REFLECTOR: Interesting Gotcha this morning

[Al Gietzen]

Might want to consider opening up the ducts, and blowing the hair dryer
through for awhile before sealing up.

Al

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Scott Derrick
Sent: Friday, November 05, 2004 3:54 PM
To: Velocity Aircraft Owners and Builders list
Subject: REFLECTOR: Interesting Gotcha this morning

After fixing the leak in my sump tank, I decided I would clean off my 
engine and reinstall my dip stick tube as it had become loose.

I used the spray on engine degreaser and hosed it off afterwards.  It took 
two applications to get it really clean as the loose dip stick tube had 
been leaking oil.  Rinsed it down real good and let it sit for an hour 
before taxing back to the hanger from the wash rack.

Fired her up this morning and taxied out to RW 13.  About half the way 
there I started getting a pop corn sound in my headset!  It was pretty 
loud.  I turned the ANR off and on, no change.  Tried EI or right mag, no 
change.  Changing the rpm did seem to increase the rate of popping but not 
as much as the rpm was changing.  Turned off the intercom, slightly less 
volume.  Turned off the strobes, no change..  changed comm's the quality of 
pops changed but still there.

All indications voltage and amperage looked within norm.

I sadly taxied back to the hanger... Damn, and we were planning a trip to 
Mesa Verde tomorrow.....

At the hanger I cycled electrical power and no change. Cycled again(I'm 
stubborn) and it stopped!!  Hmmm... Now thats good and 
bad...  Intermittents can be real buggers..  I could not get it to come
back.

I got out , looked at the alternator wiring, as much as I can see with out 
de-cowling..  Popped the nose door and canard hatch.  Nothing obvious???

My friend the local A&P/AI wandered by, he said he got worried as he heard 
me taxi out but not take off.  I told him the story and he didn't have much 
more to suggest, except that it may have been an external source, some 
local transformer or something.  that got my hopes up a bit, but not much...

I decided to fire up and see if it would come back by taxing 
around.  pushed out of the hanger,  "prop clear!" and started the 
engine.  He got this funny look on his face and gave me the kill signal 
while pointing back at the engine.  I stopped it and bent out and looked 
back.  There was a puddle under the engine. I had not primed or ran the aux 
fuel pump.

I jumped out and went back, stuck my finger in the liquid,  smelled, 
tasted, it was water??  Wow, it was coming out of he gap in the cowling 
where the vent and fuel whiffle valve lines are.

It must be from washing the engine I said.  Strange it didn't drain when 
the cowling was off..  I went to the nose and lifted.  Water gushed 
out!!!  Must have been 1/4 gallon or more!

Then I realized there are gaps where the oil lines and wires go into the 
two ducts on either side of the fuselage.  In my quest to really rinse down 
the engine and firewall to insure I got all the degreaser out I had sprayed 
a bunch of water into the ducts!  Who knows how many BNC and other 
connectors are in there getting soaked.  Not to mention the main big ol 
wires for the starter/alternator.  The shape of the fuselage is like a 
banana and any liquid put in the firewall end of the duct would migrate to 
the center of the fusalage...

  In fact I had noticed one time after I had changed the oil and really 
bothched catching the oil from the filter, its mounted right above the left 
duct. The oil poured all over that spot.  A couple weeks later I had the 
back seat out and there was an oil stain where there is access to the duct, 
the pilled oil that got in the duct it had migrated up the duct to the 
middle of teh fusalage.

I held the nose up for about 5 minutes until all dripping stopped.

Fired up and flew around for half an hour with no popping noise.  Now I 
don't know for sure if it was the water that caused the popping noise, but 
I do know I don't want to get that water in there again!  It could also 
freeze and do who knows what?

Scott

"Those who sacrifice freedom to get security, deserve neither."
- Benjamin Franklin

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