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84 Overdrive problem (4+3) temp related ?
Thread Starter
Le Mans Master
Joined: May 2007
Posts: 8,448
Likes: 27
From: Valparaiso
84 Overdrive problem (4+3) temp related ?
Today i had a ride on the 84 which is almost the same of my 87,i i didn't drive it but i felt no much difference on the passenger side,well the idle was fine today,but my friend is having a strange problem with his 4+3,he believes that the Overdrive works under certain temperature,which i dont know since im a A4 guy,i have zero experience on manual transmissions,his problem is that below 90°C the overdrive doesnt work,so but over 90° it works ...to me this is nonsense i have never seen a overdrive/temperature related thing,to me is speed related (at least on the A4) maybe its transmission is going south and the temp makes it work fine under higher temps.-
What you think ? thanks !!!!!!
btw ...his dash is not working so we cant see the OD light
He has analog temp gauge
i read the OD unit has ATF on it ? where is it located ? maybe bad fluid could be the problem as well
What you think ? thanks !!!!!!
btw ...his dash is not working so we cant see the OD light
He has analog temp gauge
i read the OD unit has ATF on it ? where is it located ? maybe bad fluid could be the problem as well
Last edited by Calderone; Sep 25, 2009 at 11:37 PM.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
His O/d operation is correct
The ECM is programmed to operate the O/d once engine gets warmed up to a set temp for fuel economy reasons.You wouldn't want the O/d loading up a cold engine.
Temp varies by year model
Min temp for O/d operation in '84 is 80
Last edited by rodj; Sep 26, 2009 at 12:10 AM.
Thread Starter
Le Mans Master
Joined: May 2007
Posts: 8,448
Likes: 27
From: Valparaiso
Got it now,must be a sensor problem then...i will check it tomorrow,but ...i want to check the fluid level,where is it located ? Maybe i will have to refill with fresh fluid.-
thanks
thanks
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
The O/D is not designed to engage below 160° F (71° C)
So as He is sitting around the temps rise like normal, then as you start down the highway, the temps come down....once it drops to 159° F (70° C) the O/D kicks out.
This is one but a few problems created when people are under the impression that a lower temp Thermostat will "cure" some over heating issue they had at one time.
Put a Stock Temp Thermostat back in and enjoy the O/D once again.
So as He is sitting around the temps rise like normal, then as you start down the highway, the temps come down....once it drops to 159° F (70° C) the O/D kicks out.
This is one but a few problems created when people are under the impression that a lower temp Thermostat will "cure" some over heating issue they had at one time.
Put a Stock Temp Thermostat back in and enjoy the O/D once again.
Last edited by jhammons01; Sep 26, 2009 at 10:47 AM.
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Race Director
Joined: Dec 2004
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The O/D is not designed to engage below 160° F (71° C)
So as He is sitting around the temps rise like normal, then as you start down the highway, the temps come down....once it drops to 159° F (70° C) the O/D kicks out.
This is one but a few problems created when people are under the impression that a lower temp Thermostat will "cure" some over heating issue they had at one time.
Put a Stock Temp Thermostat back in and enjoy the O/D once again.
So as He is sitting around the temps rise like normal, then as you start down the highway, the temps come down....once it drops to 159° F (70° C) the O/D kicks out.
This is one but a few problems created when people are under the impression that a lower temp Thermostat will "cure" some over heating issue they had at one time.
Put a Stock Temp Thermostat back in and enjoy the O/D once again.
except rodj is right about the temps.
I've got this same problem on mine. I put in one of those "never hang" thermostats. Sure enough, it hung on the first heat cycle
. Luckily, it hung open.It's usually ok, but on some cooler days (like it is getting now), once I get up to highway speeds the od will kick off.
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
Aight.....lemme get another cup of Coffee....
I know for a fact that my '84 Kicks out at 159°.......Is my temp gauge 100% accurate?? Who cares? I know I fixed mine by putting a Stock Thermostat back in place.
Calderone, You stated numerous times that the car runs too cool. There is a temp [whatever it may be] where the O/D kicks out.
You may want to revisit my earlier post and address the Thermostat and then see if that O/D stays engaged.
I know for a fact that my '84 Kicks out at 159°.......Is my temp gauge 100% accurate?? Who cares? I know I fixed mine by putting a Stock Thermostat back in place.
Calderone, You stated numerous times that the car runs too cool. There is a temp [whatever it may be] where the O/D kicks out.
You may want to revisit my earlier post and address the Thermostat and then see if that O/D stays engaged.
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
If you are like me and you hear and feel every bump or vibration or sound the car makes............you find yourself casually driving down the highway looking a cute girls etc.....and WHAM That O/D kicks out on you
You now need to clean your shorts
Race Director
Joined: Dec 2004
Posts: 15,030
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And that is one of the most knee jerk things you'll ever feel.
If you are like me and you hear and feel every bump or vibration or sound the car makes............you find yourself casually driving down the highway looking a cute girls etc.....and WHAM That O/D kicks out on you
You now need to clean your shorts
If you are like me and you hear and feel every bump or vibration or sound the car makes............you find yourself casually driving down the highway looking a cute girls etc.....and WHAM That O/D kicks out on you
You now need to clean your shorts
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
A 20 minute Thermostat change will fix you right up.
Understand, mine will run Sub 160° on cool days on the highway. Then it only gets to ~215° on Hot days in stop and go......so whoever put that Tstat in prior to me getting the car really did me no favors. After I serviced the cooling system properly the Tstat was now an issue. (yes I had purchased a new one and "planned" to get to it, but I was lazy until Winter came along and the O/D issue reared it's ugly head).
The Moral to this one? Don't modify until you verified that the stock set-up is in fact working properly as GM designed...
Understand, mine will run Sub 160° on cool days on the highway. Then it only gets to ~215° on Hot days in stop and go......so whoever put that Tstat in prior to me getting the car really did me no favors. After I serviced the cooling system properly the Tstat was now an issue. (yes I had purchased a new one and "planned" to get to it, but I was lazy until Winter came along and the O/D issue reared it's ugly head).
The Moral to this one? Don't modify until you verified that the stock set-up is in fact working properly as GM designed...
