2000 Nissan Pathfinder V6 … New battery installed 1 week ago … Starts right up no problem …. Here’s what’s going on …. You’re driving along and everything is fine. Then suddenly the engine seems to slightly shake and then suddenly stalls! The ONLY strange thing (could be related or not) is that in very cold weather without a sufficient warmup, reverse is fine but once it’s in drive there seems to be a clunking noise which you can feel. Then it drives and runs okay!!! At a loss now, any idea’s?
Slightly shake and then suddenly stalls
First place to start would be pulling any check engine light codes. May or may not show a code. If it does, post code back here in the comments. Most common cause for this issue would be the crankshaft and or camshaft position sensor failing.
For your transmission issue, check the fluid level. If it is full but dark and burnt looking instead of pinkish red, there may be internal damage. Check the color on a white paper towel. Having the transmission fluid and FILTER changed may correct this issue.