what are the causes of engine overheating ?

[bradnree]

I have a '49 Commander with an overheating problem. At an idle the engine will continue to heat and the gauge goes up.

It has a newly cleaned radiator, new hoses, the water pump is old but pumping, it has an anti-freeze water mixture, steel bladed fan.

A list of possibles for any engine: over bored, plugged some where, bad radiator, water pump bad, belt gone, timing, flex fan, collapsed hose.

What can you add to the above list that I can check ?

BRAD

[rockne10]

Thermostat stuck. Faulty temp sending unit. Accumulated sludge or original casting detritus in the block. Was the rad pressure and flow tested?

[Warren Webb]

I had on overheating problem on my 61 Champ. Turned out to be timing. I had put a Pertronix electronic ignition module in it a couple years ago & set the timing then, but somehow, thru vibration or something, the distributor got loose & it gradually started running hotter & hotter till finally I couldnt go 6 miles without it starting to steam. I was all ready to do a valve job on it, replacing with a spare set of heads when by chance I drove to a buddies garage & he heard me pull in, had me open the hood & bingo, there was the problem! Lots of things could be causing the problem, but look at the easy things first. An inexpensive but usable tool is a small thermometer that is normally used to measure the temp at the a/c ducts. When the engine is cold, remove the radiator cap & place the thermometer in the top of the radiator & let the engine warm up, so as you check not only the true temp, but the accuracy of the temp guage on the dash so you have a reference for the future. Also, while doing that, rev the engine & see how the flow in the radiator looks, so you can determine the effeciency of the water pump &/or the radiator too.

60 Lark convertible
61 Champ
62 Daytona convertible
63 G.T. R-2,4 speed
63 Avanti (2)
66 Daytona Sport Sedan

[Dwain G.]

You said this is a problem at idle, does that mean it cools okay at road speed?
The Commander engines use a water distribution tube in the block. If that tube is gone the rear of the engine doesn't get good coolant circulation at low speed.


Dwain G.

[sals54]

Make sure the pump is pumping. Some of the rebuilt ones have been known to have the impeller come loose on the shaft. It will pump some, but not enough to push the water through the engine. While your car is running and getting hot, check the radiator and see if its hot at the top as well as the bottom of the core. This will give you an idea of how well the pump is working, or not working. Sludge in the engine block is another culprit.

sals54

[rockne10]

A laser temp reader can come in handy identifying temp variations in the block, radiator and hoses. That could help isolate the problem area.

[raprice]

In my car, the culprit was a faulty temperature sending unit. The car, in fact, wasn't overheating as I originally thought.
Try the inexpensive fixes before you go spending money you don't need to spend.
Rog

'59 Lark VI Regal Hardtop
Smithtown,NY

[chocolate turkey]

Ya! Diagnose first, throw parts at it later! Try to get one of those lazer temp guns and see if in fact the thing is overheating. The worse case scerario is a plugged block. I've seen several that had to be taken apart, boiled out and reassembled in order to cure the problem.

Brian K. Curtis,
1925 Duplex-Phaeton ER
1949 1/2 ton pickup
1963 GT Hawk custom
1966 Daytona 2dr

[rusty nut garage]

The condition and presence of this "water distribution tube" is critical in the cooling of the engine. After confirming that your radiator is in good condition and the block is clean inspect this tube. First make sure the tube is actually installed, then check the condition. I caution you not to remove it if its not bad. They are hard to remove without destroying and they are made of unobtainium. Just try to find one.
The only way to inspect without removing them is remove the waterpump and using a bright light look toward the rear of the block making sure the tube is intact and not corroded.
This tube must "distribute" coolant to the rear cylinders.
Russ

quote:Originally posted by Dwain G.

You said this is a problem at idle, does that mean it cools okay at road speed?
The Commander engines use a water distribution tube in the block. If that tube is gone the rear of the engine doesn't get good coolant circulation at low speed.


Dwain G.

Russ Shop Foreman "Rusty Nut Garage"
57 SH (project)
60 Lark VIII 2dr sd (driver)