unusual wissling sound and bad overdrive shift

[Martin R]

I have a 6.5td 1995 E4L80 2500 pickup with no performance changes.I have put in about 10 000$ in one year just in maintenance. How to start, I went to a mecanik about a month ago and two dtc codes poped up, 78 turbo wastegate solenoid fault and dtc 99 accelorator pedal position 2 (5 voltreferance fault). My check engine light would pop up when the engine was close to 2200 rpm then the light dissapeard every time. He fixt the vaccum line from the wastegate to the electronik receiver that is right bessides the glow plug controller. Both codes dissapeard and life goes on. He also changed the belt on the the engine and i hoped that it wouldent cause a problem with my leaky old power steering pump and pully. The transmission was changed totaly rebuilt 6 months ago. About 2 weeks ago the engine was acting realy wierd and a wissling or wizing noise got more and more apparant within 60 KM a hour and even when the truck was idleing. The truck is now at the dealer with dtc 78 again and they say i have to change turbo actuator and valv. The truck now has a bad shift into overdrive close to 60kmanhour. Could all this be a result of the actuator and valv gone bad that cost`s 1000$.:confused:

[JFerg65]

I can't answer your specific questions, but my here is my two cents on how to proceed. I wouldn't spend another nickle until you hear back and get some feedback from the members here. As I'm sure you have seen already, the knowledge base here is second to none, and the people are always willing to help even with the smallest issue.

From prior experience, it would be really helpful if you went to the "USER CP" and posted / added your vehicles profile. This saves time and everybody is on the same page as you are when diagnosing issues.

[Robyn]

The whizzing noise may very well be the vacuum pump going south.

The failure of the wastegate solenoid (Little unit over by the GP controler)
will set the DTC 78) These fail from time to time and are about $45

There will be no connection between these items and the tranny issue.

What is a "BAD" shift into OD ??

Let us know

OH and a BIG west coast WELCOME TO TDP :D

Robyn

[Martin R]

I can't answer your specific questions, but my here is my two cents on how to proceed. I wouldn't spend another nickle until you hear back and get some feedback from the members here. As I'm sure you have seen already, the knowledge base here is second to none, and the people are always willing to help even with the smallest issue.

From prior experience, it would be really helpful if you went to the "USER CP" and posted / added your vehicles profile. This saves time and everybody is on the same page as you are when diagnosing issues.
............................ Thanks for the advice, knollege comes costley and advice is like water on a fire.

[Martin R]

[quote=Robyn;253068]The whizzing noise may very well be the vacuum pump going south.

The failure of the wastegate solenoid (Little unit over by the GP controler)
will set the DTC 78) These fail from time to time and are about $45

There will be no connection between these items and the tranny issue.

What is a "BAD" shift into OD ??

Let us know

OH and a BIG west coast WELCOME TO TDP ......................................Thanks for the advice il get back to you.

[Martin R]

The whizzing noise may very well be the vacuum pump going south.

The failure of the wastegate solenoid (Little unit over by the GP controler)
will set the DTC 78) These fail from time to time and are about $45

There will be no connection between these items and the tranny issue.

What is a "BAD" shift into OD ??

Let us know

OH and a BIG west coast WELCOME TO TDP :D

Robyn
Thanks for the west coast welcome, it reminds me of my Whistler days in BC Canada. Since the dealership couldent find what the wizzing sound was for two weeks, my brother Alain went to check it out, he found the problem in ten min. He is a diesel mecanik and loves what he does. It seem that an alternator that i changed 4 months ago has gone broke, the bearing is finished but it`s on warranty. 1st ? The guys at GM tell me that the wastegate is finished, the elec. piece that receives the vacuum line from the wastegate needs to be changed and the vacuum line also.About 800$ in part`s. Now could i run the truck without pulling for a wyle before we replace all that. Concerning the tranny now, in over drive when i come close to 60km an hour before the gear kick`s in, their`s a lag and a pretty good knock. I had the tranny totally rebuilt 7 months ago since then ive been at that shop with a problem, when i want to go forward, naturally, from park i shift to drive or overdrive but it wont go forward. For some strange reason i have to put it into reverse and back for the forward gears to work.I have a one year warranty. They tell me that i have a pcm problem and now i have a slip in overdrive. Should that be part of the warranty? In the 6.5TD volume i saw that the chip in the 1995 pcm was a problem, could that also be a solution. Tanks for your time Robyn.

[Robyn]

The wastegate issue is an easy fix.

Now the tranny issue could be casued by several things.

The switch that tells the ECM what gear its in (selector) may be bad.

The 4L80 has electric solenoids in it to select the gears too.
If the solenoids are not getting the right signal things get goofy.

I would get the thing back to whoever rebuilt it and have them scan things and find out whats going on in there.

They can drive it and watch the scanner to see if the proper signals are being sent and at the right time.

Just too many things can enter into the equation on one of these electronic boxes to diagnose without a complete view of whats happening while its operating.

Good luck and keep us posted

[DmaxMaverick]

If the whistle/shift issues appeared at the same time, the shifting should return to normal once the engine issue is resolved. When the engine is down on power (like when there's no boost when there should be), the transmission will shift out of time and pressure. The shift map anticipates a specific power level (according to RPM and throttle position), and acts up when it isn't there.

Also, whistling can be caused by loose intake plumbing, like a blown turbo hose or plenum gasket. This, too, can cause power loss and erratic shifts. That's what it sounded like in your case, until you said it was happening at idle. It's worth a check, in any case.

[Martin R]

If the whistle/shift issues appeared at the same time, the shifting should return to normal once the engine issue is resolved. When the engine is down on power (like when there's no boost when there should be), the transmission will shift out of time and pressure. The shift map anticipates a specific power level (according to RPM and throttle position), and acts up when it isn't there.

Also, whistling can be caused by loose intake plumbing, like a blown turbo hose or plenum gasket. This, too, can cause power loss and erratic shifts. That's what it sounded like in your case, until you said it was happening at idle. It's worth a check, in any case.
Thanks for the tranny ant turbo info, I`l get back to ya.

[Martin R]

The wastegate issue is an easy fix.

Now the tranny issue could be casued by several things.

The switch that tells the ECM what gear its in (selector) may be bad.

The 4L80 has electric solenoids in it to select the gears too.
If the solenoids are not getting the right signal things get goofy.

I would get the thing back to whoever rebuilt it and have them scan things and find out whats going on in there.

They can drive it and watch the scanner to see if the proper signals are being sent and at the right time.

Just too many things can enter into the equation on one of these electronic boxes to diagnose without a complete view of whats happening while its operating.

Good luck and keep us posted
Got it I`m riting stuff down and thanks again for the info:)