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weird bumping (thumping noise) sound from the Jet??? Help

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Dawg

Joined: 19 May 2013
Posts: 355

Posted: Mon Sep 10, 2018 12:33 pm Post subject: weird bumping (thumping noise) sound from the Jet??? Help

Iron count up? Do you use a pump to put oil in?What kind of oil?

Stops bumping with tail off, fly with tail off! LOL.

IS IT MORE bumping at around 80%?

On Mon, Sep 10, 2018, 12:02 skidmk <skidmk(at)gmail.com (skidmk(at)gmail.com)> wrote:



 	  Quote: 	
		  --> L29-List message posted by: "skidmk" <skidmk(at)gmail.com (skidmk(at)gmail.com)>

 

 Folks,

 

 anyone experience this issue?

 

 Low time engine 

 

 --------

 Mike &quot;Skidmk&quot; Bourget

 Ottawa, Ontario

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=483074#483074

 

 

 

 

 

 

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Dawg

Dawg

Joined: 19 May 2013
Posts: 355

Posted: Tue Sep 11, 2018 10:08 am Post subject: weird bumping (thumping noise) sound from the Jet??? Help

Did you get any of my questions via this site?





 	  Quote: 	
		   On Sep 11, 2018, at 11:23, Alekh <lekhkar(at)telus.net> wrote:

 

 

 

 Is turbine stop time no change/variance from when it was normal? 

 

 Andy

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=483108#483108

_________________
Dawg

skidmk

Joined: 19 Nov 2007
Posts: 171
Location: Ottawa, Ontario

Posted: Wed Sep 12, 2018 10:09 am Post subject: Re: weird bumping (thumping noise) sound from the Jet??? Hel

Hey Dawg,



Got the questions, we use oil from the can direct.  Mobil.  As for the thumping noises,, not really noticed at 80% or not.  Most prevalent during take-off (100%) less so in cruise 85-90.   It seems that it is getting more prevalent, up to and including the bumping on shut down this time.



there is no variation in any op specs on the T's and P's.  



there is no evidence of flaming, or pop flames coming our of the tail.



there is what I feel maybe more than normal soot on the tailcone (in the vicinity of the antenna's)



what might you be thinking about the 80%?



I will change the fuel filter tomorrow, aerate (bleed) the fuel system and see if that cures it.

_________________
Mike "Skidmk" Bourget
Ottawa, Ontario

skyking76t(at)verizon.net
Guest

Posted: Wed Sep 12, 2018 10:16 am Post subject: weird bumping (thumping noise) sound from the Jet??? Help

Have u cleaned the injectors? Had a thumping when power back in decent at 80-85%. Cleaned injectors and went away



Sent from my iPhone



 	  Quote: 	
		   On Sep 12, 2018, at 2:09 PM, skidmk <skidmk(at)gmail.com> wrote:

 

 

 

 Hey Dawg,

 

 Got the questions, we use oil from the can direct.  Mobil.  As for the thumping noises,, not really noticed at 80% or not.  Most prevalent during take-off (100%) less so in cruise 85-90.   It seems that it is getting more prevalent, up to and including the bumping on shut down this time.

 

 there is no variation in any op specs on the T's and P's.  

 

 there is no evidence of flaming, or pop flames coming our of the tail.

 

 there is what I feel maybe more than normal soot on the tailcone (in the vicinity of the antenna's)

 

 what might you be thinking about the 80%?

 

 I will change the fuel filter tomorrow, aerate (bleed) the fuel system and see if that cures it.

 

 --------

 Mike &quot;Skidmk&quot; Bourget

 Ottawa, Ontario

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=483146#483146

skidmk

Joined: 19 Nov 2007
Posts: 171
Location: Ottawa, Ontario

Posted: Wed Sep 12, 2018 10:21 am Post subject: Re: weird bumping (thumping noise) sound from the Jet??? Hel

yes sir ultrasonically cleaned, about 3 hours ago.  symptoms went away for about 3 hours, and are now back with a vengeance.

