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High Transmission temps?

8K views 17 replies 7 participants last post by  C4RN1 
#1 ·
I am at about 76,000 miles and am noticing on normal daily work commute, my transmission temps (from Torque app) are reaching into the 216ºF-220ºF ranges. I live in Phoenix and expect things to get a bit warmer here, but in non stop and go traffic, I would think the transmission would run less than 200ºF and maybe when taking trips up north and hitting the mountains would be the only time it goes up that high. I checked fluid level and is good. I haven't done any drain and fills and am thinking about doing that

Is this normal temp on sonata? If not, Any advice on what could be causing them to get so high? When idling after exiting highway, they drop back down to under 216ºF but don't drop below 200ºF for awhile or downhill coasting.
 
#2 · (Edited)
I don't have the turbo version but my commute to work is about 30min (uphill both ways :) ) and I get up to about 205 on a 85 ambient temp day. Definitely would do a drain/fill by now (did mine around 55k). There's also TSB on trans cooler flush; not sure if/when that one would get applied but maybe yours is not running enough fluid through: https://testing-public.carmd.com/Tsb/Download/5471/07-40-011pdf

There's of course the Trans Temp sensor TSB as well; have you scanned trans for codes: https://static.nhtsa.gov/odi/tsbs/2014/SB-10059669-2273.pdf ? That one wins you a drain/fill automatically.
 
#3 ·
Thanks for the links to articles. I have scanned multiple times for any codes, and nothing. Done with both handheld wired scanner and bluetooth obdII adapter with Torque pro.

I think when I do the drain and fill(s), I will try blasting out the cooler as well to make sure it isn't gummed up or clogged. Thanks again :liebe011:
 
#4 ·
If flush and drain/fill doesn't do it, I might go aftermarket cooler for trans. Even if it is "normal" for them to get into 200's....I don't want transmission fluid getting that hot...it's bad.
 
#5 ·
Instead of cooler, you might want to do more frequent drain/fills to cycle the fluid more often. What I failed to say in my response yesterday is that 200's are probably very normal and what you're seeing isn't alarming. Again, mine gets up to low 200's on a hot day after driving for 30 min and drops down just below 200 after getting on the highway and coasting more. Thermal breakdown is probably less severe in a sealed tranny and there is no fuel-dilution and shear to worry about that there is with engine oil.

I'm getting ready to do a drain/fill on our '14 SFS with 50k and will do the '13 Sonata again around 80k.
 
#9 ·
Keep in mind that this picture is for non synthetic atf's which can't withstand the higher temperatures a full synthetic atf can. Hyundai uses SP4-M which is supposed to be quality synthetic trans fluid. Though in testing we've seen that at normal operating temp on a 2.0T this fluid should be changed around 60K or soon after to prevent any issues.
 

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#8 ·
Posted this a year ago....

https://www.hyundai-forums.com/sona...-turbo-atf-temps-above-220-a.html#post5771013

Yeah 220 is about where it runs, if you beat on the car it will go over 240F and I don't care if the trans fluid is synthetic or not, that heat isn't good for it. In that link above is a diagram I made to help you install an aftermarket cooler. Honestly it's one of the best most cost effective mods you can do to prolong the life of your transmission.
 
#11 ·
Thanks for all the responses. I am not a fan of seeing many things > 200ºF. In Phoenix, it gets 115ºF in the summer and if at 85-86º ATF gets over 200.... summers gotta kill these things. I'll do the drain and fills and if they look REAL bad, i'll take some steps to improve it. Still gonna flush the cooler just to make sure.

I did transmission fluid change in my previous '09 Kia Specta using the pump inlet and outlet. put the inlet in a new bottle of fluid and outlet in a big bucket(due to splashing). Put transmission in gear on jack stands with rear wheels chucked and when it started outputting clean fluid, I was done.
After reading a bunch on the drain and fill process... I wonder why I couldn't do the same here. Does the pump not pull up all the old fluid?
 
#13 ·
Thanks for all the responses. I am not a fan of seeing many things > 200ºF. In Phoenix, it gets 115ºF in the summer and if at 85-86º ATF gets over 200.... summers gotta kill these things. I'll do the drain and fills and if they look REAL bad, i'll take some steps to improve it. Still gonna flush the cooler just to make sure.

I did transmission fluid change in my previous '09 Kia Specta using the pump inlet and outlet. put the inlet in a new bottle of fluid and outlet in a big bucket(due to splashing). Put transmission in gear on jack stands with rear wheels chucked and when it started outputting clean fluid, I was done.
After reading a bunch on the drain and fill process... I wonder why I couldn't do the same here. Does the pump not pull up all the old fluid?

You could do that but the real issue is running the pump till it sputters or runs dry between your pump and fill exchanges. Doing so to the transmission oil pump is REALLY bad. It is the reason I gave up doing this on my other cars as it still took six to seven start/stops since I did it at 1 quart intervals (and had a helper).


Since the factory method is to just do a simple drain and fill (which only gets about half the old fluid out and replaced, now diluted with the fresh fluid) I would just stick to that. You could do what other (including myself) folks have done and do one drain/fill, drive it about 20 miles and do it again. Doing so will get more of the fluid exchanged.
 
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