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Author Topic: Gear ratio problem  (Read 6159 times)

Offline SoL

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Gear ratio problem
« on: May 05, 2009, 01:27:01 PM »
I've got a weird problem with my Latio, probably something to do with the transmission(4AT).

I've got a long light outside my estate, so after a morning cold start and driving to the light, I off my engine. After switching on however, my car gives me crazy gear ratios. 60km/h at 2k rpm, constant! Stepping on the throttle gets me more speed and higher rpm, but the transmission refuses to downshift, or the torque converter does not lockup, whichever it is, I dunno.

I've tried this a few times, same results. Even when I drive to pump petrol one km away, after i restart engine, its the same. Anybody has this same problem?
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Offline Ying

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Re: Gear ratio problem
« Reply #1 on: May 05, 2009, 02:04:30 PM »
did you press the Over Drive button?
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Offline NSman

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Re: Gear ratio problem
« Reply #2 on: May 05, 2009, 02:09:14 PM »
how old is you battery?? time to get it replace.

I have sure similar case b4.. rev to 3k but speed at 60km/h nia... very very strange... off engine for 30mins & restart, back to normal... go to replace my batt (2yrs liao) now everything is fine
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"We, the La-tions of Sillypore,
Pledge ourselves as one United Road-User,
Regardless of Bhp, NA or TurboCharged,
To Build a LTA-less Society,
Based on Modifications and No TP,
So as to Acheive Roadhog Elimination, No ERP and
Automotive Progress for our Nation."

Offline SoL

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Re: Gear ratio problem
« Reply #3 on: May 05, 2009, 02:17:43 PM »
Quote from: Ying on May 05, 2009, 02:04:30 PM
did you press the Over Drive button?

Nope, I didn't touch it.

Quote from: NSman on May 05, 2009, 02:09:14 PM
how old is you battery?? time to get it replace.

I have sure similar case b4.. rev to 3k but speed at 60km/h nia... very very strange... off engine for 30mins & restart, back to normal... go to replace my batt (2yrs liao) now everything is fine

Hmm the battery? My battery is about one and a half year old bah, nid to replace now? Besides, starting the engine still feels very easy, normally <1sec can start. If the battery is weak, shouldn't it take a long time to start?
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Offline NSman

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Re: Gear ratio problem
« Reply #4 on: May 05, 2009, 02:39:00 PM »
abt time to replace for 18mths usage.. yes, if you feel that the crack have delay, means better change liao... dun get heart attack, suddenly died off...
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"We, the La-tions of Sillypore,
Pledge ourselves as one United Road-User,
Regardless of Bhp, NA or TurboCharged,
To Build a LTA-less Society,
Based on Modifications and No TP,
So as to Acheive Roadhog Elimination, No ERP and
Automotive Progress for our Nation."

Offline SoL

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Re: Gear ratio problem
« Reply #5 on: May 05, 2009, 02:50:45 PM »
Ok i'll bring it up for my next servicing, about 3k km more.
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Offline NSman

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Re: Gear ratio problem
« Reply #6 on: May 05, 2009, 03:01:43 PM »
btw, your case might be diif from mine... so you still need to monitor your issue, best is to check wif ur mech or TCM
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"We, the La-tions of Sillypore,
Pledge ourselves as one United Road-User,
Regardless of Bhp, NA or TurboCharged,
To Build a LTA-less Society,
Based on Modifications and No TP,
So as to Acheive Roadhog Elimination, No ERP and
Automotive Progress for our Nation."

Offline jliow

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Re: Gear ratio problem
« Reply #7 on: May 05, 2009, 03:57:58 PM »
Quote from: NSman on May 05, 2009, 02:09:14 PM
how old is you battery?? time to get it replace.

I have sure similar case b4.. rev to 3k but speed at 60km/h nia... very very strange... off engine for 30mins & restart, back to normal... go to replace my batt (2yrs liao) now everything is fine

Actually IMHO I cannot relate how its got to do with battery since engine already running, power will supply via the "alternator" or some engine driven electrical component

Mine is abt 1yr plus old, notice this issue since quite sometime back. I've mentioned in some post that if your engine is sufficiently warmed up, you can have normal performance. However, if engine is insufficiently warmed up, esp on a cold day, your initial drive will feel sluggish, and reving hard will somewhat not deliver the kind of torque u hoped for, but once the engine cool light goes off, your car is feeling normal again

Suggest this, upon starting up, let it idle for half a minute or so,  leave the gear at P before driving off, while at P, during a cold start, the car will autoamtically rev the engine at idle in excess of 1K rpm. However after a few seconds, u will notice it starts to wind down a little.

When U drive straight off from a cold start, just be gentle and patience, the engine and torque will perform as normal when sufficiently warmed, else u be wasting petrol

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Offline NSman

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Re: Gear ratio problem
« Reply #8 on: May 05, 2009, 05:45:39 PM »
Yes, you are right, there might be nothing related to the weak battery. I find it very strange too. was panic when i got these problem... 1st in my mind is to change my battery, are i knew is weak already

from your post, is very true that problem cause due to cold engine with insufficient warm up.  now i have a habit of let the engine run for 30 sec before move off....
« Last Edit: May 05, 2009, 05:47:18 PM by NSman »
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"We, the La-tions of Sillypore,
Pledge ourselves as one United Road-User,
Regardless of Bhp, NA or TurboCharged,
To Build a LTA-less Society,
Based on Modifications and No TP,
So as to Acheive Roadhog Elimination, No ERP and
Automotive Progress for our Nation."

Offline liewks

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Re: Gear ratio problem
« Reply #9 on: May 06, 2009, 01:33:55 PM »
I'm not sure if this is what happens, but all A/T cars are equipped with temperature sensors in the transmission. The transmissions are programmed to avoid torque converter lockup until a certain temperature is achieved. I've never understood why except to guess that somehow torque converter lock up requires the transmission fluid to achieve a certain target viscosity to avoid excess wear on the lockup clutch.

I used to drive a 4AT Sunny and it would refuse to lock-up until after about 5 mins on the highway in the mornings, after a cold start. Then the RPM's would settle down to about 2k for 70km/h (I may be remembering wrongly).
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Offline SoL

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Re: Gear ratio problem
« Reply #10 on: May 06, 2009, 01:50:50 PM »
Its 2k rpm at 60km/h compared to 1.6krpm on a normal drive. I dunno, does the TC lower the rpm that much? Besides, if I drive off normally after a cold start, the rpm is around 1.8k rpm at 60km/h, which is more like what you suggested-TC not engaging. This problem only happens after I off the engine and restart.

I thought it was the TC before, but this is weird.
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