Experts Chime in. (Engine timing)

[swissfrank]

Long story short, I picked up a X5 that needed work.

Timing chain guide failure, unknown extent.

Say worst case scenario, timing skipped or chain broke, which valves are MOST likely to get bent first? Intake or Exhaust? This question is keeping me up all night.

Discuss please

[TwinTurboGTR]

Hey bud. You picked up another E53? You have a 4.8 right? Which motor is this one? What year? The answer for which valve is bent first is hard to say. Depending on where the camshaft was positioned when the timing jumped will determine which valve is shot. I mean if the motor is dead and has damage like that. It is better to remove the head off the block and just have the whole thing machined instead of guessing which port to do.

[epdarks]

You need to open up the motor to assess the damage anyway, so why bother theorizing?

[swissfrank]

Originally Posted by TwinTurboGTR

Hey bud. You picked up another E53? You have a 4.8 right? Which motor is this one? What year? The answer for which valve is bent first is hard to say. Depending on where the camshaft was positioned when the timing jumped will determine which valve is shot. I mean if the motor is dead and has damage like that. It is better to remove the head off the block and just have the whole thing machined instead of guessing which port to do.

I wish I already had a 4.8, but I got 2 4.4's now. This one is a 2001 4.4i M62tu, I picked this up and have no clue as the the overall condition of the overall vehicle, Trans/Diff Etc. I had planned to just repair the damage and deal with the other possible issue(s) later. I inspected the intake and at the time my assessment was the intakes were most likely of striking first and they were all sound, so I could save the $70 in head gaskets by not taking the heads off...

I may have had a few to many at that point and reassembled the rest of the motor too early....

Oh well I ordered a inspection camera to have a peak before pulling the engine apart again...

Originally Posted by epdarks

You need to open up the motor to assess the damage anyway, so why bother theorizing?

I do agree, I guess I am just feeling lucky these days

I think I might just wait until either my inspection camera or Ebay key comes first and either have a look or try starting it...

[swissfrank]

**update**Bent exhaust valves, intake valves are fine.

[SlickGT1]

Take pics when you take them out.

[740ilDuke]

Cool! Just completed timing chain guide replacement, not sure Id want to go further than that. LOL. Timing the engine was pretty easy, just a learning experience that first go round'.

Good luck with the repair(s)!

[SlickGT1]

Duke, finally. You've been MIA for a while. How did it go?

[740ilDuke]

It went good. First time doing it, so it was a slow process. It took 3 weekends to get it 100% done, very much a learning experience.

Now Ive got the X5 on the road to looking better, next up tires and paint. Ready to see these style 87s in action.

Of course, I upgraded the brakes on my 740il from single piston to dual piston and they are sticking, so Im waiting on the caliper rebuild kit for that!

[TiAgX5]

Originally Posted by 740ilDuke

It went good. First time doing it, so it was a slow process. It took 3 weekends to get it 100% done, very much a learning experience.

I am at 155k miles and have the tools and parts together for the guide replacement. I plan on using the Bentley Manual to guide me thru the process and am wondering if you used the B manual, if not what guide did you use for the DIY?