When exactly DOES one replace the timing chain on a 1998 328i?

[adversus.Falcon]

I posted recently about purchasing my first BMW, and was curious about the major service, but was informed that timing chain is not one of the items required for the 60k service.

When exactly does the timing chain need to be replaced? Does it ever??

[jmo69]

Haven't heard of anyone replacing one, except maybe doing a complete rebuild, tensioner maybe. I've heard of it on a MB at 100K on Wheeler Dealer.

[bluptgm3]

Timing chain is far more robust than a rubber/fabric belt.
While I have seen timing chain failure reports (w/photos) on a high mileage M50 NV, these generally last the life of the car. Tensioners on early 325 and M3 are often times changed.

[somebody5788]

At after 150k miles it's not a bad idea to do the tensioner and guides.

At 200k miles my oil pump chain had stretched almost 1/2 inch.

[JDStrickland]

The timing chain is not listed as a service item. In theory, it should last the life of the car . I'm not suggesting the theory holds true all of the time, but there is no service schedule for it.

[jc43089]

All depends on maintenance, I replaced the chain when I rebuilt my m50 at 188k but the old timing chain and new were exactly the same, same length, same amount of side play. If I had know I would have saved the money for something else. It isn't a service item unless the car has been very poorly taken care of.

[JDStrickland]

All depends on maintenance, I replaced the chain when I rebuilt my m50 at 188k but the old timing chain and new were exactly the same, same length, same amount of side play. If I had know I would have saved the money for something else. It isn't a service item unless the car has been very poorly taken care of.

I'm not sure I agree with this. While the timing chain is a life item, this only means that there is no scheduled maintenance for it. If you had the engine apart for some reason, it makes sense to replace the timing chain so that you don't get into a position that you have to take the engine apart again later. If you are taking an engine apart enough that you use the term, rebuilt, then putting a timing chain in is probably almost a requirement. I cannot see a reason to rebuild an engine and not replace the timing chain. I cannot see a reason to rebuild an engine if it still runs, but that's just me. My '94 M50 has 170,000-ish miles and I have no plans to rebuild it.

The M50 uses a timing chain tensioner that arguably needs to be replaced, but the issue here is that the chain rattles if the tensioner sticks or is worn out.

[spyderg0d]

Easy win here. What's length spec of a good chain? If it's stretched then replace. If not who cares because it's not stretched after 20 years.

[blckstrm]

These guys are spot on.

What's your mileage?

I'd consider it if you have REALLY high mileage AND are already in there doing a head gasket or something. I would never attack it just because.

I replaced the tensioner (and only the tensioner) when I did the head gasket at 145k. I'm at 219k now, and of all the things that keep me up at night, this isn't one of them.

Belts and chains are fundamentally different. Coming from a Toyota, you'd be expected to be worried about it. My wife's Camry never made it to 80k on any timing belt we ever had on it (both failed before we hit the 80k mark).

Timing chains are no more a service item than rod bearings for an E36. In fact, I'd do the rod bearings before replacing the chain, too.

If I WERE going to replace my chain, I'd replace all the associated gears as well to prevent potential issues (if your chain has stretched, you've likely also worn the gears down). This is not discussed much around here - not much need. However, on a Ford minivan my brother in law replaced the chain without doing the gears, which killed the engine in short order.

But if you're just inquiring about regular maintenance, a timing chain is anything but...

[Mike WW]

Easy win here. What's length spec of a good chain? If it's stretched then replace. If not who cares because it's not stretched after 20 years.

It's more complicated than that. The rollers can wear as can what they ride on, so a new chain will often be no shorter than a high mileage one, but be tighter.

As to when? Whenever you rebuild the engine. I wouldn't even think about it just cause at less than 300K.

[ChuckDizzle]

It's more complicated than that. The rollers can wear as can what they ride on, so a new chain will often be no shorter than a high mileage one, but be tighter.

As to when? Whenever you rebuild the engine. I wouldn't even think about it just cause at less than 300K.

+1. Before that, the chain is probably not going to need replacement.

[Driiven]

Snap the throttle and listen for chain rattle... that is when you do your chain and guides. In all my years of working on these cars I have only seen 1 outright chain failure. Have had MANY with excessive chain noise/ worn guides.

