Turbo rebuilding..... Might just be possible?

pokesfan · **Joined:** Sat Dec 24, 2011 12:54 am **Posts:** 1

geordi,

Can you share an update on how the rebuilt turbo is performing?

geordi · **Posted:** Sat Dec 24, 2011 12:06 pm

Still haven't had time to install it, this has been an insane couple of months. I'm now without CRD for a while b/c it ate the transmission due to a problem in the transfer case, so that adds a further delay. I'll be happy to report when I have a chance to install the thing.

rebar · **Posted:** Tue Jan 03, 2012 2:25 pm

Why aren't we replacing bearings before contact? The $60 seems like a small price to pay for insurance but how much play warrants the rebuild?.

Kind of off topic.. But why is gde's turbo twice the cost of the stock? Is the hot tune included with that price?

papaindigo · **Posted:** Tue Jan 03, 2012 2:45 pm

GDE turbo cost vs. stock - I can think of a host of reasons including better more expensive turbo, machining and piping to make it fit, small (aka tiny) production run for a custom product. Does not include "hot" tune but does include ECU tune custom for that turbo installed (e.g. won't work right with other GDE tunes) and if you already have a GDE tune there is a price discount.

geordi · **Posted:** Wed Feb 22, 2012 6:25 pm

Well, I FINALLY got the rebuilt turbo back into the engine bay...

2 hours almost flat for the job, I'm getting WAY too good at doing this. And I can see myself going in there at least once more, possibly twice.

The rebuilt turbo (RT from now on, b/c I'm lazy) replaced the Brand New Turbo (BNT) which has had a problem since DAY ONE of properly building boost, and spiking the pressure a lot higher than it should be.

The rebuild was described in this thread, but after sitting in a box untouched since then (when was that, early October?) when I pulled the cartridge out to reassemble the turbo, I could feel what I thought was side-to-side play, and a decent amount of end-to-end play for reasons that escape me. The play felt about like it had on the BNT before the first installation, so I decided to try it anyway.

Result - No more VNT problem, boost seems smooth and tops out at 18/19 psi on a WOT run, so it is a little lower than I would like, but that could easily be b/c I didn't adjust the stop point of the VNT... And that is how that particular turbo was setup from the factory. It *looked* like the vanes were completely closed at the stop point... But I don't know.

The test drive seemed great, no odd noises while idling or running, no excessive turbo whine (actually can barely hear it even with the windows open) until I got home and shut the engine off. I heard a metallic scraping sound, reasonably high pitched, as the turbo spun down from idle. Started and idled again, and it could NOT be heard doing anything odd, no sounds from it at all like scraping or boost-y type noises... Shut the motor off, same scraping again.

When this turbo failed before (which caused me to want to rebuild it) it was making a jingly / higher pitched scraping sound while running. It is not doing that now at all... I'm not a fan of this noise at all, but I'm really not happy about digging back into the thing so quickly. I hate this design with a burning passion.

Anybody else had a sound from their turbo only when stopping, not when running? I'm thinking right now that if I have to pull this thing again, I'm going to use the center cartridge intact from the BNT, with this RT body and VNT section... Hopefully creating a "FrankenTurbo" that actually works.

Or I win the lottery, suddenly get rich, and can buy the GDE and say FORK THIS to this design once and for all.

LMWatBullRun · **Posted:** Tue Feb 28, 2012 4:11 pm

geordi wrote:

Anybody else had a sound from their turbo only when stopping, not when running? I'm thinking right now that if I have to pull this thing again, I'm going to use the center cartridge intact from the BNT, with this RT body and VNT section... Hopefully creating a "FrankenTurbo" that actually works.

Or I win the lottery, suddenly get rich, and can buy the GDE and say FORK THIS to this design once and for all.

how did the Frankenturbo work out?

geordi · **Posted:** Wed Feb 29, 2012 1:58 pm

With my "FrankenTurbo" installed, the EVIC is now reporting 32mpg at 80mph. I don't believe that for a minute, BUT it does seem to be running better. I'm doing a mileage run right now, for a baseline before changing the thermostat.

