Timing belt shifted by two teeth??

[gloupemilia]

Hello,
In the middle of a head cylinder gasket replacement, I wanted to check how the timing belt was, before dismounting everything.
First look: the lines on the belt are not in front of the grooves/marks on the various pulleys... the previous timing belt exchange was done with white paint and not the standard procedure :-(.
Second look: when I put the cam pulley at the right position:

The ignition seems no exactly in front of cylinder 1:

So does the intermediate pulley, it is shifted clockwise by exactly two teeth!

Concerning the crank shaft (the groove is not in front of the vertival metal part, I guess this is the mark), it is also shifted by approximately two teeth... anti-clockwise !!


How can this be? The engine was running fine...

[Bugjam1999]

I think you’re mixing up the crank markings for the bottom pulley- there are two sets that show tdc, but if you mix them up you won’t be correct.

1.) The most reliable is to use the notch on the crank and the casting mark on the front cover- see this thread and the photos in it.

http://www.turbobricks.com/forums/sh...d.php?t=325514

2.) The other method is to use the notch in the pulley and the marking on the plastic cover. This method is less reliable as the rubber in the pulley (it’s a harmonic balancer and the inner metal pulley and outer metal pulley are held together with a piece of rubber) can degrade meaning that the two halves of the pulley move independently of each other... meaning that the marks don’t line up.

Your photo suggests that you were using the casting mark from method 1.) and the pulley mark from
Method 2.)

Take the pulley off and set tdc using method 1.) and the pictures in the thread I linked to above. Does the cam pulley line up properly now?

Cheers

[gloupemilia]

Hello, thnak you for your reply!
The photo I posted before is using method 1 -- pulley removed, I can see the big notch on the crank and the smaller one on the washer, and they're not lined-up with the casting mark. My photo is not as good as in the other thread :-).

I also have a photo with the pulley on (so, method 2):



My biggest question now:
Tomorrow, I will start reassembling the engine. I guess I should put the belt in the right timing position, with all the notches/marks lined-up? Or put it back at the exact same timing as before?

Edit: I forgot to tell you the engone is the B200E. I think it makes no difference in the timing blet position, anyway... :-)

[Clifford Pope]

They may well be the same thing? Surely from what Bugjam is saying, the reason for the discrepancy could be that the balancer has slipped, so the pulley mark is not correct?
If the original timing of the belt before the one you have just removed was correct, and the paint marks were transposed accurately, then simply repeating that procedure should be correct too?

[gloupemilia]

Originally Posted by Clifford Pope

They may well be the same thing? Surely from what Bugjam is saying, the reason for the discrepancy could be that the balancer has slipped, so the pulley mark is not correct?

I'm afraid not: it's the crank mark which is not correct (pulley removed).

Originally Posted by Clifford Pope

If the original timing of the belt before the one you have just removed was correct, and the paint marks were transposed accurately, then simply repeating that procedure should be correct too?

That's definitely one possibility. I have drawn marks on the old belt, so I could put the new one with the exact same timing. But maybe I could have better results with the right one? E.g.: the engine is running fine, but I always found it a little noisy, somehow hash; I always felt some small vibrations, I suspected some ageing engine mounts; cold start has never been really good... could this come from a two-teeth shift?
And maybe this 'wrong' timing will cause further issues? I don't like when I don't understand something...

[Bugjam1999]

Well, my advice would be to ignore the white marks and use the Volvo marks. Set the crank at tdc using method 1 (method 2 may be the same but if it isn’t trust method 1 not 2).

Set the cam pulley using the Volvo marks, then set the distributor pulley using the Volvo marks (ignore where the distributor points to for now).

When you have the belt and pulley on, turn the engine over twice by hand using a socket on the crank bolt and check everything lines up again afterwards.

With the engine at tdc does the distributor arm point in the correct direction? If not, undo the bolt that holds the distributor down, then remove the distributor by lifting it straight up, turn it slightly and replace- it will turn as you remove/replace it so this might take a few tries to get it right.

After all this you will have a new timing belt and everything lined up using the Volvo marks, so no chance of confusion next time.

I have heard these engines will run with the timing belt incorrectly positioned by one tooth, although badly. I’m not sure I’ve ever heard of two teeth different though. The 940 engine I put into my 240 had the timing belt out by one tooth when I stripped it down, so I presume it was running in the previous car like that for a while.

Cheers

[gloupemilia]

Thanks Bugjam, I think I'll follow your procedure.
Definitely, the ignition has to be adjusted, it has certainly been shifted to compensate.

This evening, I cleaned out the cylinder head: ready for tomorrow!
Except that it's raining tomorrow all day and I'm working outside :-(

[Stephen Edwin]

I found with a B200F that I lined everything up definitely and meticulously though I says it myself. Turned the engine over by hand, and time after time the belt was one tooth out. So I aligned the Volvo marks again from scratch....and again....and again....and....

Crazy. And it was a lovely Sunday morning. I wanted to be out in the countryside by so called clipless, pedal power.

I stood in the sunshine with a coffee. The neighbourhood are well used to seeing me cogitating over, or underneath, the 240.

For me, the answer was. Set the tension and tighten the adjuster nut TIGHTLY. Keep that adjuster TIGHT when turning the engine over by hand. 15mm socket. 37 lb ft. I hope that might help.

*****

Be very sure to follow the advice given by previous more knowledgeable posters. And remember that You get a better view of the marks if you remove the radiator.

.

[gloupemilia]

Yes, thanks, I will pay attention to that.
The radiator and the calender grill are out, it does help, indeed.

[gloupemilia]

Hello!
News from my Swedish Saturday.
Reassembling went fine.
When arriving at the timing belt, I used Volvo marks; I made a few turns and checked: the various marks are still aligned with their reference. Only the lines on the belt itself are moving, but I guess it's normal. And of course, not piston hit on the valves :-).
I had to stop there because I detected a problem with the belt tensioner (I forgot to buy a new one...): once everything in place and tightened, when I turn manually the engine, the belt is moving laterally on the cam pulley and find a stable position slightly out of the pulley; when I release the pressure on the tensioner, it goes the other way. It looks like the tensioner plate is not exaclty 90°... I'll buy a new one!
Next episode in a few days!