set pump to 1.10?

[sethyboy85]

If I set a pump with a new belt to 1.10 it should stretch close to 1.05 right?

I am so busy with life and holiday stuff I am gonna pay somebody to swap out my NA pump for a TD pump and do a much needed timing belt.

I was going to tell him to set it to 1.05-1.10 so at least im at 1.00 after stretch. I do run vegetable oil as well so it will help with that

if im totally wrong let me know...

[sethyboy85]

ok... 1.05 it is

[jtanguay]

don't they stretch over time? main reason the engine gets louder over time? not much... but a little bit?

[larry104]

I've never had a timing belt stretch at all.

Andrew

Have you ever had pump timing change slightly (a few thousands of an inch) after locking down the pump and rotating it through two revs?

[QuickTD]

If the belt stretches, the timing should retard, making the engine quieter. In my experience the timing change is negligable. The later 1.9TD uses and automatic tensioner (same as the TDI), the adjustment pointer does not change position in 100000km of belt use, indicating very little belt stretch. I used to check it once in a while, now I just leave it alone...

 I would set the pump exactly to your desired timing and enjoy.

[QuickTD]

Have you ever had pump timing change slightly (a few thousands of an inch) after locking down the pump and rotating it through two revs?

I would install the belt and run the engine for 5-10 minutes to seat the belt before final timing. After that I don't think you'll see much (if any) change.

[zagarus]

could milage slowly drop over time as a new timing belt wears in? say 5 months worth of driving?

i've noticed a drop in mileage with my car, june (when i got the new timing belt) i was still getting like 38-42mpg in town, now im lucky if i get 35.  could this have somethign to do with it? if not what else?  im thinking its the timing cause nothing else has been changed.  Alignment is good, but i will do new wheel bearings.  just thought i'd throw this in

[burn_your_money]

Maybe your pump is moving, I had that happen to me once

[zagarus]

moving?  :shock:

[jtanguay]

it makes sense that the pump could be moving... it does pivot to change timing.  all it needs is to become a little loose and move very very slightly to throw the timing off.

[larry104]

No, I haven't, but if I ever do, I'll blame it on not properly loading the belt rather than stretch.  I've seen 60,000 miles on belts where the timing didn't change any measurable amount.  I have, however, heard other people claim to have had belts stretch so it's a possibility.  It certainly isn't something I'd count on and time my engine accordingly, rather, if I ever did positively confirm that a belt was stretching I would replace it immediately.Andrew

Hmmm... this is a new belt. And I followed the procedure to the letter on belt tightening, though one person's idea of how easy it is twist a belt 45 deg may be slightly different than another's. Then there is the possibility that I'm not aligning the flywheel timing mark exactly the same each time.  Interestingly, the timing always retards (from the initial setting) about the same amount after two crank revs. Also, I watched the dial indicator when torquing down the pump and saw no movement, so it's definetely a result of the rotation. And it doesn't retard any further after the engine has been run.  I ended up advanced the timing that same amount and checked it after it ran. It's spot on.