Shes getting hot 225

[Deleted member 220]

After fixing the exhaust i took it for a short drive and when i pulled in the driveway the temp light came so i check it with my temp gun 225 yikes so i sprayed it down with the hose to cool it. Im checking the thermostat its a 180 and it works the clutch fan is firm water pumps good radiator cap is good radiators been cleaned by previous owner at a shop but she still gets hot what am i missing

 

[jct]

i had the same issue with the a/c delco thermostat that i put in earlier this year, bench testing it worked fine, put it in the car, it over heated, so i went with one of these

Robertshaw 370 Series hi flow thermostat

just stay away from the mr gasket hi-flow thermostat

 

[Deleted member 220]

Well the heater core started leaking so its all over for this one ive done one before and they suck suck suck. I guess i know why they quick driving it

 

[stubs300]

Im checking the thermostat its a 180 and it works the clutch fan is firm water pumps good radiator cap is good radiators been cleaned by previous owner at a shop but she still gets hot what am i missing

Some comma's and other punctuation would be good, but I digress. All is not Good as you say otherwise you wouldn't be having these problems! You need to start at square one, start with the Rad and T-stat and certainly make sure they are good and not take someone else's word on it. Your block may even be plugged for all I know. Good Luck

 

[CBODY67]

Yoke seal on the bottom of the hood? Vacuum advance working? Base timing set to specs? Fan shroud in place? I guess you've cleaned the radiator core with pressurized air or a water jet spray?

Remember, too, that the pressure cap raises the boiling point of the water/antifreeze mixture. 225 is not that far off from the newer cars that run at 210 degrees F. BUT, it would be nice if it was running cooler. The thermostat temp is when it opens, although that usually can be where the "operating temperature" is. I believe the actual boiling point of the pressurized mixture is 260 degrees F, or there abouts?

CBODY67

 

[CBODY67]

Your block may even be plugged for all I know.

This IS a very good point! IF the radiator needed to be cleaned out, internally, then the internal cooling passages of the motor might not be far behind. Remove ALL of the block "core plugs", rinse it all out, especially the rear passages (the lowest part of the motor, as it sits in the car), which will be messy to do, put some new brass plugs in, and things should be better.

A "short-cut" way might be to put some flush solution into the cooling system, run the engine for a while, then drain it out. Take the thermostat out, plus remove the lower radiator hose, and rinse things through the thermostat passage. That might get some of the residue out, but it might also remove any "scale" that's been covering any pending perforations in the heater core or existing core plugs in the block. Might end up taking some of them out anyway! Of course, rinse the radiator, too!

After doing this, then put "water" back into the system and run it a while, to check for any leaks and such. Drain and flush, then add 1 gallon of anti-freeze into the next refill, as anti-freeze will leak from places water usually won't. Think "pin holes". Then, before winter comes, drain 1 gallon out and replace that with one gallon of full-strength anti-freeze.

This will not be a "quick or reasonably easy" fix, but it might be the best long-term alternative.

Of course, dispose of such hazardous waste in a responsible manner.

Just some thoughts,
CBODY67

 

[Deleted member 220]

Yoke seal on the bottom of the hood? Vacuum advance working? Base timing set to specs? Fan shroud in place? I guess you've cleaned the radiator core with pressurized air or a water jet spray?

Remember, too, that the pressure cap raises the boiling point of the water/antifreeze mixture. 225 is not that far off from the newer cars that run at 210 degrees F. BUT, it would be nice if it was running cooler. The thermostat temp is when it opens, although that usually can be where the "operating temperature" is. I believe the actual boiling point of the pressurized mixture is 260 degrees F, or there abouts?

CBODY67

Timing at 7. Motors been rebuilt so i assume its been cleaned. The heater core leaks maybe this would cause it to over heat? Never had a leaky heater core before so ill loop the hose and see if this helps

 

[Davea Lux]

As noted above a heavy duty t-stat is a good starting point. A leaking heater core will cause the engine to overheat if the coolant becomes low. Loop it as you suggested, good idea to keep any more coolant from getting on the floor boards and carpet. Check the lower radiator hose to be sure the inside liner has not come loose and started to collapse under load. Also check the heat riser to be sure it is not stuck shut.

Dave

 

[Deleted member 220]

As noted above a heavy duty t-stat is a good starting point. A leaking heater core will cause the engine to overheat if the coolant becomes low. Loop it as you suggested, good idea to keep any more coolant from getting on the floor boards and carpet. Check the lower radiator hose to be sure the inside liner has not come loose and started to collapse under load. Also checck the heat riser to be sure it is not stuck shut.

