TLS Turbo comes and goes

[chopperboy]

Hi Folks - I am a relatively new owner of a 2007 Mooney TLS with about 300 hours on the second engine. The turbocharger works sometimes, doesn't work other times. Seems to be no rhyme or reason. Mechanic has had the entire system apart...including wastegate, etc. with no definitive anomalies. Exhaust and all other plumbing in good shape. Controller was sent in for inspection and tested fine. Turbo will usually work on first test flight, but not subsequent flights if within a few hours. Thought it was a heat related problem, but sometimes it will work fine on the second flight and other times not. Mechanic is very good... but is baffled on this one. I have over 15K hours SEL and I am clueless as well. Anyone with similar experiences?

 

Thanks so much. New to the site and finding it very informative. 

[carusoam]

Welcome aboard CB,

(1) When were the exhaust clamps replaced?

They are expensive to replace and are a serious hazard if they are not...

(2) Can we assume you have a Bravo version of the TLS?

(3) Bearing oil flow? Burned oil or blockage?

(4) how long has the engine been sitting?

I am only parroting issues that have come up regarding TC'd Mooneys...

Hope that gets you started in the right direction...

Best regards,

-a-

[orionflt]

did you note what your oil pressure was doing when the turbo wasn't working?

 

Brian

[FoxMike]

chopperboy,

Do you realize that you have TWO controllers on the turbo system.  I would look at both first if they work correctly then check the hoses that are connected to them.  The TLS has 333 hoses and making a connection mistake is certainly a possibility.  Also when the hoses are made sometimes a flap gets cut on the inside of the hose.  A flap could cause intermittent problems.  Good Luck!

[chopperboy]

Thanks guys for the speedy responses. I will check all the above-mentioned items. Don't recall any oil pressure fluctuations. I'm sure the mechanic knows there are two controllers but I will check just to be sure.

 

Let me know if any others have any suggestions and I will keep you posted on what we find.

 

Thanks again!

[M20F]

Best turbo guys in the business in my opinion would give them a call and pick their brain a bit if the above suggestions don't fix it http://www.mainturbo.com

[Awful_Charlie]

I'm afraid my bet is on the turbo itself - either the bearings are shot, or for some other reason it is binding on the housing.

 

If you take the cowl off, and then the flex hose to the turbo, you can see the end of the impeller. If you can move it from side to side with your fingertip, and see the movement, then the bearings have had it. If you can just feel but not see the slightest movement, it might be ok.

[chopperboy]

One thing I failed to mention is that it will sometimes provide partial boost... not all the way to 35", but maybe to 31 or 32, and sometimes not at all. That's why so far we've been focusing on a wastegate problem. On one test flight I took the runway, slowly throttling up to full power... very sluggish with obviously no boost. Just before full throttle the turbo kicked in with very obvious full boost. Also, don't know if this may be related, but the MP gauge is very sluggish as well, and can take 15-20 seconds to finally settle in on any given throttle setting. Any more ideas?  Thanks again!

[bonal]

I was thinking that it could be instrument issues, when it goes from full boost to partial or none I would think that there would be a noticeable drop in performance. My experience is automotive but boost is boost. If you had bearings that were failing then variations in heat could be a factor. I know it's a lot easier to test a boost gauge on a car than it is on an aircraft but that's where I would start.

2 cents

[MB65E]

Check it's finger inlet fuel screen on the bendix servo. I worked on a Bravo for a while. It would do similar things. I changed the mags before I pulled the finger screen. It was full of lint some how. Cleaned it and then could get full power. Maybe pull all the rocker covers and make sure each exhaust rocker is moving the same amount, and that you don't have a short exhaust cycle on one of the cylinders.

-Matt

[jackn]

Im not familiar with the Lycoming Turbo system, but I'll tell you how my Continental system works. On TO power, the turbo controller senses a drop in upper deck pressure, closing a poppet valve, thereby closing off oil from flowing from the wategate. This increases oil pressure in the wategate closing the spring loaded butterfly valve. Once UD pressure gets to maximum(in my case 39 inches) poppet will open as needed to maintain the appropriate oil pressure at the wastegate to contol boost. I mousemilk my wategate everytime I have the cowling off, but you said that you've eliminated that already. I would then check the poppet valve as it may be sticking. There may be something in there, possibly a piece of carbon.

[MB65E]

Some of the late model controllers work differently than the continental and early Lycoming controllers. T182, are opposite for instance. I'm not exactly sure how the Bravo is set up...if oil pressure opens or closes the wastegate.

-Matt

[orionflt]

  On 12/31/2014 at 8:09 PM, MB65E said:

Some of the late model controllers work differently than the continental and early Lycoming controllers. T182, are opposite for instance. I'm not exactly sure how the Bravo is set up...if oil pressure opens or closes the wastegate.

-Matt

oil pressure always closes the wastegate, you do not want the gate to fail closed and over boost the engine

 

brian

[MB65E]

Correct, I just remember the pressure on the later T182 being opposite from the controllers.

-Matt

[mike_elliott]

Chopperboy, don't mess around here. Bad things happen if you don't have full power in a Bravo on takeoff. Ask me how I know..

Mike Elliott

N49FM @FA40

[FlyDave]

Could there be a leak in the MP line to the MP gauge or the gauge itself?

[carusoam]

CB,

Take Mike Elliot's advice seriously.

Know before you go...

Please,

-a-

[chopperboy]

To All -

 

Thanks again for all the advice. And you bet Mike... I don't screw around with power issues at all... or anything else for that matter. I figure that's why I'm not dead yet.

 

After all the comments here we're declaring "uncle" on this one and pulling it off the airplane... contacting main turbo today to send it out to them for a good look. I will keep you all posted on the final results.

 

Have a Happy New Year everyone!

[Awful_Charlie]

For the MP gauge being slow, there is a damper adjustment in the back of the unit. It's a right PITA to get to, you really need to take the instrument out of the panel and set it up. That is only valid of course if the line from the inlet port is clear, but if you're going to blow/suck that through, then you'll be disconnecting it from the instrument anyway.