Engine stalled at low RPMs, low oil pressure light on
Post Reply    Forum -> MP3 Discussion
Author Message
Member
2009 MP3 500
Joined: 19 Jul 2013
Posts: 22
Location: Seattle
Thu Aug 01, 2013 8:46 am quote
Could it have been a bad oil pressure sensor connection?

Yesterday I did my oil and filter change at 625 miles. I followed the instructions from the workshop manual. I emptied the oil completely, sucking out the remaining with a siphon pump (instead of tilting). I cleaned and re-installed the cylindrical screen tube, the end with the rubber gasket in first, then put in the drain bolt with the gasket, and tightened it to 26 NM. I used Motul 5W40 motor oil, poured some in the filter, rubbed the gasket and tightened it by hand. Initially used about 1.4 L of oil. When I started the engine, the wrench icon showed up (I was at precisely 625 miles, what a timing!) and I reset it. Let the engine run for for 30 seconds, then let it cool for 30 minutes, and checked the level. It was about 2 mm above the MIN mark, so I poured 200 ml, and it showed oil level just slightly above the midpoint between MIN and MAX. I have no leaks, everything seemed tip-top.

This morning I started off to work. The scoot started fine, and ran fine. Traffic was a bit slow, and I barely went over 30 mph. When entering the parking garage, at idling speed, the engine cut off. It was as if I pressed the kill switch. The low oil pressure warning light came on. I restarted the engine, it started up fine. I parked the scoot and examined the oil filter and the drain bolt for leaks. Everything appears to be just fine. 10 minutes later I checked the oil level. It was again between MIN and MAX, and no oil leaks have developed.

As I was fiddling around with the oil dip stick, I noticed that the boot covering the oil pressure sensor moves a bit. I pulled the boot and found that the quick disconnect of the wire coming to the oil pressure sensor is too lose. It was touching the spade connector of the oil pressure sensor but wasn't hugging it tightly. I pinched the terminals a bit and re-installed it. Started the engine, the low oil pressure light is off.

I am posting this in hope that someone had similar experience and can give me some reassurance that I did the right thing. I have changed the oil on cars and motorcycles enough times to feel confident about not making silly mistakes, but some times the attention to minute details causes me to miss big things.

I will leave the scoot in the parking until tonight. I will check for replies to this post before I start it. I am hoping to avoid a major damage.

Thanks for reading
-Stan
Veni, Vidi, Posti
Neutrino MP3 492.7 AK, 2013 Moto Guzzi Norge
Joined: 29 Mar 2008
Posts: 20973
Location: Kingston, Tennessee, Tn
Thu Aug 01, 2013 8:53 am quote
nice report and find. Thanks for giving us a heads up
Moderatus Rana
MP3 250 (sold) MP3 500 (current)
Joined: 11 Jul 2008
Posts: 21322
Location: welaka, florida
Thu Aug 01, 2013 8:56 am quote
Sounds like you did everything correctly. You probably found the problem. Keep an eye on it on your way home.
Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: 26 Aug 2007
Posts: 36635
Location: Pleasant Hill, CA
Thu Aug 01, 2013 9:50 am quote
Re: Engine stalled at low RPMs, low oil pressure light on
stgatev wrote:
When entering the parking garage, at idling speed, the engine cut off. It was as if I pressed the kill switch. The low oil pressure warning light came on.
OK, so a random stall - and with the ignition still on the oil light came on.

Well it should!

The oil light should *always* come on when the ignition is on and the engine isn't running - it registers oil pressure, not oil level, and with the engine stopped there isn't any pressure... Treat it as a lamp test.

The loose-ish connection is almost certainly a complete red herring, I bet it was making just fine all the time.
Member
2009 MP3 500
Joined: 19 Jul 2013
Posts: 22
Location: Seattle
Thu Aug 01, 2013 10:59 am quote
Re: Engine stalled at low RPMs, low oil pressure light on
jimc wrote:
The oil light should *always* come on when the ignition is on and the engine isn't running
You are correct, of course. I am not 100% sure, but reflecting upon it, it might have stayed on after I restarted the engine. I am not certain, though -- it came as a surprise, and I was too busy trying to not get in the way of cars entering the garage to take notice. Might have been off, or stayed on.

