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Lawnmower Syndrome

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

Ozark Lee
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Ozark Lee

Lawnmower Syndrome

Post by Ozark Lee » Fri Jan 09, 2009 9:48 pm

I'm not sure where the term "lawnmower syndrome" originated and while I have often thought of it as an urban legend I can attest that it is real and that the prescribed remedial actions do in fact work.

By background, "lawnmower syndrome" applies to a situation where a perfectly functioning engine will suddenly refuse to start and has no compression on any cylinders. In my case it was a 1994 2.4 liter 20 valve N/A model but other variants of the 5 cylinder engine have reported similar situations.

This particular car was parked last Saturday night when the heater core detonated. My local stealership parts counter quoted $945.00 for the replacement part handed to me over the counter and the Nissens "kit" from eEuroparts at $139.90 looked much more attractive albeit that the family is down a car until it arrived by ground shipping.

I replaced the heater core this afternoon and was going to proudly pronounce to my wife that she could take what is her car and hit the key. It fired right up and immediately died so I hit the key again and thought that somehow the starter was not engaging as the starter's pitch had significantly changed. It almost sounded like the Bendix wasn't engaging. I only put the compression gauge into one cylinder but when it barely moved and the car smelled flooded with a strong stench of raw gasoline. I knew from previous post readings and even from advising on them, that I had the mythological "lawnmower syndrome".

I removed all of the spark plugs and using a small rubber hose and a funnel I added a teaspoon or so of oil to each cylinder. I then replaced the plugs, charged the battery for an hour or so, and then cranked like crazy. It went from sounding like the starter wasn't even engaging to the sound of actual motor cranking within a couple of seconds but it kept sputtering and the motor never really took. I kept cranking. It took what seemed a minute but I really doubt that it was more than 30 seconds before the engine well and truly started and I felt it could sustain itself with some throttle feathering and I let off the key.

I then revved it to 2,000 to 3,000 RPM and kept it there for a while until it quit missing horribly.

The smoke cloud is beyond belief.

I let the car warm up so as to check for coolant leaks on my heater core repair and it continued to smoke after 20 or 30 minutes of idling. A short trip on the highway - to the delight of my neighbors since it left my driveway - seemed to clear the oil out and there is little or no smoke on startup now.

My conclusion is that:

1- The "lawnmower syndrome" is real and not a myth.

2- It is easily fixed with a squirt of oil in each cylinder.

The '94 is running like a top again and the heat works without fogging the windows.

...Lee


'94 850 N/A 5 speed
'96 Platinum Edition Turbo
'99 V70XC - Nautic Blue
Previous:
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

MadeInJapan
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MadeInJapan

Re: Lawnmower Syndrome

Post by MadeInJapan » Fri Jan 09, 2009 10:13 pm

Thanks for this...it will be indefinitely on this forum if anyone ever decides to search for it :o


'98 S70 T5 Emrld Grn Met/Beige Tons of Upgrades Mobil-1
'04 V70 2.5T Red/Taupe Some Upgrades Mobil-1
'07 S40 T5 AWD 6 speed manual! Silver/Black Stage1 Heico & Elevate
'07 S60 2.5T Blue/Taupe- my kid's Volvo

turbotim2
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Re: Lawnmower Syndrome

Post by turbotim2 » Sat Jan 10, 2009 5:01 am

Thanks, I always thought the lawnmower syndrome was what the folks who modify Honda Civics in order to keep up wuth lawnmowers do. I am now wiser.
I have a question, was the car driven a very short distance and then shut off again, remaining cold before this happened? Mine has done this several times but not in awhile.


2004 XC70

2005 S60 2.5T AWD (gone)

1996 850 GLT Wagon in Blue (gone)

1996 850 GLT Wagon in Green (gone)

MadeInJapan
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MadeInJapan

Re: Lawnmower Syndrome

Post by MadeInJapan » Sat Jan 10, 2009 7:51 am

Tim...looks like he didn't drive it a short distance (typical if you have to move your car for someone and you only drive it a few feet, etc.) but just the fact that his engine turned over and then died, probably did the same thing.


