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View Full Version : Acceleration hesitation first 10min. when engine is cool



BlackVX
12/18/2015, 09:58 AM
Hi,
I searched in vain the board to find the same issue than the one I'm having with my VX.
When I start the engine in the morning and drive away, the VX hesitate to accelerate especially when it's time to shift in second gear. To "fix" this, I leave the gear in 1 and just go out my street slowly until it warms up a bit. After, I put the shifter on Drive and I can keep going with the SUV with some clunky gear shifts for 5 minutes or so. Today it is worst as the VX wouldn't move forward for 10 minutes. I really need to address this problem.

I also have another issue with the shifter getting stuck in P when the weather is cold. I found similar posts with the same problem. I didn't work on this yet since the weather here was so mild (couldn't find the time). I'm pretty sure this is not related to the issue above but just want to mention it just in case.

Thanks for your help!
Michael

Mile High VX
12/18/2015, 11:15 AM
Sticking in Park could be the switch that is triggered by the brake pedal.

On the other issue I would start by checking the fluid level according to the shop manual instructions. It's a bit different that almost any other vehicle out there.

89Vette
12/21/2015, 09:54 PM
Yeah, check the trans fluid level FIRST...under the truck. If that's OK, my next guess is the transmission circuit board located on the driver's side of the transmission (under) the vehicle. Your mention of "CLUNKY" shifts is typical of that board having a problem. If it can't determine what gear you're in, the transmission raises pressure, shifts HARD, and (possibly) not when you want it to.

With the motor off, move the shifter fore/aft very quickly several times (to clean the contacts). Disconnect the battery for awhile (or overnight), then reconnect. See if that creates improvement.

BlackVX
01/29/2016, 05:56 AM
I had the fluid changed in December and yesterday my mechanic changed the Transmission fluid again. He said that it was very dirty. He feels that the transmission is going away. My VX has 118k and was driven gently since I got it back in 1999.

So now it's looking like it's going to be a $2k-$3k repair.

Any advice would be greatly appreciated.

Thanks!

Mile High VX
01/29/2016, 07:46 AM
132K on my 2001 and no transmission issues...Why does he think the transmission is going away just based on dirty fluid...have you had any problems?

BlackVX
01/29/2016, 08:07 AM
132K on my 2001 and no transmission issues...Why does he think the transmission is going away just based on dirty fluid...have you had any problems?

Well, there is an issue with the VX jerking for the first 5 minutes when the engine is cold. My mechanic is still trying to figure out the issue at this moment. The fact that the fluid is still really dirty within one month tells him that the transmission might be going away (I drove less than 1k mile during the 2 transmission fluid services).

Thanks,
Michael

89Vette
01/29/2016, 10:31 AM
I can understand the BASIC conclusion of dirty fluid not sounding good. But, your mechanic doesn't sound like a trans expert either. There's a Certified shop near my house that's good. Maybe you have one in your city? Mostly, I'd seek out a specialist in transmissions. They aren't rare either...as our automatics were used in many vehicles.

I remember when my fluid was changed, they didn't dump ALL the fluid. It might have to do with the valves/solonoids getting "used to" (e.g., worn in) where they work better with the heavier/dirtier old fluid? I've heard this more than once -- where a transmission doesn't get it's fluid changed UNTIL it's finally many years old.

That said, I would think metal shavings (versus "dirt") would be an indication of failure. Can you trust the shop that changed the fluid? Maybe they did just as I described...and partially flushed it? If so, that might not be bad AND it might explain a return to "contaminated" color. I still vote for the possibility of you having a problem with that sensor board on the side of the transmission.

Edit:
http://www.vehicross.info/showthread.php/26061-Transmission-Jerks-when-shifting?highlight=transmission+shifts+hard

BlackVX
01/29/2016, 11:59 AM
He has been my mechanic for many years. I never had a major issue (what seems to be) with my VX until now. I do trust this mechanic and he his really good at fixing cars. He modified a Chevette and transformed it into dragster for racing. It doesn't make him a VX expert but this guy breathes and lives automobile beside his real job, which is working on cars :)

I think you made a very good point with the dirt versus the metal shavings. He still working on it. I guess it takes a long time because he was to wait until the engine gets cold before testing it.

If I was living in Florida, this would not even be an issue. It's the cold weather that creates this problem.

Thanks for your help.

BlackVX
01/29/2016, 01:52 PM
My mechanic just called. Their diagnostic is that the problem is definitely electrical!
He is not comfortable to narrow down and fix this since his doesn't have the computer gear for it. He will refer me to his friend's shop which is specialized in transmission and that kind of issue.

So there was not metal shavings in the fluid (*phew*).

I hope this electrical fix will work and will not cost lost of money though.

Thanks!

BlackVX
07/15/2016, 08:26 AM
Long story short:
The problem was a solenoid which was making the gear going from 1st to 3rd. It cost around $350 to fix that issue.
I'm so glad I can still enjoy my 1999 VX!
Michael