The timing chain on my 94 Nissan Sentra XE 1.6L has jumped. The car will not start and when you do try and start it just lopes and then sounds like it wants to start and goes back to loping. BTW, it has 249K on it. I have removed the front cam shaft cover. The chain is intact and looks good, but can be depressed with the finger. Upon closer inspection the chain has cut a very noticeable groove into the tensioner. There is also a noticeable groove in the upper chain guide. The question here is, can I just replace the tensioner and the guides (there are two of them), without changing out the chain. One other question I have is there a possibility that I could have damaged a valve after trying to trying to start the car with the jumped chain. Someone told my that this possible, but I have also read on the NIssan Forums that damaging/bending a valve would occur only if the chain had actually broke and I tried to start it or manually (by hand) advancing the crankshaft will attempt to get to TDC? Any help, suggestion, recommendations would be appreciated. Thank you in advance.
You should replace ALL the worn parts. The chain, the guides and the sprockets…These parts sometimes come in a complete kit, 'Timing Chain Replacement kit" which will contain the gaskets and seals too…Do NOT neglect the sprockets. They may look fine but a new chain will not run properly on worn sprockets…Think of the chain and sprockets as a single unit…At 250K miles, the entire engine must be near the end of it’s useful life…
+1 for Caddyman.
The tensioner is also oil pressure operated. At 249k miles maybe low oil pressure caused a high miles chain to jump.
Candyman; Thanks for your response and recommendations. Even though, the entire recommendation is not what I wanted to hear, I figured that I would have to replace everything. In all seriousness, thank you and I will carry them out. And, yep, 250K is a lot of mileage, just want to eke out as much as I can on the car.
ok4450; Thanks for the input on the low oil pressure. I will check this out.
Put the chain and related componets on there .I’ll bet you can get another 100K useful miles out of it-Kevin
When the timing chain on that engine failed it often damaged the timing cover and oil pump. You might take a close look before re-installing the cover.