Head gasket Questions 2004 xc70 w/ 2.5turbo

[beewstew]

2004 xc70 w/ 2.5turbo

I'm trying to figure out the head gasket repair before I start tearing everything apart. I bought the absurdly expensive cylinder head (reverse) pliers and a crankshaft cam alignment tool https://www.amazon.com/dp/B07MSGBGBX and have all the seals on-hand, just trying to get up the courage to start tearing things apart.

Q: Some of the videos I've watched online include the process of removing camshafts and resealing w/ anaerobic sealant - almost like the cylinder head is being split in half. Is this strictly necessary if it's just the head gasket that's failed? I am not an overachiever if it matters...

Q: At what point do I need to use the cam alignment tool to lock the cams in place? After I've rotated the engine to have both camshaft pullies at TDC?

Q: some of the guides (Haynes) say I have to remove the passenger CV/driveshaft to get the turbo off the back of the head - true or false?

[jonesg]

cam locks are only needed if you want to change cam seals.

you don't need to remove any driveshaft,
if you can get the turbo off, go ahead.
no need to remove the exh manifold , it can come off in one piece with the cam cover.
i would buy new exh gasket and exh studs/nuts.
new turbo drain pipe gasket and O ring.

[beewstew]

Thanks for the pointers. Can the cams be rotated without penalty when I'm swapping out the hg? I've seen the alignment notches on the timing cam pullies. Do I need to lock the head/cams at tdc when the head is out of the car?

[jonesg]

Thanks for the pointers. Can the cams be rotated without penalty when I'm swapping out the hg? I've seen the alignment notches on the timing cam pullies. Do I need to lock the head/cams at tdc when the head is out of the car?

disconnect the battery first,
align the cam notches and the crank shaft before removing anything.

again, you only need the cam lock tool if you plan on removing the cvvt cam hubs from the cam shafts.
Unbolt the cam cover , as the bolts are removed the valve springs will push the cam cover up.
if the cam cover is catching on the back of the vvt hubs you can loosen 2 of the sprocket adjust bolts to get clearance.
lift the cam cover up, its easier if the cams stay in the head portion.

[brutus101]

For your 2004 XC70 head gasket repair, removing the camshafts and using anaerobic sealant isn't strictly necessary if you're only addressing the head gasket, but it is recommended. The cam cover is part of the cylinder head assembly, so it will need to be separated. Resealing with anaerobic sealant prevents oil leaks and ensures proper reassembly.

You should use the cam alignment tool after rotating the engine to TDC (top dead center) on cylinder 1 to lock the camshafts in place. Regarding the passenger CV/driveshaft, it typically needs to be removed to access and remove the turbo from the back of the head, as suggested by guides like Haynes.

[erikv11]

For your 2004 XC70 head gasket repair, removing the camshafts and using anaerobic sealant isn't strictly necessary if you're only addressing the head gasket, but it is recommended. The cam cover is part of the cylinder head assembly, so it will need to be separated. Resealing with anaerobic sealant prevents oil leaks and ensures proper reassembly.

You should use the cam alignment tool after rotating the engine to TDC (top dead center) on cylinder 1 to lock the camshafts in place. Regarding the passenger CV/driveshaft, it typically needs to be removed to access and remove the turbo from the back of the head, as suggested by guides like Haynes.

Yes, removing the camshaft cover (and camshafts) and using anaerobic sealant to put it back together IS strictly necessary for a 2004 XC70 head gasket repair. Removing the cam cover is required to access and unscrew the head bolts. It's the only way to remove the head.

These Volvo 5 cylinder engines do NOT use TDC for timing, they use a set of marks on the cams and the crank.

The crank mark does put #1 near TDC but slightly off from it. Ignore TDC, but do pay very close attention to the marks, and you will be good. With the crank on the mark (and locked there if you like, since you bought the tool), you may rotate the cams freely without interference; just make sure they are back on their own marks (i.e. slots above and below horizontal respectively) when you put it back together. I agree that using the cam tools is helpful, especially since you already have them but they are not required if you take care to lift the cams straight up. Without cam tools there is a small risk if cracking the cam guide slots near the end of the head if the cams don't go straight up.

The CV driveshaft I don't know about. I've done many heads on this engine but none yet when it was in an AWD model. Probably removing the CV helps to access the turbo oil return drain pipe, because the angle gear is also in the way and removing the angle gear is a big hassle you don't want to mess with.

[jonesg]

For your 2004 XC70 head gasket repair, removing the camshafts and using anaerobic sealant isn't strictly necessary if you're only addressing the head gasket, but it is recommended. The cam cover is part of the cylinder head assembly, so it will need to be separated. Resealing with anaerobic sealant prevents oil leaks and ensures proper reassembly.

You should use the cam alignment tool after rotating the engine to TDC (top dead center) on cylinder 1 to lock the camshafts in place. Regarding the passenger CV/driveshaft, it typically needs to be removed to access and remove the turbo from the back of the head, as suggested by guides like Haynes.

Yes, removing the camshaft cover (and camshafts) and using anaerobic sealant to put it back together IS strictly necessary for a 2004 XC70 head gasket repair. Removing the cam cover is required to access and unscrew the head bolts. It's the only way to remove the head.

These Volvo 5 cylinder engines do NOT use TDC for timing, they use a set of marks on the cams and the crank.

The crank mark does put #1 near TDC but slightly off from it. Ignore TDC, but do pay very close attention to the marks, and you will be good. With the crank on the mark (and locked there if you like, since you bought the tool), you may rotate the cams freely without interference; just make sure they are back on their own marks (i.e. slots above and below horizontal respectively) when you put it back together. I agree that using the cam tools is helpful, especially since you already have them but they are not required if you take care to lift the cams straight up. Without cam tools there is a small risk if cracking the cam guide slots near the end of the head if the cams don't go straight up.

The CV driveshaft I don't know about. I've done many heads on this engine but none yet when it was in an AWD model. Probably removing the CV helps to access the turbo oil return drain pipe, because the angle gear is also in the way and removing the angle gear is a big hassle you don't want to mess with.

shop time is 6 hrs to do the turbo drain pipe because it calls for removing the angle gear, we've all done it without doing all that extra work, book method involves more than just removing the drive shaft, you'd also have to drop the front of the prop shaft. a bit too much.
The turbo can be unbolted and left in place. Turbo water feed line might have to be shifted to get the head out.

[erikv11]

... The turbo can be unbolted and left in place. Turbo water feed line might have to be shifted to get the head out.

Good info, thanks.