before I screwed up may valves do to not knowing about this system, my check engine was on. and the code was that there was a misalignment of timing in the cams or faulty cam sensor and a low boost code. but after replacing the cam sensor the check engine light didn't go away. I hope it disappears but if it doesn't I'll keep your post in mind.Thx

 

I have an 01 S80 t6 with 105k on it, I did the timing belt about a week and a half ago, when I was finished I was not positive about my timing marks, it seemed like the exhaust cam was off one tooth (drove it around the block that night, and ran great, after that only pulled in and out of the garage a couple of times, when it started, ran, and sounded fine). I got back into it today and was able to loosen the tensioner and work the belt off just the ex. cam, move it one tooth and then slipped the belt back on - awesome, could believe it! So, then want to check that everything was good, I gave the crank two full turns and then about a quarter more, then turned it back a quarter turn - like I had done more than once last week when I did the job - but this time just as I was coming back to the top where marks line up there was this pronounced "CLICK". I don't what it was but I don't think it was good - engine doesn't seem happy now - doesn't really seem to like to turn through, I have only turned it by hand so far but to get two more full revolutions out of it was not easy. What'd I do?

 

By turning the engine over in both directions by hand you most likely forced all of the oil out of the VVT actuator. It would then no longer dampen or fully control the rotation of it's camshaft, allowing the cam's lobes to load and unload rapidly over the valve buckets. This would be normal... if that is indeed what has happened. It will correct itself as soon as oil pressurises the VVT upon start up.

Also, note a nice healthy engine, if everything is in time, will normally be difficult to turn over by hand to a degree. It's trapping compression in each cylinder every 120* of rotation. If you remove the spark plugs it should turn over more smoothly, with the only resistance being that of the cam lobes depressing each valve spring through their cycle.

I'd say double check all the timing marks and belt tension again and build a fire in it!

-R

 

I agree with TheRepairMan. IMO, you should NEVER turn the cam back, only forward (clockwise).

 

Hey thanks, that sounds really good, I understand about the resistance I feel due to compression, I feel the resistance get stronger as I come up on compression and all - my concern is that after this incident with the click sound, the engine became markedly harder to turn through - what I feel is more than compression - but obviously not sure. I am really curious to know how much damage could I have done turning it by hand? Could a person with enough determination (stupidity?) actually bend something by hand? I think I will go and pull the plugs and turn it through see how it feels and look at all the timing marks and how they are lining up as I am pretty leery about firing it.


About turning it backwards a quarter turn, I got this from a Volvo PDF Doc. and also read it at Mitchell On Demand page that gives step by step on this job, and they actually tell you to do this - bring the cam marks up to the twelve o'clock mark, then turn an additional quarter turn and then back it up to top? Is this just bad info? Is it ever ok to turn the engine CC? A quarter turn is ok, but that is absolutely all? Seems like it is worthy of a big caution note in their instructions?


Thanks so much for your time.

 

I have never read that but if it's in Volvo & Mitchell, I guess it's fine or recommended by the pro's. They surely know 100 times more than me. My deal is, if you started the car and it was running, you were good at that time. I say, pull the plugs, turn it by hand 2 full revs, if it's doesn't stop, you should still be good.

 

Yeah, turning it by hand so far forward, then backward to a degree (I don't recall the precise amount, but it is in the OEM procedure for each engine family), and that is done to force all of the oil out of the VVT actuator hub in order to complete the procedure to set it in time with the cam. If you are just replacing a belt and not taking the center bolt loose for any reason there's no need to turn the engine backwards... if you do it won't hurt anything providing all is in time.

... so the question here is... did you have the cam sprocket's center bolt loose and maybe get things out of time? If that's the case, then I'd say it is remotely possible that you could have tipped a valve against a piston. It really doesn't take much force at all to bend a valve...but...

Hopefully you can just make sure you are in time as best as you can and crank it over to start. What other choice do you have at this point? I mean, you could go through the whole timing set up with the VVT if it makes you feel any better before you go to start, I guess. I wouldn't do that unless I had to, and if you never broke the center cam sprocket bolts loose then I'd say you are still okay.

-Roger

 

It's no good, pulled plugs and it turns about 90 degrees or so and there is some interference, doesn't want to go any further. Hard to believe I drove it into the garage yesterday morning and it is now out of commission. So it seems that the cams are out of time and I need to pull the head to see whats going on?

 

You didn't answer my question.

Did you loosen the cam sprocket center bolt on either cam?

