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Discussion Starter #1
My Verde's timing belt has slipped three times now after starting from cold, running for less than a minute, then shutting off. Luckily it's always been just one or two teeth and I've got it down to a 30 minute repair.

I am using the original hydraulic detensioner with everything rebuilt and no leaks. I use 10W/40 oil and have maxed out pressure when cold (although I don't 100% trust my gauge because it is very jittery). I'm wondering if the detensioner is making the belt too slack due to the high oil pressure and not bleeding off the pressure fast enough when I turn off the engine, making the belt slip?

Has anyone else experienced this? It's quite frustrating. Maybe it's time to try a mechanical tensioner? Perhaps I just need to make more of a point of letting it run for a few minutes even if it is just to get it out of the garage.

Thanks,
David
 

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Before starting again, check condition of your de-tensioner's internal spring. I would guess that it's broken or at least collapsed.
 

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Discussion Starter #3
Thanks for the tip Graham. Unfortunately I have to drive it back home from work to check it out. Since the drive in was uneventful I'm hoping the return trip will be the same.

For what it's worth, it took the 'usual' amount of effort to move the tensioner up into the position where you can insert the pin and hold it there. I don't know if I was pulling against the external spring only though........maybe the internal one has had it.
 

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I have the oil hole welded up on mine. I have never liked that it makes it lose when cold. that is the only time there is real hi oil PSI when cold when the belt is stresed the most.
BTW do you know where to get a new hydraulic detensioner mine is geting kinda old it must have way over 200K miles on it and I would like to get a new one.
 

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My Verde's timing belt has slipped three times now after starting from cold, running for less than a minute, then shutting off.
A bit off topic, but I have to ask - but why are you doing this?

With EFI cars, it's very unadviseable to shut a car off while it's still operating under cold start enrichment. Our neighbor the Toyota mechanic has at least 1-2 Camrys, etc. come in on a tow hook per month due to what they call "Lawnmower Syndrome" - i.e. the owner starts the car, pulls it out of the garage so they can get at the lawnmower, then park it in the driveway. When they come back to the car later, it will not start due to flooding.

You really need to let the car warm up for a few minutes, or better yet drive until fully up to temp before shutting it off.

Joe
 

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Discussion Starter #6
Slyalfa, I'm sorry but I don't know where to buy a new hydraulic tensioner. The rebuild kit addresses most of the wear items but the springs seem to be another matter. They can probably be matched to something comparable if someone had unfatigued new springs to measure the constants. Is the pulley interchangeable with the mechanical tensioner?

JoeCab, I try very hard to avoid short runs but sometimes there are too many things going on and I simply forget. The previous occassions have been when I've driven the car up on ramps for exhaust work and to avoid too much heat build-up I shut it off immediately. I'm a slow learner!
 

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do you leave it in gear when parked? I have herd of this where it is left in gear and the car moves some runing it the wrong way.
 

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Discussion Starter #8
Great question. The answer is 'NEVER!'. Sometimes it would be nice just in case the parking brake lets go on a steep hill, but I take my chances. I know I could leave it in reverse with the car pointing uphill but I still take my chances. I've seen the belt jump when I've overshot the 'P' mark and turned the crank backwards, it happens very easily.

It's looking like this is not a common problem so either no-one else has to move their cars short distances or there is something wrong with my tensioner. I'm leaning towards the tensioner....
 

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As you are aware, there are three springs in play here; the large internal spring against the hydraulic piston, the preload spring semi-hidden between the detensioner casting and the back plate, and the operating tension spring with it's rubber casing. Is the preload spring in place?
 

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Discussion Starter #10
I just checked and the pre-load spring is where it needs to be. I have been trying very hard to recall how I set up the tensioner before tightening the nuts, and I am 99% sure that I turned it all the way counter-clockwise to get (I think) max tension before I released the pin (drill bit). I have just read the manual but it's not clear to me if this is right or not. I've searched the forum looking for more but can't find what I'm looking for.

Does it sound about right?
 

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when at idle is the belt smooth at the top or does it bounce? ( where it spans the cams)
when you had it apart did you hone the plunger so it would go in and out smooth?
on mine there was a spot where it would hang up I had to hone it for a while to get it so it would go in and out smoothe again..
if you reach in and tug on the belt, is it tight(again where it spans the cams) or lose?
 

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Just found this thread looking for de-tensioner rebuild info. Turns-out I have it in .pdf's from the Shop manual. IMO - the hydraulic de-tensioner looks a lot beefier than the mechanical one. The mechanical one has a very flimsy spring - I know, 'cause my last two Milano's had it.

Yours is obviously not set-up right loach. Most likely because you used a drill bit instead of the special tool to lock the de-tensioner. I hope I do as well as you on the rebuild! The leak really doen't bother me, but since it's time for a waterpump, I may as well rebuild th de-tensioner. Here is a post from Fred Di Matteo - from wayyy back.
*****************************************
From: Ferdinando Di Matteo <[email protected]>
Date: Mon, 28 Jul 1997 11:01:01 +0000
V6 timing belt tensioning.
Jonathan, The stock Alfa timing belt tensioner does not fail to cause
any major problems except for some oil leaking which, I DO NOT BELIEVE
WILL CAUSE THE BELT TO SLIP, IF, VERY IMPORTANT, IF IT IS PROPERLY
INSTALLED AND ADJUSTED. In spite of the warnings that the belt MUST be adjusted just so, many so-called mechanics still don't know how to do it right. I want to, one more time, tell how to insure the belt will not slip or jump teeth. When installing a new timing belt that uses the hydraulic tensioner, the tensioner must be held in the detensioned position using the factory tool. With the belt installed (cams oriented and distributor rotor
oriented) the tensioner is now tightened so the belt is tight as a drum
and springs fully tensioned, (you can strum it to make it sing) now
tighten the nuts and then remove the factory tool. Now the belt cannot
slip or jump even if the tensioner goes full to the full detensioned
mode. Some might say the factory tool is not necessary and that a twist
drill or phillips screwdriver will do but they're wrong. The factory
tool has two dimensions at the end to insert through two holes. I can't
draw the tool on this letter but the dimensions are 0.190" on the very
end by 5/8" long and 0.27" at the rest of the rod. We make them from a
2 inch long bolt stripped of all the threads, machine the bolt to 0.27"
diam. one inch from the head. The end 5/8 inches are machined to 0.19".
——————————— 0.19" x 5/8"
0.27" ———————
x 1" ———————
———————————
I hope everyone will get or make that tool to use adjusting the
hydraulic tensioner. Good luck Jonathan Coates and all other Down Under
owners.
Fred Di Matteo
********************************************
Hope this helps,
 

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Discussion Starter #13
Thanks! This is just what I was after - a reason to do it by the book. After looking at the manual I can see why the correct tool is important and have got one on the way.
 
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