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jcweller1
01-20-2013, 12:49 PM
Now much resistance should there be on the turbo vane bearings? I saw a video a while back
that stated that if spun with you fingers, the shaft assembly should spin freely for multiple rotations.
I checked mine because I was installing a new aluminum resonator and it was a perfect time to inspect the vane assembly; at least from the visible side.
I haven't heard the sweet whine of the turbo for quite a while. It is more like a restricted exhaust sound.
When I finger spun the shaft I could feel resistance in the bearings and only got 1-2 turns out of the assembly before it quit spinning.
After replacing the stock resonator with the aluminum assembly, you can hear the turbo more as I have been told......this however has no sweet whine as a stated above. It sounds nasty.
No LHM. Some power loss and fuel economy loss.:hmmm:
Any input would be great.

Thanks in advance,
Jim

Aqua Puttana
01-20-2013, 01:04 PM
I recall that my turbo assembly moved easily, but I don't recall that it spun many revolutions after a finger spin. What oil do you use? A 15w-40 oil may change how long it spins? :idunno:

With the speeds that the turbo turns up a bad bearing won't likely last long before total failure.

An OBDII performance monitor like a ScangaugeII would give you access to actual boost pressure (MAP) information and help eliminate guessing. Some are under 100 bucks. If you are not a gadget freak who wants to play with the unit then the differences as to checking MAP one to the other is not an issue so price can drive your selection. It would be money well spent for help in resolving issues like this. Sorry I can't provide more. vic

Now much resistance should there be on the turbo vane bearings? I saw a video a while back
that stated that if spun with you fingers, the shaft assembly should spin freely for multiple rotations.
I checked mine because I was installing a new aluminum resonator and it was a perfect time to inspect the vane assembly; at least from the visible side.
I haven't heard the sweet whine of the turbo for quite a while. It is more like a restricted exhaust sound.
When I finger spun the shaft I could feel resistance in the bearings and only got 1-2 turns out of the assembly before it quit spinning.
After replacing the stock resonator with the aluminum assembly, you can hear the turbo more as I have been told......this however has no sweet whine as a stated above. It sounds nasty.
No LHM. Some power loss and fuel economy loss.:hmmm:
Any input would be great.

Thanks in advance,
Jim

jcweller1
01-21-2013, 11:00 AM
Vic, I have the MB Star knock off that allows me to measure boost pressure and to control the actuator on the turbo. I can also control the EGR and measure boost pressure change as well.
However I don't see the boost pressures that are specified for the test results. The pressures appear lower than they are supposed to. And like I stated before, that wonderful whine of a well functioning turbo is gone as is some of the performance and economy. I would think that if there was a failure bad enough to cause these issues, that the van would go into LHM. It never has and continues to run fairly well. It definitely doesn't have the kick it used to and only has 120,000 mile on it. It used to be I could pass someone and when I mashed the pedal to the floor you felt like "Wow this is coming from this van". It would through you back and the turbo could be heard whining not choking and then on decel it could be heard winding down to where it would normally run.
The actuator appears to be working full stroke, but I did feel some resistance in the turbo shaft while spinning it. It felt like flat spots on any other bearing. Like I said the turbo doesn't whine anymore it sounds like a restricted exhaust system where the exhaust is being choked by force going trough an area that is way to small.
I thought about trying to contact Garrett and see what their take is.

Thanks,

Jim

jcweller1
01-21-2013, 11:05 AM
I forgot to mention that I run 5w40 oil and that I have run the MAP tests and it comes out fine. Now I do know that in the world of solid state electronics that just because it test fine doesn't mean it function fine.
I probably will run some repeat tests just to verify.
Still bugged by the sound of the turbo and it does seem to be getting more prevalent.

Jim

owner
01-21-2013, 11:10 AM
In your star setup, you should be able to progress through the test and you can tell it that the pressure is too low. Then it will guide you for which things to check, automatically opening the WIS etc to the correct instructions etc. Thats what mine does.

Other than that, you could monitor MAP using your star setup and go for a drive. MAP should easily get up into the high teens of PSI (or SI equivalent) on a good pull.

Aqua Puttana
01-21-2013, 02:04 PM
Have you tried lubing the actuator? There have been threads where the actuator moves, but had a spot where it hung up a bit. It can move in smaller increments during actual operation than it might during the test routine. The test may not reveal an intermittent problem.

I lube my 2004 actuator linkage with heavy duty wheel bearing grease and an acid brush. Some people have mentioned high temperature grease because it is the hot turbo. My wheel bearing grease has not melted away or moved.

While towing my boat back from New Orleans I noticed that my 2004 lacked power. No MIL (aka CEL), no LHM. After I was home for bit I got the MIL and LHM. Turned out to be an O2 sensor going bad. I'm not suggesting your O2 sensor is bad. I'm just pointing out that noticeable power loss doesn't always trigger a computer reaction or LHM.

Spinning a turbo by hand is not a very effective test. In my opinion the Garrett turbo seems very reliable. Speaking to Garrett is probably a good idea.

