Well it started as the temps have steadily climbed through the 90's and into the 100's. Upon cold start, the tranny shifts decent and holds all power, it runs like a scalded dog. After warmup and heatsoak it began to loose its forward acceleration little by little until it finally got to where it just made the grunting of acceleration but went nowhere.

I inspected the transmission fluid and as suspected, brownish with a slight burnt smell. I went to the dealer and bought 10qts of nissan matic D to replace and hopefully fix the problem. Drove smoother initially, but eventually it heat soaked and drove the same. Now, with an added hint of actual slippage this time.

So back to the autoparts store. I picked up some lucas oil stop slip to help give the tranny some friction material since the car is at 156k miles and I probably lost a bunch of the material on the fluid change. This helped it drive stronger longer but it still warmed up to the point of slipping. Ambient temps over 95.

So back to the autoparts store. I picked up and external oil cooler to supplement the radiator and hopefully quell the heatsoak issue. Installed it and tried to clean up the a/c evaporator of gunk to help get more air to pass through to the radiator.

Now it drives good for a decent amount of time, but if traffic is slow and not much airflow is happening it heatsoaks again and looses some of its acceleration abilities. So in a nutshell I might have to break down and get a new evaporator if I can't get the old one cleaned out enough and help this issue.

f.y.i. radiator is new as of 4k miles ago-had a cracked top tank. and there is no overheating issues. The fans seem to be kicking on as needed- Low/High.

thoughts/comments?

 

Im not sure why you needed 10 quarts. Did you gave a tranny flush done?

 

Pull the trans pan and inspect the magents. You'll need a replacement gasket and filter/strainer. There are three different length bolts holding the strainer in place, be careful and keep them well organized.

If you have tons of ferrous material on the magnets, the trans has an internal wear problem. Get a rebuild or low mile replacement.

If there isnt much material on the magents, it may only be a worn seal. Get a rebuild.

 

9qts is the capacity with a little more than 3qts always sitting in the pan. I pull the return hose from the radiator and start the car to push out 3qts into a bucket at a time. I then turn it off to refill 3qts into the dipstick spout. after 3 times I have done a quick and efficient fluid change with not as much mixing of new/old fluid. You can see the fluid clear up and look new right after 9qts have pushed out.






I will add that anything under 95 ambient temps the car holds all power and drives strong. This points me back to the evaporator being clogged. I am going to attempt to clean the evaporator out as best as I can. This is to confirm if that is the culprit and not an internal heat creating issue. If it fails, I will pull the pan as you recommended.

 

Update...cleaned evaporator with no change. Cleaned all electrical connections on tranny and most of the upper motor connections. I am still unsure of the problem. Its almost like I wanna throw the tranny out of the mix and look at the throttle body and components

 

Have you checked the FSM for diagnostic procedures to follow to help narrow down the list of possible failed components?

 

I was about to check into that. Yesterday I was bored and sitting alone with my phone so I did 2 hrs of research here on the forum using the search function.

I finally dwindled it down using others with EXACT same symptoms. many people did the endless replacing this, changing that, spending this, blowing that...

KNOCK SENSOR was bad(verification from multimeter)

I picked up a 470k resistor and just stuck it in the knock sensor plug that's by the driver's side of the front valve cover. It mimics a perfectly normal sensor until I scoop a new one. The car is a fighter jet now! She screams to redline and runs like an absolute champ. Thanks for the input fellas. Im in love with the VQ again

 

Well damn the knock sensor would have be one of my very last thoughts....
Did u have a check engine light on ?

 

That's pretty cool. $2 fix!

 

Hmm strange.

 

^yea, no light from it. the ecu just retards timing and trims in extra fuel in an effort to fix the supposed knock. Even if it's 100% of the time

Its how they get these things to squeeze out a little more power on 93 octane and then dial it back on 87 octane when it knocks.


I'm still just dumbfounded at how much power the stupid things pulls back, it had me absolutely sure my transmission was about to fail. And after I added an oil cooler and new 9qts of new fluid plus a lucas oil slip stop, thats when I started to suspect things like the throttle body, fuel screen, cam/crank sensors, ect.

So I was determined that others had the same issue and I searched. About 4 others had the issue and spent thousands on repairs, finally at the end of a 6 page thread one guy swore that it was the knock sensor. He described how read the output and then to bypass it with the resistor. Crazy thing is, dealerships' service departments were helping some of the guys with part after part, service after service...and all it took was the resistor temporarily or a new knock sensor permanently.

 

Great contribution!

 

I canīt believe it!

So if the KS in my car it's working in an improper way the ECU just adjust the timing with the consequences of more fuel (aka poor MPG). Damn, I need to check the KS in my car then.

Thanks for the advice!

 

it was one of the first mods I did back in 2002 when I got my Sentra SpecV. The doggone thing was so sensitive it would start pulling timing when you put a header on it lol. So the community came up with pulling it off the block and grounding it with a wire/terminal/nut/bolt. That car would have up to 30hp differences(dyno confirmed) between 93 octane and 87 octane. I think "import tuner" did that test.

That was before ethanol mixes started showing up across the country(which resist's knock better than gas)

anyway, same thing apparently on the vq35's