Nissan Repair: groan then thump during inital acceleration, nissan bluebird, backyard mechanic

Question
QUESTION: Hi, I have a 1995 Nissan Bluebird (KA24DE/U13). I replaced the upper idler pulley using the 'standard' method. i.e. I removed the engine mount, and jacked up the engine until I could access the pulley. I now have a 'new' problem in that if I accelerate from standing, the car initially groans from the drivers side drive-shaft area, and as the car starts to move, the groan terminates in a thump, also felt from the drivers side drive-shaft area. In trying to diagnose the problem, I stopped the car, and whilst holding one foot firmly on the brakes, I placed the car into drive and applied moderate pressure on the accelerator with the other foot. I was able to maintain a steady state 'groan'. Could you please tell me the 'bad' news? Could I have possibly broken something when I jacked up the engine? Ideally, I'm looking for a 'fix' within the capability of your average backyard mechanic?

ANSWER: John,

Sounds like a broken motor mount.  I would inspect all mounts and replace what is seperating.  Probably the one at the front or the one at the back.  These are round to capture the center bolt and when they crack they will do the groan thing and then make a thump sound.  Also, when you do the motor mount make sure you jack up the car evenly and support it and install the mounts with the engine level in the car.  You do not want to have the mount loaded against one another.

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QUESTION: Thanks for that. I have now replaced the rear engine mount. It was clearly broken. The front engine mount looks O.K. Should I be replacing it anyway? The 'groan' is pretty much gone now. There's still a 'thump' if I try hard enough. I think it occurs when the transmission changes from first to second gear. I probably should get the transmission serviced? I've had the car for 6 years #60,000kms# without a service. Thanks in advanced. John.

Answer
John,

I would check the engine mounts regardless. Also, I would change the transmission fluid.  No need to replace the filter since it is a screen.  Five quarts of transmission fluid. It should take 4.5 but start with four and keep checking and adding until it is at the ful line.