Serious front of engine oil leak '04 XC70

[BlackBart]

Yes, belly pan off, underside inspection showed mostly dry things.

Drove it on the freeway 10 miles, 75-ish, AC on. Yes, there is oil on everything now - all the stuff I just scrubbed.

I'm putting my money on the exhaust cam seal. The back of that wheel is slightly wet, the back of the intake wheel is dry. The alum cylindrical shape in the head casting (where the seals probably are) is wet on the exhaust side, dry on the intake side. So unless the TB is pulling a ton of oil uphill on the exhaust side and getting all over the exhaust cam area, it's coming from that seal. A lot of oil has run down the back of the plastic belt cover assembly, towards the firewall.

Is there any reason not to change both seals as long as it's coming apart? Is my newish TB wet enough to just replace it as well?

Where can I learn to align my cam wheels if the wheel (and it's timing mark) spins until that torx bolt is tight?

I'll need the cam holder tool for the back of the engine? So the cam sensor comes off, and that upper motor mount on the exhaust side?

Yes, Robert is great - they're almost all about 850s, though. This is all new stuff for me.
Thanks!

[jonesg]

Robert's video is the same 5 cyl engine, same TB and tensioner proceedure.

Sounds like you located the leak.
I changed both my cam seals, I still don't know which one was leaking.
If you don't know for certain when the TB was done, I'd change everything.

Seals (not crank seal) TB, water pump, TB tensioner etc.
You'll have the TB off and can decide , I wanted the peace of mind of installing everything new.

Upper motor mount cross bar and some other brackets at the rear of the cam shafts need to come off to get access.
If its turbo, remove the pipe over the top of the engine and the pipe from the airbox to turbo inlet.
Set engine timing to the marks, then install cam lock. Now you can remove TB.

Coolant overflow bottle and power steering bottle can both sit on top of the head, unplug overflow bottle elec plug.
Access to remove the exh cam center bolt requires moving the main elec harness slightly.
Remove wheel, fold back inner fender liner and clip in place, remove small guard under the crank gear (2 x 10mm).
Don't remove harmonic balancer or crank gear unless you have new hardware, its not necessary anyway,
you can easily slip the TB off once the belt tensioner is released.

Before loosening the CVVT cam sprockets transfer the timing marks to the back of the sprocket with white touch up paint and make a corresponding mark on the block (head). Rotate the sprockets to the end of their range and make a second mark, this is to locate the pretension location. If you don;t make these marks you'll have to go through the whole setup procedure from scratch.

Heres a link to the complete proceedure, its a PDF by user F250.
Cvvt hub change on p2 volvos

[BlackBart]

The post 2003 CVVTs usually develop so much axial slop that they pull away from the cam seal...

..You'll need the rear locking tool, some new Corteco seals and both CVVTs...

Is the axial play because of cam bearing failure? Where is the play coming from?

That's good - the Alfa guys always insist on Corteco rear main seals. Are you saying replace the gaskets under the CVVT housings?

[jonesg]

This video is good, explains the pretension of the hubs.


Its a lot of information to digest but once you grasp the big picture its ok.

[BlackBart]

Wow, those are both invaluable guides - thanks guys! The timing marks, then transferring the marks, then the spring rotation marks....how would you ever guess any of that without a manual or you people? The basic Haynes doesn't cover this stuff in this depth, does it? Do I have to invest in an old laptop and this VIDA system?

My '04 XC looks to have both intake and exhaust vvt. The housings on top of the valve cover don't need to come off, correct?

So after checking out the leak, and considering what parts and tools to order, my son and I tackled changing the worn out steering column assembly in his project BMW E30 ('86). Bottom of the dash comes out, the steering rack linkage comes out, firewall clamps come out, dremeled off the heads of cone-shaped "safety" bolts under the dash supports, swapped the lock cylinders so the keys stay the same, install new turn signal switch....

We quit for the night. Need some new bolts and hope to get it buttoned up tomorrow. Too many projects and broken cars!

[precopster]

The CVVTs themselves have a factory tolerance that is acceptable. I think jimmy57 quoted me 1.5 mm of axial movement as being the maximum.

Once you get them off you'll be able to see what I mean. The CVVT with the most axial play will most likely be the one that was leaking. It's usually not that the cam seals have failed; it's the axial play that causes the leaking.

Recently I replaced 2 CVVTs from a 2004 XC70 much the same as yours. I replaced both CVVTs with used ones that had less play than the originals but I still managed to botch it up the first two times because I drove the cam seals in too deeply into the head. Doing this causes massive leaks. You want to put the new cam seals in flush with the head; no more.

If your CVVTs have 3mm or more of axial play you will need to replace the CVVTs.

[jonesg]

it's the axial play that causes the leaking.

Mine didn't, maybe it was PCV system pressure on mine.
Either way I only changed cam seals and the leak stopped.
Its been 30K miles since.

[jonesg]

Wow, those are both invaluable guides - thanks guys! The timing marks, then transferring the marks, then the spring rotation marks....how would you ever guess any of that without a manual or you people? The basic Haynes doesn't cover this stuff in this depth, does it? Do I have to invest in an old laptop and this VIDA system?

My '04 XC looks to have both intake and exhaust vvt. The housings on top of the valve cover don't need to come off, correct?

Haynes does cover it , the procedure is fairly consistent over many yrs and models so its in there.
I got my Haynes from IPD.
Consensus says get the VIDA setup if you drive these cars.
I bought VIDA already setup on a laptop and a DICE interface off amazon.

The housing on top of the valve cover? you mean the CVVT solenoids? they stay put .
You can test them with a meter set to ohms.
They can fail and the car will still run, heres a video showing how to test them.
Unless you get a code I wouldn't bother.


Heres a view of a loosey goosey cvvt cam sprocket, I consider this bad, mine was not that bad.

[soulvoid21]

Dumb question, but have you checked the oil cooler behind the oil pan? The air is routed upward through the engine splash guard to it, and blows upward. Something easy to check before doing a lot of work.

[BlackBart]

Yes, good idea. It all looks pretty dry there. It looks like that's an oil-to-water heat exchanger / intercooler?
Thanks -