John Speake

So it seems that even when the tension is correct at the tension measuring point, the tension at the tensioner is much lower (so the warning light comes on).

That would certainly suggest that the tensioner may be the problem.

Did you dismantle it when you did the cambelt change ? If in the past it had been run without oil then the inside of the barrel can have ridges.

GEE928S

Hello John,

Yes, i dismantled the tensioner when i did the t-belt job and i put a new o-ring to the piston and i put a new boot to the tensioner, i cleaned the disks but i did not break the stack.
I did not notice anything out of ordinary when i put it back together, but this was first time when i opened the tensioner so it is possible that i missed something, i'll check it again.

WallyP

It's been a long time since I disassembled a tensioner, but isn't there an easily-lost washer in the stack that operates the warning light?

It is not unknown to have problems in the warning light system in/on the tensioner. If it has the solid metal strip to carry the current, the strip has been known to crack or break. If it has the wire, it also has been know to break inside the insulation. You can have poor electrical connection at any of the connections. All the above can cause intermittent false warnings.

And, just to make sure that the info didn't get lost in translation - You are now using "TDC - #1" each time, not just turning the crankshaft one turn between tests, right? That is, you are getting the camshaft timing marks aligned for each test, right?

Mrmerlin

GEE928S it would best to post pictures of the tensioner you have and the spring and washer setup,
if your seeing a wobble of the cam gears then a video of then engine running would also be good.

You can bend the cams or snap them by prying on the cam pulley.

At this point you should inspect every part of the belt run and post pictures of what you have.

John Speake

This is an excellent set of pictures that explain the tension light....
http://members.rennlist.com/v1uhoh/timing.htm

Jim Devine

The washer that Wally is referring to is #57 (in red) - scroll down for the diagram.

http://www.billsworkshop.com/P928S4/...rces-noWSM.pdf

GEE928S

Hello guys,

Car nose is in pieces so video is not available now and i did't take one when it was running, but I'll post you pictures tomorrow when i have them resized.

PG

GEE928S

Drivers side cam gear and you can see the drag marks in the belt






Passengers side cam gear and drag marks on the belt

GEE928S

Tensioner arm and new tensioner roller





tensioner nose assembly




tensioner nose assembly






crank, i tried to take out the small idle rolle but it's stuck. The left rail? where the circlips are is jammed, the right one is loose. I'll try to get this out and put a new bearing to idle roller. Circlips are removed.


I tested the tensioner yesterday without the tensioner arm, when i tightend the tension bolt, the tensioner axle moves out and when i measured the grounding between tension bolt and the tensioner axle it is ok, so tensioner itself moves ok.

The dragging marks on the belt: things that are contacted to the back side of the belt are main tension roller and water pump. If the belt is loose then also the idle roller beside the crank, right?

When i measure the tension of the belt, the engine is always on TDC, the crank (is 0) and cams are in they timing marks so crank and cams should be always on the same position --> there should not be any changes on the tension by those, right?

When i did the t-belt jos, a new main tension roller, the idle rolle and new water pump was installed. Water pump spins ok, no play on there, so does the main tension roller.
Those small parts, spring, washer etc on the nose of the tensioner are original, the washer thickness is 1,97mm

How much play there is in the tensioner arm (is there) when the bushings are ok. Bushings are new and so is the bolt.
There were few millimeters play when i moved back and forward the arm from the main tension roller?

Has anybody had the tensioner arm bended?

So ideas are needed as you can see

Mrmerlin

the marks on the belt are normal and indicate a new belt,
is it possible to remove the tensioner washer stack and post a picture?
leave them as you find them on the piston .
to remove them,
open the boot clamp,
remove the tensioner bolt,
then use a 5 MM allen wrench to push the stack out

GEE928S

Thank's Mrmerlin, it is nice to know that the belt seems normal, i don't have to loose anymore energy on that.
I dismantle the tensioner in near future, let's see when the govermet (wife) gives me some time to be in garage.
I'll post pictures of that when it is done.

John Speake

make sure the flat end of the tensioner pin is clean, and also where is goes into the mail tensioner part. From Tony's diagram, that is where the ground contact is made.

When you fitted the belt, you had it as tight as possible from crank to first cam wheel ? And then tight after that ? As the cam wheels want to move, I use a small clamp to hold the belt in place on the cam wheels.

GEE928S

Hello John,

I saw that good diagram abourt alarm, i tried yesterday that pin contact without the spring and it contacted ok ( i measured it to tension bolt), then i tried with the spring but i did not have enough force to make the contact with the spring.

Yes, i noticed that the it's bit tricky to keep the belt tight when you put it on. My case the cam gears turn a bit off the timing marks when i loose the belt off the gears.
I pull the belt from the cranck as tight as i can by hands, then i take a wrench and turn the cam gear a bit and same time match the belt to gear, then i take the slack off by turning the cam gear with wrench and see that timing mark is alligned. I belive that there is no slack between crank and first cam gear. I have also small clamps that i use to lock the belt to cam gear. It's bit hard to explain by words, lets see if i can some day put the timing parts back together and if i have enough free hands, i'll take some photos.

PG

GEE928S

Start





Boot off




piston head




Stack coming out




Piston & stack




assembly




Stack

Do you see is there something out of ordinary?

I'll order new gasket for the tensioner and other stuff, please let me know if you notice something odd on the tensioner.
Inside the tensioner i did't see any marks and the piston came out easily.
There is a small valve in the piston, what it is for?

I asked about the tensioner arm and how much there is play (or is there any) when you crab main tension roller and move it back and forward (new bushings and bolt), did you notice when you made the service and put your tensioner arm in place?

John Speake

Tensioner looks OK to me.

There is some movement front to back on the tensioner arm normally. But that wouldn't account for the varying tension.

I think you will need to put the belt back on and turn the engine by hand, and see you can see varying degrees of slack anywhere in the two turn cycle. (take the plugs out to make it easier ?)

Obviously there should be any slack from the crank pulley until after the RHS cam wheel.

Personally, while it is apart I would fit a Gates belt.