GN overheats, FMIC...

Phoneguy said:
Have you checked the AC system ? An incorrectly filled or failing system will produce much more heat across the condenser.

Bryan
Click to expand...


A/C system is all there...but not charged...one of the four things on my to do list!

1) overheating
2) No overdrive (will not engage into 4th gear) At 65 MPH my rpm's are around 2800
3) A/C service
4) get is smog'd or keep it register out of state...(hopefully)!
 
based on your statement that it is flowing coolant, I focused on the cap as opposed to the thermostat. I think you can stop in autozone and borrow a coolant pressure tester that comes with the adaptor needed to presuure test your cap. Then jump over to NAPA and go get a cap somewhere else if you need one.. lol
 
rad cap is cheap, i always get the ones with the pressure release handle on top
 
If it's getting that hot without the AC on , I would bet your radiator is severely clogged at the bottom or you have a large amount of air in the system.
I have a large FMIC , F body radiator, Intrepid fans and never see above 180 running the car hard on the street. 175 is typical until the AC is turned on, then about 205 if it's in the 90s.

Bryan
 
ITSAV6 said:
The fans do nothing at highway speeds. ........
Click to expand...

Statements like that should be expressed as an opinion as we have found here in the desert we have experienced fans DO make a difference.

With front mount IC on street performance cars we use high performance fans with the option to run one or both.

At highway speeds and 100+ degree temps we need both fans to keep the coolant temps under control. Yes, I know the fan turns, but the extra velocity of the air with the fan on does remove additional heat especially when it must pass through the condenser, the IC and then the radiator. :)
 
DeltaBravo said:
A/C system is all there...but not charged...one of the four things on my to do list!

1) overheating
2) No overdrive (will not engage into 4th gear) At 65 MPH my rpm's are around 2800
3) A/C service
4) get is smog'd or keep it register out of state...(hopefully)!
Click to expand...
For #2 it sounds like your converter is not locking up. Make sure you have power at the wires on the driver's side of the transmission case.
 
With car at operating temps, feel radiator from top to bottom. If it is not same temps at top and bottom, radiator is plugged.
 
Nick Micale said:
Statements like that should be expressed as an opinion as we have found here in the desert we have experienced fans DO make a difference.

With front mount IC on street performance cars we use high performance fans with the option to run one or both.

At highway speeds and 100+ degree temps we need both fans to keep the coolant temps under control. Yes, I know the fan turns, but the extra velocity of the air with the fan on does remove additional heat especially when it must pass through the condenser, the IC and then the radiator. :)
Click to expand...
There are a lot of opinions expressed in here, his f body fans are working, don't believe fans are the issue...IMO Post the fix when you figure it out. Peace out;)
 
Sam Colalillo said:
based on your statement that it is flowing coolant, I focused on the cap as opposed to the thermostat. I think you can stop in autozone and borrow a coolant pressure tester that comes with the adaptor needed to presuure test your cap. Then jump over to NAPA and go get a cap somewhere else if you need one.. lol
Click to expand...


I will test this weekend and post results
 
regan j said:
With car at operating temps, feel radiator from top to bottom. If it is not same temps at top and bottom, radiator is plugged.
Click to expand...


Good tip. I guess that would have to be done with the fans partially removed or at least unplugged...don't want to loose any fingers! I will post after this weekend.

Thanks
 
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I'd add a Flow Kooler hi flow water pump near the top of your list. No mods, direct replacement. The other day was almost 90° and not getting too crazy, I stayed in the 162°-165° range. I spiked at 167° for only a minute whenever my fan kicked on, then right back down to 162°-163°. Btw, I run a 160° thermostat, water/reg antifreeze mix(no additives), and a 30yo rad/electric fan. Also, I recently installed a Chris Alston's Chassisworks Fab 9 rearend with 3.70s and Detroit Locker, so I tach about 200rpm higher on the freeway. I don't know if you're running a thinner core aluminum rad, but if so they go hand and hand. They're also highly recommended for stop and go, parade driving, and in line at car shows, where air flow is nil. Similar air flow restrictions to a giant fmic. Just the pump alone will keep your engine running cool. I know it does mine. It's funny how it seems that so many people go to such extremes upgrading their cooling system, but neglect its weakest link; an antiquated water pump.

You should check out his website, it's very educational in regards to the science of cooling and components. He has this whole science thing behind his water pumps and claims you can even gain hp with one. You gain hp, because you use less to turn it. And at the same time, improving your flow efficiency will conserve your hp. He can even custom fab copper rads, fan shrouds, heater cores, and intercoolers. All made in the USA.
 

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DeltaBravo said:
A/C system is all there...but not charged...one of the four things on my to do list!

1) overheating
2) No overdrive (will not engage into 4th gear) At 65 MPH my rpm's are around 2800
3) A/C service
4) get is smog'd or keep it register out of state...(hopefully)!
Click to expand...

Number 2 is going to cause extra heat at 65, this should be at the top of your fix list!
 
UPDATE!

Just took my radiator cap and tested it....IT FAILED MISERABLE! Wouldn't even hold 1 lb...let alone 16 lbs. Bought a new one...tested it with the same tool and it holds as advertised, 16-17 lbs. Currently not with my car, but as soon as a can, I will install and post results.
 
rodruckus said:
One last thing, no overdrive is bad. Those extended higher rpms are murder, look into fixing that problem immediately!
Click to expand...
What's the afr at those higher rpms??
Also, not only does the non lock cause issues, it also causes high trans temps. Those btu's are then absorbed in the rad.
 
UPDATE!

New radiator cap installed...could not take it for the standard driving test due to the weather (too much rain). However, I notice something else...

The connection to my fan was extremely hot, burned my hand hot! Turned out I isolated the heat was coming from the ground (solid black wire). After I let it cool down, I disconnected the plug and started the engine. Wire was cool...but after reconnecting, the fans would start up and after about 10-15 sec the ground would start getting hot again until either I unplugged it or turn off the car.

Not sure right now if the cause is a bad ground or the fans...
 
Do you have two separate grounds spliced into one? If so try running two dedicated ground wires, one from each fan.
 
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