98 V70: Hard Plastic PCV Pipe Broken

[sleddriver]

After reading about this recurring fault on others car, I gave mine a tug while reinstalling the intake pipe after replacing the rear hydraulic MM. Lo and behold, it was already broken after replacing the whole thing about 5 yrs ago. Thanks Volvo for such a lousy expensive piece of plastic! It snapped about 6" from the intake pipe connection.

So now I have unmetered, unfiltered, HOT air entering right at the turbo inlet and no vacuum pulling on "the box".

Looks like I'll be doing CN90's & Robert's true upgrade to fix it once and for all!

[MadeInJapan]

Oh Noessss!!!

[scot850]

Sorry to hear of the problem!

Neil.

[sleddriver]

Update:
Last night before going for groceries, I pulled the large elbow off, put a piece of duct tape over the PTC port, then secured it with a ZT. While driving with the A/C on, I began smelling fumes!! Like an old car, pre-cat days. At first, I thought it was just that as I was in traffic. However, it followed me on my trip. So I opened the sunroof.

Not sure how the exhaust from the catch-can-box can get into the fresh air intake???? Someone please explain that to me. I'm all ears.

So today, it looks like I'm going to have to peel back the foam insulation and temp reattach the broken piece using either metal or UL 181B duct tape until I can properly fix this. Don't want to GAS myself in my own car I've spent every avail free moment the past few months working on.

I will add that closing off that open PTC port sure made a difference in pick-up, low RPM performance, and "eagerness" of the sled! Quite profound actually. More "fun" was back. These turbo cars sure are quirky & finicky......never made the connection that if your PCV system has this pipe cracked/broken, your turbo performance will suffer. And since Volvo didn't see fit to outfit my dash with a turbo gauge, it's tough keeping an eye on it.

[sleddriver]

Update II:
I discovered I had a piece of silicone tubing whose ID just fits the OD of the large hard line, so I'm abandoning the tape idea. The break occurred directly under the dist. cap. Since performing the SAS delete, I no longer need the rock-hard pipe in front of the above, so I cut it in two pieces and removed it. The cam position sensor plug just shattered when trying to unclip it.

I lubed both ends of the hard line with mineral oil as I recall somewhere that you (strangely) shouldn't use silicone grease with silicone tubing. Odd that.

Only a short (3-4") piece is needed to rejoin the two ends. No clamps either. Works for me.

[erikv11]

... Not sure how the exhaust from the catch-can-box can get into the fresh air intake???? ...

Any fumes that accumulate under the hood can be drawn into the fresh air intake, especially at idle. Intake is under the cowl, passenger side, and the cowl has vents.

If you go with 5/8 hose for the PCV then be sure to get a quality hose not a cheapo, or better yet fuel line or a pre-formed hose. The problem is a cheap hose can easily kink and get blocked and sabotage your PCV efforts, hence also be very careful about how you route it. In my opinion the easiest and best way to go is something like Gates 28471 with a pre-formed 90 degree elbow, see https://www.matthewsvolvosite.com/forums ... =1&t=75631 for pics. Well, here's the basic idea:

[98v70dad]

I replaced one with 5/8 heater hose and the one from the intake manifold nipple with a few feet of metal brake line,a foot of reinforced rubber fuel line, some screw clamps and an OEM 90 degree rubber fitting similar (or the same as) the one used on the plastic OEM tube. I ran the metal brake line on top of the manifold so that it can easily be replaced if necessary. I've had this mod in place for 2 years with no issues. Lining up the 5/8 heater hose can be a challenge. I went to autozone and found a 5/8 hose with a "mild" bend on one end and spliced it with a brass heater hose splice so I could rotate the bend a bit and align it as necessary.

I'm a design engineer. Plastic has no place in an engine compartment where it will be baked by extreme heat. On top of the engine below the intake manifold where it can't easily be replaced is that place...incredibly bad design choice.

[sleddriver]

Update III:
Just back from a test drive. No more crankcase fumes inside. All appears OK. The take-off isn't nearly as "eager" though.....rats.

I discovered that the fumes were entering between the gap made by the metal firewall & the plastic cover holding the intake vents. The later is gasketed all around. Evidently it has also warped from heat/age and there are not enough screws in it to prevent warping. May have to remove the cover and lay down a compressable gasket of some kind, so that the only air drawn is from above the hood.

I slid individual pieces of heat-shrink over the 3 male terminals of the camshaft position sensor to prevent shorts with vibration. Clearly I'm going to have to replace it. For now though, this works.

Since my ECC is Tango Uniform, I'm only using it for A/C on/off, & fan speed. Recirc doesn't work unfortunately and it's been raining here for days & days, with more to come. It's very muggy out. Coolest the A/C would blow was about 52°F with outdoor temp of 88°F and Rh of 63%. Makes for a solar HI of 99°F. So I manually closed the RECIRC door by using a 9V battery on the damper motor. With this, the vent temp dropped to 38°F and stayed there. Further, I did the ZT mod on the compressor clutch yesterday and lowered it from 0.889mm to 0.49mm. I thought it might be slipping due to age, heat & increased gap.

Re: Erik
Thanks for the photo and quality hose ID. A pre-bend would be nice. I could also use a hard nylon 90° fitting to eliminate any chance of kinking. Right now, I'm just worn out from working on this car. I'm very fortunate to have been able to do the work with OEM parts. Saved me several thousand $$$$, but enough is enough. Other things have been piling up. I definitely have a bad case of Volvo Fatigue Syndrome....

[sleddriver]

Update III:I discovered that the fumes were entering between the gap made by the metal firewall & the plastic cover holding the intake vents. The later is gasketed all around. Evidently it has also warped from heat/age and there are not enough screws in it to prevent warping. May have to remove the cover and lay down a compressable gasket of some kind, so that the only air drawn is from above the hood.

Update:
I noticed recently that while on VENT (no A/C), the air temp coming out of the dash vents sure was WARM compared to outside; especially after the car sits when I come back from groceries. Then I got to thinking about the above experience....hot engine is heat-soaking with hood closed and no ventilation. Hot air rises so it does so through the crack and into the fresh air duct, as it's now open in places to the engine compartment.

IOW, the fresh air is not 100% coming through the vent openings where the windshield wipers are. Thus really HOT air is mixing into it from the engine compartment. That's why I smelled fumes as noted above.

Fortunately, this will be an easy fix with a tube of black 100% silicone. The LAST thing I need is for HOT engine air to be pulled into the fresh air intake. And also on those days when the A/C is not needed, but cabin air ventilation still is.

These days it's taking me a bit longer to connect-the-dots......

[Jaguar xjs]

Where can I find a link to the PCV upgrade? I tried PCV upgrade in search to no avail.

Gordon