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Author Topic: Compression test  (Read 4472 times)

Garry

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Compression test
« on: December 22, 2011, 20:43:44 »
A compression test was done on a car that I was interested in and the figures are as follows.

Dry Compression test

1:125psi
2:130psi
3:130psi
4:140psi
5:140psi
6:145psi

A wet test gave similar results.

To me these are not very good.  Any comment?

Garry
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Garry Marks
Melbourne/ Kyneton, Brisbane. Australia
1969 MB 280SL 5 speed RHD SOLD.
1965 MB 230SL Auto RHD Lt Blue 334G, Top 350H, 213 Leather, Tourist Delivery.
1972 MB 280CE Auto RHD 906G Blue Grey
2005 MB A200.
2006 MB B200
2019 Izuzu DMax 4x4 with Slide-on camper.
2022 Volvo XC40 Twin Electric

wwheeler

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Re: Compression test
« Reply #1 on: December 22, 2011, 21:01:17 »
#1 looks bad and #2 and #3 aren't far behind. Too much difference between cylinders especially given that a wet test was done with similar results. Given that everything else is up to par (dangerous assumption), I guess that points torwards the valves and some work needs to be done. I am not sure a valve adjustment would help.
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Wallace
Texas
'68 280SE W111 coupe
'60 220SE W128 coupe
'70 Plymouth Roadrunner 440+6

stickandrudderman

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Re: Compression test
« Reply #2 on: December 22, 2011, 22:49:41 »
A cylinder leak test followed by a vacuum test would give a more reliable indication as to engine condition, but it doesn't look brilliant.
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DaveB

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Re: Compression test
« Reply #3 on: December 23, 2011, 03:35:38 »
Factory specs from the technical data booklet are: new 156-171 psi, minimum 128.
If that is the ebay UK car for £37,5k I think you can, eventually, find something better in Australia for a similar price (notwithstanding our recent car-chasing frustrations).
« Last Edit: December 23, 2011, 03:42:07 by DaveB »
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DaveB
'65 US 230sl 4-speed, DB190

ja17

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Re: Compression test
« Reply #4 on: December 23, 2011, 05:58:22 »
Hello Gary,

Try it with a warm engine, and a different compression gauge. I open the throttle also.
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Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
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69 280

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Re: Compression test
« Reply #5 on: December 23, 2011, 09:57:03 »
Quote from: DaveB on December 23, 2011, 03:35:38
Factory specs from the technical data booklet are: new 156-171 psi, minimum 128.
If that is the ebay UK car for £37,5k I think you can, eventually, find something better in Australia for a similar price (notwithstanding our recent car-chasing frustrations).

Hello Dave
I think there is a blue 280 for sale in WA. It has been up for a while. have you by any chance seen/inspected the car?
Hamid
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