That paragraph was copied from the thermostat thread, to keep things organized here. I had to drive from Savannah to Tampa, so that offered a nice long drive to establish some MPG numbers. Filled to the lip of the neck both times for accuracy, and almost exactly 300 miles (299.7) per GPS... It took 10.4 gallons to refill. All highway, not towing, and 70mph average speed (yea, I was moving!)

I'm dang impressed, I hope it stays that high. I did my best to be accurate in my measuring.

Now, about the turbo itself: I may have gotten VERY fast at swapping them out... But I hate doing it. I hope to only ever do it once more. What I have now is only the VNT turbine housing from the RT, everything else from the BNT. This means the VNT has 120k miles on it, while the center cartridge has only 30k or so.

The boost comes on smooth and consistent, 10 psi and 700 deg at 70mph. Is this normal performance? I don't know, but I like it!

CATCRD · **Posted:** Wed Feb 29, 2012 2:22 pm

geordi wrote:

The boost comes on smooth and consistent, 10 psi and 700 deg at 70mph. Is this normal performance? I don't know, but I like it!

That's about what mine reads.

RJM · **Posted:** Wed Feb 29, 2012 2:39 pm

Same boost on mine but only 550 on the egt. Water injection prolly brings it down a bit.

geordi · **Posted:** Wed Feb 29, 2012 3:00 pm

Good to know, thanks.

I just filled up on the way back, this leg has been towing 3500 lbs of generator. For anyone curious, it is a Multiquip DCA25-ssiu if you want to look up the specs, but this is an older model with a 70 gallon or so belly tank as part of the trailer, plus a 17 gallon above it. The top tank is about half full, so there is a LOT of fuel weight here.

Drumroll please...... 329.5 miles, 15.37 gallons, 65-70mph... 21.4 mpg! I'd call that a SOLID 2 mpg pickup from towing before with the bad VNT turbo.

In other news, I forgot to mention the technical glitch I had on the drive yesterday: I've had the oil pressure light on for about 400 miles now. Yea, it scared the spit (rhyme that) out of me when it came on and chimed at me while coming down an exit ramp. You've never seen an engine tossed into neutral and shut off so fast. Checked the level... It was in the middle of the range right after shutting the engine down, which could easily have been from just driving - it takes time to settle back to the pan. It came up a little after 10 minutes or so, so I added a half-quart just to be safe... Level now at the top. Start back up, all sounds normal and smooth (quieter than I remember it being normally, really a happy engine sound) but the idiot light is still on. Rev it up, it goes away. Ah, sender failure. No big deal. (PHEW!!!)

The light and chime every time I touched the brake was annoying, so I go to unplug the sensor... And discover the little bugger is LOOSE in the hole! Not so loose that it might fall out, but just less than finger tight, so it could easily be the source (when under pressure) of my phantom oil leak. I had filled the sump to full on the stick at the last oil change, just 3k ago... It shouldn't have lost 1/2 a quart by now. I never see it leaking b/c it would only leak while running, but the oil filter is FILTHY already. I couldn't figure out why the last filter looked the same, now I know.

PSA: CHECK YOUR OIL SENSOR FOR TIGHTNESS!!! Should you lose that while running, you WILL have just seconds to discover it, and simply shutting the engine off IS NOT ENOUGH. You must throw it in neutral FIRST or the engine will remain spinning attached to the transmission. It needs hydraulic pressure to unlock. If you don't catch it in time... You can guess the rest.

geordi · **Posted:** Wed Feb 29, 2012 3:04 pm

FYI: my egt numbers are pre-turbo, it is in the mouth of the turbine inlet just behind the flange. Should be the hottest spot.

Turbo rebuilding..... Might just be possible?

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