[toddmwood]

My water pump pulley is a little smaller than my fan pulley. When I pulled my thermostat today I noticed antifreeze filled all the way up to where the thermostat goes. I don't remember seeing that the last time I changed one but maybe that is normal?

[2x1968muscle]

I'm hoping for you that the new Rad Cap will be a miracle cure.

If the cap "hisses" when you open the hood, it sounds like one of the cheap parts might be the solution

[onovakind67]

Originally Posted by Luwi67

X2 on the shroud. It's an absolute must.

Taking the thermostat out will cause it to run hotter as the coolant does not spend enough time in the radiator.

Actually it's just the opposite - the faster the water goes thru the radiator ( up to the point of physical damage), the more heat is dissipated. Here is some good cooling info from folks in the business of cooling:

http://www.arrowheadradiator.com/14_...utomobiles.htm

[Steptoe]

Actually it's just the opposite - the faster the water goes thru the radiator ( up to the point of physical damage), the more heat is dissipated. Here is some good cooling info from folks in the business of cooling:

This has been argued, discussed and therorised about...
Then comes the real world practical reality....a raditor with few or no blocked cores and no thermostat restriction will run a car hot....the hot water goes from one side of the raditor too fast, therefore the temp on the 'cold ' side is warmer...warmer coolant into the engine doesnt pichk up as much heat...also because it is moving faster , hotter in the inlet side, again even less time in the raditor and even hotter on the colder side.
All substantuated with thermeters, and even covered in detail by the old school guys of the time like Smokey Yunick.
There is therory and what happens in the real world
And there are now a lot of us who have chassed our tails in cicles and found , like the Smokey Yunicks found the GM cooling system in our 1st gen era NEED a thermostat, not just to contol temps but restrict flows....

[toddmwood]

New radiator cap and 195 degree thermostat, no help. The car runs hot in traffic with no thermostat or new thermostat. Back flushed the radiator until the brown turned clear with the engine running and heat on. Re-serviced, exactly the same problem. My next step will be to remove the radiator and take it to a shop and have them work it. Only other thing I can think of is the water pump which seems to work to me.

[Steptoe]

New thermostat...that mean u assume it is working corectly? Its not uncommon to have a new thermostat , even out of the box to be faulty...always "know" check in a jug and a thermometer.
U cant "back flush" with the engine of... back flush is reverse flow.
Checked behind the stop **** yet?... what is in there is best indicator of the internal condition of the cores...

Quich check of water pump... ie the rear occassion of a spun impeller in the shaft splines....with cap off, rev up, watch inside the radiator (correct water height) and the coolant will hit the opposite side of the header tank in a very big way....
Note here a impeler that is sliping plus a radiator with blocked cores will do the same...raditor in good condition the water flow will be weak.
A quick check for blocked cores... leace car over night to cool right down.. (or after a full flush fresh water) idle engine on fast idle....and feel how the raditor heats up...blocked cores... usually lower in the raditor...stay colder longer

[onovakind67]

Originally Posted by Steptoe

This has been argued, discussed and therorised about...
Then comes the real world practical reality....a raditor with few or no blocked cores and no thermostat restriction will run a car hot....the hot water goes from one side of the raditor too fast, therefore the temp on the 'cold ' side is warmer...warmer coolant into the engine doesnt pichk up as much heat...also because it is moving faster , hotter in the inlet side, again even less time in the raditor and even hotter on the colder side.
All substantuated with thermeters, and even covered in detail by the old school guys of the time like Smokey Yunick.
There is therory and what happens in the real world
And there are now a lot of us who have chassed our tails in cicles and found , like the Smokey Yunicks found the GM cooling system in our 1st gen era NEED a thermostat, not just to contol temps but restrict flows....

How does a radiator work at all? Long before Smokey there was this guy called Newton. If the engine produces more power, say going from and idle to highway speed, how does it dissipate the increased heat? Could his problem be too much air flow, maybe the air is going through the radiator too fast to pick up any heat....

Why does a thermostat open when the engine warms up? A: to reduce the flow so the water stays in the radiator longer? B: to increase the flow so the radiator will get hotter and it can dissipate more heat by using the laws of physics?

[Eleanor's Nemesis]

Originally Posted by toddmwood

Maybe I should take the car to a radiator shop and let them check it out after I try a couple simple things. Thanks, I agree with your analysis. Give me some time to look into this more and I'll post what I find and do. Thx.

