Leaking cam seals and exhaust VVT

[sprocket007]

Hello from Canada,

2001 volvo v70xc experienced a cam seal failure on the intake cam causing a severe oil leak, the seal could be easily be moved with fingers behind the cam gear. This cam seal leak would empty the 5L of engine oil in a distance of 30km

Of course the timing belt was saturated in oil so, I decided to change the T belt, serp belt, idler, tensioner and water pump along with the intake and exhaust seals on the cam shaft.

I also took off the oil pan to inspect for damage to the engine in the form of metal in the pan as I'd run the car low on oil and had to refill it with oil a couple of times in order to get home. I also wanted to inspect the PVC breather passages through the engine and sump. I'd actually done service recently to the PVC system and was concerned that I hadn't paid close enough attention to these passages but, they were all clear...

Ok, so I get everything set up, crank and cams rotated to their marks, cam locking tool installed, I marked the crank, marked the backs of the cams to the head with paint pen so I'd know their orientation for reinstall as they have no keyway internally. I marked my old timing belt with the crank and cam timing marks transcribing them to the new timing belt.

New cam shaft seals installed, Cams installed according to marked timing, VVT cam installed and clocked forward to timing mark and tightened to spec while cam locked, new idler, new timing belt and tensioner on and snugged up, all timing marks look good, maybe off by a quarter of a tooth...

Now here is my issue or question:
I've taken the cam lock off and I'm rotating the engine by hand before I start it up for safety...

However, as I turn it by hand I can hear a slight tap as I rotate. I don't get any binding but I'm concerned that I may be just kissing the valve on the piston.
Any tips here??
I'm gonna take the plugs out so it should be even easier to turn the engine and ensure there is no contact.
I'll get the bore scope out and look in there to see if there has been any contact with the piston but, I don't know if that camera has the resolution to see a small mark like that if they are just kissing...

Someone must have a trick out there for this... It cannot just be trial and error like taking it all apart locking cams making a small adjustment and putting the belt on again and tensioning it up and checking by rotating!??
I believe I was very careful with marking everything...
I'm at a but of a loss here, any guidance would be appreciated!

Thanks

[oragex]

There should be no tapping at all in my experience. Yes, without the plugs it's easier to turn the crank

For the seals, could they have been already weak from the old PCV ?

The belt is the right brands ? (Gates, Continental, Aisin)

This is a very good video explaining these VVT, worth a look to check everything went properly in place

[sprocket007]

Its a Conti timing belt kit, I'll double check the number of teeth on the belt...
Thanks

[- Pete -]

Wow, you've spent a lot of time tinkering. Way to go!
I think I'd pull the plugs & maybe see if you can detect it more accurately, or hopefully get a better feel for if contact is being made without having to do that and fight compression strokes.

Did you pull the rod bearing caps when you had the pan off? Or at least grab the big end of the rod & see if there was any palpable "play" up/down? Some side to side is normal but zero up/down.

Do you still have the oil pan off? Or have the filter/cup removed? The reason I ask is below.

I did cam/crank seals on 2 P2's & 1 oil pan service on another recently and I heard (easily mistakable) sounds when cranking them over manually. In all 3 of those jobs I had either the oil pan or filter/cup removed & sump drained of oil. I wasn't used to these sounds because in all my other manual cranking experiences (timing belt et/al tasks) I've had the oil pan/filter/cup installed & oil in the pan. My timing marks were all perfect as well. I used my stethescope & didn't detect any noise from any of the cylinders. Then thinking what it could possibly be coming from, I thought that it was oil pump sounds reverberating through the empty passageways. I also pulled plugs to see if I could better "feel" the strange concerning noise coming from whatever contact was being made. I could feel none & my compression checked out as well.

One small thing I've always disliked about the 2.4T is the cam timing marks are misleading (to me) by about 1/2 a tooth, compared to the 2.5T. In my opinion, because of this, it can be easy to get it off a tooth or two & visually appear to be "on the marks". The crank marks are pretty hard to misread with everything off, but this changes once the serp pulley is on the nose of the crank.

[sprocket007]

Pete!
I was excited to read your reply!
I have the plugs out and I feel no increased resistance or hitting when I hear the tap sound so, I was very interested to read your information and experience!
Thank you for your information and time to reply to my post, much appreciated!!
I'll get a stethoscope out and take a listen as well!
I still have the sump off I'll check the things you mentioned

[- Pete -]

It’s easy to get queasy when you’ve come as far as you have & still have no joy.

