Let me be perfectly clear when I say I never would have bought this car if I knew this would happen.
Yep, I still love my sentra. Or at least I loved having a dependable car that I wasn't still paying for. But my timing chain f'd me at 122k. Are you kidding?
I thought I lost my throwout bearing (standard trans) so I pulled engine and trans together as per FSM and separated. Everything cool in the trans. Don't ask me why I thought that was the problem, cause I have no idea what I was thinking.
I started to read about the dreaded "timing chain rattle" and it came closest to describing what I heard before the s hit the fan, so I decided to check. Disaster, one of the engine slingers my hoist was holding bolts onto the timing cover. Had to remove flywheel to put on a stand. That disaster was documented in full in an earlier topic, "trouble removing flywheel."
I took all the chain and stuff out, ready to put the new kit in. Just wondering if there's anything I should be careful about going back in, and I wanted to hear an opinion on some cracks I found.
OK, first pic is just a shot inside the cover. Here cylinder 1 is at top dead center. Two blue links in the chain should line up with matching marks on top center of each cam sprocket. Second picture shows where the blue links actually are when cylinder 1 is at TDC.
As many rotations as I did (FYI, I did them before pulling out tensioners or guides not seen in photo) I could not get the links to line up with the matching marks, or if I could get them up there, cylinder 1 was not at TDC. This led me to wonder if the tensioner, not the chain, was what led to failure...
Third pic is what worries me. These cracks are in the block right where the timing chain tensioner bolts on. Now, I didn't see any coolant or oil oozing out of them, but I just wonder if the whole engine is gone now. Any thoughts are appreciated. My super expensive dual mass flywheel is on backorder til mid December so I have some time!
Some other thoughts for those considering taking on the repair at home:
If you think it would be easier to pull the motor to do this job, you are wrong. I went through a hell of a lot to get here including pulling steering shaft to be able to drop entire front suspension. That's right, it doesn't fit out the top.
Use the FSM here for tightening order on the cover. Also shows pry points to remove cover so you don't damage any mating surface.
No timing kit on earth includes the o-ring for the cover at the oil pump. Don't spend 100+ on a cover to get the o-ring, spend 15 bucks on a 500 piece metric automotive o-ring assortment. You'll never need an o-ring again.
Sentra, Versa and Altima owners be warned! Get your chain changed before this happens to you! The 2.5 L (QR25DE) is the same thing! Eric the Car Guy has extensive video on his fight with a 2.5 altima SE-R. Provides a lot of insight.