I read the first half of this thread, in your initial post you wrote that it cools when driving but it gets hot in traffic. If that is the case, andyou have the appropriate shroud, I would look into the clutch fan. You could try a 'flex fan' as they are cheap and the ones I have seen and used had no clutch. If you do this just make sure you get the fan so it is about an inch inside of the shroud.

Has the block been bored? If so, how much?

[Luwi67]

I have another tid bit on fan shrouds, while they are essential for low speed cooling by creating a suction that pulls air through the radiator as well as channeling that air to help remove surface temperature off the engine surface they are also essential to high speed cooling. At high speed, without a low pressure area behind the radiator, the front of a car acts more like an air dam and, just pushes through the air. When the engine cycles to the temp where the clutch fan engages a low pressure is created behind the radiator via the proper location of the fan in the shroud and helps all that high speed air to funnel through the grill, through the radiator and so on. Without the shroud, the fan by itself is largely inefficient for the task.

I know the op has the proper shroud, I just thought this was good info for the topic of efficient cooling.

[Steptoe]

Why does a thermostat open when the engine warms up? A: to reduce the flow so the water stays in the radiator longer? B: to increase the flow so the radiator will get hotter and it can dissipate more heat by using the laws of physics?

Why does a GM...( well most) thermostats have a restrictive opening? when fully open...would not take much to make a thermostat that has far less restriction right?
As ?I said above... there is therory, and what happens in real life...and when monitored , to which I repeat... one finds because that because a given volume of water passes thru the same raditor at a far shorter time at a constant, given air flow, it exits at a higher temp (basic Newton Physics).. If there is a higher temp of coolant entering the engine, it will...(bastic Newton physics) exit at a higher temp...
The difference with our 1 gen raditors and modern radiators is ours are way over built, no significant internal restriction .. modern factory raditors with modern building budgets are made to the min requirements of cooling.

[toddmwood]

BTW, I can't put my hand on the front of the radiator because the a/c condenser is in the way so I can't tell if some areas of the radiator are cooler that others. I wonder if it's my console gauge? I doubt it bought it was brought up as a possibility to me. It seems to work normal but after running a long time in traffic it will climb into the red pegged area but the car is not smoking or making overheating noises but it seems really hot. I guess I could order a new $50 gauge. I have a new temp sender I'll put in later this week because it was cheap.

[toddmwood]

Does anyone know if I can hook my multimeter into my fuel gauge wiring at the console and read what the temp is by converting ohms to temp. Like so many ohms = a certain temp? Same with my fuel gauge because that reads E when ten gallons left. Haha, another problem.

[Steptoe]

I wonder if it's my console gauge?

From you descriptions of behavour, in particular using the word "climb" doesnt indicate issues with gauge or sensor..
In saying that it is good to know...more happier driving... exactly what temp the gauge reads at what postion the needle is in...
'calibrating' is simple...
remove the sensor....clip a ground to the body, connect the gauge wire and hang in a cold electric jug of water (gauge wire not in the water)
Now turn the jug on and with a thermometer u know the temp of the water, and compare with what the gauge reads...
I adjusted my gauge to read at the RED band (Red=stop rght?) temp of 235 degs...
Sorted that temp and temps above 212 F using oil rather than water..
235 is also the idoit red light temp....

I also run idiot lights for water temp and oil pressure...
One doesnt spend a lot of time watching gauges, espec on a road trip....and track cars usually run idiot lights for similar reasons.
A red light come up on the dash gets ones attention immediatly
The oil pressure sensor hole behind the dizzy, has a T into the block....one end has the idoit light switch, the other the gauge sensor
I use the switch for the water temp in the head and gauge in the valley cover by the thermostat.

[toddmwood]

What is an electric jug of water and what kind of thermometer do you put in the water?

[Everett#2390]

Originally Posted by toddmwood

Does anyone know if I can hook my multimeter into my fuel gauge wiring at the console and read what the temp is by converting ohms to temp. Like so many ohms = a certain temp? Same with my fuel gauge because that reads E when ten gallons left. Haha, another problem.

Generally,
water temp, 200 ohms referenced to ground is approx 180°;
fuel gauge, 0 ohms is empty, 90 ohms is full, 45 ohms half, 20-25 ohms is qtr tank, tan wire.