'99 S70 T5 CVVT Clicking, Reset Procedure? Topic is solved

Post by **bmdubya1198** » 21 Jun 2016, 15:45

I've finally determined that the problem with my cousin's '99 T5 is the CVVT. There is a clicking when I manually turn over the engine, and after removing the rear cam cover/cam position sensor, I noticed the exhaust cam skipping back a tiny bit when I hear the click. I think that the CVVT needs to be reset somehow, but I'm not positive on how to do that.
If I'm thinking this through correctly, I saw a video on Youtube that showed locking the cams from the rear, removing the T55 plug on the CVVT hub on the exhaust cam, removing the center bolt, removing the cam sprocket w/ CVVT hub, and replacing it all.
Will this stop the clicking and "reset" the CVVT?
I think this happened after manually turning the cams and crank so many times after a failed timing belt job where nothing was lined up quite right. When I crank the motor, it wants to start, and I haven't been as close as I am now after lining the cams up from the rear. It almost started twice.
Only problem is that the exhaust cam doesn't want to turn back that little bit that will make the slot even with the seam of the cam cover. I tried to rotate it with a flat screwdriver like the guy did in the video, but I chipped it a small bit

.
Anyway, does anyone know any special procedure for resetting the CVVT, and stop this clicking?

Post by **Ozark Lee** » 21 Jun 2016, 18:09

I have not witnessed behavior like you describe but the position of the center hub, and hence the exhaust camshaft position, is controlled by the CVVT solenoid. The solenoid directs oil pressure to the hub to alter its relative location to the sprocket but I don't think that the solenoid can do much without the engine running since there is very little oil pressure when it gets cranked. I don't think that just removing and re-installing the CVVT hub will do anything for you by itself. If the hub is bad then you describe the correct procedure to remove and replace it although you need to offset the timing mark one tooth, with the cams locked, for the initial setting anytime that the hub is removed.

The rear cam locker tool, and a real one at that, is pretty much mandatory to do the job since the T50 bolt is torqued down very tightly, something along the lines of 90 ft lbs as I recall. Using the homebrew cam position holders like the one described in the Haynes manual simply aren't stout enough to withstand that kind of torque.

An interesting experiment might be to unplug the CVVT solenoid and see of the clicking changes when the engine gets cranked.

...Lee

Post by **bmdubya1198** » 21 Jun 2016, 18:29

Ozark Lee wrote:I have not witnessed behavior like you describe but the position of the center hub, and hence the exhaust camshaft position, is controlled by the CVVT solenoid. The solenoid directs oil pressure to the hub to alter its relative location to the sprocket but I don't think that the solenoid can do much without the engine running since there is very little oil pressure when it gets cranked. I don't think that just removing and re-installing the CVVT hub will do anything for you by itself. If the hub is bad then you describe the correct procedure to remove and replace it although you need to offset the timing mark one tooth, with the cams locked, for the initial setting anytime that the hub is removed.

The rear cam locker tool, and a real one at that, is pretty much mandatory to do the job since the T50 bolt is torqued down very tightly, something along the lines of 90 ft lbs as I recall. Using the homebrew cam position holders like the one described in the Haynes manual simply aren't stout enough to withstand that kind of torque.

An interesting experiment might be to unplug the CVVT solenoid and see of the clicking changes when the engine gets cranked.

...Lee

That seems like something worth trying. Obviously, something was messed up with it with all of the moving around. I just don't understand how I'd be able to undo it without having oil pressure.
Although, I do know that the exhaust cam sprocket is not in the correct position. The slot in the camshaft is as close as it can be to being flat, while the sprocket alignment mark is far out from where it's supposed to be. Would removing it and putting it back "reset" the mechanism? It's obvious that it was removed by someone at some point, but the car was running all this time. I don't know why it would wait until I change the timing belt to get out of whack.

Post by **Ozark Lee** » 21 Jun 2016, 20:05

If it was previously removed and if there is a possibility that it wasn't properly aligned when the hub was cinched back down then I would say yes, it is possible that it could be repaired by simply removing the hub and bolting it back at the proper position.

