Beisan or OEM upper chain guide

[sapote]

As my car is ready to hit 100k miles...
A few questions... how involved is it to replace the upper guide? Can this be addressed during a RB job? What are the symptoms of it failing & what happens when that thinner-end breaks off? (Will this lead to a catastrophic failure?)

If it's original then the guide tip is about to break off if not yet.

How involved? remove vanos, EX hub, EX cam sprocket. But before that, look to see if the tip broke off or not, then carefully fish it out and don't let it fall down into the oil pan -- means the vanos needs retiming after. This has nothing relate with rod bearing process, but if the broken tip already fell down in the pan.

If the tip broke off, the lower guide -- which the chain tensioner presses on -- will wear out faster as it now pushing the chain at a sharper angle. At very high rpm, lacking a functional upper guide, the chain could jump on the EX sprocket and engine damaged.

[Sprp85]

As my car is ready to hit 100k miles, I am contemplating tackling some of the maintenance items;

I know for a fact that previous owner of the car performed full VANOS overhaul using everything Besian & DrVanos parts back in 2016; But I do not believe upper chain guide was touched.

So, every time when I see pics of the broken upper guide, it gives me a bit of uneasy feeling.

A few questions... how involved is it to replace the upper guide? Can this be addressed during a RB job? What are the symptoms of it failing & what happens when that thinner-end breaks off? (Will this lead to a catastrophic failure?)

[Obioban]

Guess you can never say never, but I bought the car with 110k on it and a 3" thick binder of service history that never mentioned it having been replaced, and the PO thoroughly documented the vanos lockdown at 100k. Perhaps it was done then, but there's no record of it.

Regardless, the stock parts are clearly suboptimal and was glad to see an updated version was available when I checked it during the process of changing out rod bearings 3 years ago. Was a no brainer.

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I’d put money on that having been replaced with the vanos.

[Rhythim]

I think that has been replaced before at some point-- that looks most like 50-60,000 miles of wear than 138k. I don't think I've ever taken a car apart with over 100,000 miles that didn't have a completely failed top guide.

Guess you can never say never, but I bought the car with 110k on it and a 3" thick binder of service history that never mentioned it having been replaced, and the PO thoroughly documented the vanos lockdown at 100k. Perhaps it was done then, but there's no record of it.

Regardless, the stock parts are clearly suboptimal and was glad to see an updated version was available when I checked it during the process of changing out rod bearings 3 years ago. Was a no brainer.

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[Obioban]

Well if the beisan piece lasts forever then I suppose it makes sense.

Nothing is forever, but it's ~10x the service life... which is functionally forever for most people.

[Arehman]

Beisan, no brainer.

[jet_dogg]

Well if the beisan piece lasts forever then I suppose it makes sense.

[M9Seth]

Have one for sale, BNIB. PM me if interested.

[Obioban]

This is one of those things that finds a solution to sell a problem.

On the other hand I suppose it's good for those who don't want to stay on top of their maintenance.

No.

This is an actual problem that can be easily and cheaply solved. If you're doing anything in that part of the engine, it makes sense to replace the upper guide with the Beisan part. Pulling the VANOS unit off to address anything should not be considered "maintenance". Do it once to address the fundamental engineering issues with the engine, then never worry about it again.

[Obioban]

New Beisan piece on top, 138k mile original below. Made sense to go with the solid part.

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I think that has been replaced before at some point-- that looks most like 50-60,000 miles of wear than 138k. I don't think I've ever taken a car apart with over 100,000 miles that didn't have a completely failed top guide.

[jet_dogg]

This is one of those things that finds a solution to sell a problem.

On the other hand I suppose it's good for those who don't want to stay on top of their maintenance.

[Rhythim]

New Beisan piece on top, 138k mile original below. Made sense to go with the solid part.

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[maupineda]

I would go with Beisan, the OE has some hollow sections which may not be as sturdy.

[Arinb12]

Beisan it is.

Cars on 155k don't see it's ever been done in the vast history I have for it...

Was fine 4k miles ago when headgasket was done but why not ey

[heinzboehmer]

Yeah if you plan to keep the car for any significant amount of time just get the Beisan one. When you're back in there replacing the oem one for the second time, you're gonna wish you spent the extra $40 the first time.

Honestly, I'd just get the Beisan one regardless. It's not really that much more expensive.