Mechanical Belt Tensioner - INA vs. BMW

[paul somlo]

Regarding the spring loaded accessory belt tensioner on the M44 - does anyone have experience with INA vs. original BMW? Price difference is about half. Some concerns I have, other than longevity, are whether replacement pulleys can be ordered for the INA. The original (for which pulleys are available) used a hex head bolt that recessed deep into the center of the pulley, while it appears that both the INA and the current BMW offering use a Torx head fastener that is flush with the pulley face. I also saw a review on Pelican Parts that states the dust cover doesn't fit the pulley used on the INA. In the pictures that I'm seeing online, the BMW part appears to use the same pulley as the INA, that is, no provision (groove) for the dust cover. Wondering if the pics are wrong, or if BMW made a change. But more important than the dust cover, I want to be able to replace just the pulley when the bearing goes dry.

Paul
'96ti 231,000 mi

[e30topdown]

INA is the OEM supplier for BMW. Excellent quality. I always order INA for pulley and tensioner parts for my e36s and for the timing belt tensioner on my e30.

As far as the pulley bolts and dust covers go, these have changed on some, but not all. The last M44 tensioner I did was August of 2015 and the bolt head was unchanged and I was able to reuse the dust cover. It snapped right on. But I had to put a new serpentine tensioner on an M52 (98 328i) in February and the bolt was completely different and the dust cover wouldn't fit. I also put a new idler pulley on and it was unchanged from the original. Didn't really matter to me as I was rescuing the car from a crap head PO and finding a new home for it.

Know that changes are more and more likely as production spreads out all over the world. A hex bolt may take the place of a torx bolt or vice versa, a groove for a dust cap may be omitted, or in my case, the bolt head was no longer recessed enough and the dust cap wouldn't go on at all. I have seen Behr parts over the last couple of years that were made in a variety of countries: Germany, Turkey, India, and Indonesia.

I still have confidence in Behr and INA parts, though.

Ken

[paul somlo]

I noticed in the online pictures, that the OEM version is stamped both "BMW" and "INA", while the OEM version is stamped "Germany", the INA version is stamped "Slovakia". Of course that is always subject to change, and maybe the OEM versions are now being made in Slovakia as well.

The one thing that I can't get a good feeling for, is whether the pulley alone can be replaced on the INA, as it can on the original BMW tensioner that the car came with.

[e30topdown]

On a tensioner, I wouldn't change the pulley out. I now only replace the entire tensioner. I have had two tensioners on 15+ year old cars (and low mileage <50k miles) break when I was unbolting them. They are made from cheap pot metal that doesn't stand up well to vibration and engine heat over the years. They must develop stress cracks. I used to replace the pulleys but don't any more. Not worth my time to have to go back in and do it again later or risk the tensioner cracking apart while the engine is at speed going down the highway.

Hope this helps.

Ken

[paul somlo]

This is the original tensioner, and this is the 3rd pulley in 20 years. I had a chirp, on startup and acceleration, which I traced to the pulley. After replacement, the chirp is now intermittent, still coming from the pulley, but I believe is due to the tensioner internals, not the pulley. I don't know if the pivot point is worn or something is going on with the spring. I'm probably going to replace it with the INA part.

[bazar01]

Originally Posted by paul somlo

This is the original tensioner, and this is the 3rd pulley in 20 years. I had a chirp, on startup and acceleration, which I traced to the pulley. After replacement, the chirp is now intermittent, still coming from the pulley, but I believe is due to the tensioner internals, not the pulley. I don't know if the pivot point is worn or something is going on with the spring. I'm probably going to replace it with the INA part.

I am also changing my belt tensioner assembly due to metallic chirping.
I am not sure if the Gates will be ok but I bought it from Rockauto and will give it a try.
I should get it tomorrow and install it this weekend.

[paul somlo]

Originally Posted by bazar01

I am not sure if the Gates will be ok but I bought it from Rockauto and will give it a try.

I had the Gates tensioner in my cart at Rockauto for a few days, but ended up ordering the INA from ECS for $56 shipped. I almost went with BMW on this, but the $120 price tag was a bit hard to swallow. INA is the maker on the BMW branded part, although online pics show the BMW part stamped "Germany", while the INA branded part is stamped "Slovakia". I wouldn't be surprised if the pics were old and all production had moved to Slovakia. I tend to trust Gates parts, though, and have never lost sleep over using their belts and hoses.

Just a tip - after replacing the pulley and still experiencing chirp, I tried to remove the original tensioner to check for play, etc.. I say tried, because I stripped the head of one of the two fasteners that secure it. They require a 6mm hex bit. I don't normally have trouble with fasteners on that car, but the one fastener stripped almost immediately, while the other loosened with no problem. My advice would be to spray some Kroil or what have you, then make sure to clean out the center of the hex head, then put a small punch in the hex and rap it with a hammer a few times. When my part arrives, I'll be doing some bolt extraction.

[bazar01]

Originally Posted by paul somlo

Just a tip - after replacing the pulley and still experiencing chirp, I tried to remove the original tensioner to check for play, etc.. I say tried, because I stripped the head of one of the two fasteners that secure it. They require a 6mm hex bit. I don't normally have trouble with fasteners on that car, but the one fastener stripped almost immediately, while the other loosened with no problem. My advice would be to spray some Kroil or what have you, then make sure to clean out the center of the hex head, then put a small punch in the hex and rap it with a hammer a few times. When my part arrives, I'll be doing some bolt extraction.

