A couple of months ago I noticed that I was really down on power, especially in the 4000+ RPM range, it just won't go. At times, even under WOT, above 4000 there are little 'hiccups'. When the engine is hot it sounds like it knocks, especially when the ambient temperature is hot. The knocking is only at low RPM (500-1000). The low end power (lower than1500 to 2000 RPM) seems a bit low too. Mid range (2000-4000) all is well.

Over the weekend a 'knocking-whine' stared under the hood. I don't know where it is comming from. It does not whine just revving the engine. It only whines while in gear (manual) and under power. It seems worse in 1/2 but is still there in 3/4 and possibly 5. The sound is related to engine speed/input shaft speed. By that I mean that at the same engine RPM the sound is about the same, regarless of the gear I am in. It does not follow the output shaft / tire rotation speed. Could my tranny be going too? Could the tranny be the source of the problem?

I am thinking of something in the top of the engine and wishing that it's not in the lower part: fuel delivery problem, bad MAF, broken variable intake, broken valve spring, timing problems, etc. ****, if it's the tranny I am going to scream.

The plugs are new changed 15k KM ago. everything else is original.

 

Are the two noises related or is it possible you have a whine starting and previously a knock? What grade fuel are you running and have you tried to switch stations?

 

The whine-knock is getting worse and is in lock-step. Dropped by the dealership on the way home and concensus is that there is a chipped tooth or something. The sound has gotten worse over the past few days so I think that I shall be buying a tranny job soon.

I always run 91 octane. I generally run Shell but in the past 4-6 months have been mixining it up with Esso and Ultramar. I do quite a bit of milage so I tend to get to see a variety of different stations. At all costs I avoid small stations in the middle of nowhere. Changing brands/stations has not helped. I usually run the tank down to less than 2 gallons before filling.

I am starting to think that the two are not related since one started months ago and the other only recently. Though I am no expert and I do not play one on TV. However, if the crank bearing is seizing, it would certainly hurt the engine performance.

 

Are you talking about a chipped tooth on the flywheel? If so that certainly does not mean a tranny is in order. Does the knock sound like two pieces of metal hitting each other or an internal engine knock??
Also a chipped tooth on the flywheel would not cause any power loss. It would cause some grinding noises occassionally when starting the engine.

 

5thgenmaxima,

I don't think it's a flywheel related thing, at least in the way you describe possible symptoms.

From what the mechanic said at the dealer I understood a chipped tooth on a gear or a syncro or something of the sort.

I would love for it to be a flywheel / clutch problem as it would probably be fairly cheap to fix. But me thinks that a new gear-set is on the menu.