Absolutely check the big ends of the rods if you have the pan off still. First just by hand grabbing the big end to check for up/down. If you remove any of the rod caps youMust mark each cap so it goes on in the exact orientation as it came off the bottom of the rod. They are “cracked”. Jimmy57 explains it in the thread I’ll link.

I personally would just do JUST one to begin with. Definitely just 1 at a time and would start with #5 seeing as it gets oil PSI last & this bearing/shell will be the first to show signs of wear. You will need a set of 12pt sockets for the rod cap bolts, and an accurate torque wrench (and maybe some plastigauge).

I’ll link in my thread where I was in a similar boat as you (well, maybe the same river) & was so fortunate to be helped out by the real pro’s here.

Several of these awesome guys here have been very influential to me with my own queasy moments, which I am eternally indebted for.


Here it is viewtopic.php?f=9&t=87109

[SuperHerman]

Based on experience and reading countless posts - these engines will start and run (usually they will code) if they are 1 to 2 teeth off. They will not suffer any valve to piston contact. As I cannot see your work - assuming it is spot on what is described is the latitude the engines seem to have with timing being off. But your spot on may not be my spot on so proceed with caution.

Recheck your work.

That said - are you sure you are not hearing or feeling the cams and valve springs operating? In my experience valve to piston is usually a hard stop. Are you sure one of your cams is not 180 degrees out of phase? This is not uncommon with the rear cam slots, but if the tools are on it doesn't seem plausible.

You can pull your spark plugs and look down the holes and get an idea where the pistons and valves are - piston all the way up should equate to a closed valve. If you can do a leak down test you can confirm this. You can pull off your intake manifold and you will have a full view of your intake valves - compare to piston position. You can also attach a mirror to your scope and look at your valves, although when the piston is all the way up there isn't much you can see at this point. Still you can see if they are behaving as they should. Pull up a firing sequence and do some thinking and you should be able to figure out if everything is playing nice. Finally, if you do have contact you may be able to see a mark on the piston. Focus on the spark plug hole/piston position to figure out where the contact may be.

[sprocket007]

Thanks,
I've gone over the timing again, everything looks good!
Unless I have some major tunnel vision but, I don't think so...
The tap/light clunk persists with no perceived increase of effort on hand turning the engine. I'm not convinced what I'm hearing is coming from the head. I don't have a helper to turn the engine, if I did that might help to more accurately identify where is making the sound.
I do still have the pan off, sounds like rod#5 can be damaged when run low on oil is what I'm gathering from Pete. What I could be hearing is a rod sound? This could be conceivable as I did have to stop a few times to add oil to get home...

thanks for the assistance here I persist with getting this running and I'm gonna lean towards that the timing is correct.
If I fire it tonight and toast the engine I'll let you know!

Wade

[- Pete -]

Hey Wade, I forgot a couple things. How crusty was the interior of the oil pan? Did you verify that the infamous “square passage” was clear & clean? The one that vents to/from the breather box. Maybe take a close look at the screen in your pickup tube.

I’m just thinking if, at one point, your PCV was clogged up & engine sludgy the screen in the pickup tube can sometimes become compromised, which you don’t want. I took some really great photos of this once. I’ll see if I can find them. Here's the thread.

Also, one other thing another member shared recently about intake cam seal being pushed out due to ________ (fill in the blank, crankcase psi, blow-by, etc) is that the banjo bolt on the early P2 turbo’s had no check valve in it. This means that theoretically, under boost, positive psi was being fed through the banjo bolt, through the breather box & into the crankcase & also the valve cover. He took back to back measurements with a manometer at the oil filler cap with the old banjo and then with the new banjo bolt (the one that has the check valve) and the psi difference was ultimately cut roughly in half. I’ll see if I can find the post. Just saying, if once you are running, the cam seal seems to pooch out again this could be something to look at. Here is the thread. I linked it in starting on page 4, Chad reveals his setup on page 5.

After recently doing the same job you’re finishing up (fixing an enormous oil leak due to intake came seal push-out) and then reading his post, I bought a manometer & a couple of the check-valve banjo bolts to conduct the same experiment on my own 2.4T 01 VXC. I’m still mentally recuperating from my last battle with the car so I haven’t done this experiment yet, but can’t wait til it’s done.

[xHeart]

FWIW:

VIDA procedure for setting belt tensioner has 2 variations by engine serial#. In my case, it was tensioner needle causing the click.

I believe, Oragex has clarity on tensioner application.