With my car approaching 200K miles it’s running well and I have to keep it this way for as long as possible so last week as preventative maintenance I dropped the oil sump to replace seals and to check for any blocked PCV passages since I also planned to service the PCV system. The good news is all the PCV passages in the block and oil sump were very clean, no blockage at all.
The bad news is after replacing all the parts in the PCV breather kit from Fcpeuro my car developed an oil leak from the front cam seal on the intake side, maybe both sides. All parts replaced were Volvo OEM parts. I even purchased a new banjo bolt but had a problem getting the bolt started in the manifold so used the original bolt initially.
The one problem I had (other than with the banjo bolt) was the vacuum tube from the intake manifold banjo bolt to the elbow above the breather box is a hard plastic tube that crumbled into many pieces after removing the banjo bolt from the manifold and disturbing the brittle tube. There’s a Volvo part (30731007) that includes this tube along with the banjo bolt fitting with coolant connections that I needed for replacement but didn’t have it and I needed to the car back together so I used a new 4mm ID silicone hose. The hard tube has an ID of 3mm.
Since doing all this work and now having a new oil leak I’ve done some more research why an oil leak may have occurred. I’ve read Howard’s PCV system information, which is very good and very helpful and also useful information from Lloyd Dobler about the newer revision banjo bolt with a check valve and how it can prevent too much crankcase pressure under boost.
With this information I’m starting to suspect the hose I used with a larger inside diameter in addition to using my original banjo bolt I may have created a problem with crankcase pressure under boost conditions. Thinking there may be too much pressurized flow under boost through the vacuum hose I went back and replaced the original banjo bolt with the latest revision bolt with a check valve. It’s still difficult to tell if this has solved the new oil leak problem because there was so much residual oil on the engine (which I’ve cleaned off today) but I think it’s better because I don’t see fresh oil around the cam seal on the one I can see (intake) so more time will confirm if the leak has stopped, or not. The cam seal looked like it was leaking from around the outside of the seal and not the seal around the camshaft itself. It could be I just need to replace the cam seal or seals and the new leak is just a coincidence but with the recent PCV work I’m inclined to believe it’s related. A next step will be to measure the crankcase pressure at idle and under boost. I've already done the glove test and it's fine so need to verify when under boost.
It’s hard to believe a 1mm difference in the inside diameter of the tube may make a difference but I do think the original 3mm ID hard tube is used as a restrictor under boost conditions since the older revision banjo bolt has no check valve and is free flowing. I would appreciate any other thoughts or experiences with this PCV system.
I will offer these suggestions for others that go down the PCV DIY path.
This is pretty good video on PCV parts replacement
https://www.youtube.com/watch?v=oEOzIoVxO4s&t=737s
It’s a fairly big job so get all the parts that are needed before beginning the job, you don’t want to do this twice, trust me. Get the new banjo bolt and the part with the banjo fitting and tubing, get an ETM and intake manifold gasket, copper washers for the banjo bolt and all the parts needed to change the breather box, hoses and clamps. A flex head ratcheting 17mm box wrench is almost essential in my opinion for this job and even better also having a stubby version of the same type of wrench.
Be prepared if the banjo bolt doesn’t want to thread into the manifold. I removed the ETM and loosened the breather box to provide wrench room and also some wiggle room with the banjo bolt fitting since the hoses connected to it make it very difficult to get the bolt exactly aligned with the manifold. I still had way too many problems with the finicky new banjo bolt and after a couple of hours I just put the original banjo bolt back in since I was able to thread the original bolt into the manifold rather easily as compared to the new bolt. I later filed the end of the new bolt and the starting thread to help enable threading the bolt into manifold easier. The second time I installed the new bolt it threaded into the manifold instantly although this time I also removed the power steering pump and alternator, which provided so much more room to work and a solid manifold position to work with, it really was worth the extra effort removing the P/S pump and alternator as compared to fighting with banjo bolt the first time.
Highly recommend doing do the extra work removing additional items to give yourself enough room for the banjo bolt installation. Start with the minimum of removing the fan shroud assembly and with a loose manifold install the banjo bolt, Howard mentioned tilting the manifold up on the driver’s side, which may help getting the banjo bolt started. If you’re still unable to start the banjo bolt then remove ETM for more wrench room and to enable loosening the breather box (2 10mm bolts ) from underneath the manifold, which can help better align the banjo bolt. The breather bolts can be tightened after connecting the banjo bolt. If still having problem with the banjo bolt then remove power steering pump, try again and if needed loosen or clamp and remove coolant hose to banjo bolt fitting and if this doesn’t work then move or remove alternator to provide more room. It’s really not that much more work at this point to remove alternator and it helps so much. The banjo bolt can be a real bitch to get back into the underside of the manifold so just be prepared to methodically do each additional step to provide more working room instead of fighting to start the bolt in the manifold, which can go on for a very long time based on my experience and that of others.
Excellent PCV system information from Howard…
http://www.volvoxc.com/forums/showth...176#post187176
Great info from Lloyd Dobler here, he measured crankcase pressure on two of his Volvos and found each had 2 psi under boost on both car and both had the older revision banjo bolts. He updated with new banjo bolts and now 0 psi crankcase pressure under boost. His cam shaft seal had original actually pushed out of the head.
https://forums.swedespeed.com/showth...=1#post2803169
updated banjo bolt
https://www.fcpeuro.com/products/vol...BoCM5QQAvD_BwE
have this part on hand too
https://www.fcpeuro.com/products/vol...BoC5_gQAvD_BwE
One of these tools would have helped me with the new banjo bolt
http://uniburr.com/
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