Transmission Temperature?

I have just completed installing my eternal coolers, filter, bypass valve and temp gauge. I used two 3/4" B&M cooler in front of the condenser. The Perma-Cool filter. The Hayden bypass valve and a Dakota Digital gauge with the sender installed in the filter housing. It goes like this. Filter-Stock Cooler-2 B&M coolers-Return. I replaced the fluid by draining and filling 3X.

My temperatures seem alot higher than I had anticipated. The system seems to be operating correctly, However I am routienly reaching 200-215 degrees. I did not expect readings this high. They seem to increase rapidly when I climb any hills. The system seems to be operating well in that the inlet to the coolers is hotter than the outlet and there is no temperature rise on them when the fluid temp is below 160 degrees indicating that the coolers are cooling and that the bypass is not opening until 160 or so. The filter is under the battery box. I thought this would be better from a heat standpoint than near the exhaust manifolds which would have been my second choice for location. Any ideas?
Others indicated on their posts that their temperatures never reach these levels. I can only immagine what temperature levels I must have been operating at prior to installing the system.

Thanks,
Tom

[lee]

that doesn't seem all that bad to me, although I too would have preferred to see lower temps.

Here's the thinking I have on why that's what it is.

First, the temp where you are measuring it is in the hottest place, after it leaves the torque converter.

Running through the OEM cooler can't lower it below the coolest part of the radiator, say 160-170.

So the B&M coolers are seeing the 160-170 temp fluid, they then cool it down some more, how much I have no idea. I'm guessing it won't be below 150 or the torque converter would never lock up. Plus you said the by-pass kicks in at 160 or so.

What I don't know is if a temp rise from 160 to 200-215 is "normal".

I live in an area that is flat as a pancake. I get to 200 max in stop & go traffic. That's at 80s in outside temp and the A/C running. So 215 with hills seems about right, and I'm back to my original guess that what you see isn't all that bad.

IMO, if you want lower temps you will half to remove any bypass and let the add-on coolers do their thing full flow. I believe it would be near ideal to dump 150 degree fluid in the pan.

[svx_commuter]

The flow going to the cooler is only a partial flow from the tranny pump. So there is some mixing of hot and cold in the transmission. You might be getting heat from the engine. A little insulation would let you know.

[benebob]

My guess is you are getting some heat from the engine. My sensor is in the tranny pan smack dab in the center. It has never gotten past 210 and that was stuck for 3 hours on 95 in NYC in 95+ degree weather. Granted it might have climbed a little higher if I didn't turn the air off periodically. Try putting some insulation around it just for a test.

[Landshark]

what benebob said - i insulated the temp sender (on top of my external filter) with some adhesive foam-backed aluminum tape (Home Depot, etc.) and it dropped the temps a bit. you're probably getting an inaccurate reading.

also, remove your plastic belly pan in the summer, and replace it in the winter (keep the heat in, and road slush and salt out ). this will have a pretty big effect on reducing your tranny temps in the summer. i usually change my oil twice a year (approx every 4k miles or so), before the under tray goes on, and then right after it comes off, for convenience.

benebob,

Where did you install your filter? Mine is under the battery. I can try insulating it. I kind of doubt I'll see much difference with the filter so far away from the engine. If it were mounted on the frame rail near the exhaust manifold I can see where this would cause some induced heat. That is why I chose not to mount it there.

Also I am still trying to find out if anyone else is seeing a rise in temperature when going uphill. I am guessing this is caused by clutches slipping inside the tranny with the additional loading going uphill causing friction heat.
Tom

[oab_au]

Originally posted by tmaslar
benebob,
snip,
Also I am still trying to find out if anyone else is seeing a rise in temperature when going uphill. I am guessing this is caused by clutches slipping inside the tranny with the additional loading going uphill causing friction heat.
Tom

Gid'ay Tom, the rise in temp when going up hill is due to the torque converter unlocking to multiply torque. when it does this, heat is the by-product. This is normal, but can be reduced by using 3rd in this situtation, the lower gearing provides the higher torque, without the converter heating the oil up, to do so.

If you are doing less than 100k/60mph, or driving in the hills, shift to 3rd, better performance, less heat, easier on the transmission.

Harvey.

[Landshark]

going up hills will cause more heat than anything. i know - i live in Pittsburgh.

as Harvey said, keep in in 3rd for city driving, transmission cooler, remove belly pan in summer, insulate gauge sensor, and consider synthetic fluid. my tranny stays under 190 except for the occaisional short spike if its a 90 degree day and i'm doing an extended hill climb after some stop-n-go traffic.

Landshark,

Are you using synthetic ATF? If so which one?
Where is your Temp gauge sending unit located?

Tom

[Landshark]

Originally posted by tmaslar
Landshark,

Are you using synthetic ATF? If so which one?
Where is your Temp gauge sending unit located?

Tom

i have Mobil1 in the engine, transmission and differentials. some like Redline, etc., but Mobil1 is easy to find, and i think its good stuff. pick your flavor.

temp gauge sender is located in my PermaCool external filter mount (comes with a receptacle for it that gets plugged if you aren't using a gauge.)

Landshark,

I guess I meant to ask where is your filter and sender assembly located? Also where in the fuid flow path is it located?

Tom

[Landshark]

Originally posted by tmaslar
Landshark,

I guess I meant to ask where is your filter and sender assembly located? Also where in the fuid flow path is it located?

Tom

the fluid comes out of the tranny into the filter (and sender), and then to the cooler. it reads the fluid temp before any cooling. i mounted the external filter below the battery.

Alan,

I was hoping you had located your sending unit after the cooler. Now this means I really do have higher temperatures right out of my TC than you do. I was beginning to think that my readings were normal for oil leaving the TC. I am hoping that switching to synthetic ATF will lower my readings a bit. I hope it does not indicate impending tranny trouble.
Tom

[dcarrb]

This thread raises a question:

At what temperature does the AT OIL TEMP warning light illuminate?


dcb

[immortal_suby]

I have buried the needle on my tranny temp gauge and not seen the at oil temp light up - so it is above 250 at least.

I think it is kindof like laser warning on a radar detector - if you see it light up you're already screwed.