Stripped allen cap screws suck.

I am replacing the tensioner assembly.
It looks like I have to remove the power steering pump because the pump pulley is blocking the screws.
Is this correct?

[paul somlo]

Originally Posted by bazar01

It looks like I have to remove the power steering pump because the pump pulley is blocking the screws.
Is this correct?

I've seen that mentioned in other posts, but I was able to get a ratchet on both fasteners without removing the pulley. On one of the fasteners, it helped to rotate the tensioner all the way and pin it (the shipped configuration on a new tensioner). This is on the M44, and I didn't remove the screws all the way, just loosened (or attempted to loosen).

[e30topdown]

Originally Posted by bazar01

Stripped allen cap screws suck.

I am replacing the tensioner assembly.
It looks like I have to remove the power steering pump because the pump pulley is blocking the screws.
Is this correct?

I loosened the steering pump enough to get wiggle room and get bolts out. I do remember locking the tensioner back with a small screwdriver like it was before installation. Good memory, Paul!

[e30topdown]

Sucks on the bolt extraction. I concur on the penetrant though. Those bolts can be stuck from corrosion. Probably why I broke one of those tensioners. It was the hydraulic style and didn't have a lot of thickness in the metal wrapped supporting that bolt area.

Gates would be fine, too. I use Gates on all domestic cars. Prefer Contitech belts and INA tensioners and pulleys for my BMWs.

[paul somlo]

The INA tensioner arrived today, installed it, no more chirp. It's marked "Slovakia" and has the torx head fastener holding the pulley. It doesn't come with a dust cover, and the original cover won't fit.

Bazar - when you put the belt back on, did you just pull the pin on the tensioner, or did you use a t-50 bit to rotate ccw, then pull the pin?

When I started researching this, I came across a bunch of threads with people complaining about stripped torx head screws - now I understand. The torx bit engagement is somewhat shallow. Combined with the fastener head being moved away from the plane of rotation of the tensioner, I can see what a pain in the ass removing the belt is going to be now. Before, I was using a 16mm socket with an 18" breaker bar and rotating the tensioner was easy. I tried using a 3/8" long handled flex head ratchet (as the t-50 bit is 3/8" drive), and I was barely able to get enough rotation to free the pin. I tried the 18" 1/2" drive breaker bar with an adapter, but that just makes the situation worse, as the bit slipped out of the torx fastener. And that's a sure fire way to strip it. Maybe the answer is a 3/8" breaker bar, to get closer to the torx head, with a pipe over the handle. Maybe I can manipulate the tensioner somehow with a long pry bar instead?

I don't suppose that either of you would have an old tensioner laying around with the torx head fastener? I'm curious as to whether the old LH hex head bolt could replace the new torx head (which is also LH). Now I'm wishing that I had taken the impact wrench and removed the torx head, just to see what's what, but I wanted to get the car back on the road.

[bazar01]

Originally Posted by paul somlo

Bazar - when you put the belt back on, did you just pull the pin on the tensioner, or did you use a t-50 bit to rotate ccw, then pull the pin?

.

Installed the tensioner with the pin still installed then put the belt on and around the tensioner pulley.
Once the belt is on correctly around all pulleys, I relieved the tensioner CCW with a torx bit and pulled the locking pin.
No way you can pull the pin on the tensioner without relieving the tension.

When I bought the Gates tensioner, the image showed a hex bolt but it came in with the torx head bolt. Oh well. I will not be touching it again until another 100k miles. I will deal with it then.

Oh, don't forget the bolt is left hand thread. Righty loosey, lefty tighty

[paul somlo]

Originally Posted by bazar01

When I bought the Gates tensioner, the image showed a hex bolt but it came in with the torx head bolt. Oh well. I will not be touching it again until another 100k miles. I will deal with it then.

Oh, don't forget the bolt is left hand thread. Righty loosey, lefty tighty

Yes, I saw the images of the Gates part on Rockauto.com. I wouldn't be surprised if all vendors have gone to the torx head, at this point. The torx bolt head is actually marked "LH" with a rotational arrow for emphasis.

The problem is that, while the tensioner may well last 100k miles, there are many other items, as you're aware of, that will require the belt to come off in order to service. Belt changes, PS pump, water pump, alternator, lower timing cover gaskets, etc.. And with 231k on the clock, this being my daily driver, I remove that belt on what seems to be a fairly regular basis. Given my initial experience and other's experiences, I see trouble down the road.

The pulley on the new tensioner is slightly different than the one on the old tensioner. The center hub appears to be more recessed, especially on the backside. More notable, is that the center recess has been reduced in diameter. It appears that the old style hex cap bolt will still fit, but I don't believe that the 16mm chrome socket will fit the new recess. If the old pulley doesn't fit the new tensioner, we're stuck with the torx head. And I'm not seeing replacement pulleys, other than those available for the old tensioner (same PN as the idler pulley). And all this supposes that the torx head is the same thread as the old hex head.

By the way, I did remove the pulley bolt from the old tensioner, it's M10-1.5x24 LH hex cap head w/flange, 10.9 strength.

If I can find someone who has replaced a tensioner with the torx head pulley bolt, and is willing to do some tear down and take measurements, I could lay this to rest.

Paul

[paul somlo]

Just came across this post: http://forum.roadfly.com/threads/131...Belt-Tensioner

It appears that the bolt thread may be the same. Still, I'm thinking that the pulley recess ID got smaller. He doesn't say how he got the torx head bolt out the 1st time, when he didn't have the "tool".