_________________
Mike "Skidmk" Bourget
Ottawa, Ontario

l29delfin(at)yahoo.com
Guest

Posted: Wed Sep 12, 2018 10:36 am Post subject: weird bumping (thumping noise) sound from the Jet??? Help

What exact oil are you using in the M701p?

On September 12, 2018 13:11:53 "skidmk" <skidmk(at)gmail.com> wrote:



 	  Quote: 	
		   



 Hey Dawg,



 Got the questions, we use oil from the can direct.  Mobil.  As for the 

 thumping noises,, not really noticed at 80% or not.  Most prevalent during 

 take-off (100%) less so in cruise 85-90.   It seems that it is getting more 

 prevalent, up to and including the bumping on shut down this time.



 there is no variation in any op specs on the T's and P's.



 there is no evidence of flaming, or pop flames coming our of the tail.



 there is what I feel maybe more than normal soot on the tailcone (in the 

 vicinity of the antenna's)



 what might you be thinking about the 80%?



 I will change the fuel filter tomorrow, aerate (bleed) the fuel system and 

 see if that cures it.



 --------

 Mike &quot;Skidmk&quot; Bourget

 Ottawa, Ontario





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=483146#483146

Dawg

Joined: 19 May 2013
Posts: 355

Posted: Wed Sep 12, 2018 12:34 pm Post subject: weird bumping (thumping noise) sound from the Jet??? Help

Stock engine uses a mineral oil. Royco 481. (or Shell sp3 or 3sp, can’t remember which) Mobile jet and 2380 are synthetic. May cause metal in your sample.



Had several airplanes that rumbled around 80% never had any other issues.

Is the thumping a metallic sound? Had one of those. Required new engine to stop the thumping.



 	  Quote: 	
		   On Sep 12, 2018, at 12:16, Anthony Royal <skyking76t(at)verizon.net> wrote:

 

 

 

 Have u cleaned the injectors? Had a thumping when power back in decent at 80-85%. Cleaned injectors and went away

 

 Sent from my iPhone

 

> On Sep 12, 2018, at 2:09 PM, skidmk <skidmk(at)gmail.com> wrote:

> 

> 

> 

> Hey Dawg,

> 

> Got the questions, we use oil from the can direct.  Mobil.  As for the thumping noises,, not really noticed at 80% or not.  Most prevalent during take-off (100%) less so in cruise 85-90.   It seems that it is getting more prevalent, up to and including the bumping on shut down this time.

> 

> there is no variation in any op specs on the T's and P's.  

> 

> there is no evidence of flaming, or pop flames coming our of the tail.

> 

> there is what I feel maybe more than normal soot on the tailcone (in the vicinity of the antenna's)

> 

> what might you be thinking about the 80%?

> 

> I will change the fuel filter tomorrow, aerate (bleed) the fuel system and see if that cures it.

> 

> --------

> Mike &quot;Skidmk&quot; Bourget

> Ottawa, Ontario

> 

> 

> 

> 

> Read this topic online here:

> 

> http://forums.matronics.com/viewtopic.php?p=483146#483146

> 

> 

> 

> 

> 

> 

> 

> 

>

_________________
Dawg

migfighter42(at)gmail.com
Guest

Posted: Wed Sep 12, 2018 10:06 pm Post subject: weird bumping (thumping noise) sound from the Jet??? Help

My previous L-29 would make that kind of noise (hollow thumping) at cruise settings 80-90% power. Not engine related, I believe it was just the inlet ducting. I inspected it numerous times and found no issues. Normal. 



Bill Culberson 

Red Star Aero Services

251/716/8119



 	  Quote: 	
		   On Sep 12, 2018, at 3:22 PM, William Geipel <l129bs(at)gmail.com> wrote:

 

 

 

 Stock engine uses a mineral oil. Royco 481. (or Shell sp3 or 3sp, can’t remember which) Mobile jet and 2380 are synthetic. May cause metal in your sample.

 

 Had several airplanes that rumbled around 80% never had any other issues.

 Is the thumping a metallic sound? Had one of those. Required new engine to stop the thumping.

