timing belt tensioner pulley, how necessary is it to replace

Mon Mar 21, 2016 12:50 pm

How necessary is it to replace when doing timing belt/water pump.

They are over 50 quid now....

cheers

Mon Mar 21, 2016 1:05 pm

£50 now, or ££££ if/when an old tensioner gives up....

Mon Mar 21, 2016 1:59 pm

Depends if the belt is being replaced for reasons of age or mileage.
The tensioner in a car doing 2000 miles a year will see off four belts before needing a tensioner change.

Mon Mar 21, 2016 2:44 pm

For reasons of age, but I'll just get it changed anyway but it wont be coming from the stealers, they have done nothing to help me today.

Cheers lads

Mon Mar 21, 2016 4:59 pm

Mega important, like more important than changing the belts in the first place.

I have seen several with loose rivets at belt change time and when they get loose they throw the belt out against the covers, slowly eating away the belt.

I have one aside that is loose as proof for anyone that asks.

Mon Mar 21, 2016 6:28 pm

HairyScreech wrote:

I have seen several with loose rivets at belt change time and when they get loose they throw the belt out against the covers, slowly eating away the belt.

I have one aside that is loose as proof for anyone that asks.

That's a separate discussion altogether! The failure of the join between the pulley spindle and the mounting bracket isn't age or time related - it's a design/manufacturing fault that affected a very large batch of tensioners, and was the subject of a TIS. Affected tensioners are marked Z something, IIRC.

Mon Mar 21, 2016 7:01 pm

After market tensioners do it as well far as I can see. Seen it with Contitech and INA ones.
So not even cheap crap.

Your right the bearings are always fine so I don't know what causes it, wonder if it's belt slap at high RPM?

I'm thinking that he next one I put in gets a spot of mig weld on the back of it on the side in tension.

[Edit] - I think I read that wrong, are you suggesting it was a known recall at some point as I keep seeing it even with modern kits, Last two belts on mine have been like it when they came off at about 30k on them, both contitech kits.
I have a Dayco kit I am reluctant to use but has an SKF tensioner I might try out to see if it's better. Used INA before but INA still had the issue and the INA stuff has been really well made for other stuff.

The crimped shaft is a bad design.

Mon Mar 21, 2016 9:16 pm

i try to only buy genuine ones made by SKF iirc but these are getting harder to find. the aftermarket ones especially URO and MTC are inferior and ive heard too many bad stories to quibble over 20 or 30 . the INA one seems the better aftermarket brand if you cant get a genuine one

Mon Mar 21, 2016 10:07 pm

I bought a LUK tensioner in the end.

Have used their clutches before in other cars and can't say anything bad about them.

Tue Mar 22, 2016 5:42 pm

HairyScreech wrote:After market tensioners do it as well far as I can see. Seen it with Contitech and INA ones.
So not even cheap crap.

INA is EE garbage from what I've seen...

Wed Mar 23, 2016 12:42 pm

INA own FAG and the INA tensioners are FAG bearings, always had good results with FAG stuff but as always this is the automotive aftermarket and suppliers change year on year so your mileage can drastically vary.

Thu Mar 24, 2016 7:43 am

For the past 15 days my car after start up was making squeaking noise for 5min and it was from timing belt cover (removed belt from alternator to roule him out).. Service was done before 16000 km as I was told, but I did not want to take risk, and removed everything..

Belt was new, and INA tensioner is new but hed big play in mounting bracket join just like Brianmoooore described .. But I assume the failing of tensioner is because someone put it in without PIN and SPRING, just 2 bolts and that is it..

belt has big paly on tensioner side..

I order continental timing belt INA tensioner (again) and new pin and spring, should I go on with INA or?

Thu Mar 24, 2016 10:21 am

The pin and spring are only used to set the tension. After that is done, it doesn't matter if they are fitted or not.
One end of the pin and spring locate against the water pump, and make it difficult to fit a new pump while keeping the pump gasket in place, so the pin and spring are often discarded at this point.
No problem with a bit of weld to tighten the pin up. I've done this on more than one occasion.

Thu Mar 24, 2016 11:39 am

Thanks for the info again

either way I will need a pin and spring to set the tension.. And new tensioner will be welded..

Spring tension is all the tension that belt needs? no need for eny extra pressure before tightening up bolts?

Thu Mar 24, 2016 1:55 pm

The spring is designed to set the tension exactly right, then you lock the adjuster off.
Be careful that there's no slack on the other side of the belt when you do this.

Fri Mar 25, 2016 7:54 am

Ok, thanks.. One more q, on which side you welded your tensioner, block or radiator? Assuming on radiator side..?

Fri Mar 25, 2016 10:18 am

On the back, where it's riveted. Just a touch of weld is needed - you don't want to get things hot and damage the bearing.

Fri Mar 25, 2016 10:41 am

Thanks for your help..

Sun Mar 27, 2016 8:48 am

Tensioner after welding..

Fri Apr 01, 2016 6:36 pm

Did not want to open new topic, it;s kind a related...

New belt and tensioner is on.. Tension is set with new spring, car runs ok but ones when fully warmed up it kind of making some noise, little bit of contact spray on tensioner, end the noise stops for 10s.. No noise when engine is cold..

Is this normal for some time, should I be worried?

