Advice on purchasing 147 GTA

[wankski]

i think he meant pulley? i kinda know what he means tho, its wedged b/w the tensioner and the inlet cam sprocket... it is indeed responsible for the large flexure in the 4cyl cam belt... so when leaky leaks right on top of the tensioner...

[colcol]

On the inlet cam on the left side, the tensioner is under the camshaft so that the belt wraps around the inlet sprocket, this 'tensioner' is the waterpump, the tensioner on the right side is under the exhaust cam, so that the belt wraps around the sprocket of the exhaust cam, this is just a normal tensioner that doesn't multifunction, and yes a leaky waterpump would cause the belt to slip a cog or two, introducing mr valve to Ms Piston, causing ruined motor, hope that clears it up, Colin.

[wankski]

the tensioner is directly under the waterpump (both of which under the inlet cam), the other thing to the right of that is an idle pulley.

[colcol]

Correct!, in my workshop manuals, the water pump, under the inlet cam and the idler under the exhaust cam can be refered to as tensioners, idlers, followers and pulleys,  the tensioner under the water pump is refered to as a AUTOMATIC tensioner that varies the tension on the cam belt pulley by having a spring in it so as the engine heats up and the cam bely stretches over time and the pulleys wear out the tension has to be varied otherwise, too loose and the cam belt slips and too tight and the cam belt would be noisy and would break early on in its life, the automatic tensioners were the ones that caused so much grief for Alfa Romeo, they were plastic and  brittle, they would shatter causing the belt to slip, but apparantly is was a big problem in cold climates as the plastic was more brittle when cold and in Sweden for example they used to break on start up, early on Alfa Romeo replaced these with steel material on the cog, Colin.

[wankski]

true enough.... it's certainly not a fixed tensioner! you can only set it against the mark at TDC.... in operation the thing bounces around like a madman!

The waterpump pulley as mentioned causes maximal wrapping of the belt against the inlet cam, so it definitely keeps the belt routed and taut.... the other thing to the right (exhaust) i refer to as an idle pulley cos it really does nothing other than push the belt closer to normal (as in vertical) back to the crank sprocket and moves it away from the timing belt guard.... that said, i guess it does also exert force on the belt and keep it taut against the crank...

good show colin!

umm, no fair! what factory manual do you have for the 156??

[colcol]

I have 3 manuals on cd for 156's, they were puchased on the net, 2 from England, 1 from Queensland, and they are all the same!, they are a genuine factory rip offs, as they have the factory logo's and part no's , i had plans to put them onto paper and have a hard copy of all the repairs i will ever need, but it would take forever, so now i only print off what i need to fix, poor old windows don't have a facility for printing whats on the screen, so i use a Gadwin print screen program so i can bring it up on the screen, and press Prt Scr [print screen], and it goes straight to the printer, not a perfect situation, but the best i can manage, Colin.

[Jekyll and Hyde]

Correct!, in my workshop manuals, the water pump, under the inlet cam and the idler under the exhaust cam can be refered to as tensioners, idlers, followers and pulleys,  the tensioner under the water pump is refered to as a AUTOMATIC tensioner that varies the tension on the cam belt pulley by having a spring in it so as the engine heats up and the cam bely stretches over time and the pulleys wear out the tension has to be varied otherwise, too loose and the cam belt slips and too tight and the cam belt would be noisy and would break early on in its life,

By that logic, the cam gears and crank gears are also tensioners.  After all, if they weren't there, the belt would be pretty loose, wouldn't it.  Pray tell, how do you adjust your water pump to re-tension the cam belt?

true enough.... it's certainly not a fixed tensioner! you can only set it against the mark at TDC.... in operation the thing bounces around like a madman!

That's because belts flap on their undriven side, which is part of the point of the tensioner - to dampen the flapping of the belt and keep the variance in tension to a minimum.  The other point of a tensioner is to allow adjustment of the belt tension by physically moving it in relation to the others, particularly when installing a new belt.  Which is why it has slotted mounting holes, unlike the waterpump.

the other thing to the right (exhaust) i refer to as an idle pulley cos it really does nothing other than push the belt closer to normal (as in vertical) back to the crank sprocket and moves it away from the timing belt guard....

Well, actually the idler on that side does wrap the belt further around the exhaust cam gear... Which again, is the point of an idler pulley - to allow routing of a belt in such a way that you can achieve the best amount of contact around the pulleys around it.

If you must call the damn water pump something other than a water pump strategically placed to optimise belt layout, call it an idler pulley.  Not exactly accurate given that it's driving the waterpump, but a lot more accurate than calling it a tensioner.


At this point, I'm just waiting for someone to get their cambelt changed at a workshop, be told the tensioner will be changed and assume that this means the waterpump is being changed (due to Colin insisting that the waterpump is the tensioner).  Then have a waterpump leak start 3 weeks later, and ask why they have to pay to have the cambelt removed again (shouldn't it be under warranty if it was just replaced?)...

I know what he's on about, Wankski gets what he's on about, but many of the people who read these forums looking for advice may not have much, if any mechanical understanding at all, and to call the waterpump a tensioner will drastically confuse this issue for them.  THAT is the main reason I'm bothering to argue this point, aside from the fact I disagree with a fixed pulley of any kind being called a tensioner.

And finally, why the hell is this discussion on the mechanical layout and faults of a 4 cylinder cam belt being brought up at all in a thread about buying a V6 powered alfa?  Again, confusing the issue for those with less understanding of all matters Alfa.

[MJF]

And finally, why the hell is this discussion on the mechanical layout and faults of a 4 cylinder cam belt being brought up at all in a thread about buying a V6 powered alfa?  Again, confusing the issue for those with less understanding of all matters Alfa.

Haha not a problem,  I'm glad that we're all on the same page

[colcol]

The water pump is a water pump and is called a water pump cause it pumps water, but it also acts as a idler, guide, pulley, and it should be changed every second cam belt change, ie 100,000klms or 6 years, whichever comes first, if it leaks 3 weeks after a cambelt change, then thats the owners fault for not changing at the due date, you can hardly claim a warranty claim on the mechanic, if the owner didn't change it, over the years my various manuals have called tensioners all different things, it does not matter what you call it, as long as you know what it is, one of my English manuals has a translation for all the names of different parts from all over the world, no wonder we get confused, i hope that clears it up, Colin.

[colcol]

oh, and i found a manual that called a idler\pulley\tensioner\follower a jockey wheel!, and then called a constant velocity joint a Homo Rzeppa joint, for once i am speechless, Colin.

[gbernard]

hehe, and I thought we went off topic on ausalfa.com . . .  

I wonder how many responses on this thread are from people who have actually owned a GTA . .  

versus the self indulgent "I have access to an online manual and theoretically I know more than someone else mentality" . . .

[colcol]

I have never owned a 147 GTA, TOO much power for me, but being a club member for 25 years you do pick up snippets of information, and for what its worth, you pass it onto other owners, i don't have a online manual, just a CD i bung in my computer,  i don't know more than every one else, just lots of passion for our favourite Marque, and yes we have totally got off the subject again, so let me take this moment to remind all 147, 156 and 166 owners of the Technical Workshop night at Maranello Pur Sang motors on Friday 27th May, bookings, phone 0407 090 826 or email drtool@bigpond.com.au, Colin.