Hey guys, so I've got a 01 F4i, with 24k miles. I'm running Rotella T full synthetic, about time for a change.
I was on the interstate on an evening run, I was in 6th then dropped into 5th gear normally, and topped the RPMs in 5th out then dropped the throttle. I don't know if sudden engine braking caused this but coming off the exit I heard a disturbingly loud engine knocking. I hopped off, and when I went to look at the engine it cut itself off. I went to start it again, heard the loud knock and it died again. Also heard during a no fuel engine turnover w/ starter.
The fuel indicator had just displayed on my run on the interstate, and I can't remember if my oil indicator was on during riding.
So I'm thinking a few things:
1) Reserve gas was overestimated and low fuel caused detonation of some kind.
2) I spun a bearing or damaged a rod.
3) The sudden engine breaking messed up CCT Timing.
4) A valve got struck by the piston

What experience can you folks give on this situation?
I pushed the bike off the interstate, and waited all day for a pickup to avoid further engine damage. Where should I start? Most likely culprit? Thank you!

 

compression test. it was the engine knocking and not something in the transmission right?
none of those things should of happened but if the CCT did jump a link im not sure i would want to check the compression without first manually rotating the crank.
if it is hard to turn something is hitting, but the damage is already done..
pretty sure the engine has to come out to do anything other than the valves
personally i would just check the compression at WOT and go from there.

 

yeah. good idea. Turn this thingy clockwise a few times manually. If it doesn't jam then compression test it.

 

Thanks for the advice guys! I'm about to try and turn it manually. From the sound of it I've concluded that it isn't the CCT for sure, unless a link slipped or something strange. If the piston struck a valve, or something is stuck flying around in the cylinder wouldn't that cause more damage? I'm trying to fix it myself because I have little money, I lived on ramen noodles for a year to buy it just to put it into perspective. I'm guessing in any situation I'm going to have to dismount the engine and open up the top end. Hoping to god the rods are still fine and this is a valve or top end cheaper problem.

 

yeah, but if something is in the cylinder the damage is probably already done, but turning it by hand slowly and listening you can be sure you won't further damage it when you turn it over for the compression test.
unfortunately i think you do have to drop the engine to do the top end. knocking doesnt sound good whether its a spun rod or slapping piston.
a bad FPR will make it run horrible and sound bad but i wouldnt say a knocking sound but who knows.

 

Hey guys I've been taking the bike apart to try and figure out this knocking. I came across something I thought might be of great concern or help identify the problem. What is this adjustable bolt? The CCT? I grabbed it and it is almost loose to the point of coming out of it's hole. I have 2 other concerns but I'll figure those out later. Is this a possible culprit, can someone help explain it? Thank you!

 

So this IS the Cam chain tensioner after looking up some images of it. I'm not sure if mine is missing the tightening bolt or if it's meant to be that way. I also found a youtube video that demonstrates very closely the sound my engine makes. If that helps

 

that is a manual cam chain tensioner, and if it is loose that is not good, you need to adjust it while its running because once it warms up things change.
^ get confirmation on that though, its just how i read people do it.
nice find on the video, are you going to take the valve cover off to inspect or adjust the CCT? 3 for 1 while your in the top end, bolts, timing, and clearance.
on that CCT you're supposed to have a few more nuts on there i imagine to lock it at its position

 

Yeah I just emailed a local shop to get prices on inspecting it, and if it's just a bad cct related issue I'm getting my timing chain replaced, CCT replaced, and valve clearances checked. Anything else I should get taken care of while it's out? I hope the cylinders are ok, the intake valves looked okay (intact) when I looked in it.

 

man, that isnt going to be a cheap service, my dealership wanted 500+ bucks for a 15k mile service on my parallel twin with tappet valves.
i would say tighten the cam chain tensioner but with the issues you had with it dying on you and sounding horrible, it sounds like something internal is going on.
its a toss up, i would think the first thing they would do is turn it over, or do a leakdown test.. actually i guess having them diagnose it for 80-90 bucks would be helpful.
if you have the tools you can do a leakdown test on it, im not sure how but it would check your valves.