Nissan Rogue 2017:
Faulty transmission cooler replaced 2 weeks ago after transmission oil and water mixed.
Entire transmission fluid line flushed. Transmission fluid cooler bypassed until a replacement could be found.
Transmission cooler replaced but only 2 weeks after flushing.
Day after changing transmission fluid cooler, transmission begins slipping.
Bypass the new transmission cooler.
Now car does not engage in reverse gear and only moves forward + loud sound when starting.
What could be the fault?
Me thinks coolant damaged the transmission before noting the contamination. Bypassing the transmission cooler may have caused the transmission to overheat.
What I do not understand, is your transmission cooler not part of the radiator and would require radiator to be replaced?
Nor do you indicate transmission fluid was changed, only that transmission lines to cooler were flushed.
You might get lucky with changing the transmission fluid and filter/screen, but my guess a new or rebuilt transmission is required.
I’ve heard of folks putting larger coolers on Nissan trans to extend life. And you went opposite way?
The transmission is now junk.
Others have already explained that running the transmission with contaminated fluid and then apparently overheating it has killed it. My suggestion is that you find a better transmission shop for the repair, as I certainly wouldn’t use one that bypassed the cooler.
That is the automotive equivalent of touching-up a set of X-rays in order to conceal a malignancy.
Who did this? No reputable or knowledgeable mechanic would do such a thing.
The damage started when the cooler ruptured and coolant contaminated the transaxle. You now need to repair or replace the entire unit.
Why not just bypass your radiator??? Same reason you don’t bypass your transmission cooler… You will overheat either one… I agree, what “mechanic” said to bypass it???..
They should be paying for your new transmission that you now require…