XC90 2.5t dead #3 cylinder

[mrbrian200]

69ragtop, a new banjo bolt from a dealer will be an updated design that doesn't have this issue. Yes the check ball needs to be there. It allows PCV air to flow in one direction only under a certain pressure condition. I forget which direction/condition, without the ball either under boost or vacuum conditions the engine would be running rich or lean.

[69ragtop]

I just pulled the bolt from the dead engine. No ball bearing or spring, although it certainly looks like there is a machined seat for a bearing to seal against and the end of the bolt appears to have been rolled over to retain something, but any ball or spring is missing. I will pull the bolt from the replacement engine and check it out.

[SuperHerman]

Interesting theory. I would think something larger was involved but the facts and other cases sure points to this as the issue.

Why couldn't one remove the ball bearing and put a plastic check valve further down the line? Other parts of the PCV system has these.

I would suggest just ordering the replacement part and swap it out regardless of what you find. The banjo bolt in discussion may be considered a wear part now??? No sense in doing the work twice.

[mrbrian200]

Yes check the bolt on replacement engine. If it doesn't have the updated part (with a pin through the end to keep that ball from sucking into the engine as pictured below), replace it pronto with PN 31325709.

I believe the new 'fixed' bolts are stamped 2014 on the bolt head. The original ones with their naughty little balls that may not stay contained don't have this marking.



IMO this should have been a recall item. Other OEs have been raked over the coals over engine destroying stuff like this which can be easily prevented/corrected when not properly addressed via a recall or extended warranty item. All it would take would be for one of the auto sites like KBB, consumer reports, or edmunds to decide to add "stupid little metal ball on the intake system gets sucked into the engine destroying it" in their notes on reliability...

[69ragtop]

I pulled the banjo bolt from the replacement engine and sure enough it has a pin running across the passage in the bolt, what appears to be a cap on the spring, the spring and finally the ball. The pin is loose in the cavity but is held in place by the end of the bolt being rolled over. Since it's not marked 2014 and the pin is just floating around in the bolt I'm guessing this is the old style and an accident waiting to happen. I'll be ordering the new improved one along with some gaskets and seals before this car takes to the road.

[mrbrian200]

So, the one on the left.. the pin isn't pressed (and held fast) in through holes on sides of the bolt, but can move around meaning it may eventually wear, misalign, or dislodge spewing the entire contents of the bolt (Pin, cap, spring, ball) into the engine?!? Oh the humanity.

[SuperHerman]

I find this interesting so I have been following the thread. I thought the updated design had the pin and the old design did not. But now I see the issue. Both banjo bolts have the pin - the difference is how the pin is secured within the banjo bolt. Old by the curled end and new by drilling through the side..

The old design kept the pin in place by rolling the machined out banjo bolt at the end. It appears in your picture the banjo bolt on the right actually has a small piece missing where the pin and then the ball bearing was able to escape.

The new banjo bolt design actually drills out the banjo bolt from the side to insert the pin. I assume they then smash the two side opening to keep the pin from coming out from either side. In addition I assume the pin can not come out in the updated version as it would be restricted by the manifold where it is threaded in. Actually an elegant, simple and cost effective solution.

Now that I see the pin I can see how it would cause the damage. So your engine had a spring, pin, ball and cap getting pounded through Cylinder #3. Curious that all the parts ended up only in #3. Maybe one piece found its way and kept the valve open and the rest followed their friends.

To check my thoughts - both banjo bolts you show in the picture are the old design. The one on the left is intact but in your new engine, while the one on the right is from your old engine and missing parts. The stock photo another posted is the new design.

[mrbrian200]

I thought the updated design had the pin and the old design did not.

I sorta think there have been a couple revisions over the years.

Oldest design = no pin, original problem, though somewhat rare it can happen and Volvo attempted to address it by:

Second design sometime during the 2000s = added the pin but it's still janky (what was on 69ragtop's replacement engine). So Volvo revisited it yet again with:

3rd design/current = pin is secured (good so far as we know).

I seem to recall reading something to all that effect in a previous thread a couple years back, maybe on another site. At the time I said to myself: I shall replace that on my own car! Then promptly forgot about it. Being a MY06 I believe mine would have the middle 'janky pin' version.

[69ragtop]

On one hand I am relieved to have found out what caused the problem but on the other I'm really ticked off that Volvo didn't make this a recall, and in my searches for what caveats to look for when buying or servicing a newly acquired model with the 2.5t I didn't catch this. I must have more than half a million miles on various Chevy trucks that have a simple PCV valve that costs about $5 to replace and never lost an engine because of one, or anything else for that matter. I would think that the engineers at Volvo could have come up with something a little less complicated, easier to service and not prone to ruining your engine if it failed. This was a healthy engine prior to the PCV banjo bolt disaster: great compression, very little varnish or sludge in the oil pan when I checked it out while servicing the PCV system, didn't smoke, good mpg, etc. I'm hoping that with this new engine, which looks to be well cared for, and the many little fixes done during the engine swap, I can get another 50k miles out of this car (with normal maintenance).

[Pilgar]

I have the same xc90 and the same thing happened, the top of the #2 piston looks the same as yours. It was a BB/check valve from the banjo bolt on the underside of the intake manifold. Seems like some years had this type of check valve and others just had a small hole. The top of my #2 piston cracked.