Serious front of engine oil leak '04 XC70

[BlackBart]

I've searched and read a lot of threads on oil leaks. It's obviously hard to diagnose over the innerwebs, but I'm still unfamiliar with this car and its plumbing. You might have some ideas.

First long trip in this car, 1000 mile round trip. Before the trip I noticed the oil low a couple of times and became worried about oil burning or maybe a turbo seal. Only 125,000mi on it.

On the trip, I was putting a $10 quart in every 2 to 300 miles. Back window covered with oil spray, so I assumed it was coming down the bottom of the car.

We are home now and I lifted it up, pulled the right wheel and the liner flap. There's a serious leak at what looks like the front crank seal area. All the plastic around the crank pulley is wet, as well as the guard over the CV boot, and everything below and rearward. Dry above that. I'll pull the plastic timing cover to take a better look at maybe a cam seal(?), but it seems like it's much lower. I read that a crank seal failure is rare.

Lots of advice in threads here about a clogged PCV box, so I'll check on that. Too much crankcase pressure and it blows out a seal? I changed out that system on my 850t.

One question - there is a small diameter metal pipe along the frame rail right there - is that an oil feed pipe? To the turbo or a cooler? Seems like it switches to rubber at some point. Could that fitting be spraying oil when under pressure? There's no way the pan joint would be spraying oil, would there?

Don't have a manual yet, nor access to this VIDA system.
Thanks for ideas -

[abscate]

It could be a crank seal or a cam seal running down the front of the engine. Pull the timing belt cover to verify. Easy to trace oil. The P2s have a lot less blow by problem than the P80s

[BlackBart]

Can I use my ipd cam lock tool that I have from the 850 if it's not the cam seals? I see videos of people using a factory cam lock tool at the back of the engine - looks involved and expensive. But how do you keep them from turning?

VVVVV.jpg (211.76 KiB) Viewed 7003 times

If it is a failed cam seal, do the toothed wheels only go on in one position so you can realign your marks?

[jonesg]

If the cam seals leak you have to lock the shafts from the back end with the other locking tool.
You can get it a LOT cheaper on amazon $50.
https://www.amazon.com/EWK-Locking-Cran ... T374HCPPGS

If its the crank seal you could use the sprocket lock.

I never bothered, as long as the sprockets are not loosened they are very simple to set up, if you have CVVT hubs its probably better to use the lock on the sprockets , it will save 5 minutes if nothing else.

But I don't see that you have located the source of the leak yet. Is this speculation, paying interest on borrowed trouble?

[jonesg]

If it is a failed cam seal, do the toothed wheels only go on in one position so you can realign your marks?

Ahh, ok, now I see your confusion...

No, the sprockets are not "keyed" to the camshaft, they can spin freely if the sprocket bolt is not tightened to approx 83 ftlbs.
Thats why you'd need the camshaft lock.

If the leak is at the crank pulley you need a method to lock the crank when torquing the nut, there is a crank lock for that.
On the older volvos they used the rope trick in a cylinder, I just used an impact wrench but these 5 cyl's are prone to that nut working loose and blowing up the valves. Its highly recommended to use a new nut too.
So either use the crank lock tool or rope....no impact.

[precopster]

The post 2003 CVVTs usually develop so much axial slop that they pull away from the cam seal. This causes MASSIVE leaks. Your cam belt will be absolutely soaked with oil if this is the case. Never seen a leaking crank seal on a Volvo white block.

You'll need the rear locking tool, some new Corteco seals and both CVVTs (it's almost possible to tell which one is leaking though statistically speaking the exhaust fails more often).

[BlackBart]

This is all very good information - thanks all. More special tools to buy...

So yes, a bit of speculation still on my part. The covers are off, and I studied all of it with a bright light. No obvious source. The belt is surprisingly dry. There is some wet up on the plastic between the cam wheels. Some wet bolt heads around the exhaust vvt housing, lots of oil below the crank area and frame. My son ran it at about 2000 while I watched - no oil pouring out of anywhere. There are 4 bolt heads on the vvt housing (top), then below that on the back of the engine in a slight recess is another bolt head, that was making a tiny air bubble every so often. No obvious oil, but an air bubble. Very odd.

So I decided to degrease it all and spray it off and let it dry for another test. If you drive it, it usually blows all over and fools you.

SO....some more questions -
Is there oil pressure up in that vvt housing? A gasket below?
The bolts below the vvt and along the edges are holding the "valve cover" to the cam housing, correct? There's a gasket there - does this ever fail?
If the exhaust cam seal was going, I'd think there would be oil on the back of the wheel, spraying all over. I don't see any yet.

I'm obviously not schooled in how the newer cam wheels connect compared to an 850, so I'll have to study that before removing anything.

It has a 20,000mi Conti TB, water pump etc. Unless the belt was soaked in oil, I don't see the need to change that now.

It's almost dry - after dinner we'll run it again and see what we find.

[BlackBart]

Ran it at 2500rpm for 15 minutes and no drips - crazy. It was after dusk and I had a bright light and a mirror, so pretty hard to miss. Maybe it needs to be loaded up at freeway speeds and AC on....?

I'll pull the belly pan tomorrow and look from underneath.
hmm.. Pan gasket?
Oil pump o-ring?
PCV box leaking out the bottom? (With a mirror it looks pretty dry so far)

What's behind the water pump flanges? Any oil passage near there would seem to be a bad idea.

[BlackBart]

I'm ruling out PCV box and plumbing. Ruling out pan. I'll have to take it out on the freeway and run it a while and see if I can reproduce it.

Alternate theory: It's not leaking because there's no oil in it! HA! The Italian method of oil leak diagnosis. (I have an old Alfa)

I did the dipstick test - no smoke. Did the rubber glove on the oil filler and it sucks in. Still, the PCV parts look original and there are no records of it being replaced. 125k now.

Sort of related question -
The TB tensioner has an engine temp component to it? So should that tab on it be vertical when cool? I watched it as someone else ran the engine at 2500. As it got hot, that tab clocked to about 1:00, and was doing a bit of shaking back and forth.

I really need a book - I feel like I'm doing some of this blind.
Thanks for the help.

[jonesg]

Did you pull the belly pan?
Unless you get a CEL the tensioner is ok, if its set wrong it will set the fault light.
And it isn't the cause of the oil leak....so fugetaboutit.

When my cam seals let go the oil was all over the belt and everywhere under the TB cover,
it was not losing copious amounts of oil either. It doesn't take a lot to make a mess.

Watching youtube TB videos will help you grasp the idea. Robert usually has decent vids.