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Lawnmower Syndrome Volvo 960

Help, Advice, Owners' Discussion and DIY Tutorials on all Volvo's "mid era" rear wheel drive Volvos.

1975 - 1993 240
1983 - 1992 740
1982 - 1991 760
1986 - 1991 780
1990 - 1998 940
1990 - 1998 960
1997 - 1998 V90/S90

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precopster
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Lawnmower Syndrome Volvo 960

Post by precopster »

My Volvo 960s cranking tone has changed. It spins too easily and sounds as though there's no compression. I've moved it a couple of times and started it for less than 5 seconds a couple of times today.

I went to start it tonight and the tone changed mid crank and went fast. I smell unburned petrol at the exhaust. Will check the cam belt tomorrow but this happened about a year ago and it took a jumper start to get it going.

What's the procedure of re-oiling the cylinder walls to gain compression? Will some WD40 do the job?
Current cars VW Transporter 2.5TDI, 2010 XC90 D5 R Design

Kmaniac in California USA
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Post by Kmaniac in California USA »

Sounds like you have a valve or two that may not be properly seating during the starting process. They can get slightly stuck if they have sat partially open for a while. As long as the engine starts and runs well once started, you have little to worry about. Just get out there and drive it more often.
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jblackburn
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Post by jblackburn »

Drop about a tablespoon of oil into each cylinder and replace the plugs, then crank until it can stay running on its own. Once it sputters and tries to catch, you will have to hold the idle up with the accelerator pedal until all the oil burns off again.

In the future, let the engine run for more than 5 seconds at a time. If I'm just moving my car to the other side of the driveway, I try to let it run for at least 30 seconds before shutting it off.
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Post by Retired MVS Contributor »

If you smell gasoline at the exhaust the cylinders are being flooded and wash-down is occuring...The spark plugs are most likely wet and it will never start with wet plugs...If they look wet or oily when you remove them to squirt in the oil to restore compression, they will not dry in cold weather and should be replaced, or, at least, dried with a bernzomatic...Once you get it running, change the oil ASAP because it is diluted with unburned wash-down fuel...WD40 is too thin for compression restoration....The thickest oil you have is good for restoring compression, although you won't want to use thick oil otherwise...

precopster
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Post by precopster »

Thanks guys. It's 10:00am in Melbourne & I just woke up after a restful sleep; knowing that one or two (in this case three) of my online friends would have an answer by the morning and look here presto!!

The cam timing is OK, but just found out my water pump and cam seals are leaking: does it ever end??? :roll:

So I'll squirt some oil down there. It's a hot day today, over 85F so the plugs should dry out quickly.

Thanks again.. I'll chime back in once it's started.
Current cars VW Transporter 2.5TDI, 2010 XC90 D5 R Design

precopster
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Post by precopster »

I had a big day getting another car (my long term Volvo 850 wagon project) driveable today so I jump started the Lawnmower syndromed 960 wagon with the running 850 car for about 10 minutes on & off until it started.

I was using the fuel washing down the cylinders as a means of sealing the rings by cranking for twenty seconds then waiting for ten seconds. I know this isn't the preferred method but it eventually worked. My starter will never be the same, though :)

I'll be doing an oil change tomorrow and using a metal treatment called Roil. I'm hoping to get better compression and mileage.

I have another thread open which I will continue with about Roil once I have some data from the fuel consumption. I need a car that gets 25mpg minimum to justify keeping this beast.
Current cars VW Transporter 2.5TDI, 2010 XC90 D5 R Design

precopster
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Post by precopster »

I pulled the plugs after realising the motor was bogging down upon starting after repeated 10 minute drives.

What does it mean when plugs have a white, powdery deposit on the earth?

I swapped the plugs with Bosch Platinum (advertised as giving 25% more life)
Current cars VW Transporter 2.5TDI, 2010 XC90 D5 R Design

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