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Discussion Starter · #1 ·
I been fighting to save this 2001 Isuzu Rodeo 3.2 2wd sport tranny with flushes and lucas and a prayer and it seemed to come around(Lot less slipping) unless i was in the city and stop and go it seemed to act up occassionaly. So i noticed it had an external radiator cooler and it was small and it made me think that its been over heating doing stop and go and hot days. I got this car as is but been diving in on various issues and kept thinking the transmission is low or hot or both. Well one things for sure that small exterior tranny cooler aint cutting the mustard so i decided to trace all the lines out from the tranny and found out they capped the2 radiator in/out and was only using the small exterior cooler. OK here in lies the issues. I un capped the radiator lines for the tranny to see what would come out and it was tranny fluid. Pretty dark but some red in it. Like a table spoon worth. So to me that means there SHOULDn't be an issue of a bad radiator to mix the coolant with ATF to make the MOD(Milk shake of death). If i run atf through the radiator now and fill it and get it pressurized and have the return capped so not to go back to tranny and it holds do you guys think its worth to try it? I dont know why they did this in the first place and the radiator looks "Newer". Diagram included as how I found it. Thanks ahead of time guys
Rectangle Font Parallel Slope Diagram
 

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Discussion Starter · #3 ·
Why not use some compressed air to check for leaks?
plug one side and blow the other and look for bubbles? might try it as i got the things to do it ...You know what... I think I can do that. ill plug one side run long hose up by radiator cap to fill so at same time i can look for bubbles. Good idea
 

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Discussion Starter · #7 ·
Update: I did put compressed air through the tanny tubes in the radiator and they held and no bubbles in the radiator. I got a 3ft hose and c-clamped it on one side and hose with a bolt in other side to keep it blocked and pressurized to force any air into the radiator. Once that was done i routed the lines to the external and ran it back to tranny. Still seems same temp though. was hoping to get it cooler
 

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Discussion Starter · #8 ·
update. My hand method of checking the temp was not so good. Got me an infrared thermometer from lowes and got to checking...trans at sitting operation temp reaches around 150f. City driving it reaches around 175 and highway 160-165. So far so ggod
 

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Note that your Rodeo (most likely) has a GM 4L30E automatic transmission. There are underdesigned for the heavy Rodeos and Troopers, and there have been MANY failures. There have been a few who had good luck with them too. If it's shifting properly, it probably means your shift solenoids are okay. Sometimes they shift weird (or won't shift when cold (how mine died). Other times they start out okay, then shift to NOTHING (no drive). (my SECOND one). User Buster28 on here is the EXPERT on these trannys. Whatever he says is the way to go. Dennis
 

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update. My hand method of checking the temp was not so good. Got me an infrared thermometer from lowes and got to checking...trans at sitting operation temp reaches around 150f. City driving it reaches around 175 and highway 160-165. So far so ggod
For reference, I have a temp sender in the test port on the bell housing, wired to a gauge on my a-pillar. My consistent temps from there are:

Highway cruising: Ambient temp + 75 to 80F.
City driving it gets to Ambient + 100 to 105F.
There is a "floor" of about 115F (e.g., in sub zero weather it will still run at least that temperature).

My cooler is oversized and downstream of the radiator cooler, fyi.
 

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Discussion Starter · #11 ·
For reference, I have a temp sender in the test port on the bell housing, wired to a gauge on my a-pillar. My consistent temps from there are:

Highway cruising: Ambient temp + 75 to 80F.
City driving it gets to Ambient + 100 to 105F.
There is a "floor" of about 115F (e.g., in sub zero weather it will stiff run at least that temperature).

My cooler is oversized and downstream of the radiator cooler, fyi.
i am not understanding. lol. sry! "floor"? 75 to 80F? Its hotter outside than that!? i am confussed. Are you saying you start at 115F then add those temps for Hwy/city driving?
 

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Yeah, he's saying the floor, or lowest that the temp gets to, is 115 degrees, regardless of how cold it is outside.
Ambient temp means whatever temperature it is outside. So for Highway driving, he's saying that it usually operates at ambient temp + 75-80 degrees. So if it's 80 degrees out, the trans will be running at around 160 degrees while driving on the highway.
 

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Discussion Starter · #13 ·
Yeah, he's saying the floor, or lowest that the temp gets to, is 115 degrees, regardless of how cold it is outside.
Ambient temp means whatever temperature it is outside. So for Highway driving, he's saying that it usually operates at ambient temp + 75-80 degrees. So if it's 80 degrees out, the trans will be running at around 160 degrees while driving on the highway.
TY for explaining
 

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Yes, Enemigo explained it the way I meant. I thought you could use another data point of a comparable set up. having a transmission temp gauge in the cockpit adds a real peace of mind if you've ever had transmission issues with these, not hard or expensive to do.
 
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Discussion Starter · #15 ·
Yes, Enemigo explained it the way I meant. I thought you could use another data point of a comparable set up. having a transmission temp gauge in the cockpit adds a real peace of mind if you've ever had transmission issues with these, not hard or expensive to do.
I am def going to install one
 
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