Engine won't start after oil change

FPK1

FPK1

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FPK1
Lycoming IO-390 engine was running fine. Just under 300 hours on the engine. Immediately after an oil change, I now have great difficulty starting the engine (cold starts). Following the exact same check list, the engine won't start. Finally got it started one time, two other times I flooded it and followed flooded engine instructions successfully, and now for the fourth time it won't start at all.

One of those flights was for the $100 hamburger, so after lunch a warm start was successful. Lowest temps were in mid-60s...

Run-ups and once running/flying, everything is normal.

Hope to get on the mechanic schedule for this week, any ideas?

Thanks.
 
What aircraft? What magnetos are installed? Is this an impulse coupler setup/electronic mag/starting vibrator?
 
From my limited mechical experience I cannot fathom any reason why changing the oil would make the engine not start ...
 
Ignition component failure independent of oil change? Impulse coupling failure (actually, internally the start magneto, so techincally not the coupling, I misremembered. The airplane before that one is the one that had the coupling fail) is what got me the last time I got bent with AOG. Started without hesitation in the morning, let me fly 400NM away, and stuck I got on the attempt to start to fly back. Yipeee.

Things are that fickle. #webethriving! #JurassicPark
 
Ryan Klems said:
What aircraft? What magnetos are installed? Is this an impulse coupler setup/electronic mag/starting vibrator?
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Tecnam P2010 with normal magnetos(?)

Magneto inspection due at 500 hours... I don't know the manufacturer name (at this time).
 
So looks like this would be an IO-390-C3B6, with 4345 and 4370 slick mags based on the updated aircraft info. So no electronic components to the starting side, so unlikely someone broke a wire, etc while R&R'ing oil filter. Nothing else was done at the same time (mags weren't timed or anything?) I always hate to suggest rotating the prop, but with the mags in the off position, if you rotate the prop through, while standing out of the propeller arc, do you hear the snap of the impulse coupling?
 
FPK1 said:
Hope to get on the mechanic schedule for this week, any ideas?
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Hi.
It sounds like you should not take it back to the same mechanic.
Oil change is fairly easy, but when done, and I've seen some do it, by a careless mechanics things can go very wrong.
The problem typically is the the mechanics no longer do the work, they have some completely irresponsible individual do it that do not know, or care what they are doing.
Look at the wiring around the oil filter, kinks, connectors...
If you had it done in FUL? I suggest that you take it somewhere else. As I recall you were based there?
 
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Ryan Klems said:
So looks like this would be an IO-390-C3B6, with 4345 and 4370 slick mags based on the updated aircraft info. So no electronic components to the starting side, so unlikely someone broke a wire, etc while R&R'ing oil filter. Nothing else was done at the same time (mags weren't timed or anything?) I always hate to suggest rotating the prop, but with the mags in the off position, if you rotate the prop through, while standing out of the propeller arc, do you hear the snap of the impulse coupling?
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Thank you. Nothing else done at the time, however, 24 hours prior, annual completed that included new spark plugs...
 
FPK1 said:
I assumed since all was fine for the last 24 hours it was not related... Obviously, I'm learning here.
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Hence the reason for my first post noting that simply (and properly) changing the oil should have zero effect on the engine starting. Perhaps call the A&P that performed the inspection and ask if there was anything that was done that might be causing the concern you are having now ...
 
Are you starting on the LEFT mag only or both? The left is a retard mag, and is used for starting. What is your mag check drop off RPM on both? Has it changed at all since the oil service? Might also have the timing checked on both mags, and do find out if the retard mag impulse coupling snaps when prop is rotated. It's a definite sound from the impulse coupling.
 
Happened to me one time. The mechanic used Aeroshell 100+ and ALSO camguard. Engine wouldn't start. He drained the oil and went back without the Camguard and it started fine.
Apparently the mix was too slippery for the starter adapter, or at least that's what he said.
 
Did he put in W200 oil, in the winter, after it's best use by date?
 
JOhnH said:
Happened to me one time. The mechanic used Aeroshell 100+ and ALSO camguard. Engine wouldn't start. He drained the oil and went back without the Camguard and it started fine.
Apparently the mix was too slippery for the starter adapter, or at least that's what he said.
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The "starter adapter"?? "Too slippery"??

????
 
FPK1 said:
Thank you. Nothing else done at the time, however, 24 hours prior, annual completed that included new spark plugs...
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Who changed the oil? You? An A&P? The same one that did the annual? If the plane was due for an oil change at annual time why not do it then? Did you fly the plane between the annual and the oil change? How much time between annual and oil change? I’m confused here. Ain’t making’ sense. 24 hours? That’s a day.
 
Jim_R said:
The "starter adapter"?? "Too slippery"??

????
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That's an issue with Continental, not Lycoming. Another guess to add would be magneto not tightened enough after timing during annual. Got knocked in the process of oil change as filter is kind of near mags.

There's a pretty logical process to follow to solve, some of the bits here are part of them. I'd start with timing, impulse coupler and spark plug wire connections at mag and plugs. That all assumes it's spark related.
 
“Engine won’t start”
“Great difficulty starting”
“Flooded start”

All vastly different things.
 
If the engine won't start after the oil was changed, then either it's a coincidence or the mechanic disturbed something while he was poking around. Did he possibly remove and reinstall something to gain access? Once it does start, what does the mag drop look like on each side? Does it respond properly to throttle and mixture control adjustments?

