4.4 4.8 Timing Chain Guide
 

I was doing some searching here and found the 4.4's 4.6 and 4.8's suffer from failed timing chains around 100-140k that render the engines useless. So I did some digging on the net. People here seem to think the guides just fall apart and fail due to age...I found the timing tensioner fails causing slack in the chain and the loose chain demolishes the guides. By the time you get the rattle noise or the power steering noise ...it's to late.

The solution is to change the tensioner at 90k

http://www.partsgeek.com/gbproducts/...Fel9OgodkCcAMQ

Bmw E39 540i timing guide chain tension er replacement e53 X5 4.4 - YouTube

My 4.4 has 85k...changing mine this week.

Are you separating the M62 and N62 or generalizing that they all have the failure? I haven't heard about any N62 issues on this board............yet. As the mileage increases on the motors this could potentially be a problem.

I've read here 2000-2003 4.4 4.6 & 4.8's were reporting the issue and all over 100k.

I'm not sure what model engine generation they have.

Sure seems like cheap and easy preventive measure.

The 4.4 and 4.6 use the M62 power plant and the 4.8 uses the N62. Different designs but I'm sure it wouldn't hurt to look into changing the tensioners on all models.

Mine has almost 150K on it (N62) and not a peep from the timing chains.

So saying that most fail between 100 and 140K is nonsense. Most of the chains/guides I've heard of making noise are past the 150k mile mark.

Um.. The later model 4.4 (starting in 2004) uses the N62.

The 4.4 model the OP referred to uses the M62. Thanks anyway

He's talking 2000-2003

Yet you bring up the 4.8is... which wasn't built in these years. So I'm sorry for assuming you were talking in general and not in the model years he was talking about.

Thanks anyway.

2 different interpretations of what was written. That's all. The point of the thread is change your tensioner if you think it will help no matter what V8 motor you use.

Haven't seen the TC Tensioner problem on N62 engine, not yet.
Fail TC Tensioner on M62TU -> fail TC Guide -> damaged engine.