The Stovebolt Site Forums The Shop Area Engine Shop Overheating

We'll I thought I could find this issue on my own, but I think I need help. My engine, a 228, is overheating. Once it reaches operating temperature, 180 degrees, it doesn't stop. The heat gauge continues to rise well into the 200's before I panic and turn it off. Here are the things I have done.

1) Replaced the water pump (more about this below)
2) Replaced the thermostat. I tested it in hot water and drilled a 1/8" hole in the flange.
3) I Took the radiator to a shop, had it cleaned and flow tested.
4) Back flushed the system with water. When the radiator was out, I plugged the lower water pump inlet, looped the heater hose connections and removed the block drain. I stuck a pressurized water hose in the thermostat housing and flushed until the water ran fast and clear out of the block drain. I also ran a wire up the drain hole to remove the sludge.

Here are my observations and questions. When the truck was running and getting hot, I took the radiator cap off and the water was not running. The upper radiator hose was very hot and the lower hose was cool. The new (remanufactured) water pump has a high pitch squeak. Besides being a nuisance, could it not be working correctly? Do you have any suggestions? Any help is appreciated.

Thanks,
Dale

New water pump should not have a high pitched squeak. So it needs to be replaced or find out what is making it squeak.

Another thing to check is the distributor timing. If it is off it can make it run hot.

If the upper hose is hot and the lower is cold (cool), then the water is not going through the radiator. This could be one of two things, first, the water pump is not pushing water, or the radiator is plugged and it can not get through. Does the engine have heater hose outlets? undo the hot side and see if it pushes water out that hose.

Sounds like you could have lost the impeller off the water pump or its loose, I would start with the pump since the radiator has been cleaned.

Joe

OK here's an update.

I replaced the water pump and no more squeak. I check the timing and it is dead on the line. That's where I want it. I also pulled the choke about half way and let it idle. I wanted to assure it wasn't a lean fuel situation. The end result... it is still running hot.
So, I bought a infrared thermometer and found something. After several minutes at idle, the temperature at the temperature sending unit is between 200 and 210. The termperature at the thermostat housing is 140 to 150. There is a 60 degree difference in about 2 feet!! I checked it many times (at least 10). This also validates the temperature gauge is working correctly.

So, I plan to re-flush the water jacket again this week. My question for everyone is, does this sound logical? Is there something I am missing? Besides water, What type of flushing fluid should I use?

Thanks for any help,
Dale

might check the real easy thing, is the fan belt as tight as it should be........just a thought but then I suppose if not you would be having a problem with it charging..

with a new pump, radiator being clean, timing set, good hose,should not be running hot... water should be ok for flushing besides you stated you had already done that

might take out the thermostat and see what happens,, it might be sticking...

I would say that the coolant isn't moving and the thermostat isn't opening. With my 216, if I don't remove the air after putting a thermostat in, I get an air block which won't go away by itself. I initially run it until the temperature gets above 180. I then turn it off and pull off the heater hose. Steam and hot air comes out then then the coolant starts to emerge. At that point I put the hose back on, wait for a few minutes and start it up. The thermostat then opens and it works correctly.

I would also try running it without the thermostat to see if it stays cool that way. That would give you an indication of what is going on.

I had the same problem with my 283. In this case it ended up to an air pocket that kept the water from moving. I came to that conclusion because of the difference in temperatures between the upper and lower radiator hoses. No matter how I tried to relieve the air from the system, nothing seemed to help. Someone on this forum suggested the old trick of drilling a small hole in the thermostat to bleed the air. Worked great, temperature is rock steady.

I have a read problem with my gauge. the new temp. sender reads head temp. because it is shorter than the old one. it reads 180 degrees at the gauge and 160 at the radiator. i have a radiator cap that has a thermometer in it and it reads normal.

A good trick is to place a aspirin in the thermostat to hold it open. Once the coolant fills the area it desolves and closes.

