Starting Issue

[Tahir K]

Alright guys I need some help with this one. I've attached a video with sound to give you guys an idea of what's happening. 
 

Tried to start the plane this morning with no luck. 31°F so I'm not surprised. Cranked for 15-20 seconds with the prop spinning but no start. Tried again, prop spun, but still no luck. Third time the prop wouldn't even spin and the plane just made this whirring noise. 
 

Any idea what's making this noise?

 

Thanks,

Tahir

Edited November 30, 2020 by Tahir K

[N201MKTurbo]

If you are getting a whirling noise and the prop isn’t moving, your bendix is stuck.

What starter do you have? Before I put the cowl closure on my F, I could get it engaged with a bic pen and start the engine.

 

[PT20J]

Hard to tell from the movie, but it sounds like the chatter a starter relay makes when there isn't enough battery power to run the starter. A stuck Bendix should be more of a whine. Batteries have lower capacity when cold, and if it was low to begin with it doesn't take much to run it down. 

Starting requires air and fuel in the proper amounts plus spark and rotation. The problem when it is cold, of course, is getting the air fuel mixture right (priming) because avgas doesn't vaporize all that well. It takes more prime when it's cold. If it cranked but didn't fire at all, it probably needed more prime.

Skip

[Yetti]

sounds like grease on the bendix is old and yucky.

They usually get stuck engaged and then spin when the engine starts.

charge your battery slowly and properly

Tell us your start sequence.

[carusoam]

Below 40°F you are entering the world of pre-heat...

not because it is required... but because things start getting more challenging...

Bendix drives like to be cleaned and lubricated at least twice each year...

+1 for affects of cold on batteries... cold cranking amps...

+1 for adjusting the amount of prime for temperature...

Real challenges for pre-heat come in at 20°F... below 20, pre-heat is a requirement because evaporation rate of 100LL becomes tiny...

Our battery capacities is quite small... we get two good attempts at starting... so knowing what the fuel is doing is key...

The IO550 has an amount to prime for above 40°F and about double that below 40°F... using time in seconds...

I had difficulty keeping the video running...

Best regards,

-a-

[Tahir K]

Thanks everyone for their response. I went to the plane the next afternoon after it had warmed up. Charged the battery for a few hours as well and primed for an extra 5 seconds. Plane started up just fine! I will definitely have to get the mags greased. Priming the engine extra and charging the battery also helped.

In terms of preheating the engine...can I leave the heater on through the night? Will the engine be damaged if I keep the heater plugged in constantly or should I only heat for a couple of hours before flying?

Thanks for all the help as always, MS

[PT20J]

21 minutes ago, Tahir K said:

I will definitely have to get the mags greased.

I think there is some confusion here  The Bendix drive is the part of the starter that engages the starter gear with the engine ring gear for starting and then disengages the starter gear from the ring gear once the engine starts. When they hang up (rare in my experience) it's caused by dirt. Greasing is a bad idea as it attracts dirt and can also make the drive fail to function properly in cold temperatures. 

https://www.lycoming.com/content/how-clean-your-direct-drive-engine-starter

149-NL.pdf

Skip

[Tahir K]

I think there is some confusion here  The Bendix drive is the part of the starter that engages the starter gear with the engine ring gear for starting and then disengages the starter gear from the ring gear once the engine starts. When they hang up (rare in my experience) it's caused by dirt. Greasing is a bad idea as it attracts dirt and can also make the drive fail to function properly in cold temperatures. 
https://www.lycoming.com/content/how-clean-your-direct-drive-engine-starter
149-NL.pdf
Skip

Skip,

Thank you so much for this article and your clarification on my confusion. I'll pass this onto my mechanic and have it cleaned properly!

[Yetti]

Unless you were only priming for 1 second before you are in the risk of flooding zone.

1. Open throttle 1"

2. Boost pump on

3. Open mixture  full

4.  Count to 6 seconds.   In cold I will go 7 or 8

5. Close mixture

6. Boost pump off

7.  Crank and add mixture when pops

[carusoam]

Tahir,

There are good instructions for everything in the certified world....

Including the goofy things like engine pre-heaters...

Turn it on by a remote switch...  turn it off when your plans change...

Leaving it on can be done when you have a PhD in air conditioning science... and a few sensors...

This assumes you have a popular electric heat system...

Best regards,

-a-