2008 Renault Master 2.5 G9U engine

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2008 Renault Master 2.5 G9U engine

Postby Neilcur » Wed Dec 04, 2013 4:33 pm

Got above vehicle is with a misfre.

Carried out a relative compression check and got an odd result!

I'm just wondering why one peak is higher than the rest?

Poss a sticking valve?

Done a comp test through pico diagnostics and all cylinders were in the green so not sure which to believe

Thanks Neil
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Re: 2008 Renault Master 2.5 G9U engine

Postby Avdr » Wed Dec 04, 2013 4:41 pm

Interesting, would be good to see a physical compression pressure comparison.
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Re: 2008 Renault Master 2.5 G9U engine

Postby Robski » Wed Dec 04, 2013 6:09 pm

WPS/FLS owner ?

MAF or MAP ?
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Re: 2008 Renault Master 2.5 G9U engine

Postby Neilcur » Wed Dec 04, 2013 6:16 pm

One of the 4 compression humps is higher than the other 3 indicating higher compression in that cylinder?

Also noticed when it runs it is making 'puffing' noise out of the air intake.

Don't own a FLS or WPS.

Struggling to find an adapter to do a physical comp test to compare to scope trace which does not help.

MAF sensor on this engine

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Re: 2008 Renault Master 2.5 G9U engine

Postby Robski » Wed Dec 04, 2013 6:23 pm

One of the 4 compression humps is higher than the other 3 indicating higher compression in that cylinder?

I saw that, i edited my post as i missed you say in for a misfire.

Well without WPS or FLS i can't think of a way to 'none intrusively' see the valve events ........... only if it was MAF & an intake valve, looks exh valve to me with the comp hump......

Have you ID'd the cyl with a sync ?
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Re: 2008 Renault Master 2.5 G9U engine

Postby Neilcur » Wed Dec 04, 2013 6:30 pm

Yeah i replied and your post had changed!

Yes i have identified which cylinder looks 'high'

Scan tool does not list fuel correction factors, thought numbers may of backed up trace

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Re: 2008 Renault Master 2.5 G9U engine

Postby Fat Freddy » Fri Dec 06, 2013 9:49 am

Just a thought.

Leaking inlet valve. Two normal humps - compressions, followed by a slightly lower hump which I'm thinking is air leaking into the inlet manifold which
is making 'puffing' noise out of the air intake


The next cylinder now has a better VE there fore shows the higher comp hump. :shock:


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Re: 2008 Renault Master 2.5 G9U engine

Postby Neilcur » Sun Dec 08, 2013 5:56 pm

Customer gave the go ahead to strip engine down to inspect what was going on but we didn't get far, on this engine the injectors need to be removed along with the glow plugs to remove the rocker cover.

All 4 injectors are seized solid and will need someone in with the gear to pull them out.

Phoned customer and explained costs would go up before we even got cylinder head off and also gave the option of a s/h engine but they are pricey units for this vehicle

At 200k miles and also needing other work on the vehicle, he has decided to scrap it due to lack of funds so this one won't have an outcome which is a shame as i would of liked to seen what was causing the fault.

Thanks to Robski, Fat Freddy and Avdr for the help/suggestions
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Re: 2008 Renault Master 2.5 G9U engine

Postby Avdr » Mon Dec 09, 2013 9:05 am

Have heard of people using the chain blocks and home made adaptors to pull injectors out. Lot of messing though.
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Re: 2008 Renault Master 2.5 G9U engine

Postby Neilcur » Tue Dec 10, 2013 8:31 pm

No room to get anything in apart from screwing a puller to body of injector but don't have the tools.

Had them hanging before on a trafic with a plate under injector and a chain onto engine hoist and front wheels off the ground and no movement :D

Once they seize, nothing will get them out unless you have the proper kit!
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