a tube behind the water pump that can be clogged, if it is, you will never be able to get it to cool. It goes deep into the block and gets removed by a slide hammer. I just swapped engines in a 58 Plymouth and changed this in the new block to avoid troubles like this. I got my replacement at Vintage Power Wagons in Iowa. Check out there website and you can see one.

 

Good point about the pan - and yes I am that dumb but I was careful


Poverty leaves an impression

 

That was my original thought and they sell a tool to stick on your slide hammer specific to removing the tube but I was able to fish around in the tube the entire length and saw no signs of corrosion - I hope it's **** tstat or water pump - the idea of slamming out that tube - must remove grill some - doesn't appeal


Poverty leaves an impression

 

****er fly is loose - vac lines are in proper place


Poverty leaves an impression

 

did the timing slip to a more advanced postion of is the breaker plate stuck in the advaced position?

 

Mmm good thought I'll double check - when I got the car back from my brothers estate it was way out...also he had -3 an line for vacuume


Poverty leaves an impression

 

I have alway drilled three or four hole in my stats just to make sure they flow. It helps get any air in the system out of the system. hope this helps

 

Well it's raining and I am lazy so I decided to do some dry research a.k.a. HAMB slacking and lo and behold I get to u tube and here is proof of the Devil hisself at the end of this ad
http://www.youtube.com/watch?v=APoF4kE7h00&feature=youtube_gdata_player

Knew it!