Is my 4l60E messed up?
Thread Starter
Joined: Oct 2005
Posts: 1,687
Likes: 0
From: Fairfax, Virginia
Is my 4l60E messed up? Is it possible for a transmission to all of a sudden bog down the engine?
My new setup was dyno tuned today and there is a problem we believe to be because of the transmission. Every time at about 4,500-4,800 rpm the power curve will dip down then go back up after that RPM range. You can hear the engine changing pitch when it does it. It's as if something is bogging down the engine at that RPM range every time. These are 3rd gear pulls and it does it with the converter locked or unlocked. The trans has some upgraded parts (corvette servo, shift kit, beast sunshell, better clutches) and a Yank SS3200 converter.
My new setup was dyno tuned today and there is a problem we believe to be because of the transmission. Every time at about 4,500-4,800 rpm the power curve will dip down then go back up after that RPM range. You can hear the engine changing pitch when it does it. It's as if something is bogging down the engine at that RPM range every time. These are 3rd gear pulls and it does it with the converter locked or unlocked. The trans has some upgraded parts (corvette servo, shift kit, beast sunshell, better clutches) and a Yank SS3200 converter.
I really cannot think of any trans issue that would cause this, Basicallya trans does one of two things it either transfers power or slips and slipping would be obvious.
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Thread Starter
Joined: Oct 2005
Posts: 1,687
Likes: 0
From: Fairfax, Virginia
Thanks guys. I've talked to my engine builder. He said it wouldn't be anything mechanical like valve springs. It only does it in a certain RPM range. It clears up above that RPM so that tells you it isn't springs.
It's probably in the tune or a sensor acting up. Maybe the distributor messing up in that frequency.
Actually I found a vacuum leak from a split vacuum line. It would leak off and on depending on where you wiggled the hose. It's possible when the engine started to rotate under heavy load, it would then leak. That's what I'm hoping anyhow.
It's probably in the tune or a sensor acting up. Maybe the distributor messing up in that frequency.
Actually I found a vacuum leak from a split vacuum line. It would leak off and on depending on where you wiggled the hose. It's possible when the engine started to rotate under heavy load, it would then leak. That's what I'm hoping anyhow.
Teching In
Joined: Apr 2010
Posts: 11
Likes: 0
Thanks guys. I've talked to my engine builder. He said it wouldn't be anything mechanical like valve springs. It only does it in a certain RPM range. It clears up above that RPM so that tells you it isn't springs.
It's probably in the tune or a sensor acting up. Maybe the distributor messing up in that frequency.
Actually I found a vacuum leak from a split vacuum line. It would leak off and on depending on where you wiggled the hose. It's possible when the engine started to rotate under heavy load, it would then leak. That's what I'm hoping anyhow.
It's probably in the tune or a sensor acting up. Maybe the distributor messing up in that frequency.
Actually I found a vacuum leak from a split vacuum line. It would leak off and on depending on where you wiggled the hose. It's possible when the engine started to rotate under heavy load, it would then leak. That's what I'm hoping anyhow.
