2005 XC90 2.5T with 120K and leaking cam seal, do I leave crank seal alone?

[cn90]

...We are talking about old and aged seals that don't have to be broken to leak oil, but when there is extra flow from leaking VVT o-rings, it can definitely leak the volume of oil you see on your vehicle.

Again, you will need 4 cam seals not 2 since the rear will be exposed anyways, 2 o-rings, and 2 end plugs. The end plugs can leak too when re-installing with its aged/worn/flat o-rings. You will need a new belt too if there was oil. Best to remove the timing cover to inspect the solenoid gasket as well. Hope my direct experience helps.

- No end plugs for the 2005 XC90 2.5T dual VVT.

- In my 1998 S70 GLT (Sold) w/o VVT, the cam leak was the same: one drop on garage floor/night. Very very slow leak.
The leak I have in my 2005 XC90 2.5T with 120K is the same: one drop on garage floor/night. VERY SLOW leak.

As to the leaking O-ring: the oil simply returns back into the camshaft area, nothing to do with the CAM seal.
In other words, let's say the cam seals are new (replaced) and the O-ring is leaking, you will not see any external leak.

[cn90]

Below is the cutaway view supplied by the Volvo guru mechanic jmmy57:

viewtopic.php?t=81207


I redraw it to label the relationship between VVT O-ring and Cam Seal...

[cn90]

Image provided by precopster...

One O-ring is replaceable, the other 2 O-rings are very difficult to find. Also, by the time the VVT has > 160K-180K miles, the axial/radial play may be too much. You are better off with new genuine Volvo VVT x2.

[chitownV]

Again, I have done it and yes oil from the VVT o-ring that goes on the camshaft can make its way out. All doesn't stay inside the engine and it definitely can leak out via the cam seal. You are forgetting that sometimes things are not an all or nothing. Like, a hand-drawn pic of a part does not factor age/wear related issues, such as hardness, slight rubber wear, heat cycles, expansion/contraction, etc. An o-ring doesn't have to be 100% blown or leaking 360 degrees. So, yes, the o-ring can still leak and provide some VVT movement. The way to know this is from experience with the parts in hand, not desktop studying alone. Call it surface adhesion of oil, flow, pressure, centrifugal force that whips the oil out towards the cam seals, whatever, oil from the VVT can make its way out.

Why not do the VVT (external) o-rings? You have to remove the VVT hub anyways. Then the o-ring is right there, exposed, and literally 10s to replace.

If you are thinking, why do it anyways if in 60k miles the VVT hub wears out (or internal o-rings), I don't understand. You are talking about the VVT designed in the latest iterations (so good quality) and you have been using synthetic oil. What if it lasts past 200k miles? I did both on a Volvo with over 125k miles and the VVTs were tight (fluid smooth, but tight) and the o-rings leaked, but was caught early.

I am not sure it is wise to skimp on cheaply priced rubber known engine parts that go bad when they are wide open for easy fixing when doing the camshaft seals job. O-rings definitely flatten and harden with heat and age, both for the VVT and the end plugs. Rear cam seals are ~$4 each and are exposed in order to use the alignment tool. When the timing belt is off too, a great time to get a new one if it has been soaked or exposed to oil. Not sure what the argument is of not changing the worn rubber parts when it is already exposed or removed.

From someone who has done these, trying to help so the job doesn't have to be done twice and prevent something worse.

[chitownV]

- No end plugs for the 2005 XC90 2.5T dual VVT.

- In my 1998 S70 GLT (Sold) w/o VVT, the cam leak was the same: one drop on garage floor/night. Very very slow leak.
The leak I have in my 2005 XC90 2.5T with 120K is the same: one drop on garage floor/night. VERY SLOW leak.

As to the leaking O-ring: the oil simply returns back into the camshaft area, nothing to do with the CAM seal.
In other words, let's say the cam seals are new (replaced) and the O-ring is leaking, you will not see any external leak.

