P0016 after cleaning CVVT Solenoids

[ZuluSafari]

Very informative! This brings together several different sources in an easy to understand narrative. The CVVT video online shows the spring loaded exhaust hub, while other timing videos show very little. I was getting confused by everyone's assertion to pull the crank forward another 1/4 turn, then going back to relieve the CVVT loading. I think that applies only to the spring-loaded ones, and even then, doesn't seem necessary. The fact that they had to further move the camshaft backward to move the exhaust CVVT into position for the cam locking tool further reinforces that it isn't nearly as important to load,unload, as long as the cams are correctly timed and held in position. I see now why a few posts were so forceful on their assertions that the timing marks on the gears aren't nearly as important as properly holding the CVVT in the furthest Clockwise position, AS LONG AS the cams are properly aligned/locked at the rear.

This cleared up so much, and I am going to tackle the project this coming weekend when my tools arrive. I may end up replacing the hubs, just for security/peace of mind.

[F250]

I'm glad that you found it to be clearer than all the other reference information. I was in your boat exactly, and the varying explanations with only varying levels of detail made it hard for me to know exactly how to translate the different approaches into reality. What I came up with is nothing more than how I ended up making sense out of it all, and some of that was only after-the-fact.

When you run through it this weekend, if you find any errors or additional helpful details, let me know and I'll revise the document to include them.

[F250]

If you downloaded the file yesterday, or any time up to 9:30 AM this morning, delete the file you downloaded adn replace ti with the one in Post #3 of the other thread. There were some critical errors in a few steps which I did not catch until late last night. Corrections have been made and the old document replaced.

I apologize for any confusion or inconvenience this may have caused.

[ZuluSafari]

Well, an interesting day!

I replaced the timing belt, tensioner, and idler. The belt looked in pretty good shape, until I bent it around the tensioner - it had crazing in the backbone - it also has been subject to some oiling over its life. The idler and the tensioner both had measurable wear into the surfaces, leaving pronounced shoulders where the belt hadn't tracked. Glad I put new parts in! I changed out the oil fill gasket, and cleaned all oil from the top of the camshaft cover.

I locked the cams after timing the engine, and the crank was forward almost one full tooth - the timing marks on the crank gear did not frame the oil pump mark, and the crank flange timing mark was not in line, either. I properly aligned the crank, intake CVVT and Exhaust CVVT, installed the new timing belt, rolled the engine through two revolutions, and reinstalled the cam lock to verify everything was still lined up correctly. I also spent quite a bit of time running the CVVT hubs through their ranges of motion, and both felt very smooth, with slightly more play in the Exhaust hub vs the Intake one. Once I was completely satisfied that the timing was now 100% correct, I reinstalled the cam sensors, serpentine belt, etc., buttoned her all up, and started the engine. It ran just as loping and rough at idle as it did before the timing belt change.

Needless to say, I was pretty down! I took the timing covers off again, ran the engine around, and verified the marks lined up. I checked the cam ends, and they lined up perfectly at the rear of the head, so I locked them in again, removed the belt, and verified the hubs were fully clockwise before reinstalling the belt again. I buttoned everything up once more, and was met with the same result. P0016, loping idle, and rough acceleration.

I then installed the remanufactured Intake CVVT Solenoid and gasket I ordered along with the cam locking tool from FCP Euro, and was met with sewing machine smooth idle, and spirited acceleration! I had to slightly modify the solenoid wiring connector, though, as the reman unit had a slightly different socket than the stock Volvo unit it replaced!

So -- The P0016 was apparently due to a faulty Intake CVVT Solenoid all along, though replacing the stretched and worn timing belt components was definitely a great and appropriate preventive maintenance activity. I also learned quite a bit more about my engine and it's valve train in the process!

If I had not removed the old belt and bent it to a smaller radius than the visible curves of the timing gears, I wouldn't have found the fine cracking beginning to form in the backbone, nor would I have found the worn faces of the idler and tensioner pulleys. It made me realize how easy it is to believe things are in better shape than they really are as seen during a cursory inspection when purchasing a vehicle.

This experience brought me back to trusting my instincts that if a new problem arises following servicing a component, then the fault likely is related to the components worked on! Apparently, the stuck intake solenoid had allowed oil pressure to bypass in an OK amount for normal (if sluggish) operation before I freed everything up, but was not operating properly to modulate idle valve timing once I cleaned everything out to free movement again.

I have no regrets doing a full retiming job, as the crank did appear to be off relative to the cams, and therefore the engine should run much happier than if I just replaced the solenoid. After resetting the system, I have no more timing codes coming up, and the check engine light is off for the first time since I bought the car late last month!

I really want to thank F250 for the excellent compilation on inspecting and setting the CVVT hubs!! While I didn't remove the hubs from the camshafts this time, his inspection description gave me confidence to feel how the hubs should operate on the camshafts. I also felt much more comfortable doing the work with the camshaft locking tool firmly holding my camshafts in the proper orientation throughout the timing belt change. I could not imagine how I would have succeeded without the tool or F250's information. Once again, Thank you!

[F250]

Excellent! It is so satisfying to work through a problem to success. I'm really glad you got it worked out.

[jmartin919]

Regarding turning the crank 90 degrees (1/4 turn) past the marks and then back to the marks, I don't think it applies to the hydraulic CVVT's but it does to the spring loaded ones like on my exhaust cam (2000 S70 GLT SE). If you don't turn the belt 1/4 turn and then back, when you take the TB off the CVVT cam will spring back a bit counterclockwise. When you attempt to put the TB on you will have to simultaneously turn and hold that CVVT clockwise to the timing mark. If you turn it 1/4 turn past and then back this will lock (unload) the CVVT cam in position at the timing mark - so you don't have to fight it when installing the belt.