What others said also. Have you changed your fuel filter lately? A diesel mantra is "Lack of power? First change the fuel filter". vic

Vic, I have the MB Star knock off that allows me to measure boost pressure and to control the actuator on the turbo. I can also control the EGR and measure boost pressure change as well.
However I don't see the boost pressures that are specified for the test results. The pressures appear lower than they are supposed to. And like I stated before, that wonderful whine of a well functioning turbo is gone as is some of the performance and economy. I would think that if there was a failure bad enough to cause these issues, that the van would go into LHM. It never has and continues to run fairly well. It definitely doesn't have the kick it used to and only has 120,000 mile on it. It used to be I could pass someone and when I mashed the pedal to the floor you felt like "Wow this is coming from this van". It would through you back and the turbo could be heard whining not choking and then on decel it could be heard winding down to where it would normally run.
The actuator appears to be working full stroke, but I did feel some resistance in the turbo shaft while spinning it. It felt like flat spots on any other bearing. Like I said the turbo doesn't whine anymore it sounds like a restricted exhaust system where the exhaust is being choked by force going trough an area that is way to small.
I thought about trying to contact Garrett and see what their take is.

Thanks,

Jim

jcweller1
01-22-2013, 11:00 AM
Owner, That is the one thing I haven't had time to do, go through the diagnostic tree and measure and test. I know I have to. Most of the time there is no failure or codes. But as you say the tool gives me this gift to use and I just don't do it.:snore:

Vic, I have pulled the linkage off and lubed it, but never as you have done. I will try it.:hmmm:

One more thing that I noticed the other day when checking my air filter. I had the heat shield off for access and noted that there appeared to be carbon soot neat the area that the actuator shaft enters the turbo unit. I don't know if this is normal or not.:thinking:

Jim

jcweller1
01-22-2013, 11:08 AM
Yes, new fuel filter about 2 month ago along with all other filters.
Modern day electronics........can't live with then can't live without them.
I have seem faulty O2 sensors in GM vehicles go bad with no code or
test results that could prove that they were bad. Just replaced them on a hunch and
fixed the issue. Sometimes I wonder if there is a pinhole in my fuel line coming from
the tank. I have noted that with a full tank of fuel the engine runs smoother and quieter
but I smell diesel. Just wondering if when the tank get lower, it sucks air into the system.
That is for another day.

Aqua Puttana
01-22-2013, 12:29 PM
... I had the heat shield off for access and noted that there appeared to be carbon soot neat the area that the actuator shaft enters the turbo unit. I don't know if this is normal or not.:thinking:

Jim
I just went out to plug in my oil pan heater. Tried to look at my turbo linkage for soot with a flashlight. Couldn't even see it. Maybe if I crawled under and looked up from below... except that ain't happenin' this morning at 5F. :bash:


...
I have seen faulty O2 sensors in GM vehicles go bad with no code or
test results that could prove that they were bad. Just replaced them on a hunch and
fixed the issue. ...
Interesting. Thanks for the confirmation.

Keep in mind that although not all the sensors contribute directly to the turbo actuator control position there are many different sensors which are involved in the boost calculations and operation verification. It's easy to consider just the MAF sensor proper, but the O2 sensor, boost temperature sensor, boost pressure sensor, EGR, and other sensors are all involved. If the computer senses a boost anomaly (not necessarily a full blown "problem") then one of the tools it has is full power limitation. I think that full power limitation doesn't necessarily set a DTC when it is enabled.

Just a comment. It may not even apply to your problem. Good luck. :cheers: vic

owner
01-22-2013, 10:07 PM
Usually if there is a fuel supply issue during running the engine will cut out and the EDC light will switch on in the dash. That is when the target rail pressure cannot be achieved.

If its only a slight starvation issue the ECU will try to compensate for it to get the pressure into the target range. So its either working or not, there should be no in-between with regards to fuel on common rail diesels. And there would be codes logged in all cases. This is different to old skool mechanical diesels.

This problem is more likely to be on the boost side of things if there are no codes. Id physically check if your EGR valve is closing properly, star cannot check that. Then do a serious check for boost leaks and lube your turbo actuator it cant hurt.

In star there are things like "diagnosis based on customer complaint". You could try that too.

Aqua Puttana
01-23-2013, 12:21 AM
There are some design concepts which are common to the Bosch controls.

"Codes Present in the Absent of Trouble Light

Not all control systems will trigger codes or turn on malfunction lights when codes are stored.

INJECTION/IGNITION system problems will trigger trouble codes, but may not turn on the MIL unless the fault results in a change in the exhaust gases or can damage the engine in the short term. Also some mechanical problems in earlier cars (pre 1988-96) can cause poor drivability without ever tripping a code or turning on the light. On later models that is much less likely."

There are quite a few limits which can be imposed by the computer(s) which don't necessarily trigger the MIL (aka CEL or ECU) indicator displayed in the dash.

vic

jcweller1
01-23-2013, 10:57 AM
Thanks for the great input guys. Narrowing things down for me.
5f Vic..........that's why I moved to FL. Used to be a Northern Michigan Boy.

I'll use the input from you guys and work through this. Thanks again for the help!:cheers:

Jim