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All,
I'm looking to purchase a 2007 XC70 that is going to need a new head as the water pump let loose and threw the timing when it when south.
My question to all of you out there is how hard is this job since its a variable valve head as opposed to simply a dual overhead cam head like on the 1998s.
I'm familiar with the procedure on the 1998's and have done it successfully twice, but need to know if this job will be worse than what that was.
I need to let the guy know before the weekend so if any of you here have had experience with this procedure on the variable valve timing heads, how hard it is, and how much does it vary from the non-variable valve heads.
Thanks in advance,
Matt
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1989 - 245, 1990 - 245, 1991 - 245, and 1993 - 245
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All,
I've finished this job last night and there is much rejoicing.
I took my time in getting the timing right.
The first attempt had the crank being off by 1 and half teeth after I spun the engine twice by hand, the CAMs however were still dead on, though I wasn't happy them as they were not quite where they should have been.
I removed the belt again, reset the crank correctly, while the CAMs were still locked and did the belt a second time. This time everything was spot on. I rotated the crank twice and everything was exactly where it should have been.
I finished installing everything and started the car.
It took awhile, about 15 seconds for everything to finally fire up, but when it did it just purred like new. I was impressed and now look forward to getting it on the road and really usable.
I want to thank all of you who aided in this endeavor. Without your knowledge on the dual VVT, I may have bitten more off than I normally would like to chew. Having the CAM locking tool was key, and it made all the difference in the world in putting the valve cover back on, and Jeffs suggestion of not removing the hubs and just placing the seal on before you put cover on and not after, was also a great suggestion. Normally I would not have done that as its not the correct way of doing it, however I do like to work smarter and not harder, and this way was definitely smarter as I saved a lot of time getting them on vs. pressing them in.
Once I get around to it, maybe this weekend I'll post some pictures of the car now that its running.
Regards,
Matt
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Beers are earned and deserved!!
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Keeping it running is better than buying new
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Jeff is right, if you know which valves are 'bad', you can replace them without removing the head. Just the cam cover and cams.
With the head in the car, be prepared to do a lot of bending. Yoga might be of help!
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Keeping it running is better than buying new
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Klausc,
I mean no-disrepect here, but how do you remove a valve without removing the head???
Of all the heads that have had bent valves due to them being interference engines, I've had to remove the head, as they come out the other side of the head.
Inquiring minds want to know.
Regards,
Matt
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Sorry, but the gray matter no longer works. I was just thinking about doing my valve stem seals when I answered your question.
Of course the head has to come off, makes it easier to work on... and get the valves to fall out. Not only do you need to buy new valves, you will need new head bolts, which are not cheap.
I suggest putting a drop of paint on the crank so you can easily see the timing mark.
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Keeping it running is better than buying new
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KlausC,
Plan is to once it is off, do what Jeff suggested, I think, and fill all the valve area's with windshield washer fluid to see which ones besides the visibly obvious ones need to be addressed.
I'll remove the ones that don't appear to be bent, but have leaked and then either replace if they are bent, or just re-lap if they are not bent and go from there.
Plan to check the head for flatness as well just so I can say that I've done my due diligence.
I will mark the sprockets before the valve/cam cover is removed, but it really won't matter too much as the head is already screwed, so I'll remove it before setting the pistons to top dead center, at least that way I will have remove most of the pressure of the remaining valves.
It will be a nightmare I'm sure, but I'm up for the challenge.
I'll have to post pictures of the car once I get it as it is just spotless on the outside and inside. Too bad about the engine though.
Matt
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1989 - 245, 1990 - 245, 1991 - 245, and 1993 - 245
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I assume you have a cam locking tool, so the cam marks won't matter. But the crank sprocket mark is terribly hard to see and painting that will make life easier. You can't use 'actual' TDC on #1.
I don't recall ever seeing a warped head or block with these aluminum engines. I guess that a severe overheating would mess up the head, but your car didn't do that.
You will see an indent on each piston crown, your valves didn't do that. That comes from the factory, tight clearance indeed!
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Keeping it running is better than buying new
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Ditto on marking the crank sprocket in a way that YOU understand. Do this before you remove the T-belt. I you use Jeff's method of not disturbing the sprocket's or hub's relation ship to the cams, then in theory you shouldn't even need to worry about locking the cams. That's what I like about his method.
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Chris and KlausC,
Thanks!
I will paint the sprockets, and yes, I do have a cam locking tool as I've done this before on my 98' V70, but never on a CVVT head before so this will be somewhat of a new twist to an old song.
I have found a series of 5 video's online that walk you through the whole process on what to do.
I've watched all of them and for the most part it is very straight forward.
A question I have is since everything is all out of time at the moment, will I cause any more harm to the head if when I start this process, if I manually rotate the cams and crank to there correct position before removing the head? That way I know I'm starting from a known good position?
Thanks in advance,
Matt
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1989 - 245, 1990 - 245, 1991 - 245, and 1993 - 245
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Because you are removing the head, you don't care about cam markings. Just rotate the crank before the head is put back on and make sure the mark lines up. The cam locking tool that is used to hold the rear of the cams will insure proper alignment. Hmmm, not sure if the VVT will change that.
Doing a timing belt replacement, I always remove the spark plugs. It is easier to rotate the crank.
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Keeping it running is better than buying new
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I'm not sure if it was mentioned yet in this string, but the factory index mark on the crank sprocket doesn't indicate TDC but rather it places the crank in a "safe" zone where none of the pistons are at the top of their stroke. This allows the cams to be rotated without causing any valve/piston contact. When manipulating the crank and/or cams it's best to have the spark plugs removed to eliminate any compression resistance. That way it's easier to detect any valve/piston contact that may occur.
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)
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Darn push rods on the brain.
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Keeping it running is better than buying new
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posted by
someone claiming to be Jeff
on
Wed Feb 21 20:02 CST 2018 [ RELATED]
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I highly doubt you'd need a "new head" from that sort of damage. i have done about 5 of these from timing belt snapping. its always the same case. new valves. and move on. never had to replace the head itself.
i also never remove the "hub" from the camshaft. i have found no need to do so. i always just replace the seal behind the hub from the back. sneak it in. place the camshaft in place in the lower part of the head WITH the seal already in in place and then just carefully bolt down the top part and never had the need to detach the VVT hub from the camshaft itself.
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Jeff,
I’ve never had to do this task on a FWD but wondered if your method was possible. Thanks for the input - your simplistification is quite refreshing!
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)
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What brand valves do you use when performing this job?
Thanks,
Matt
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posted by
someone claiming to be jeff
on
Fri Feb 23 10:57 CST 2018 [ RELATED]
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For me i test each of the combustion chambers for leaks past the valves. i turn the head up side down. fill the combustion chamber with windshield washer fluid and leave over night. if none leaks out i leave those cylinders alone. otherwise replace the valves. use some grinding paste in the trouble cylinders.
as for brand, whatever fcp sells
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Jeff,
Great advise!
Thanks,
Matt
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Jeff,
Do you replace all the valves, or just the offending ones?
Thanks,
Matt
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