[somebody5788]

Snap the throttle and listen for chain rattle... that is when you do your chain and guides. In all my years of working on these cars I have only seen 1 outright chain failure. Have had MANY with excessive chain noise/ worn guides.

For me I've seen 100's of chain failures on other makes so I just did it while my engine was already out to be safe. Now these days MINI's are having massive timing chain issues and supposedly it's the same chain that BMW is using on the modern I6 engines, I don't get why BMW doesn't have the problem and Mini does....

[adversus.Falcon]

Thank you for all your help guys, I did a short stint in a workshop with Renault, Citroen and Peugeot, and they all had timing chains listed as service items, we replaced them at 120k normally, but I don't know if that was just us, or just Renault, Citroen and Peugeot...

[ChuckDizzle]

Maybe the French just do it differently?

[DotBeta]

[JDStrickland]

Thank you for all your help guys, I did a short stint in a workshop with Renault, Citroen and Peugeot, and they all had timing chains listed as service items, we replaced them at 120k normally, but I don't know if that was just us, or just Renault, Citroen and Peugeot...

Chains or belts? Big difference.

[adversus.Falcon]

Chains, we obviously did the belts but we changed chains as well

[pizzaman09]

Wen I broke a tensioner the chain busted on my M52. However my engine is a unique case and wouldn't use it for a data point for any maintenance schedule.

That being said, if you are lazy and don't want to deal with the OEM continuous chain, I found out that a Mercedes master link with fit an e36 chain. (Mercedes also uses Iwis chain).
Don't be afraid of the copper side plate master link, they are plenty strong, when my chain busted the link the broke was a few links away from the master link with the copper side plate.

Granted if you are doing your chain the correct way you shouldn't need a master link.

[bluptgm3]

Don't be afraid of the copper side plate master link, they are plenty strong, when my chain busted the link the broke was a few links away from the master link with the copper side plate.

How is it that the engine was not destroyed?


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[bluptgm3]

I replaced the tensioner (and only the tensioner) when I did the head gasket at 145k. I'm at 219k now, and of all the things that keep me up at night, this isn't one of them.

Just to be clear, there are two - one in the head on the secondary chain. And you are correct, only one on the primary chain on the RH side of the block. The 328/M3 M52/S52 one piece tensioner is an upgrade for the multi piece 325/M3 M50/S50 multi piece tensioner.

If I WERE going to replace my chain, I'd replace all the associated gears as well to prevent potential issues (if your chain has stretched, you've likely also worn the gears down). This is not discussed much around here - not much need.

Good advice. In addition to new guides and tensioners.



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[pizzaman09]

How is it that the engine was not destroyed?


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That is the uniqueness of my engine. If you have seen my rotary valve engine head build thread you would note that I no longer have poppet valves. Basically the engine is not an interference engine anymore. At one point I had too much drag on the rotating valves which required too much chain tension. The old guide broke and when it did the chain caught on the rail and busted.

https://www.bimmerforums.com/forum/s...engine-project

[doclees]

I'd like to resurrect this thread because it covered some questions I had concerning what to do when I'm doing the 94s 325 head gasket. 185k on the engine and it wasn't abused until I overheated it. Daily driver. Besides head gasket I know it needs the Vanos seals. Got the besian kit.
1. So probably don't need to worry about replacing chains.
2. Good idea to replace both chain tensioners? Last set I did was on an 89 SHO. Chains stretched. Gear teeth bend. Chain tensioner rubber guides develop deep tracks. Common at 100k miles.
3. The upgraded lower tensioned is just a redesign used on the M52 or S52 engine that is backwards compatible for the M50?
4. Is the chain guide a wear item or generally subject to failure?
thanks

[bluptgm3]

281K S52 on original chains and guides.
Late model primary tensioner is backwards compatible.


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[pbonsalb]

So far, failed chains does not seem to be a problem. Broken guides and failed tensioners are occasional problems. Worn out vanos is a more common problem. Oil pump sprockets have come loose. But these E36 motors are getting up there, with the youngest being 20 years old and the oldest being 27 years old, with the mileage going up as well. How much of a project do you want to get into? The easiest time to remove the front cover and replace anything behind it is when the head is off. At that point you might as well pull the pan and check the oil pump.