4l80-e OVERHEATING!!! Why???

[ZipTy]

Ok i finally got done with my 4l80-e swap and cam and i go out to start her up this afternoon and everything went to plan including going through the theft deterant unlock process. After giving it about 15-20 min to warm up i took it out for about a 6 mile test drive and my trans temp started to skyrocket from a cool 150 to a HOT 220 in a matter of 5min, as soon as it got to 220 i pulled into a parking lot and waited for about 30min and let it cool down got it back home with it back at 220 when i pulled into my garage. Ok now this is the weirdest part to me i let it cool back down to 150 and just let it idle for about 10min and it jumped up to 200 again. As far as the set up for cooling it down im running schaeffer's synthetic fluid and still running the lines through the radiator and then to a hayden cooler. I also filled the trans to the specs that Monster Transmission included in there instructions (12.4 quarts). At this point i don't really know where to start on solving the problem because the temps are rising uncontrollably.

[Maui4x4]

Take the radiator out of the loop and just run your hayden cooler, should drop the temp abit.

[ZipTy]

yea im gonna try that this after but im still concerned becuase the tems are rising so quickly even when i let sit and idle.

[ZipTy]

ok so i just routed my trans cooler lines to bypass the radiator and running only the hayden cooler, and i still cant keep it below 225. What now??

[Frenchy]

Looking at a guage or a scanner? If it's a guage, maybe it's f'd.

[truckinL33]

Looking at a guage or a scanner? If it's a guage, maybe it's f'd.

+1

[rutroe]

Are you driving it like a madman or normally? After the conversion, my 80 heats up mucho quick if I get on it. It's a little better if I drive like a sane person but it still runs warm (180-200) especially if it's hot outside. Stop & go driving heats it up pretty good as well but it cools back down when I get onto open road.

+1 on the gauge theory as well.

[ZipTy]

I've been reading the stock guage that the NNBS have in the guage cluster. As far as the temps raising like crazy it does it weather im driving like a grandpa or letting it idle in the driveway. I did notice my guage is reading 210 but my trans cooler is still cool to the touch. So tomorrow im going to blow out the lines to make sure nothing is stuck im them from my 4l70e going out, Also to extend the back trans line I used a 3/8" steel fuel line with compression fittings which might be impeding the flow seeing as though the compression fitting down sizes by about a half.

[pl4yboy]

I've been reading the stock guage that the NNBS have in the guage cluster. As far as the temps raising like crazy it does it weather im driving like a grandpa or letting it idle in the driveway. I did notice my guage is reading 210 but my trans cooler is still cool to the touch. So tomorrow im going to blow out the lines to make sure nothing is stuck im them from my 4l70e going out, Also to extend the back trans line I used a 3/8" steel fuel line with compression fittings which might be impeding the flow seeing as though the compression fitting down sizes by about a half.

If the trans cooler is cool, I'd bet there is a restriction of some sort.

[kyhunter89]

If the trans cooler is cool, I'd bet there is a restriction of some sort.

x2 forsure