How Can I Tell If My Turbo Is Working?

[wingman5th]

Rich,

Engine rpm seems normal. No load in neutral, rpm increases to 2700 with throttle to the floor but Turbo psi remains at 0. No indication of a fuel leak. Driving to shop this am, I could slowly but gradually increase speed to 35 to 40 mph. RPM seemed to peak around 1700 as transmission tried to shift. Could only get to 4th gear.

[wildebill308]

What are you measuring Boost on? You said you aren't experiencing any heavy smoke right? I think you may have a FUEL problem as your main issue. You may have some kind of boost problem but if it was just boost you would be rolling coal as the kids say.

Let us know what you find out.

Bill 

 

[wingman5th]

Bill

I am observing boost indication on driver information readout and correct, no smoke.

Thanks, 

Karl

[dickandlois]

Karl, by chance can you hear the turbo spool up, like a high pitch wine? that being the case the turbo did not fail and it is possible one of the silicon hoses coupling things together slipped of or popped a hole. The second possibility is the hose coupling the intake air to the air compressor failed. you maybe making air pressure but it is going out as fast as it goes in = zero psi.

Hope it is some thing simple. need boost and fuel to make power.

Rich.

[wolfe10]

Rich, think that was a Freudian slip.  Agree, if the turbo doesn't whine, just go wine!

Absolutely, if you went from good performance to no performance at one instant, visually check these connections on the intake side of the plumbing:

Turbo to connector

Connector to CAC IN (Charge Air Cooler)

CAC OUT to connector

Connector to intake manifold.

Also the hose from intake manifold to air compressor.

 

Yes, will likely require access from both top and bottom, but once you gain access, should not take 10 minutes.  Make sure hose connections are tight and that there are no holes worn in any of the connectors.

[wingman5th]

Thanks Rich. Not hearing the spool up but haven't gone back to listen. I've checked all visible hoses and all appear intact. A friend had the same compressor issue so I checked that as well. Hoping it is simple and inexpensive as well. Any thoughts on wastegate being stuck open?

[dickandlois]

Wining is alI can do for now! We are getting real wet again !!! 

[dickandlois]

Karl, Not sure what turbo set up you have - Waste gate or VGT? Waste gate issue is a possibility if it is stuck open - the control link is set to close the gate and open it at set pressure point. the control is spring loaded and that sets up a situation of getting to much boost if the boost pressure hose between the exhaust and the control module failed.

A Variable Gate Turbo change there internal geometry,(They are controlled buy electric motor or air pressure) with a sliding internal gate and when they start to fail - more often then not - they get cranky before they seize up. Kind of thinking you are outside both of those scenarios, there is always one that will through you a curve ball now and then.

So just maybe it si a fuel issue, a couple of quick pressure checks will cover that. and if one disconnects the exhaust line from the turbo and look into the discharge side of damage can get some clues to what happen to the Turbo internally.

Rich. 

[wingman5th]

Rich,

Based on my limited research and knowledge, I have a waste gate with the vacuum controlled diaphragm. I tried to move the control rod by hand with no joy. At this point and time of day, I will just wait to see what the mechs tell me tomorrow.  Thanks to all for the input and I will update once i have an answer.

[kaypsmith]

Be sure to check exhaust to turbo input, happened to me 2 years ago coming home from Tennessee, right hand exhaust cracked and broke into, replaced that tube all was well till 3 weeks ago on trip to Florida, lh pipe broke into again next to the flange. Both times no turbo boost until those pipes were replaced, couldn't even see the breaks until I had my wife to step on the accelerator while watched. Same symptom, no power for acceleration and no black smoke.

[wingman5th]

Thanks, will have them check

[jleamont]

Just a tutorial, I had to tear down a VGT turbocharger today that was stuck. Here is the inside of a Garrett.

 

IMG_3479.MOV

[wingman5th]

Update: They tore it down today and the turbo failed. Apparently bearing failure causing vanes to strike housing and eat themselves. Oil went into CAC so they have to pull and flush it out. Picture attached.

[wildebill308]

Yep, thats ugly.

What I don't understand is why it wasn't smoking heavily. More fuel less air ashley makes lots of black smoke. 

Bill

[desertdeals69]

Thats one of the reasons you don't shut down a hot turbo.

[jleamont]

Wingman, keep one thought in mind...all of those particles went into your engine . That could show its ugly face later in life and cause low compression. I'd consider having the Air charge cooler replaced at a minimum, if it were mine it wouldn't be an option.

That also looks like you are sucking dirt, what air filter do you have and has the intake system been inspected for unfiltered air entering?

[wolfe10]

1 hour ago, jleamont said:

Wingman, keep one thought in mind...all of those particles went into your engine .

Hopefully, particularly with oil leaking along with the bits of turbo blade that the CAC caught most of that.

 

[dickandlois]

Wingman, one more it them that you might want to consider is an oil analysis to see if there is some unusual material in the oil sample.

Regardless of the situation - when we pull off - the engine idles until the oil pressure rises and the manifold has time to cool. The boost pressure on our coach is always changing between 5 and 15 psi. even on fairly level roads and the exhaust temps are hotter then one would expect.   

Rich.

[wildebill308]

Yes oil sampling is a good idea. I would look in the tube where it attaches to the intake for any metal particles. 

I recommend a good EGT gage and boost gage are essential for knowing what's going on in a diesel engine. I also run a good full synthetic oil to help protect the turbo and engine, I like Shell Rotella T6. I am geting good oil sample results.

Bill

[wingman5th]

Thanks for all the input. CAC is being flushed and cleaned, pyro/EGT being installed, air filter replaced and oil sample taken.

[jleamont]

Sounds like you are headed down the right path.

[wingman5th]

One last question for everyone. Now that I have a pyro kit installed, what is thr normal temp range that should I be looking for and what would be my yellow and red lines?

[wolfe10]

Where was it installed?  The closer to the head, the hotter the acceptable temperature, so location is important in determining how hot you want to go.

[wingman5th]

Wolfe10, sorry for the delay but I wanted to get you the right answer about the EGT sensor location and I haven't had a chance to get under the rig.

It is actually mounted post turbo, which I know is not best and it is actually post exhaust brake. I have included a picture. As you can see, the sensor is to the left of the brake which is left of the turbo exhaust outlet. Hopefully you can give me a good idea what my temps should be ay this point.

[wolfe10]

Because I don't know the answer, I reached out to a retired Caterpillar tech.  Here is his reply:

 

Caterpillar does not give a spec for electronic C-7.  Reason for this answer with electronics sensors, regulators , switches,  the value of electronic components have a preset value that the ECM monitors.

If a problem happens check engine light will come followed by engine reduced power ( derate ) then complete engine shut down.

The time before electric engines checking exhaust temp was very popular. One thing to note as in this case turbo failure ( bearing failure ) the loss of oil into CAC in most cases rod bearing failure from lack of oil before heat build up.

This is where all the electronic sensors come into play with engine ECM and shutdown. Just another add that Caterpillar has covered with electronic systems.