Mechanics

OMG, DID THE TIMING CHAIN FINALLY FAIL?!

Nissan Altima

Worst fear realized. My 1998 Nissan Altima GLE with 140K miles has been in need of timing chain replacement (confirmed diagnosis) for a " while". I haven't been hammering it, and fully intended to have the work done once I got paid (. It's been about five months since I received my last commission check). As cruel irony would have it, the night before (literally) I got paid, accelerating from a stop light on the way home the vehicle instantaneously lost compression (for lack of a better descriptive), only reaching about 20mph. No idiot lights, no whacked gauges, no smells, etc. I was so close to home, I continued. The car dropped to about 10mph for the last mile, and then completely crapped out. Would not (and now won't) start, but does crank. Is this immediate, yet gradual, loss of power indicative of the timing chain having finally failed and the gradually diminishing performance/compression(?) The result of valve deformation? Or could it have been something else? (. Which would be the 'good' news, leaving me the timing chain replacement as a needed repair subsequent to this). Would not a timing chain failure result in the 'immediate' failure of the vehicle to be propelled? Thanks!
Avatar
PurpleHazy
December 11, 2006.




A loss of the chain, more likely a loss of the guides and tensioner. That can let the chain jump on the cam and crank gears resulting in loss of power and if it jumps enough, the engine will die. Have a compression test done to see if the chain is on. If you knew in the first palce it needed a chain set, then it probably still will.

Tiny
Jack42
Dec 11, 2006.
Thanks. What is the likelihood the chain jumped teeth accelerating from the light? Also, I had presumed the aging chain had 'stretched' somewhat. Shouldn't it be replaced if/when tensioners/guides are replaced? Finally, how likely is it there has been valve damage, if the chain jumped teeth to the point of killing the engine?
AD

Tiny
PurpleHazy
Dec 11, 2006.

AD