1999 V70 B5254T VVT Head Removal Advice Needed

[deepsouth]

Hello!

A good friend of mine just bought a 1999 V70 with a B5254T motor and it runs ROUGH. Did the usual tests and everything checks out (spark, fuel, etc) except for the compression. Cylinders 1, 2, and 3 are in the 170's while 4 and 5 are at zero. Yes, zero. (I actually rechecked the others because I thought my gauge malfunctioned )

Anyway, I'm going to the pull the head and have a look around but--thus far in my mechanical experience--have never pulled a head with the VVT solenoid. What am I up against? As I don't know how it works that little VVT solenoid scares the bejesus out of me.

Any and all thoughts and advice are welcome!

Eric

[j-dawg]

from what i've read, this job is made a lot easier if you have the cam locking tool.

some people scoff at it; i think it's always worth investing in tools if you value your time and don't want to make your own. you can always buy it used and sell it after the job's done - you won't need it for the next couple hundred thousand miles.

[Ozark Lee]

The solenoid isn't a big deal but the CVVT hub on the exhaust cam is a big deal. It isn't keyed in any way and, if you remove the hub, you are looking at needing a cam adjustment tool to get the sprocket properly indexed on the camshaft.

My suggestion is to leave the hub on the camshaft. You can thread the front seal off through the lobes when you replace it. The only thing that will be a bit odd is that the front seal will need to be put in its final position before the cam cover is drawn down to the head. It works OK so long as you pay attention and don't get it cockeyed.

After you repair the head (assuming that you have valve problems and not cylinder problems) you will need to go through the CVVT preload procedure which is actually fairly easy once you get past the poorly written VIDA or VADIS procedure.

The cam locking tool is particularly worthless with CVVT since the sprocket and the cam move independently over a limited range.

...Lee

[j-dawg]

The cam locking tool is particularly worthless with CVVT since the sprocket and the cam move independently over a limited range.

...Lee

my bad.

[deepsouth]

Thanks! The two other head jobs I've done were hydraulic tensioners and I didn't use a cam locking tool. I timed the engine before removing the cover and cams and didn't have any problems--this looks much scarier.

So if I understand correctly, I don't really need a locking tool and don't fool with CVVT hub on the exhaust cam? Install the new exhaust seal from behind and then when I go to reinstall double check the pre-load and mechanical tensioner? Anything else vastly different between this and the 1998's?

[Ozark Lee]

It isn't a matter of double checking the preload, it is a matter of setting it in the first place.

What you can do, after things are back together, is set the timing marks to their proper references (the cams shaft marks will line up at the 12:00 position rather than the 15 degrees or so off like on a '98 where you line up to the V notches) hand crank the engine a couple revolutions and go 90 degrees past the timing mark clockwise. From there go back counterclockwise until you are at the marks again. Remove the belt from the camshafts and, as you thread the belt back across the cams, starting at the intake cam, line the mark on the exhaust sprocket to the 12:00 position as you thread on the belt across the exhaust cam. At this point the bolts that go through the sprocket to the hub should not be at either limit on the slots that they go through. They won't be perfectly centered but they shouldn't be at either end.

Set the tensioner and then crank it through a couple of revolutions and recheck your marks.

Unless you are horribly wrong on the crankshaft mark the worst thing that can happen is that the car will pop code P0014 and the CVVT will be deactivated. It won't cause any permanent damage.

...Lee

[deepsouth]

Thank you Lee! Tore it down this afternoon. Needed a beast of cheater bar for the head bolts and still didn't think they would ever budge! Gonna wait until tomorrow evening to finish pulling it--it'll be interesting to see what I find.

[Ozark Lee]

Use steady pressure on the pipe, don't jerk it. Steady pressure will reduce the chances that a bolt snaps.

Broken head bolts make your life more difficult.

...Lee

[deepsouth]

Got the head bolts off without a hitch--even with enormous cheater bar took serious effort. Too tired tonight to pull the head, off for beer at the local gastro pub.

[deepsouth]

Found the cause of no compression in cylinders 4 and 5. Pistons look to be in good shape. Any ideas on how to prevent this from happening again? Car has 206K on the clock. This is my first run-in with burned valves.