 

 

 

 

 

> On Sep 12, 2018, at 12:16, Anthony Royal <skyking76t(at)verizon.net> wrote:

> 

> 

> 

> Have u cleaned the injectors? Had a thumping when power back in decent at 80-85%. Cleaned injectors and went away

> 

> Sent from my iPhone

> 

>> On Sep 12, 2018, at 2:09 PM, skidmk <skidmk(at)gmail.com> wrote:

>> 

>> 

>> 

>> Hey Dawg,

>> 

>> Got the questions, we use oil from the can direct.  Mobil.  As for the thumping noises,, not really noticed at 80% or not.  Most prevalent during take-off (100%) less so in cruise 85-90.   It seems that it is getting more prevalent, up to and including the bumping on shut down this time.

>> 

>> there is no variation in any op specs on the T's and P's.  

>> 

>> there is no evidence of flaming, or pop flames coming our of the tail.

>> 

>> there is what I feel maybe more than normal soot on the tailcone (in the vicinity of the antenna's)

>> 

>> what might you be thinking about the 80%?

>> 

>> I will change the fuel filter tomorrow, aerate (bleed) the fuel system and see if that cures it.

>> 

>> --------

>> Mike &quot;Skidmk&quot; Bourget

>> Ottawa, Ontario

>> 

>> 

>> 

>> 

>> Read this topic online here:

>> 

>> http://forums.matronics.com/viewtopic.php?p=483146#483146

>> 

>> 

>> 

>> 

>> 

>> 

>> 

>> 

>> 

> 

> 

> 

> 

>

skidmk

Joined: 19 Nov 2007
Posts: 171
Location: Ottawa, Ontario

Posted: Thu Sep 13, 2018 8:09 am Post subject: Re: weird bumping (thumping noise) sound from the Jet??? Hel

Use Mobil jet.  I’ll change it at the next oil change <5 hours. 



New this am I saw today.  Start up only 540 on the get, goes to 38%,  then the get drops  down to 370 and stabilized there. (To low imho)  Upon shut down loud bump.  I’ll try and record it. 



The manual talks about an air filter??  Never heard of that

_________________
Mike "Skidmk" Bourget
Ottawa, Ontario

cslamuseum(at)gmail.com
Guest

Posted: Thu Sep 13, 2018 10:13 am Post subject: weird bumping (thumping noise) sound from the Jet??? Help

Mobil is absolutely wrong and damaging for m701p.

Only mineral oil.

On September 13, 2018 11:11:44 "skidmk" <skidmk(at)gmail.com> wrote:



 	  Quote: 	
		   



 Use Mobil jet.  I’ll change it at the next oil change



 --------

 Mike &quot;Skidmk&quot; Bourget

 Ottawa, Ontario





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=483161#483161

Dawg

Joined: 19 May 2013
Posts: 355

Posted: Thu Sep 13, 2018 2:45 pm Post subject: weird bumping (thumping noise) sound from the Jet??? Help

It might scrub the engine a little to much maybe creating a little iron in the stew.



Sent from my iPad



 	  Quote: 	
		   On Sep 13, 2018, at 10:09 AM, skidmk <skidmk(at)gmail.com> wrote:

 

 

 

 Use Mobil jet.  I’ll change it at the next oil change 

 

 --------

 Mike &quot;Skidmk&quot; Bourget

 Ottawa, Ontario

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=483161#483161

_________________
Dawg

skidmk

Joined: 19 Nov 2007
Posts: 171
Location: Ottawa, Ontario

Posted: Wed Sep 26, 2018 5:52 am Post subject: Re: weird bumping (thumping noise) sound from the Jet??? Hel

so, an update.



noise on shutdown isolated to the bottle left burner can.  It sounds like the injector, or the liner has broken/come loose.  The EGT on start up goes to 575, then settles at 325 which is too low.



Taking the can off to inspect the can, and the blades. Evidence of scorching on the outside of the can.  I'm hoping a simple burner/injector replacement will solve the issue.  



Otherwise a new engine is in order I would suspect

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_________________
Mike "Skidmk" Bourget
Ottawa, Ontario

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