There are definitely end plugs that I linked before from FCP. Here it is listed for your 2005 from Volvo Parts: https://www.volvopartswebstore.com/prod ... 75364.html

Rofl, still don't understand what the argument is with not replacing the o-ring when it is exposed and it's cheap, or the end plugs which have their own o-rings and also hold VVT pressure. And again yes, unfortunately, oil doesn't just move in one direction and the VVT o-ring over the cam can leak out the cam seals.

I hope that helps because again, this is from experience, not desktop studying alone. I too missed the end plugs the first time and had to make a dealership run.

[cn90]

- FYI, end plugs refer to the plastic plugs the REAR side of engine w/o VVT.
You used terminology that caused confusion.
https://www.fcpeuro.com/products/volvo- ... 90-1397381

- What you referred to is the VVT center bolt. A plug is a plug. A bolt is a bolt.

- Again, you completely miss all the points I made. I never said I won't replace the O-ring. I am simply doing research.
From diff forums, the ebay O-rings can fail quickly, turning a non-issue into an issue.
I am researching for proper brand. FCP carries "Allied brand" but no feedback on FCP website yet.

- I think you complete miss many points I mentioned above. You misread my intention.
I usually do proper research before doing a job like this bc I don't want to do it twice.


PS: I am not new to Volvo repair.

[cn90]

Also, O-ring Debate:

https://www.volvoxc.com/forums/showthre ... -Cam-Seals

[chitownV]

- FYI, end plugs refer to the plastic plugs the REAR side of engine w/o VVT.
You used terminology that caused confusion.
https://www.fcpeuro.com/products/volvo- ... 90-1397381

- What you referred to is the VVT center bolt. A plug is a plug. A bolt is a bolt.

- Again, you completely miss all the points I made. I never said I won't replace the O-ring. I am simply doing research.
From diff forums, the ebay O-rings can fail quickly, turning a non-issue into an issue.
I am researching for proper brand. FCP carries "Allied brand" but no feedback on FCP website yet.

- I think you complete miss many points I mentioned above. You misread my intention.
I usually do proper research before doing a job like this bc I don't want to do it twice.


PS: I am not new to Volvo repair.

I actually linked the part for the end plug way earlier in this thread from FCP...double check...so there wouldn't be any confusion. When you mentioned the plastic end caps at the rear, I told you you don't have them because you have camshaft position sensors there. Then after I posted here about the rear cam seals, you went on another forum asking if there were rear seals. I said there are, but if you are talking about the rear camshaft position sensor housing, I said no.

The bolt that holds the VVT hub is different from the threaded "plug" (which Volvo calls "plug") that covers the bolt. After removing the (tight) plug with a torx bit, you have to remove the VVT bolt. Again, based on doing it, not just looking at diagrams. Lo and behold that I can add valuable information that you might not find.

If you are doing research, why not accept some of my experience here because it helps other people too. edit: removed suspension

I never said you are new, but you can miss many things without the experience of doing them or avoiding people's first-hand experience. I would have spent more time removing the timing cover to expose the VVT/timing belt area of your actual engine instead of looking at pics online so I know more about what parts I may need, like getting a new belt if soaked in oil. This would also confirm the camshaft seals leaking. There's never debate about looking at your own engine for its own diagnosis.

[chitownV]

Since you asked this also in another MV thread, it looks like I'm not the only one who has experience doing the cam seals to suggest to do the all 4 cam seals (front and rear), and the VVT o-rings. What people don't add is to do the end plugs on the VVT, which hold oil, and the o-ring on the end plug gets flat/old and can break upon reinstalling. Those plugs are cheap. In your other thread, you also mentioned how you were replacing the rear plastic plugs, which you don't have since there are camshaft position sensor housings, something I also mentioned in my first reply to this thread.
viewtopic.php?f=9&t=94256&start=10

[abscate]

We get very few crank seal leaks in these Fora, so I would not break down that assembly. As pointed out above, you don’t have all the work of setting cam timing to do that seal later so Labour has small overlap.

I think I would use genuine Volvo seals on everything here, though.