Date: Sat, 22 Aug 2009 22:05:39 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: '90 2.1: What are the chances that I just fried my engine?
UPDATE 2
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Hi, you should be concerned that the other 3 read so low.
Assuming your compression gauge is fairly accurate .......
100 psi is a traditional 'borderline OK' number for gasoline engines.
In Bentley, they give it in Bar........if you convert it, it's something
near 100 psi.
What you'd like to see is perhaps 125 to 145 in all cylinders - around
there.
your numbering is incorrect.
correct is
3.........................1
4........................ 2
I would do the compression check again, but 'wet.'
put about 3 teaspoons of oil into a cylinder, crank the starter few seconds
to run the piston up and down some to spread the oil around,
then check compression again.
If it jumps up significantly, that points to rings, since you sealed those
better by adding extra oil. ( like from 120 to 190 )
if it barely goes up .......like say 120 to 130 ........you conclude that
sealing the rings doesn't help, and it's valve leakage ( or head gasket in
some engines, though not likely in waterboxer engines too much - not at
those metal rings that seal in the combustion ) .
sure, I would expect the # 's to a bit higher if it was all warmed up first.
That it's run fairly recently ..........( and not sitting for months ) makes
me lean toward accepting this compression test as fairly accurate.
I doubt it would just jump up to say 130's where you just got 100's , but
if it still runs, you should warm it up some first, at least a few minutes
of running, then do compression test, and always do a wet test on low ones.
My guess would be you could get 10 to 15 psi higher readings that way.
new pistons and barrels can restore a lot of lost power. I have a 1.9 I'm
going to fire up with new pistons and barrels and good heads and new gaskets
as soon as I get one head back.
Will be interesting to see how it comes out.
At least nothing is blown up on yours !
Scott
www.turbovans.com
----- Original Message -----
From: "Jeff Lincoln" <magikvw@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Saturday, August 22, 2009 9:43 PM
Subject: Re: '90 2.1: What are the chances that I just fried my engine?
UPDATE 2
> Ok, we got much of the prep work done today and stopped just shy of
> removing
> the heads. It's kind of a mess in the engine bay - not super terrible but
> I've found several smaller things that show signs of the extreme heat.
>
> Anyhow, we did a compression test first - I've been searching the archives
> for what numbers would be considered "normal" but no matter what I search
> the archives are returning no results. I also don't have my Bentley right
> at
> the moment (loaned it to a friend) so I'm not even sure what cylinder is
> which although I believe it is as follows:
>
> front of van
>
> 3.....................2
> 4.....................1
>
> rear of van
>
> So using that as a model here were the results of the compression test.
> Test
> was obviously done cold - and we checked each one twice - so the first
> number is reading one and the second is reading 2.
>
> Cyl 1: 100 / 120
> Cyl 2: 100 / 110
> Cyl 3: 125 / 143
> Cyl 4: 100 / 110
>
> So am I at least in the ball park? Should I be concerned that #3 read so
> much higher? Can I assume the numbers would have been a bit higher if I
> were
> able to do the test on a warmed up engine?
>
> That's it for now - nothing more to report really. Thanks again for
> everyone
> who has replied to this thread - it really has helped.
>
>
> --
> Thanks,
>
> Jeff
> '90 Carat (Grover)
> '86 (We call this one Parts)
> '78 Bus (Melissa) Patty's Bus
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