Dave

I checked the exhaust and its running up to 615 is this normal i guess ive never checked temps before

 

[Davea Lux]

I checked the exhaust and its running up to 615 is this normal i guess ive never checked temps before

Exhaust manifold temps will vary widely depending on load and how hard the engine has been run. Check the temp on the heat riser passage in the intake manifold, if it is running the same temp as the exhaust, odds are your heat riser is stuck shut. If the manifold on the same side as the heat riser is running hotter than the one without the heat riser, the heat riser is probably stuck. Try rotating the weight for the heat rise after the engine has cooled, it should turn freely.

Dave

 

[Deleted member 220]

Exhaust manifold temps will vary widely depending on load and how hard the engine has been run. Check the temp on the heat riser passage in the intake manifold, if it is running the same temp as the exhaust, odds are your heat riser is stuck shut. If the manifold on the same side as the heat riser is running hotter than the one without the heat riser, the heat riser is probably stuck. Try rotating the weight for the heat rise after the engine has cooled, it should turn freely.

Dave

I eliminated the heat riser. I fear it might be a head gasket from previous owner using eather. On a side note the a/c blows cold i can even see my breath

 

[Deleted member 220]

But before i jump too far in it ill drain and check the block if its dirty

 

[Davea Lux]

If you suspect a bad head gasket, I suggest running a hydrocarbon test on the cooling system. Most quality auto parts have the test kit.

Dave

 

[furious70]

My egt is maybe 1100* idling? I'll pay more attention next drive.
You can't tell if a clutch fan is any good by spinning it by hand unfortunately.
I for one would not attempt replacing old nasty core plugs with the engine in the car unless they were already leaking.

 

[Deleted member 220]

My egt is maybe 1100* idling? I'll pay more attention next drive.
You can't tell if a clutch fan is any good by spinning it by hand unfortunately.
I for one would not attempt replacing old nasty core plugs with the engine in the car unless they were already leaking.

Wow my small block is around 550 or less

 

[furious70]

Might be a small difference between an actual pyrometer in the exhaust vs an infrared gun

 

[Davea Lux]

My egt is maybe 1100* idling? I'll pay more attention next drive.
You can't tell if a clutch fan is any good by spinning it by hand unfortunately.
I for one would not attempt replacing old nasty core plugs with the engine in the car unless they were already leaking.

Usually if the clutch fan is bad, it will slip even after the engine has warmed up. The next time you have the car at operating temp, stand where you can see the fan and have a helper turn the car off. If the fan continues to free wheel with the engine off, odds are the clutch unit has failed. If that is all that is wrong, it is a cheap fix.

Dave

 

[CBODY67]

For the clutch fan to work, it has to get warmer air THROUGH the radiator. If the radiator is blocked/plugged/gunked such that no hot air gets to the clutch fan's thermostatic spring, the clutch fan perceives it's not needed AND will not engage to better cool the motor. A radiator might look "clean" when viewed through the filler neck, but use that heat gun to check the whole radiator core, inlet area, outlet area, and in between, to look for "cool spots" where the coolant isn't circulating.

On stock motors, checking the EGT at the exhaust manifold can be tricky and "iffy". On our '66 Newport 383 2bbl ('70 OEM Holley 2210 replacing the orig Stromberg WWC-3) and our '72 Newport 400 2bbl (OEM Holley 2210), with the idle speed set in gear, a/c running, at a speed where the exhaust pulses just smooth out, idle mixture to Lean Best Idle, the exhaust temp (at the end of the tail pipe) is tolerably warm on the '66, but definitely HOT on the '72. Major difference is the lower compression ratio on the '72.

When the '66 was newer and I was reading the service manuals about how the heat riser worked and why, I discovered the one on the '66 was stuck and would not free-up. It was stuck 1/2 open, not full-closed. So at my recommendation, the dealership put in a new kit. Same 1/2 open stuck situation later on. The second time it was replaced, the supplied bushing was reamed for clearance so the weight moved smoothly from the start. I could tell NO difference in how the cold start performance changed afterward. Up narth, it might be more beneficial, especially to choke performance.

I remember reading that lower CR engines had more heat rejection to the exhaust temperature, than higher compression motors did. So, use the exhaust manifold temps as a reference point, NOT as a hard, fast, universal data point. Check the port side of the exhaust manifold rather than the outside of "the log" area.

CBODY67

 

[jct]

View attachment 211615

how did that manifold break at the neck?

 

[Deleted member 220]

how did that manifold break at the neck?

No clue