CVT or IMA Slippage??

[swat49833]

I have had this problem twice now... With cruise on, while raining, going up a hill the RPM's jump by 1000 to 1500 with no speed increase. On this same hill when dry and cruise on RPM's only go up the typical 200-250. I noticed this during the first rain the car saw right after purchase. I again noticed it this past rain we just got. This is the only 2 times I have drivin the "Z" in rain. At first thought it was slightly hydro-planing, but after the 2nd time, and paying closer attention, it definetly feels like slippage. Anyone else experencing this out there??? Also my check air press warning keeps showing when first leaving work, then goes away half way home. Is this normal for the temp changes here in TX.

One other thing on the tranny/IMA prob. I have also noticed that it takes the tranny longer to engage into "D" once I put the selector to "D". A longer hessitation if you will. I can speed the process up by tapping the accelerator to raise RPM's a little but don't like doing that for obvious reasons. After posting this I am taking to dealer and dropping off. I will post all info once I have it. BIZZY this was the only forum I saw to post in, however, may I suggest a "WARRENTEE WORK ONLY" forum..

[human668]

Maybe you have experienced the rubber band effect of cvt?
Rubber band effect: when the accelerator pedal was pressed, conventional CVT immediately brings the rpm up to a high level. The engine put out its maximum performance with the corresponding level of noise but the car slowly catches up in acceleration. This gives one the feeling of a slipping clutch.

[ammocj]

My CVT seems to hesitate engaging when cold.
I checked the fluid once or twice and it seems OK.
I'm not sure if its reason for concern since I also hesitate to engage when cold.

Haven't had mine in rain yet, won't see any for a couple of months here.
Al

[swat49833]

Originally Posted by ammocj

My CVT seems to hesitate engaging when cold.
I checked the fluid once or twice and it seems OK.
I'm not sure if its reason for concern since I also hesitate to engage when cold.

Haven't had mine in rain yet, won't see any for a couple of months here.
Al

Yes you are correct. When car is cold is when the engaugement takes longer. Sorry forgot to say that it was occuring when cold. It does still hessitate when warm, but much longer when cold.

[swat49833]

Dropped car off at dealer. WAS NOT happy with the service writers initial responce. He asked if check eng lt came on or is on? I said no. He said, well, we probably won't find anything. I told him, you guys are too dependant on that eng lt. If you guys can't fix a problem unless the damn comp tells you what to fix, then I don't need to be here. I then told him to try fixing it the old school way. Diagnose it, test drive it and fix it. No call all day today...

[bizzybear]

proper forum for me

it seems like it's been answered with the cold info above...

the other part about the rpms shooting up may be b/c the car needs to work harder to maintain speed... on the CVT, it can create an almost unlimited number of gear ratios w/o changing rpms... this is why you can hold the throttle down and it will sit at an rpm and not "shift" but speed goes up... so even though the engine is working harder the car will still be at the same speed b/c that's the nature of the transmission... best answer i got

as for the service writer, they can be jerks sometimes... remember that they are people too... i'm not excusing the behavior b/c he's right to tell you that if the light isn't on, they probably won't find anything wrong with it... look at it like this; imagine if everyone brought their car in to get "checked," they don't get paid for checking cars... so NOBODY is making money and when you're using up a technicians time, that's money lost for them and the shop... so they don't like to do things unless there's a definite issue... more than likely they will drive it and say "cannot duplicate the problem or customers concern... vehicle drives fine." then send you on your way... that's why i always recommend to document these things with video...

oh and the tire thing means that you need air in your tires the reason the light goes away is b/c as you drive the tires heat up a bit from road friction, increasing air pressure inside the tires thus making the light turn off... the cold air really compresses the air inside and drops the pressure... just add like 5-7psi on the lowest tire and/or match the other tires to that...

[swat49833]

Originally Posted by bizzybear

proper forum for me

it seems like it's been answered with the cold info above...

the other part about the rpms shooting up may be b/c the car needs to work harder to maintain speed... on the CVT, it can create an almost unlimited number of gear ratios w/o changing rpms... this is why you can hold the throttle down and it will sit at an rpm and not "shift" but speed goes up... so even though the engine is working harder the car will still be at the same speed b/c that's the nature of the transmission... best answer i got

as for the service writer, they can be jerks sometimes... remember that they are people too... i'm not excusing the behavior b/c he's right to tell you that if the light isn't on, they probably won't find anything wrong with it... look at it like this; imagine if everyone brought their car in to get "checked," they don't get paid for checking cars... so NOBODY is making money and when you're using up a technicians time, that's money lost for them and the shop... so they don't like to do things unless there's a definite issue... more than likely they will drive it and say "cannot duplicate the problem or customers concern... vehicle drives fine." then send you on your way... that's why i always recommend to document these things with video...

oh and the tire thing means that you need air in your tires the reason the light goes away is b/c as you drive the tires heat up a bit from road friction, increasing air pressure inside the tires thus making the light turn off... the cold air really compresses the air inside and drops the pressure... just add like 5-7psi on the lowest tire and/or match the other tires to that...

Hey Bizzy, I accept everything you say. And yes, I too was expecting the same responce as you gave. However at least it is documented.

They just called: couldn't find anything and suggested me to take serv tech on test drive with me to duplicate---I already suggested this at time of write up.

Still puzzled on why higher rpms while raining than dry day. Very large difference between 200-250 rpms and 1000-1500 rpms. It is suppose to rain again Sunday if it continues I will let you know.

[CRX-SiRT]

Sounds like the VSA is doing what it's designed to do....

[gomarlins3]

As Bizzy said, check your tire pressure now.

As for the other problem, I haven't had that problem and I have driven mine in the rain and snow and haven't had experienced it, sorry.

[Shatner]

Bizzy has it right. The CVT is optimizing the ratio to maintain vehicle speed. This will cause a jump in RPM, just as you described, OP.