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1996 960 Cylinder compression specs

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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Ethan Rode
Posts: 41
Joined: 2 August 2013
Year and Model: 960 1996
Location: Arizona

Re: 1996 960 Cylinder compression specs

Post by Ethan Rode »

Those numbers are low.

The service manual indicates the minimum should be 184 psi on a warm engine.

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93Regina
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Post by 93Regina »

Ethan Rode wrote:Those numbers are low....service manual indicates the minimum should be 184 psi on a warm engine.
I suspect the throttle plate needs to be opened when doing a compression test.

All you'll need to do to test it is remove all the spark plugs and install a compression tester. Then disconnect the coil, hold the throttle wide open, and crank the engine over several times with the starter. You'll see pressure build, and finally peak, on the compression tester's gauge. Make sure to count the number of engine revolutions it takes to reach max pressure and repeat the test for each cylinder, cranking the engine the same number of revs every time.

lummert
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Post by lummert »

93Regina wrote:
Ethan Rode wrote:Those numbers are low....service manual indicates the minimum should be 184 psi on a warm engine.
I suspect the throttle plate needs to be opened when doing a compression test.

All you'll need to do to test it is remove all the spark plugs and install a compression tester. Then disconnect the coil, hold the throttle wide open, and crank the engine over several times with the starter. You'll see pressure build, and finally peak, on the compression tester's gauge. Make sure to count the number of engine revolutions it takes to reach max pressure and repeat the test for each cylinder, cranking the engine the same number of revs every time.
I was going to suggest opening the throttle plate. Can't make compression without intake air.
1988 Volvo 760 Turbo Wagon

jimmy57
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Post by jimmy57 »

You shouldn't be fueling while compression testing.
There is a starter lead on that car. I can't remember if it is stored in the underhood electrical box or is a loose pink wire hanging out of harness near that box.
Apply 12v to run starter and crnk engine.
Plan B is remove the starter relay in the same box and apply 12v to term 3. Terminal 3 is the outboard one of the two parallel next to each other when relay is removed. The pin on relay that goes into #3 is labeled 87 on relay.

Ethan Rode
Posts: 41
Joined: 2 August 2013
Year and Model: 960 1996
Location: Arizona

Post by Ethan Rode »

You're right, those numbers look fine.

The coolant light is triggered by low coolant in the reservoir. May I suggest that you make sure yours is full, and that there are no cracks. I'd replace the coolant cap for good measure as well. The green Stant cap from your FLAPS is the same as OE.

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