Swagger93

harmonic balancer?

Dilberto

I agree- balance shaft belt misalignments of a tooth, are often assumed as "good enuff, fer me" ....and somewhat accepted. I paid a Porsche specialist just to align my engine's timing belt/balance shaft. I know how to do this myself- and has many to my credit....but still not confident enough to charge money, and offer warranties for doing it. Paying somebody who has the "TOOLS" is good insurance. My recent rebuild experienced upper-rpm sensory vibration, because the idler roller of the balance belt co-tensioned the belt itself, resulting in noise, vibration and eventual failure.

hosrom_951

Luis: Nope, it was running synthetic ALL it's life

BUT, switched from 15w~50 to 0w~40 (the only thing Mobil 1 has for me)

But i was using that oil for over 4+ months, this leak is quite recent.

Anyway, REMOVE THE BELTS AND REINSTALL THEM

Danno

He's got an '84 944, so the U and O marks don't have to be swapped like on the later cars. Also you want to check for the notch on the rear of the balance-shaft pulleys to line up with the pointers on the belt-covers. That way, even if the front sprocket-covers are off, you can still be assured that the pulleys and balance-shafts are oriented correctly.

Dave951M

So what's the verdict?? I'm betting on balance shafts being mistimed.

Geo

Well, this is what we did. The notches lined up where they were suppposed to be as well as all other marks.

Seems really weird.

How can the balance shafts be off by 180 when everything lines up? I'm not challenging anyone, but would like to understand before we pull it aparat again.

Dave951M

You don't have to pull it apart to verify timing marks. Line the engine up TDC, take the covers off and look closely at the notches on the bal shaft sprockets. I have seen this exact problem and it was the bal shafts being off.

goingboeing737

I'm for trying the dowel in the #1 cylinder to make sure we are on the correct TDC.

From some other post I've read, and with the dificulty in seeing the "OT" mark on the flywheel, I think that is going to put us more in the ballpark for getting it set right.

Here is link to a thread on Pelican. He is having trouble locating the "OT" mark as well. Several good explanations on being 180 degrees out.
TIMING THREAD ON PELICAN

If we are confusing the same "OT" mark as whoever did the work, that is why it is "looking" correct. Did that make sense ???

Geo

What you describe is EXACTLY what we did.

So are you saying all the marks lined up with the engine at TDC the shafts can still be off by 180*? If so, how? Again, I'm just trying to figure out how this can happen before we go back in.

Geo

I am 100% certain we had it at TDC. No doubts what so ever. That is why I made us go through so much work on it.

Dave951M

They can be off, at least in a post 85.5 car. We had this problem with my brother's car and you couldn't tell it until we removed the bolt on the sprocket faces. It wan't a huge production to get to, just set TDC, remove the front cover, remove the bolt on the face of the bal shaft sprocket. There's a thin metal piece that helps keep the bal shaft belt located on the sprocket. On the later cars, it's possible to mistime the bal shafts because of the way these are made. I was a skeptic too, until convincing him to take off the bolts and checking against the manual and the sprocket marks.

goingboeing737

So, if they replaced the sprokets, THEY could be mounted 180 degrees out?

Am I following this at all ?

And, this is on a 1984.

Dave951M

Yes, it is possible, check it.

Geo

I'm not skeptical. I'd just like to know how it can go wrong when all the marks line up so we don't make the same mistake the PO's mechanic did.

Sysgen

Old thread I know, but the answer isn't clear. Is it possible to have the marks line up and still be 180 degrees off?

Anyone?