4l80e whine, could use some help

[Shortie]

Hey everyone. I have a 4l80e behind my 6.0l. Last winter trans was rebuilt, transgo hd2 kit, and a revmax 3300 stage 3 stall installed. Currently has a little over 1000km on it.

The other day I was leaving a local show and started hearing a whining noise that happens in all gears (sounds like power steering or a supercharger whine). Got it home and when backing in also noted that it took a good 5-6 seconds to go into reverse after shifting.

Assuming that I have either burnt up the converter already, or that the pump is shot.

Just wondered everyone's thoughts before tranny comes back out and gets a full re & re
Also anyone know if I can test and monitor line pressure using hptuners?

Thanks

[Mr. 250r]

I had this problem after i went through a pond what happened is the big plug for it came unplugged barely but you couldn't see it the only way i knew it happened because it started leaking tranny oil there and when this happens you won't have overdrive, hope it helps

[Shortie]

Checked connectors, unfortunately no problem there. I'm still thinking torque convertor
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[JJAB]

Drop your pan and replace your filter. I had a 4L80E that was purchased from a wrecking yard. Well after the motor rebuild, it was brought to my attention that the engine/tranny apparently had been submerged underwater once before. The tranny shifted fine in all gearsm just had this bothersome whine. Local tranny builder said it was a filter whine. Low and behold, dropped the pan, changed the filter and fluid, no more whine. Good Luck!!!!!

[clinebarger]

I would check the fluid level
GM doesn't use pressure sensors to monitor line pressure.

[Shortie]

Fluid level and filter are all good, looks like it's coming back out
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[Shortie]

How does gm monitor line pressure anyways in the electronically controled trannys? Just wondering cause in hp tuners when tuning line pressure it's done directly with a line pressure psi.
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[clinebarger]

Originally Posted by Shortie

How does gm monitor line pressure anyways in the electronically controled trannys? Just wondering cause in hp tuners when tuning line pressure it's done directly with a line pressure psi.
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The PCM does not monitor line pressure, The PCM controls the PCS solenoid with varying current (amp's). In theory it will produce the correct line pressure.

The line pressure tables in HPtuners are based on the same theory.