4.4 4.8 Timing Chain Guide

[electricalserv x5]

Originally Posted by StephenVA

Thanks for the insight as it coresponds to what I call "Good Practices" of vehicle maintenance. Replace and repair as required before total failure occures. Always cheaper than the alternative results. (ask me how I know...did wheel bearings once on another vehicle, after I egnored the squeeks, creaks, and noise. Welded bearing races on the spindles, trashed the rotors due to heat warping, had to replace the spindle, brearings, rotors, brakes, ball joints, tie rod ends, etc. Out in a driveway while it was snowing. What fun that was. Lesson learned the hard way.)

Keep up the great posts as it help us all to do preventive repairs to avoid the death rattles.

Hi , your 4.8is[n62] has two tensioners and two timing chains.keep running good oil.

[StephenVA]

Originally Posted by electricalserv x5

Hi , your 4.8is[n62] has two tensioners and two timing chains.keep running good oil.

I follow the preventive maintenance model for severe vehicle mileage. I change the oil (Mobil One) every 12-13 months or approx 3,000 miles. Lots of short distance trips (less than 6 - 50 miles), followed by a run around the interstate with a heavy foot. All the fliuds are getting replaced this winter (49K) as I have another vehicle or two to use when weather sucks or have a meeting where safe parking will be an issue.
The X5 sits outside with a Battery tender on her and lots of Wax. One very clean 4x4 beast.

[carl0s]

I'm googling "n62 rattle noise" and I ended up here on the topic of chain guides again!

I posted a bit about the N62 chain guides previously on this forum. They did update the guides on that engine as well, and I can tell you that I had bits of plastic in my oil pan from them, and so they do fail on the valvetronic N62 engine as well!

I did end up replacing both sides in the end - heads off on the side that needed it to get the chain guide off, and head off on the other side as well 'cause it seemed stupid not to do the stem seals and secondary air whatsits at the same time.

some pics here:

http://www.xoutpost.com/948285-post16.html

Now, anyone know why my engine has an intermittent rattle from around the alternator area? It seems like it could be the idler pulley. i hope so! waiting to cool down to see. It sounds *bad*.

[Rockit]

Originally Posted by carl0s

I'm googling "n62 rattle noise" and I ended up here on the topic of chain guides again!

I posted a bit about the N62 chain guides previously on this forum. They did update the guides on that engine as well, and I can tell you that I had bits of plastic in my oil pan from them, and so they do fail on the valvetronic N62 engine as well!

I did end up replacing both sides in the end - heads off on the side that needed it to get the chain guide off, and head off on the other side as well 'cause it seemed stupid not to do the stem seals and secondary air whatsits at the same time.

some pics here:

http://www.xoutpost.com/948285-post16.html

Now, anyone know why my engine has an intermittent rattle from around the alternator area? It seems like it could be the idler pulley. i hope so! waiting to cool down to see. It sounds *bad*.

The timing chains guides break due to age and have zero to do with wear...very scary. Guys here have broken guides and only know it...I did and found it when I changed the valve cover gasket.

I have the same noise still, it's the vanos losing oil pressure from a bad seal. Beisan Systems - Procedures - M62TU Vanos Procedure

I'm going to post pictures of my guides that look new but broke because of defective material at 85k. I have an 2002.

Every timing chain guide repair also needs the vanos rebuilt no matter what.

[carl0s]

Originally Posted by Rockit

The timing chains guides break due to age and have zero to do with wear...very scary. Guys here have broken guides and only know it...I did and found it when I changed the valve cover gasket.

I have the same noise still, it's the vanos losing oil pressure from a bad seal. Beisan Systems - Procedures - M62TU Vanos Procedure

I'm going to post pictures of my guides that look new but broke because of defective material at 85k. I have an 2002.

Every timing chain guide repair also needs the vanos rebuilt no matter what.

Mine is N62 and has the cam-spocket type vanos adjuster unit, which is actually a reliable unit and I have searched and have never heard of a failure. I guess your M62 vanos units are the same as the M54 6cyl engine - those that require a rebuild with new teflon sealing rings & o-rings.