A5INKY
Vendor , w/Business number
I replaced the TB at 155K miles prior to major mods (see sig for the basics) that came a bit after 190K miles. Even though the head got a full rebuild I reused the 35K mile TB, figured I would let it live it's life. Fast forward about a year and I found myself in a very messy divorce from my wife of 17 years, two kids - no fun. Went many months without a reasonable work space, tools in storage - really bad deal. Finally just got set up again with a place to work and dove back into the car and all the maintenance that was allowed to slide. Worked on it all last weekend but ran out of time to inspect the cam (Colt Stage II that went in with the TB at 155K) and decided to wait until this weekend. Once the cam was inspected, I planned to order all needed parts including a TB kit and replace it in the next couple weeks. I am right at 250K miles now, so that 100K mile TB has 5K miles of life left, right? WRONG.
Merging on to the expressway today, I put my foot in it to blow past a D-bag that tried to close the gap I was shooting for once he saw my turn signal. Full boost and pulling hard it just shut down - no bang, no nothing. Didn't initially register it was actually dead and I though it might have gone into limp mode. Tried to restart, nothing. Coasted to the next exit and into the nearest parking lot, no start. No bad sounds, just no start. Called a tow truck and began to wait. Just for giggles tried to start it again and it fired up, sounding fine - hmmm. Canceled the tow truck and headed for my shop and tools, seemed to be running fine, boosting well sounding good. Got on the throttle a little again and it nearly died but stayed running, not sounding so good this time. Was really close so I limped it to my shop and started the diagnostic. VC came off, cam actually looked pretty good. Removed the IC pipe and TB cover and found this:
Sheared 21 teeth off the TB - really not good. I went home to make dinner for the kids, enough of that for tonight.
Before it is asked, yes it was a quality belt kit (Bora Parts) installed with the correct tools (Metalnerd) and procedure (Bentley "Repair" manual). Job went by the book both times with no question of perfection.
I will lock the crank at TDC tomorrow and see where the timing is sitting right now. I have no hope that there was no piston / valve contact, that seems too unlikely. I'm not that lucky.
Why this thread?
- First is to ask what the chances are of not smacking valves with a one tooth TB jump (assuming that is what happened)?
- Second as a caution, this happened on a belt with 95K miles on it. It doesn't make that much sense to me, but I have heard it said that the TB change interval needs shortened with a modded engine. Never heard any evidence or rationale for this before, so I didn't put too much stock in it. However, you can see what waiting did for me.
Merging on to the expressway today, I put my foot in it to blow past a D-bag that tried to close the gap I was shooting for once he saw my turn signal. Full boost and pulling hard it just shut down - no bang, no nothing. Didn't initially register it was actually dead and I though it might have gone into limp mode. Tried to restart, nothing. Coasted to the next exit and into the nearest parking lot, no start. No bad sounds, just no start. Called a tow truck and began to wait. Just for giggles tried to start it again and it fired up, sounding fine - hmmm. Canceled the tow truck and headed for my shop and tools, seemed to be running fine, boosting well sounding good. Got on the throttle a little again and it nearly died but stayed running, not sounding so good this time. Was really close so I limped it to my shop and started the diagnostic. VC came off, cam actually looked pretty good. Removed the IC pipe and TB cover and found this:
Sheared 21 teeth off the TB - really not good. I went home to make dinner for the kids, enough of that for tonight.
Before it is asked, yes it was a quality belt kit (Bora Parts) installed with the correct tools (Metalnerd) and procedure (Bentley "Repair" manual). Job went by the book both times with no question of perfection.
I will lock the crank at TDC tomorrow and see where the timing is sitting right now. I have no hope that there was no piston / valve contact, that seems too unlikely. I'm not that lucky.
Why this thread?
- First is to ask what the chances are of not smacking valves with a one tooth TB jump (assuming that is what happened)?
- Second as a caution, this happened on a belt with 95K miles on it. It doesn't make that much sense to me, but I have heard it said that the TB change interval needs shortened with a modded engine. Never heard any evidence or rationale for this before, so I didn't put too much stock in it. However, you can see what waiting did for me.
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