JOhnH said:
Happened to me one time. The mechanic used Aeroshell 100+ and ALSO camguard. Engine wouldn't start. He drained the oil and went back without the Camguard and it started fine.
Apparently the mix was too slippery for the starter adapter, or at least that's what he said.
Click to expand...
Different situation from the OP, of course. It's not the camguard, it's the Lycoming anti-wear additive (the "+" in 100+) that makes it too slippery.
Jim_R said:
The "starter adapter"?? "Too slippery"??

????
Click to expand...
Some Continentals have a slip clutch in the starter adapter; the anti-wear additive makes it too slippy.
 
FPK1 said:
Nothing else done at the time, however, 24 hours prior, annual completed that included new spark plugs.
Click to expand...
So between the annual and oil change it started normally?
Any worked performed in the 2 weeks prior to the annual?
What checklist did the mechanic use for the annual?
 
Hang 4 said:
Another guess to add would be magneto not tightened enough after timing during annual. Got knocked in the process of oil change as filter is kind of near mags.
Click to expand...

POA Maintenance Roulette is fun (except for the OP). I like this guess. I’ll put $20 on this one. :)
 
Could it be a dying battery? That has happened to me too. When the engine turns over, does it sound sluggish?
 
In September engine came back from Lycoming after they fixed small oil leak in the seal under warranty. Engine installed and mineral oil used since they honed the cylinders. Annual also completed. Test flight and engine break in completed. Started fine, runup fine, flew great. No issues!

After 24 hours on engine I asked mechanic to drain the oil and he refilled with AEROSHELL 100 SAE 50 MINERAL OIL and camguard, 1.6 oz per quart.

Tried to cold start the plane following same instructions as the last 34 months and it failed. Crank crank crank and nothing catches. Had to play with mixture and throttle to get it to start. It was not a flooded start as there was no fuel on the ground. Flew to lunch, warm start was fine, and came back home no issue.

Second normal cold start failed, was flooded, and started by following flooded start procedure. Same with cold start three, flooded, started by following cold start procedure. Cold start four also flooded but I could never get it to start.

Could it be the mineral oil and camguard? Maybe I should drain and just put mineral oil back in with no cam guard and see what happens...

Mechanic will look at it tomorrow but I was looking for suggestions from POA experts
 
Definitely not the camguard. Not sure of the sequence. You have 24 hours with nothing touched, running fine, then the oil change? If so I’m pretty certain that something got jostled during the oil change. Did you do a run up once it started and was that normal?
 
Hang 4 said:
Definitely not the camguard. Not sure of the sequence. You have 24 hours with nothing touched, running fine, then the oil change? If so I’m pretty certain that something got jostled during the oil change. Did you do a run up once it started and was that normal?
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Yes, 24 hours of no issues then oil change. Started normal, run up was normal, flights were wonderful. Then oil changed and the very next normal engine start failed... And all subsequent.
 
Run ups normal AFTER the oil change?
 
FPK1 said:
In September engine came back from Lycoming after they fixed small oil leak in the seal under warranty. Engine installed and mineral oil used since they honed the cylinders. Annual also completed. Test flight and engine break in completed. Started fine, runup fine, flew great. No issues!

After 24 hours on engine I asked mechanic to drain the oil and he refilled with AEROSHELL 100 SAE 50 MINERAL OIL and camguard, 1.6 oz per quart.

Tried to cold start the plane following same instructions as the last 34 months and it failed. Crank crank crank and nothing catches. Had to play with mixture and throttle to get it to start. It was not a flooded start as there was no fuel on the ground. Flew to lunch, warm start was fine, and came back home no issue.

Second normal cold start failed, was flooded, and started by following flooded start procedure. Same with cold start three, flooded, started by following cold start procedure. Cold start four also flooded but I could never get it to start.

Could it be the mineral oil and camguard? Maybe I should drain and just put mineral oil back in with no cam guard and see what happens...

Mechanic will look at it tomorrow but I was looking for suggestions from POA experts
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Just curious....why have the shop do the oil change when it's owner maintenance - and considerably cheaper. Or was it supposed to be done at the annual and they forgot?
 
It was done at annual and I thought it might be a good time to change the mineral oil... I'm not all that handy so I don't trust myself to do it.
 
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I’d suggest two things;
1. make sure nothing was done other than oil change
2. Have the impulse coupling and timing checked.

Run up ok makes impulse coupling more likely, but my money is still on a mag getting bumped and shifting
 
Something happened to your start magneto during the oil change.
Oil spilled and somehow got on the points, so now you have a bad contact? Or something slightly conductive/hygroscopic got on the P-lead terminal/wire, providing a weak path to ground? As things get hot moisture evaporates or things expand and remove that path.
Maybe troubleshoot by disconnecting the P-lead and cleaning the post well? If next start is good, reconnect P-lead and see if things get worse. That would point to something with the actual lead going to the mag switch.
If next start is bad, remove mag and inspect points at a minimum.
 
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Like others , I a little confused. Is the situation:

1. Engine not cranking?

2. Lack of combustion?

I’m inclined to think that maybe a piece of safety wire is shorting

out the left mag under some conditions. Several things can cause the issue.

How do they “ cure” is the miracle?
 
Note that with a Slick the p- lead attaches to a capacitor.

Over torque the lead and it is $$$ to resolve.
 
Magman said:
Like others , I a little confused. Is the situation:

1. Engine not cranking?

2. Lack of combustion?

I’m inclined to think that maybe a piece of safety wire is shorting

out the left mag under some conditions. Several things can cause the issue.

How do they “ cure” is the miracle?
Click to expand...
Engine cranks just fine, just never fires up...
 
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