Cam Seals leaking at 120K, leave Oil Pump Seal alone?

Post by **cn90** » 14 Jun 2020, 13:31

Hi guys,

Since the 2.5T engine is common to S60, S80, and XC90, I am posting it here bc this forum has more traffic than XC90.

My 2005 XC90 2.5T with 120K develops an oil leak at the right subframe area, very classic for cam seal leak.

My plan is to replace both cam seals (I have the cam lock tool), and both rear plastic plugs.

My question is about the crank seal (oil pump seal): I rarely see this leak before 200K.
So I can leave this crank seal alone bc I hate removing the crank pulley and oil pump if I don't have too!
Please advise...

Post by **firstv70volvo** » 14 Jun 2020, 18:45

Just my two cents worth. Not long ago I replaced the front crankshaft seal while replacing all the camshaft seals. At 20 years and 200K miles on my car the front crankshaft seal had no evidence of any leakage at all but I replaced anyway since I already had the pulley off. If you see no evidence of the front crankshaft seal leaking then I'd say leave it alone because it's not something that's going to fail all of a sudden and leave you stranded somewhere. That's my critera for preventive replacement of parts, if the part can fail and leave you stranded (radiator hose, serpentine belt...) or do severe damage (timing belt) then I replace the part but if I think the part will provide a warning before failing catastrophically then I tend to wait on the replacement, especially is there's a high cost in terms of dollars or time to replace the part. This assumes your PCV system is in good shape and won't blow out any of the seals, which would be a catastrophic type of failure.

Post by **SuperHerman** » 14 Jun 2020, 20:50

I would look at your PCV system - check it for positive pressure. You may replace the seals only to have another seal start to leak b/c many times the problem is the PCV systerm is restricted.

Post by **jonesg** » 14 Jun 2020, 22:39

I did both cam seals front and rear of cams but the crank seal was dry so I left it in place.
Still dry 3 years later....220k miles.

Post by **- Pete -** » 15 Jun 2020, 21:38

The problem is you really don’t know for certain unless you pull that timing gear off the nose of the crank. I guess I don’t see an issue with a 10 minute crank timing gear/pulley removal. Once the serp pulley is off it just takes a puller & the timing gear is off as well. Then you can verify that the crank seal is good or bad. On my last one, a 2001 V70XC 2.4T, I got lucky & didn’t need to replace the crank seal (et.al) after removing the timing gear.

Post by **jonesg** » 16 Jun 2020, 09:37

its a matter of tools, Getting stuff loose isn't the same as having a puller on hand and a counterhold to tighten up the center nut again.
Unless you have a trick method for torquing the crank nut again?
Thats where I am now, debating whether to splash $50 on the pulley holder or pound it with the ugga dugga.
I wouldn't go in there unless I had the tools to get out again, on mine the center nut went missing, volvo says that nut is single use,
I can attest to that.

Post by **- Pete -** » 16 Jun 2020, 11:12

Impact on & off is the way to go. I’ve reused the crank nut on my 288k XC70 many times. I marked it long ago with a white paint marker & also the face of the serp pulley so I know how far to impact it back on. I’ve never used a crank counterhold & have had a dozen or more P2 timings to show for it.

Post by **jonesg** » 16 Jun 2020, 13:02

- Pete - wrote: 16 Jun 2020, 11:12 Impact on & off is the way to go. I’ve reused the crank nut on my 288k XC70 many times. I marked it long ago with a white paint marker & also the face of the serp pulley so I know how far to impact it back on. I’ve never used a crank counterhold & have had a dozen or more P2 timings to show for it.

Thanks, thats the way I am leaning too, I've never had a fastener work loose when hammered home.
did that on my old 740 and it was never a problem.
I don't know the previous history of my current V70, so who knows what someone did prior.

Post by **cn90** » 16 Jun 2020, 18:14

I am buying parts for the job, so RELATED question:

- Looking at my 2005 XC90 2.5T (dual VVT setup), there are 2 cam sensors. Each sensor is housing is held by 2 Torx bolts.

- So, the question is: for the REAR side, any seal, plastic plug to buy? Is it just simply remove the cam sensor housing, install locking tool, do the job and re-install the cam sensor housing?

PS: I don't see any REAR plastic plug in my car....

Post by **- Pete -** » 16 Jun 2020, 19:22

Dual VVT engines do not have the large plastic plug on the rear of the cams. They do have seals, however. I have a thread with the part numbers and comparison notes of seals available.

Remove the cam sensor (black plastic housings), then remove 10mm bolt which secures hall effect sensor pickup. You can’t mess these up, they only fit on in one orientation. Then you can replace the rear can seals or lock the cams & do the front seals first, makes no difference in ease. I like to tap a hole in the old seal with a sharp pick, then screw a drywall screw into the hole & pull the old seal out. Install for rears is easy, just push them in until they stop.