2006 3500 Sounds like Turbo not Spooling Up No power at Top End

[GhostZero]

I have a 2006 3500 with the G56, 4x4. I recently had a basic SB Clutch put in it, and the truck has about 100k miles. After the transmission swap the clutch was super heavy, but since then it's eased up a bit. Other than an AFE intake it's bone stock.

The other day AFTER a long freeway drive I *THOUGHT* I heard a brief grinding-ish noise as I was turning at slow speed. It happened once, was brief, and the truck didn't shudder or otherwise miss a beat. No codes.

I drove home on the freeway, about 20 miles at 65, no issues.

Today, after not driving the truck since then, I noticed that it was revving close to the red zone at 65mph. The truck seemed a little weak, and when I got it to 65 it really didn't want to go over that. I could push it to 70, but the RPMs looked really high, like very close to the red zone. I listened for the turbo, and the customary whine wasn't there at all. Maybe a little, faintly, but for the most part the turbo was silent. I have not noticed an increase in smoke.

Does anyone have any thoughts about what could be wrong?

Thanks-

Mark.

 

[Motorhead]

Does the clutch feel like it is slipping? Are you saying that at 65-70 mph, the tachometer is reading near 3200 RPM?

 

[lpennock]

Clutch is slipping if you have higher than normal rpm. Probably burnt now. You will need to pull to see what is wrong.

Leonard Pennock (AD7AS)
Sent with Tapatalk

 

[AH64ID]

The clutch pedal feel does increase with a SB clutch due to the design vs the OEM one, so that's normal.

Aftermarket SMF clutchs will also create a noise called gear rollover which can be interpreted as grinding, thou it's not. This is also likely normal.

The increased rpms is not. Does the tach appear accurate? There is a potential issue with some 2006 tachs.

If the tach is correct and your rpms are higher than they should be for the speed/gear then it sounds like the clutch is slipping. I would take it back to the shop that did the install.

 

[GhostZero]

Ok, thanks guys, I'll talk to the shop. I know about the clutch noise and the increased feel- I watched videos before buying the clutch so I'd know what to expect noise wise. That wasn't the noise, unfortunately.



It doesn't FEEL like it's slipping at low speed, it feels fine. But it is indeed hitting around 3200rpm at 65-70mph. Funny thing is that it doesn't sound like it's terribly high...

 

[GhostZero]

I think I may be wrong.

I drove it to work to gather a little bit of "hard" data.

The truck is at 2750 rpms at 65mph.
70mph it's at 2950.
75mph it's at 31-3200.

If I'm at 70mph and I goose it the turbo spins up and it accelerates as expected. The turbo sound is there, it's just not as loud as I recall it. After goosing it and easing back on the throttle I hear the BOOSH sound that I think the turbo makes. For as long as I've driven it I know little about how it ticks...

Anyhow, the truck has power, it accelerates, and if I'm just going by feel I'd say it's fine. I imagine it's terrible for the clutch but I stalled it just to make sure it would, and it does, but that's not something I want to try more than once.

When the clutch was slipping pre replacement I could let out the clutch on a steep hill and the truck would slooooooowly start to move. It was clear it was slipping. it's not clear that it is slipping now, and when I goose it the damn thing spools up and goes.

So maybe false alarm?

As a data point I drive it empty, mostly in traffic, 14 miles to/from work once or twice a week. It's 11 years old in July and just ticked over 100k. So I'm not hard on this thing at all. Other than that I drive it a couple of miles to school every week. I have a Lance camper, but I haven't had it out in a couple of years. I never tow.

 

[AH64ID]

What gear is that in?

 

[cerberusiam]

If the engine isn't screaming at you when it says 3000 rpms the tach is wrong. It will be LOUD at 3000 rpms.

 

[GhostZero]

What gear is that in?

6th. Sometimes it feels like it needs a 7th, but that'd be to go well above 70, and I shouldn't be driving that fast anyway.

 

[GhostZero]

If the engine isn't screaming at you when it says 3000 rpms the tach is wrong. It will be LOUD at 3000 rpms.

It's not even remotely screaming... At 3300 it feels higher than I'd like it, I haven't had it much beyond that. At 3000 rpms it sounds like it's running reasonably hard but not out of breath.

If I don't look at the tach I would say the truck feels like it has for thousands of miles, and wasn't behaving strangely. So I am guessing you're right, the tach is goofy.

 

[AH64ID]

Your tach isn't accurate. You should be closer to 2200 at 65.*

 

[bigceltic]

I would recommend getting an UltraGauge - that way you can see what your RPMs are really are. I have noticed that my '06 Tach is starting to act strange (the known issue with the solder) so I display my RPMs on my UltraGauge along with the other stuff I watch.

 

[GhostZero]

Correct, it's the tac. I have a scangauge, a little device that plugs into the ODBC port and displays engine data. At idle it's 800 flat. At 65 it's 2200. The truck is fine.

Thanks everyone!

 

[promisedland]

I down loaded a $5 app for my android called torque pro, then bought a $24 blue-tooth obd2 scan tool, this would work as well and prob be less $