Noise coming from newly replaced turbo

**Matt_B** · #1: 11-06-2009, 05:59 PM

Hello all:

I've search the forums as well as I could and haven't seen anything on this issue:

I have an 05 LGT wagon with a 5 speed. ~124,000 miles. Only mod is a SPT cold air intake.

A few weeks ago I was driving to work on the highway when I heard the infamous "marbles in a blender sound" I instantly knew the turbo was toast. I got it to a local shop for an estimate. Oil pressure checked out fine, at the engine block, so the suspected that wonderful banjo screen.

After researching what was involved in the turbo swap, I realized that it was something that I could handle without much issue. I found a NEW turbo on ebay, flushed my oil, changed the turbo, flushed the oil again. The banjo screen was pretty plugged up. I bout the car with over 100K, and I doubt it was ever cleaned. It did not appear to be sludge, it really just looked like tiny flakes of carbon. After reviewing the forums here, I decided to leave the screen out when I reassembled.

Other than a coolant leak (it helps if you put the hose clamp completely on the tube not half way on the barb

) I didn't have any issues for about a week. It did sound like I may have had a slight boost leak near top end, but nothing serious.

Today pulled off the highway and pulled away from the red light, and at about 2500 it began to sound like someone was running a vacuum cleaner in the turbo area. It responded directly to throttle position. I quickly got it into 4th and idled it to the nearest parking lot (~half mile). I shut it off and let it cool down. After it was cool I started it again and revved it up to 2500 and it sounded normal again. I decied to try to drive it under low rpm to my dad's house. About half way there it started making the same noise again, so I pulled off into another parking lot and that's where it stands.

I've only put on ~150 miles on the new turbo. I have been constantly checking the coolant and oil and everthing is full and clean. I was also planning on doing another oil change tomorrow, but it may not have made it that long...

Any ideas of what may be going on? I didn't look at the intake, would something coming loose there make that sound, or did I toast another turbo?

**darkfox1** · #2: 11-06-2009, 06:29 PM

does it sound like any of this?

http://www.legacygt.com/forums/showthread.php?t=124435

This seems to be originating from an airfilter in my case.

**Matt_B** · #3: 11-06-2009, 08:12 PM

It's hard to say for sure...I would probably say that mine is more noticable. What worries me is how it started happening so suddenly. Did your car start making the noise right after you changed the filter, or after you drove it for a while?

**testes1010** · #4: 11-06-2009, 08:32 PM

did you 'prime' the turbo with oil directly after installation before starting the car?

**Matt_B** · #5: 11-07-2009, 05:13 AM

My repair manual didn't say to do that...There seemed to be assembly lube in there. Shortly after I first started it, I cracked open the oil inlet banjo a little bit to make sure there was oil pressure, there definitely was.

**testes1010** · #6: 11-07-2009, 07:29 AM

Its very important to 'prime the turbo with oil since majority of these turbos are journal bearing turbos(meaning they use an oil film as a 'bearing' between the two journal surfaces). Typically you would pull the fuel pump fuse and/or crank & cam angle sensors and crank the car after installation for 2-4(15sec) interval to get oil into the journals before actually running the car.

Not priming the turbo is probably the biggest reason new turbos fail.

**underpowerd** · #7: 11-07-2009, 10:49 AM

sounds like tear/clamp pop-off on turbo inlet hose, either at turbo, or bpv hose connect.

**Matt_B** · #8: 11-07-2009, 07:53 PM

A few more questions...I'm new to this turbo stuff:

1. Wouldn't lack of priming the turbo cause the turbo to start making noise right away, rather than after 150 miles? After the turbo gets oil from running it, the damage should be done, right, it shouldn't continue to happen, shoud it? I let it idle when I initially started it to check for leaks, so it shouldn't have been spinning too fast...

2. It there an easy way to check for leaks on the inlet side of the turbo? I haven't gone in depth much, but nothing seems loose/torn..

**Matt_B** · #9: 11-07-2009, 07:57 PM

I forgot #3...

3. If the lack of priming was the problem, is there anything I can do at this point? It didn't seem to be losing power or anything. Overall, it seemed very different from how the original turbo acted when I grenaded it...

**enthusiast** · #**10:** 11-07-2009, 08:00 PM

Have you looked at your TMIC connections?

**holyjoetart** · #**11:** 11-08-2009, 07:03 PM

Lack of priming a turbo will cause failure, but not instantly. In the heavy equipment world, a turbo that isn't primed properly fails between 10 and 50 hours of operation. That's what my experience has been. Sounds like you have an intake leak pre-turbo.

**Matt_B** · #**12:** 11-16-2009, 10:44 AM

Well, I've had a lot of other things going on, so I just got a chance to BEGIN troubleshooting yesterday. I checked out the intake from the filter to the turbo. I was unable to find any loose connections or tears in this area, but I couldn't really see what's going on with the section that goes under the intake.

What's interesting is that I cant hear the noise until around 4K with no load, but it makes the noise just off idle when under load (in gear). It does seem to be coming directly from the turbo area though. Could issues with the wastegate cause this type of noise?

On another note, it did look like some of the tabs on the TMIC were bent just near the outlet of the turbo. I did my best to bend them back with pliers, but it looks like a few of them are cracked. I don't think that this is the source of the noise though, because I couldn't feel anything in that area while it was making noise. Plus I would expect that to be more of a "hiss" than a vacuum sound.

I think I will remove the down pipe tonight and see if I can get to the turbine wheel and see if there is any more play than when I installed it. If there is, I'm guessing I've toasted the bearings. If this is the case, can I get this rebuilt? I don't think I've run it enough for anything to hit the housings and get damaged. It didn't seem to totally lose power like before, but then again, I haven't really run it since it started making noise.

**schwinn** · #**13:** 11-16-2009, 12:33 PM

Journal-bearing turbos typically cannot be rebuilt, as the journals get damaged within the housing. Ballbearing turbos can be rebuilt, since you can replace the bearings within the housing.

I assume that you got a journal-bearing turbo, but if it's BB, then you can rebuild it. Chances are, if it's BB, it didn't really take much damage anyway... but at least you can rebuild it.

**Matt_B** · #**14:** 11-16-2009, 12:43 PM

It's a VF40, so I'm guessing its journal...that sucks! I'm going to be a bit PO'd if I fried a brand new turbo beyond repair!

**Matt_B** · #**15:** 11-16-2009, 07:37 PM

Ok,

I pulled the down pipe, and there didn't seem to be any play in the shaft. However, there was moisture around the waste gate area, and there seemed to be a powery residue on the turbine wheel. You can see my fingerprints in it from spinning it. Does this mean the turbo's on it's way out?

I posted a video of the turbo making "the noise" on youtube:

YouTube- Subaru Turbo Noise

Any ideas?

Now after listening to it from the outside, it sounds more like a slide whistle than a vacuum cleaner.

I also attached a photo of the turbo outlet to the downpipe. Notice the moisture around the waste gate. It didn't smell like antifreeze and it didn't seem oily. Could it just be condensation?

Another thing I noticed was that the waste gate didn't do anything while the engine was revved with no load, should it, or only when it goes over a certain boost limit?