[W126 Coupe] Compression Check

[Steve Nervig]

On Sep 4, 2007, at 7:49 AM, Barry Corno wrote:


> Question on Compression

>

>     I had my valve guild seals replaced last week

>

> On my 2nd engine at 236K. Checked each cylinder

>

> And found 6 at 180 1 at 185 and 1 at 170. For

>

> All you guys that in the know what does this tell

>

> Me?

>

>

>

> B.C. “83” 380 SEC AMG    525K

>


As the others have said, you are OK.

The manual states that:

Normal Compression:		approx 8.5 bar (123 psi)
Low Compression:		approx 7.5 bar (108 psi)
Permissible Difference:	max 1.5 bar (21 psi)

While these numbers are much lower than your numbers, I believe (and  
someone can  please correct me if I'm wrong) these are pressures of  
an engine with the throttle open using a factory pressure recorder.

But as you can see, a 21 psi variance is permissible between  
cylinders (at these lower pressures), so your 15 psi variance at  
higher pressures is quite acceptable.

Steve


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