Fri Apr 01, 2016 8:03 pm

HairyScreech wrote:INA own FAG and the INA tensioners are FAG bearings, always had good results with FAG stuff but as always this is the automotive aftermarket and suppliers change year on year so your mileage can drastically vary.

I was under impression that INA, FAG and SKF are one company

Fri Apr 01, 2016 8:18 pm

Brianmoooore wrote:
HairyScreech wrote:

I have seen several with loose rivets at belt change time and when they get loose they throw the belt out against the covers, slowly eating away the belt.

I have one aside that is loose as proof for anyone that asks.
That's a separate discussion altogether! The failure of the join between the pulley spindle and the mounting bracket isn't age or time related - it's a design/manufacturing fault that affected a very large batch of tensioners, and was the subject of a TIS. Affected tensioners are marked Z something, IIRC.

I was under the impression that "Z 127" marked tensioners were a modified unit and these were the recommended fit?

Im fairly sure that the ones I have been supplied with from BMW have all been marked with it. The last one I bought was 18 months ago.

Sun Apr 03, 2016 12:48 pm

pianist wrote:
HairyScreech wrote:INA own FAG and the INA tensioners are FAG bearings, always had good results with FAG stuff but as always this is the automotive aftermarket and suppliers change year on year so your mileage can drastically vary.
I was under impression that INA, FAG and SKF are one company

Schaeffler are the parent company of INA, FAG and LuK. All 3 are legally independent companies owned by Schaeffler.

Schaeffler are nothing to do with SKF and SKF list them as a competitor.

Sun Apr 03, 2016 2:02 pm

Brdjo wrote:Did not want to open new topic, it;s kind a related...

New belt and tensioner is on.. Tension is set with new spring, car runs ok but ones when fully warmed up it kind of making some noise, little bit of contact spray on tensioner, end the noise stops for 10s.. No noise when engine is cold..

Is this normal for some time, should I be worried?

I'd normally associate a noisy belt with excess tension.
Mark the tensioner in its current position, slacken the bolts and tension the belt up again, in case the locking bolt has dragged the tensioner a bit as you torqued it up. Any change in position?

Sun Apr 03, 2016 5:09 pm

The bolt has a flat washer, yesterday i was checking the tension again, but did not mark position, ges i going to do this all over again :S the spring is new maybe she is the reason why...

Sun Apr 03, 2016 10:35 pm

csl wrote:
Brianmoooore wrote:
HairyScreech wrote:

I have seen several with loose rivets at belt change time and when they get loose they throw the belt out against the covers, slowly eating away the belt.

I have one aside that is loose as proof for anyone that asks.
That's a separate discussion altogether! The failure of the join between the pulley spindle and the mounting bracket isn't age or time related - it's a design/manufacturing fault that affected a very large batch of tensioners, and was the subject of a TIS. Affected tensioners are marked Z something, IIRC.
I was under the impression that "Z 127" marked tensioners were a modified unit and these were the recommended fit?

Im fairly sure that the ones I have been supplied with from BMW have all been marked with it. The last one I bought was 18 months ago.

So are these Z 127 marked tensioners that I keep getting supplied by BMW, from the faulty batch?

Sun Apr 03, 2016 11:22 pm

TIS was a long, long time ago. I vaguely remember Z???a being mentioned.
If the genuine ones supplied now are marked Z124a, then these are the replacement ones.

Sun Apr 03, 2016 11:41 pm

One think I have noticed is some belts are a little rough in surface finish on the back face of the belt, makes them noisy over the tensioner for a few miles then they settle down.

I ended up stripping and checking the whole timing assembly to work that one out, it was only when comparing belts did I even think of the surface finish of the back/outer side.

Mon Apr 04, 2016 8:19 am

hmm did noticed that raff side.. will leave him for 100-200 km more and than if sound do not stop, tear it down again..

Mon Apr 04, 2016 12:02 pm

It sounded exactly like an over tensioned belt or a bad accessory bushing, a whuuring sound.

I pulled it all apart, checked everything, checked the tension, etc,etc and found nothing wrong so just left it after a few miles it quietened down. I'm a bit paranoid about timing belts and it just didn't seem right.

But be absolutely sure that there is nothing else wrong before leaving it as it could be a disaster if something else is wrong

Tue Apr 05, 2016 5:50 pm

after reading this thread and whilst stripping the front of my engine down for a motronic conversion i found my new cambelt had been rubbing, thinking it was because of the old tensioner i used i replaced it with a new one and guess what it's still rubbing.
should i put this down to the new tensioner or could it be something else?

Tue Apr 05, 2016 7:09 pm

Did you replace the belt again?

Tue Apr 05, 2016 7:33 pm

no ive only done a few miles on it.
will try that next though, thanks

Tue Apr 05, 2016 9:17 pm

Was the shaft for the bearing loose or bent on the old tensioner?
Is the new one still OK?
If the original had failed and the new one is still OK, my theory is that the belt has worn/stretched on one side, so is pulling to the outside.

Tue Apr 05, 2016 10:20 pm

the bearing and shaft were good i did notice that the mounting plate was bent (may have been fitted with something behind it) and thought that that might have put the pulley out of line
i'm thinking it's a duff new pulley and i need to start again with a new tensioner and belt.