Hi All, Short question on the vacuum lines. Hard to find diagrams for this stuff.

1989 Turbo 745

This newer car to me has a capped off (screw) 'Flame Trap/Breather Nipple' line AND a capped off intake hose (just about where the Idle Air Vacuum Hose and the Dash Vacuum Hose are)

The large hose from the breather goes to the Turbo which appears correct, but I'm assuming the small one goes to the intake?

Would this incorrect set-up cause high oil consumption? Excessive crankcase pressure?

Thanks,

Greg
86 744 - 500,000+KM's (retired gracefully)
89 745T - 371,000KM's (lots of life left we hope!)

You're saying that the PO rigged it so the "flame trap" is really just an elbow...with no vacuum line running to the intake? The PO of my 740T had done the same thing. There was no noticeable improvement by putting it back to stock. Although for such low cost, plumbing it the correct way was worth it for the placebo effect alone. For whatever reason, 240 turbos had this line capped off.

The FAQs have good information about what things can be done to improve the breathing of the crankcase system, and those often can help oil consumption.

That's right. The breather nipple is capped and the big hose runs right back to the Turbo. Basically the Turbo ends up being connected directly to the top of the oil trap (no real 'flame trap' in these Turbos as I understand it). At what I presume is the other end of the stock set-up, the intake has a short hose with a screw in it.

I'm concerned because the oil consumption seems pretty high, I'll be watching more closely now (maybe a litre every 3K). Also, the Intercooler Hoses (really big ones) seem pretty oily.

Thanks,

Greg

Just to be clear (because there are so many hoses down there), there's a 5/8" hose that runs from the "flame trap" up and over the valve cover. This hose T's into the intake hose for the turbo. The idea behind this is that the intake hose will always be at vacuum. This way the vacuum just upstream of the turbo helps to draw air up through the oil trap. The little hose on the elbow is to help keep vacuum on the crankcase at those moments when there's a better supply of vacuum at the intake (snapping off-throttle for instance). Even though the 5/8" hose T's into the intake hose, the vast majority of the air feeding the turbo is coming from the air filter/AMM.

For a much better description of the PCV system, and some creative ways to improve it, check out the site below courtesy of someone at turbobricks. Do keep in mind that there is a theory that some of the restriction in the system is intended to keep the airspeed up in the plumbing. If the air moves too slow, moisture may condense and freeze in those places with a real winter. Have fun...it's an evening's worth of reading.


http://www.pbase.com/stealthfti/pcv

Thanks for the background. That confirms that I'm only missing the small vacuum that would come into play at the quick throttle close then. I'll get a new Flame/Trap/Breather nipple (the nipple part has broken off) and re-attach the small hose to the intake, but really won't expect any noticable changes. I suspect my oil trap needs cleaning as the next job.

Greg