The procedure for re-installing the hub properly is in this document:

99 XC Cam Seal Replacement.pdf: (3.5 MiB) Downloaded 306 times

That is written for a LP turbo but it is exactly the same for the high pressure version.

...Lee

Post by **bmdubya1198** » 22 Jun 2016, 11:39

Ozark Lee wrote:If it was previously removed and if there is a possibility that it wasn't properly aligned when the hub was cinched back down then I would say yes, it is possible that it could be repaired by simply removing the hub and bolting it back at the proper position.

The procedure for re-installing the hub properly is in this document:

99 XC Cam Seal Replacement.pdf
That is written for a LP turbo but it is exactly the same for the high pressure version.

...Lee

Thanks for the link, I'll try this out once I have a good cam locker!

Post by **bmdubya1198** » 17 Aug 2016, 08:20

Figured I'd revive this thread for more attention. Maybe I'll get this solved quicker...
I took this video yesterday after replacing the CVVT hub. The car starts now and it will run, but it sounds absolutely terrible. I don't know what it could be now. Maybe I didn't align the exhaust cam gear perfectly enough, but I don't see how it could be making that much noise. My cousin thinks the valves may be damaged, but the car cranks normally, so I don't think it's an issue. I also lost a screw for the cam position sensor, but again, don't think that's going to cause a problem like that.
When I manually crank the engine, I still get a click, but it's a lot quieter and it's much less often than before. When I look from the back of the engine, the cam doesn't move as much as before. Before, it noticeable clicked back a little every time I heard the click sound. Now it doesn't move much, if at all.
I apologize for leaving out any other details, but anything that was left out in this post and my previous posts can be found at this link: http://volvospeed.com/vs_forum/topic/17 ... cam-click/
Video:
By the way, he turned the car off himself. The car did NOT stall.

Post by **bmdubya1198** » 20 Aug 2016, 19:26

I am VERY happy to report the car is running properly now, and better than the day he bought it!

After I fine tuned the timing today, the car was still misfiring on cylinders 1 and 2, even though the CEL was off and the ECU wasn't throwing any DTCs. The coils were getting spark, the fuel injectors were working, I had good gas in it, I replaced the fuel filter, and the spark plugs are almost new. None of us had any idea what the problem could be.

So, thinking that valves could be damaged, we went on to run a compression test. Cylinder 3 (which was firing correctly) had 165 PSI. Cylinder 2 (one of the misfiring cylinders) had 155. Normal for a T5, from what I've read.

So we went on to replace the boots and springs on the first two ignition coils. Nada. Eventually, after messing around with a few more things, we swapped the connectors for coils 1 & 2 while we had it running. The engine INSTANTLY smoothed out! It sounded beautiful purring on all 5 cylinders again!

I'm happy with the timing adjustment now and my cousin has put over 120 miles on the car already and she has been running beautifully. Very happy we didn't have to give up on the car at 202,000 miles. Now for another 200k!

Post by **abscate** » 21 Aug 2016, 05:28

That's a tough one on ME7. Did you mess up 1&2 at the front of the engine or 4&5 at the rear? I thought my number 2 connector could not reach my 1 coil. That would be a real hassle to troubleshoot without fancy stuff.

Next time that cover is off, I'm marking mine with sharpie and/or tape.

Post by **bmdubya1198** » 21 Aug 2016, 06:24

That's definitely a good idea. I'll do that for his car before we replace the covers.
That's what threw us all off, the wires looked correct, like they couldn't reach the wrong ones. We twisted the wires around and conected them the other way and the engine instantly smoothed out. Back on all 5.
You can't overlook the simple things, no matter how unlikely it seems!

Post by **abscate** » 22 Aug 2016, 00:38

Good on Volvo for this one.

Checking the diagram, each coil has a different colour trigger wire to the ECU so it is possible to sort this out without tools

Wiring diagram here

https://www.matthewsvolvosite.com/forums ... il#p325109