'98 S70 T5 Emrld Grn Met/Beige Tons of Upgrades Mobil-1
'04 V70 2.5T Red/Taupe Some Upgrades Mobil-1
'07 S40 T5 AWD 6 speed manual! Silver/Black Stage1 Heico & Elevate
'07 S60 2.5T Blue/Taupe- my kid's Volvo

biggytwo
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biggytwo

Re: Lawnmower Syndrome

Post by biggytwo » Sat Jan 10, 2009 8:35 am

1994 850 N/A - same thing happened to our car and in my opinion the legend is not a myth. In my case, I once just started the car and immediately shut it off without ever putting the car into gear.

When we went out to move the car later on that day, the starter would engage but the car would not start. Spark was checked and it was there and I had no idea why it would not start.

But with the help from this forum and the advice given, I put the gas pedal all the way down and I kept cranking the engine over and after about a minute of cranking the engine, it sputtered into life. It idled rough for a few minutes and then smoothed out.

We have had no problems since (now knowing better) and the car has been going strong.

Steve


1994 Volvo Wagon 850 NA US version, 234 K miles
2002 PT Cruiser Dream Series 1
2001 Nissan Pathfinder
1967 Ford Mustang Conv.

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billofdurham
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Re: Lawnmower Syndrome

Post by billofdurham » Sat Jan 10, 2009 3:42 pm

I put the gas pedal all the way down and I kept cranking the engine over and after about a minute of cranking the engine, it sputtered into life. It idled rough for a few minutes and then smoothed out.
Going back into the mists of time when cars did not have electronic whatnots, fuel injection, electrically powered everything and all manner of 'can't do without' gadgets, this was how we started cars on a regular basis when the engine was flooded with petrol. Your symptoms sound exactly the same.

If tha didn't work we would pull the plugs and dry them out on the gas ring of the cooker. Whilst they were out the petrol in the cylinders had a chance to evaporate.

Excuse my short stroll down memory lane.

Bill.


Work was good - retirement is better.

1996 850GLT 2.5 20v Estate Manual.
1995 Peugeot Boxer 2.5Tdi Autosleeper.
Previously:
1984 244DL, Manual, Beige.
1987 744GLE, Manual, Green.
1991 960 3.0 24v, Auto, Silver.
1994 940T Wentworth, Auto, Blue.

wheelsup
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Re: Lawnmower Syndrome

Post by wheelsup » Sat Jan 10, 2009 4:16 pm

I read about this somewhere on here and now generally just put it in neutral with the car off to move it.


1995 850 GLT Wagon w/ 185,000 miles

Ozark Lee
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Ozark Lee

Re: Lawnmower Syndrome

Post by Ozark Lee » Sat Jan 10, 2009 6:19 pm

I'm with Bill that it was flooded. While I was working on the car I was also trying to listen to the radio but the danged door chime kept irritating me to the point that I would turn off the key. I think every time I turned it back on I hit position II before drawing it back to position I.

I've dealt with a lot of flooded motors but never one that exhibited no compression after it flooded. It normally just got the plugs so wet that they wouldn't fire. Like Bill, on those I just pulled the plug(s) and was very patient - for a minute or so.

The best explanation for the "lawnmower syndrome" is that the rush of petrol washes the oil away from the rings and the tolerances on these cars is so close that it relies on a film of oil around the rings to achieve compression.

At the end of the day I don't know what causes the problem but the car is running just fine now - still a bit of residual oil smoke but not bad. It has only traveled 15 miles or so in stop and go traffic other than the one run down the highway for a mile or so.

...Lee


'94 850 N/A 5 speed
'96 Platinum Edition Turbo
'99 V70XC - Nautic Blue
Previous:
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

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