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 Post subject: Re: Diagnosis help
PostPosted: Sat Jul 11, 2015 5:28 pm 
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Joined: Mon Aug 18, 2014 6:02 pm
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Location: calgary AB
Yeah I was looking at it today and those were my thoughts as well.

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 Post subject: Re: Diagnosis help
PostPosted: Sat Jul 18, 2015 1:40 pm 
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Location: calgary AB
Well I got rid of the hesitation/misfire turned out plugs were over gapped probably over time. And a really bad ignition wire basically crumbled when I pulled it out. But now my concern is I'm down about 1l-1.5l in oil. Pretty consistent smoke at idle and visible smoke from the turbo when car is hot. I'm hoping it's not turbo and maybe breather plugged or something.

Any suggestions

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 Post subject: Re: Diagnosis help
PostPosted: Sun Jul 19, 2015 8:20 am 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
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Location: Lethbridge, AB
Check your PCV system...if it's plugged (and they often are) then it pressurizes the crank case and the easiest path out is the turbo seals. Check the compression as well.

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 Post subject: Re: Diagnosis help
PostPosted: Sun Jul 19, 2015 3:24 pm 
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I took the breather box out and as much of the pcv hoses I could find cleaned them all out. They all seemed pretty clean. But when I was knocking the crud out the breather I could have knocked something loose that was plugging it up not sure. I'll see how things go over the next couple days

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 Post subject: Re: Diagnosis help
PostPosted: Tue Aug 18, 2015 5:24 pm 
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I've been diagnosing a few things and just curious if anyone has any suggestions what I should do.

I've found out that I have a bad intake manifold gasket that is causing my surging idle on cold start pulling way too low of vacumn. I'm just curious if low vacumn could be causing my blue smoke puffing problem? Not sure if that's related at all hahaha

If that's not affecting my smoking issue then I've pretty much settled on a weak seal in the turbo that's letting oil pull through on extended idle. Or possible valve seals leaking. or bad rings causing excessive crank case preassure pushing oil through the seals. Is there a definitive way to narrow this down

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 Post subject: Re: Diagnosis help
PostPosted: Wed Aug 19, 2015 7:42 am 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Dec 21, 2005 8:40 pm
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Location: Calgary, Ab
Intake manifold gasket... I don't know how it could cause blue puffing, to be honest. A vacuum leak will cause funny things to happen with the idle and all that, as you've guessed, but LH2.4 should compensate for much of that. Any other explanation I can dream up using the intake gasket seems less and less likely.

While you've got your intake manifold off have a look at your valves. If one or more are wet & gooey, that tells a story. It's not a guarantee, but it's more information. If they all look clean, the problem could be downstream of your intake valves, but port fuel injectors do a great job at keeping valves washed clean. If one is gooey and the others are clean, it could be a valve guide seal or it could be the injector is not spraying well. If all are gooey it could be that all your guide seals are leaking a little or it could be your turbo or PCV are introducing oil into the intake. If it's your turbo, your intercooler will probably be full of oil - check that. There will probably be SOME oil/water in there anyway, turbos do that. If you've got access to a leakdown tester you can check the health of your rings. This isn't a guarantee that you're leaking oil past them, but it's a safe bet. Your turbo could also be pushing oil into the exhaust, but that'll normally happen under more load than just idle. Pulling the downpipe off might show you a slimy turbine, it might not.

Puffing oil after an extended idle is most commonly intake valve guide seals. You've probably nailed your problem right there. It's not a new engine, it may be something you have to live with unless it's a lot worse than I remember (I don't remember Dale's car puffing except for very occasionally).


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 Post subject: Re: Diagnosis help
PostPosted: Tue Aug 25, 2015 9:10 am 
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Yeah everything I've read said there's no connection between them just wanted to ask to make sure haha.

A lot of people have said valve seals so I think I'm going to go that route first then if still an issue Gonna tackle a turbo rebuild. The smoking issue isn't major its very random but only at idle. Even just sitting at a stop light it will sometimes start puffing away. It's more embarrassing than anything else. And seems to be happening more often every day. I pulled the drain on the intercooler and the amount of oil wasn't excessive It seemed pretty minimal

I think that plan is to find a beater volvo for the winter put the 740 up on stands and plug away at all the little things that have crept up and have a fresh 740 turbo for next spring

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