Do you change cam chain?

[Fast4esT]

Just purchased a used awm head with I’m told 120k on it, seller recommended I change the cam chain since it’s a good opportunity to do it. I can’t find any info on anyone just changing the chain and not the tensioner, perhaps he meant the tensioner. Thought I would ask here first.

[Fast4esT]

he was confusing cam chain for timing belt

[IndoReef]

If you ever do the tensioner, do the chain at the same time.

[Fast4esT]

That’s what I’m thinking, doing chain without tensioner sounds silly

[walky_talky20]

I used to think replacing the chain was unnecessary as it was pretty heavy duty for what it is actually doing (running a single camshaft). But I've found that with average maintenance on the 1.8T, there is enough stretch in the chain to cause problems at higher miles. Problems like extra noise and even VVT trouble codes.

I would say if you are replacing the tensioner and the chain has over 100k miles on it, I would advise replacing it. This does escalate the job into messing with belt timing, which is not otherwise necessary to service the tensioner alone. Specifically: when changing the tensioner alone, you can leave the exhaust camshaft in place (and thus the timing belt is not touched). In order to replace the cam chain, you need to move both cams - so belt timing becomes part of the job.

[Dr.B6Banter]

I used to think replacing the chain was unnecessary as it was pretty heavy duty for what it is actually doing (running a single camshaft). But I've found that with average maintenance on the 1.8T, there is enough stretch in the chain to cause problems at higher miles. Problems like extra noise and even VVT trouble codes.

I would say if you are replacing the tensioner and the chain has over 100k miles on it, I would advise replacing it. This does escalate the job into messing with belt timing, which is not otherwise necessary to service the tensioner alone. Specifically: when changing the tensioner alone, you can leave the exhaust camshaft in place (and thus the timing belt is not touched). In order to replace the cam chain, you need to move both cams - so belt timing becomes part of the job.

I guess the hack way would be to zip tie the belt to the sprocket of the exhaust valve to keep it in time, then undo the cam caps for both cams and lift the back end up enough to remove the tensioner and replace the chain.... But what do I know, I'm one of those dummies that only changed the tensioner and not the chain

[Spike00513]

supposedly Audi chains can stretch over time
idk about Mercedes
since they also use chains

wondering if there's a way to check
besides removing it and holding it up next to a new chain to see if there's a length difference

[Fast4esT]

Perhaps you can gauge chain stretch by how much the tensioner moves to keep tension on the chain?

[Kevin C]

The chains do wear over time but typically its a small amount. The GDI engines have had a history of chain wear that is supposedly due to the higher soot level from direct injection being abrasive. Direct port injection motors have not had a history of chain problems. I'm sure that with poor maintenance and high miles one could end up worn, I bought a cheap chain to use a reference.

[old guy]

I replaced my cam chain around 200k miles during one of my CCT replacements. I measured the sag and stretch as well as the pin diameters against a new chain. I was surprised with the results. The difference between the two chains was barely measurable.

You can change the chain without having to redo the timing belt. I removed the exhaust cam caps and was able to lift the back of the cam high enough to remove old/install new chain. Be sure to mark the timing belt to the cam gear for peace of mind.

[GTA]

I replaced my cam chain around 200k miles during one of my CCT replacements. I measured the sag and stretch as well as the pin diameters against a new chain. I was surprised with the results. The difference between the two chains was barely measurable.

Does this mean that you wouldn't have replaced your chain if you knew in advance? Or that it's a good idea to replace it 'while you're in there"? I'm asking because I intend to just replace the CCT tensioner pads soon as preventative maintenance and would love your opinion whether or not I should replace the chain. It's more $$ and may be more prone to a mistake so I'm on the fence whether or not a chain is in the cards.

[Fast4esT]

I think consensus is to replace the chain if you are replacing the whole tensioner/getting chain interaction with valve cover. If you are just replacing the pads, leave the chain alone. where are you sourcing the pads from?

[old guy]

Does this mean that you wouldn't have replaced your chain if you knew in advance? Or that it's a good idea to replace it 'while you're in there"? I'm asking because I intend to just replace the CCT tensioner pads soon as preventative maintenance and would love your opinion whether or not I should replace the chain. It's more $$ and may be more prone to a mistake so I'm on the fence whether or not a chain is in the cards.

In my case the OEM chain was fine and had I known how little wear was present I would not have changed it. But keep in mind that I purchased the A4 new in 2003 and consequently I know the complete maintenance history. If your A4 has had the factory recommended 10k oil changes i suspect the wear could be significantly more.

[GTA]

I'll be looking at ordering the pads from eBay as they seem to be the only place to source them. All the other sources only have the complete after-market tensioners, and from what I've read, may not be the best choice due to the failure rates. As for the chain, I have to make a decision on replacement.

The next decision would be whether to purchase the black colour pads or the beige ones the majority of eBay sellers are offering - and mainly from China. All the complete tensioners I've seen are packaged with beige colour ones. Hmmmm. How to choose?

[GTA]

UPDATE:

I replaced the Cam adjuster pads last weekend and while I expected to find lots of wear and other not-so-good things like chain scrape on the VC as well as deeply grooved and/or broken pad pieces, I was pleasantly surprised at what I found, or didn't find.

As you can see, the only real damage was a couple of very small pits in the pads. Don't mind the broken pieces, I broke the lower pad while prying them from the adjuster (CCT). It was definitely brittle because I didn't apply much pressure with a screwdriver when removing them. I guess after 17 years and 250,000Km, it's to be expected from plastic.



No chain marks :



I had a replacement Iwis brand timing chain on hand but decided against changing it because I didn't want to mess with the exhaust cam and the original chain "looked' very good; as well as the cam sprockets themselves. It pays to keep up with quality oil changes (Motul 8100 X-cess & Mann 940/25 big filter).

When I started it after re-assembly, it sounded like it had no compression for a couple of rotations before it fired up and ran 'like an Impreza' for about 3 to 4 minutes before it smoothed out.

I got the pads from eBay and ordered two sets of them from two separate places. I choose the best looking two pads from the the four. They were the beige ones. Also used were: Elring Tensioner gasket and valve cover gasket kits. For less than $30 plus the OE compression tool ($25), I can rest easier knowing that the pads won't crumble and clog up the oil passages. And added bonus is that the car seems a little bit more eager to accelerate on throttle application. This I didn't expect at all.

[Kevin C]

The upside of a used chain on new pads is the chain links have been nicely polished on the original pads and should wear less on the new pads.

[EuroxS4]

supposedly Audi chains can stretch over time
idk about Mercedes
since they also use chains

wondering if there's a way to check
besides removing it and holding it up next to a new chain to see if there's a length difference

They do but not those,newer sure as they are using less material and smaller pins. The chain in question has massive pins that connect the links. I have never seen a chain fail on a 1.8T EVER!! If you want to change it just unbolt the intake cam you will have enought room to remove cam and tensioner and chain. If your gona changing the chain but removing it make sure you mark the running direction as Ive seen them fail after being installed in the opposite running direction but only under those circumstances.

[GTA]

The upside of a used chain on new pads is the chain links have been nicely polished on the original pads and should wear less on the new pads.

I haven't considered that but there's some logic to it.

The chain in question has massive pins that connect the links...

Funny, that was what I thought when I first saw the chain. Pretty beefy and relatively short in length for what it actually does. Pictures of it on the inter-web doesn't do it justice.