-R

 

I'm a little lost I guess. You replaced the belt and what ever else, you started the car and moved it, you thought you may have been 1 tooth off so you took it loose and moved it 1 tooth, now you're convinced that it's out of wack. I'd take it loose and move the thing back the 1 tooth and see what happens then. Other than that I would take it to a shop and let them fix it. Chances that you bent a valve turning it by hand is very slim to me. I could be wrong. I promise you, I have messed up a tb - cam alignment pretty bad and got it back together good because of the marks that I had on it. I really had no idea if the motor would start or not but I did turn it by hand 2 or 3 times and then turned the key. I had to turn one of the cams back a little but not with the belt on it. Hope you get it worked out.

 

Sorry Roger,

No, did not loosen any cam bolts at all.

 

rspi,

Yea, I am little lost too. Yes, I figured that I should try going back one tooth and seeing what it gets me, thanks for the optimism. I would love to be able to sort the timing out without opening it. I am wondering if you or anyone has any theory about this click noise I described because in my mind it marks where things changed - was able to turn the engine through without difficulty right up to this point and after that click the problem started.

Thanks

 

Okay. I must not have explained it clearly enough, but you still have hope being that you haven't taken the cam bolts loose. The clicking most likely is there due to no oil remaining in the VVT advance mechanism (sprocket). In effect, it is disconnected to its camshaft to a degree... or certain number of degrees, therefore, as you turn the engine that cam will be forced to snap forward as any lobe passes its apex. This happens because the valve springs are almost always trying to roll the camshafts either forward or backward.

It's always possible something else is going on, but you should re-install the belt in time and see if it will run. If it won't then the outcome would be the same... tear down, but if it does run on all cylinders, you win!

Make sure it's in time!!!!!!!!!

-R

 

Lots of great information here about the morass that is Volvo's VVT, etc. I am waiting for my parts to arrive so I can change my timing belt, and I have read hundreds of posts regarding the procedure. The one question that I can't seem to find an answer for is, does one HAVE to remove the crankshaft gear in order to remove/replace the belt. The fewer gears touched, the less likely the timing can drift. I'm just sayin'.

 

The crankshaft pulley can stay on the crankshaft - it does not have to be removed. But it's much easier to do the job if you remove the harmonic balancer which is also the drive pulley for the serpentine belt. You need to remove the crankshaft nut in order to remove the harmonic balancer.

You can change the timing belt without removing the harmonic balancer if you remove the lower timing belt guard, but it's much easier to do the job with the harmonic balancer off. For one thing, it's hard to see the crank pulley timing mark with the harmonic balancer in place.

I recently did the timing belt on my V40 and if I were to do it again I'd change two things. (1) I'd buy a crankshaft holding tool to make it easier to torque the crankshaft nut. (2) I'd buy a good quality all-metal cam holding tool like this one. The red plastic cam holding tool I bought on Mr. Winkey's recommendation was worse than useless. It did not fit and after I modified it so it did fit it immediately popped out and lost cam timing for me.

 

I've done about 4 belt jobs and never pulled a crank to get the belt on or off. Off is easy, just cut the belt. On is not bad when the crank guard is removed as explained in most instructions. I also do not have a cam locking tool.

A lot easier than people make it to be. Just take your time.

 

I've got a 99' S80 that I bought a few months ago. The previous owner told me that the timing belt was indeed changed around 100M mile. I now have 146M on it. I just changed the serpentine belt and while I was doing that, I popped the cover off the timing belt. The belt looks good with no visible cracking on either side of the belt. Tensioners look good with no grease slinging. Is there a better way to evaluate the condition of the belt? Or should I just change it for peace of mind?
Thanks

 

You can not tell much about the condition of a timing belt by looking at it. If this were my car I would definitely do a complete timing belt job right now unless I could verify exactly what was done at 100M miles from a service invoice. Best prices on OEM parts - tascaparts.com.

 

There is NO WAY I would replace a belt with 50,000 miles on it unless there was a problem with a water pump leaking or roller howling. Not sure what the maintenance book suggest but do what the book says.

I purchased a car a year ago and had all the parts needed to do the belt but waited untill I was 4k past the change due. There is no reason to rush to change it if you have evidence that it HAD NOT been done. There should be a sticker, receipt or something. If you have no proof go ahead and do it or have it done. Just replacing a accessory belt has nothing to do with a tb job.

I will agree that you can NOT tell if any of those parts are near failure. Seized or nearly seized rollers LOOK GOOD. I pulled a belt from a 960 once and a good looking roller was locked up, took 2 hands to turn it.

 

Many of the Volvo OE timing belts I've taken off during replacement were showing fine cracking all along the back of the belts. No question it's time if you see that. Even if you don't, I wouldn't take a chance on a Timing Belt that I couldn't confirm the history of.

If any of you have ever had to make repairs to one of these engines that broke a belt you know how expensive and time consuming it can be. I'd rather spend a little on the preventive maintenance first.

-Roger