Any suggestions on where to look for trouble other than the lose oil pressure sensor connection? I read about faulty kill switch, but mine seems solid, and clicks very reassuringly.
Addicted
2009 Piaggio MP3 250
Joined: 19 Aug 2011
Posts: 788
Location: Michigan; USA
Thu Aug 01, 2013 11:07 am quote
Check your battery terminals to see if either cable wiggled loose. I had the same issue and tightening the cables took care of my problem. And it acted the same way as yours, once I pushed it into a parking lot it fired up with no problems - but I discovered the issue with the cables after I got home.
Member
2009 MP3 500
Joined: 19 Jul 2013
Posts: 22
Location: Seattle
Thu Aug 01, 2013 12:06 pm quote
The battery terminals seem fine. The screws are very tight, no play at all.
Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: 26 Aug 2007
Posts: 36635
Location: Pleasant Hill, CA
Thu Aug 01, 2013 2:20 pm quote
Occasion stalling is reported quite often - have you ensured you've got the latest firmware update?
Member
2009 MP3 500
Joined: 19 Jul 2013
Posts: 22
Location: Seattle
Thu Aug 01, 2013 2:34 pm quote
jimc wrote:
Occasion stalling is reported quite often - have you ensured you've got the latest firmware update?
I don't think I have the latest firmware updates. When I spoke to the dealer about other things, I also inquired about software updates. According to him, there has been an update on the mapping to address the backfiring which occurs when reducing RPMs, but he did not mention stalling. Maybe I should do that update anyway.
Member
2009 MP3 500
Joined: 19 Jul 2013
Posts: 22
Location: Seattle
Sat Aug 17, 2013 10:34 am quote
No problems since tightening the oil pressure sensor connect
Just a quick update -- two weeks and 200 miles later, the problem has not yet reoccurred.
Veni, Vidi, Posti
GTS 300ABS, Buddy 125, Typhoon 125
Joined: 29 Dec 2007
Posts: 10167
Location: Oregon City, OR
Sat Aug 17, 2013 10:43 am quote
stgatev wrote:
Maybe I should do that update anyway.
Yes, you should. (as an aside, sounds like you did the oil thing just right)
Lurker
2010 GTS 300
Joined: 11 Nov 2018
Posts: 2
Location: Tulsa, Okla. USA
Thu Nov 29, 2018 8:36 am quote
I had the same stall happen to me this morning. 2010 GTS 300 with about 4,500 miles. It's new to me and I just changed the oil and followed instructions to a T. I'm confident I made the oil change correctly. Also installed a battery tender. The engine stalled when coming to a stop as I entered low RPMs. It started back up easily so I drove it slowly and watched the engine temp. It never went above about an 1/8 or slightly more of the needle range. Each time the engine stalled, the oil light went on. By about halfway through my ride to work (about a 25 minute commute), the stalling stopped and it ran fine. Cooler weather this morning, about 45-50 degrees F. Any thoughts welcome.
Lurker
2010 GTS 300
Joined: 11 Nov 2018
Posts: 2
Location: Tulsa, Okla. USA
Thu Nov 29, 2018 8:37 am quote
jimc wrote:
Occasion stalling is reported quite often - have you ensured you've got the latest firmware update?
How do you update the firmware? Assume dealer does this?
Veni, Vidi, Posti
GTS 300ABS, Buddy 125, Typhoon 125
Joined: 29 Dec 2007
Posts: 10167
Location: Oregon City, OR
Thu Nov 29, 2018 9:32 am quote
JesseB wrote:
How do you update the firmware? Assume dealer does this?
Yes. A Piaggio dealer.
Hooked
Joined: 06 Nov 2014
Posts: 240
Location: Uk
Thu Nov 29, 2018 12:22 pm quote
my first reaction when people complain of stalling when revs released is to advise to clean throttle body as the small bypass hole by the butterfly gets blocked thus stopping any air entering the engine when revs ie butterfly valve is closed. its a very easy thing to remove and takes around 1 hour if you have the time. ow of course and the number one fault is loose battery connections but I know you were all over that already.
Rallies Europe 2016   vespa scooterwest scooter west Motorsport Scooters   Cool Ass scooter seat cover
Post Reply    Forum -> MP3 Discussion
[ Time: 0.5522s ][ Queries: 23 (0.0587s) ][ Debug on ]