Very Cold Start

[ricksigler]

My 2007XL has spent all of it's life in a hanger until February 15, 20015 when the FBO terminated my lease. Now I have to tie down outside. I've never had any problems starting the engine, either cold or hot until now.

Because of bad weather here in Albuquerque I hadn't flown for three weeks. I went to the airport yesterday morning to do our Santa Fe breakfast burrito trip. The outside temp was 30F and the low that night was 20F, so I suspect the engine temp was between the two. I did my normal prep before trying to start the engine which consists of moving the throttle forward about one and one half inches, turning the fuel pump on, moving the mixture control to full rich for a count of seven then to off, moving the throttle back to just off idle, engaging the starter and slowly moving the mixture control forward.

The engine didn't start and didn't even fire one cylinder. I tried the same procedure once more and nothing. I then tried everything I could think of including my procedure for a flooded engine start (fuel pump off, mixture off, throttle full open, crank and throttle slowly back to idle). Nothing worked. Towards the final tries, I finally heard a cough, but by now I was worried about overheating the starter. I finally gave up and we took my buddies C150 to KSAF.

We got back about noon and the temp had warmed up to about 45F. I decided to give the start one more try before giving up and letting the A&P look at it. I went out to the plane and noticed a small blue patch that had leaked out of the breather tube which I normally see after a flight. I then suspected the engine was probably badly flooded. I got in and did my normal cold engine prep and the engine fired after one or two revolutions. I flew the plane down to E98 to get gas and charge the battery. The hot start after the short flight was not an issue.

I need some help on figuring out how to start the engine in the early morning cold and I'm sure I'm not the only one that has to tie down. Putting the plane in the hanger to warm up is not an option because of the FBO policy. Any ideas will be greatly appreciated. Thanks.

Rick

[Chris B]

I need some help on figuring out how to start the engine in the early morning cold and I'm sure I'm not the only one that has to tie down. Putting the plane in the hanger to warm up is not an option because of the FBO policy. Any ideas will be greatly appreciated.

Hi Rick -

Hopefully you are using a multi-viscosity oil. That is essential for cold starts.

Remember to let the fuel vaporize for a minute or two after priming when the engine is cold. Imagine how long it takes for spilled fuel to evaporate on the ground at cold temperatures. And only vapor will ignite.

If you are going to consistently be starting a cold-soaked engine, see if there is any way to get access to an electrical outlet for an engine heater. You might need to invest in a very long extension cord, but hopefully the FBO will provide *some* means of accessing power! Four cylinder engine heaters only draw 300-600W, so an inexpensive 16GA cord should work fine. Heater installation is straightforward, but involves semi-permanently affixing at least one heating element to the oil pan.

Personally I prefer the standard Reiff design (link), but Tanis (link) is also a popular choice. Another alternative is something that blows hot air, but this is obviously a bulky solution if you have limited storage at a tie-down. However, it is by far the fastest!

We often fly to Lake Tahoe, where overnight temps commonly get below freezing even in the summer. The standard Reiff engine heater can take a while (~25F/hr), but they also offer higher-wattage kits which speeds things up considerably. My personal policy is to not turn the engine over until the oil temp is 50F - though that is probably overly conservative.

Hope this helps,

Chris

[Steve]

Rick:

I'll bet you flooded the engine. I have done many cold starts in the temperature range you describe (yes, even in S. TX it occasionally gets below freezing). Throttle wide open. I never prime for more than 5 seconds, less the warmer it is. Throttle back to about an inch open. The other thing I do is wait for 10-15 seconds after priming before I crank the engine, to allow the fuel to vaporize better.

The other possibility is that you froze the spark plugs.

Steve

[rwtucker]

Rick,

It does not sound like you had a choice or the Tannis kit but my personal rule is "no starts below 45 degrees oil." As you know, wear accelerates significantly as you drop below that.

It sounds to me like you flooded the engine. I sometimes start in OATs of negative 10 or 20. Oddly, my aircraft starts better at low temps.

I follow the 3-second method:

- Mixture & throttle full forward
- 3-seconds fuel pump (after fuel flows, usually 4-seconds total)
- Fuel pump off
- Mixture full aft
- Throttle to the cold start mark indicated in the POH (I have a fine pencil line on all three marks)
- Wait 2-3 seconds
- Engage starter while gradually advancing mixture

Under these conditions, I always get a start in less than 2-seconds. Very hot starts, on the other hand are a different discussion.

[ricksigler]

Thanks guys. I've always used Aeroshell 15/50 in the plane. The way Atlantic has the tie downs set up, there is no chance of getting power out to the plane. I do remember that the oil temp read 27F while we were trying to start it. I didn't know about the "vaporize" issue so I never waited. You've given me some great methods to try. Thanks.

[rwtucker]

Another thought Rick.

If you do have the Tannis option, I have a possible solution that doesn't involve running an extension cord (although I toss in a 100 foot cord in the winter when I fly into low service airports like Jackpot Nevada).

As I recall, the Tannis pre-heating system draws around 400-450 watts for the four barrel heaters and the small pan heater. That's around 3.5 amps. If you attach a 12 volt, 7 ah gell cell battery (like you see on your home security system, etc.) to a common 500 watt inverter, you have a compact portable 117 vac supply for your pre-heater. These small inverters run about 85-90% efficiency meaning that your draw on the gel cell will be around 4.0 amps. The inverters shut off automatically when the supply voltage drops to a level that would harm the gel cell to go lower. You should get close to an hour of heating while you have a cup of coffee at the FBO. (Blankets and nose plugs help a lot.) An hour won't heat your oil to run-up temps but it will expand the barrels, which is critical, and warm the oil enough that it will get to your cylinder head walls before they scuff excessively. Even 30 minutes at winter temps in your area will get you into the safety zone, especially in terms of expanding the barrel fittings.

If you don't like that idea, I have another one that involves a small Coleman backpacking stove, a short length of collapsible aluminum dryer hose, and a couple of lengths of safety wire. I used that solution for years on my PA28-201T. Toasty warm in 30 minutes.

[Gasser]

The best advice I ever got is what Chris gave you. My cold weather routiene is to prime then wait about 60 seconds then fire up the starter. Makes a hughe difference. It just takes time to form the right amount of vapor to fire off when very cold.

[Colin]

When you are paying the FBO for a tie-down you should get some service in return. I don't think it is outrageous to call Atlantic and say, "I'm going flying in two hours, please tow my plane over to the ramp and plug in the engine heater. Thanks."

If they won't do it, switch to Cutter.

I use three seconds on the fuel pump.

[rwtucker]

When you are paying the FBO for a tie-down you should get some service in return. I don't think it is outrageous to call Atlantic and say, "I'm going flying in two hours, please tow my plane over to the ramp and plug in the engine heater. Thanks."

How sweet that would be. I no longer tie down but if I asked for that service when I did, I would be presented with a $60 ticket to sign, and my nose wheel fairing would be scuffed around the tow-bar holes. Ramp tie down fees go to the city or county at all of the airports in my neighborhood.

[mhoran]

Thanks for the tips! We're in a similar situation. With expensive tie-downs and even more expensive hangars, we've got a ground crew that does an extremely poor job of plowing in the winter -- let alone provide any additional services.

I tried waiting for one minute after a three second prime yesterday, and the engine started up on the first crank. That's something that hasn't happened all winter! We've also got 15W-50 oil in her, but vaporization seems to have been the main issue.