My 250 runs about 20 degrees hotter between #2 and #3 cylinders then it does at the thermostat housing. My guage always read hot till I moved the sender to the t-stat housing.

Joe

Sounds as if the head gasket holes are crusted over and cannot cool. Been there done that, same deal. Also flush the lower block petcock before u go to a head gasket. Ive had to do all my 216's head gaskets, its a common problem. Once they r clean and flushed with a new head gasket they can idle all day long.
Good luck

Thought this might help a bit. Some comments on descaling from: http://www.siegmundguitars.com/Techtips.html

[b]Block and Head internal descaling[/b]

Professional cooling system de-scaling is done with Sulphamic acid for hard water, lime and antifreeze build up. Oxalic acid is used to remove rust.
Sulphamic acid crystals are available at the hardware store in form of 'grout and tile cleaner'.
Oxalic acid crystals are available in form of 'wood bleach'.
Containers say what acid is used and its pure acid crystals with no other additives.
Available in 16oz. containers, which gives the right mixing ratio with water for the typical car cooling system with 3-4 gallons capacity.

Properly diluted, both acids are just as mild and safe as vinegar (acetic acid) and citric acid, but are more effective and cost is the same.
These treatments are safe to use with copper/brass radiators.
It is supposed to be safe with aluminum radiators as well, but I would do some tests first to determine how much reaction time is actually safe.

Oxalic acid used to be sold as a heavy duty 2-part cooling system cleaner over the counter until a few years ago. Recommendation said to do this annually...

For best results it's essential to keep temperature at engine operating temp and to keep the flow going.
Instructions are to drain and flush first, then fill with the diluted acid mix and run the engine at fast idle for 3 hours.
Do one acid treatment at a time, starting with the sulphamic acid, then drain and flush, followed by oxalic acid, then drain and flush.
The final step is to neutralize any remaining acid with a mix of washing soda and water and run the engine again for a while, then drain and flush and finally fill with coolant, but using distilled water instead of tap water, this time.

These methods really work exceptionally well.
I did both, back to back, on my old engine that had serious scale and rust build up.
Before the treatments and despite a new 3 core radiator, coolant temps easily climbed above 180 during the hot summer months with harder use.
After the treatments, the same engine now needs the thermostat to even get up to 180 degrees, even in the summer.

Cheers,
Fraser

Well, I wanted to complete this thread for closure. This has been a very long and very, very expensive journey. I have explained the overheating issue and all that has been done to multiple mechanics and to everyone who would listen. I have replaced, repaired and cleaned, virtually everything in the cooling system... except the temperature sending unit (which was brand new from the beginning).

To make a long story short, I stuck the unit into a pot of water and brought the pot to boiling. I used a candy and meat thermometer as controls. The sending unit was accurate up to 150 degrees, but at 160 it started to rise exponentially. At a water temperature of 180 degrees the gauge showed 215. At 190 degrees it was beyond 220.

Well, the moral of the story is to always test aftermarket parts.

Dale

I thought you confirmed the accuracy with an infrared thermometer?

I sure did... and that's the $2,000 lesson I learned.

The sending unit sets on top of the head and extends down into the coolant. The infrared thermometer can tell you the temperature of the nut that holds the sending unit, but it really doesn't tell you the temperature of the coolant. So the nut can be at 200+ degrees, with the coolant at 180 degrees.

I will never forget that!!

I never trust a gauge. Unless the coolant is boiling, IT'S NOT OVERHEATING! If there's no loss of coolant volume from the radiator overflow, it's highly unlikely there's a real problem with heat. Testing the gauge, whether it's a direct-reading type or electric, should be one of the first things that's done if the routine fixes don't seem to be helping.
Jerry

Jerry and Ron (we b old) actually told me this several months ago. But being a hard-headed, jack-a** I just went on. At this rate, I'll never graduate from the school of hard knocks (I'm now in my 55th year).