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Over heating, and not just the car??

P

PNYGTA

New Member
First post with a technical question fellas, so please be gentle.

Ok, I have a standard A code 289 fitted with hooker headers.

Some time back I was having some overheating issues, I replaced the radiator, thermostat (180 degree) and the water pump. I am also running a 7 blade clutch fan.

In a test run I lost about 1/3 of the coolant, at the time I was using a standard 13PSI radiator cap, I replaced the cap with a 16PSI one, have not lost any coolant but the car still seems to be running a bit on the hot side.

So, what PSI cap should I be running, 13 or 16, and any ideas on what might be causing the overheating? The timing is currently set at 10 degrees BTDC, could this be the problem?

Any help here would be appreciated.

Thanks

Cheers

PNYGTA
 
Most importantly, welcome to the fix.

Cooling issue-What radiator are you using? Do you have a fan shroud connected to it? Is the fan half way into the shroud? What is your cooling mixture ratio?
 
Firstly thanks for the replies and really do appreciate the warm welcome from all.

Car is running a stock three core radiator without a shroud, coolant mixture is approx 1/3 coolant to 2/3 water.

I have been changing the timing in the hope it might fix the problem, but to no avail. Timing was set at 6 degrees BTDC, as per the manual but the engine reached near the full temp, as indicated by the stock gauge, then I reset it back the 10 degrees BTDC, which seemed to be better, but not yet completely happy.

What I mean by a bit on the hot side, is nearing the furthest the needle can travel on my stock gauge.

Would a shroud make that much difference?

Cheers

PNYGTA
 
"PNYGTA" said:
What I mean by a bit on the hot side, is nearing the furthest the needle can travel on my stock gauge.

Would a shroud make that much difference?

Cheers

PNYGTA
Click to expand...

Yes Shroud will make a difference
 
Welcome, The coolant mixture sounds good. Water is a better coolant than antifreeze. Antifreeze is only good for it's rust inhibitors, lube, etc. and of course to prevent freezing. I run 15% antifreeze and water wetter with good results. The pressure is a matter of debate. Higher pressure raises the boiling point which is why modern cars have pretty high pressure. The debate come from whether a stock type Mustang radiator can handle the pressure. They have a tendency to leak at the tank seam over time, that's why many run even lower pressure than 13 (I've seen 7lbs caps before).
The stock gauge and sending unit is a bit questionable on accuracy. It may be a matter of the sending unit going bad that gives you a false reading or something like that. The gauge system works off electrical resistance, as heat increases the resistance changes causing the gauge to move. Ideally I would get a temperature gauge to check it (even if it's not a permanent addition). Of course air flow is crucial as stated so a shroud and distance from the fan to rad is critical.
 
"PNYGTA" said:
What I mean by a bit on the hot side, is nearing the furthest the needle can travel on my stock gauge.
Click to expand...

I would confirm the accuracy of your gauge, a shroud helps cool an engine but I don't think it's the answer for a 289 with a pegged gauge.
 
These guys are right - before you chase too much down, confirm the accuracy of your guage. Lots of ways of doing that, not having a mechanical guage I could use, I have used the following method:

Remove temp sender. Hook a jumper a few feet long from the post to the sender wire and another from the sender body to the car ground.

heat water to the temp you want to run at (normally 160, 180 or 190 - a whole 'nother debate) and hold it there. I use a small hot plate I had laying around, but you can also heat it to the temp and put it in a insulated coffee cup.

Place sender in water, and note position on guage (allow a few minutes to respond).

You can also do this at boiling temp, so you know where 212 is.

You may find your engine temp is OK, but the guage & or sender are off. I suspect this, as a stock guage pegged to hot usually will result in a boilover, even with a 16 lb cap.
 
Thanks apollard, that is good advice, seems everytime I am chasing some issue I come up with a solution before trying to eliminate the problem, hopefully it is the gauge.

Cheers all

PNYGTA
 
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