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Discussion Starter · #1 ·
After 155,000 miles of trouble free service my v6 has been playing up lately.

First it ate a fuel pump and I didn't have a chance to research and find the recall before the shop it was at had fixed it. But 155k isn't that bad for a fuel pump. Anyway, next the CEL came on, I was getting long term fuel trim issues and great economy... but also less than perfect running. But not bad. I drove gently while I was researching and waiting for the new MAF... which seems to have cured the CEL.

But while I was really paying attention hard I noticed a vibration around 2800-3000 rpm. Maybe as low as 2500. It is certainly load and rev related. On idle throttle there's no vibration, with throttle there's vibration. Change gears and it goes away. Push it hard in first and it goes by so fast you don't feel it.

So... what do you think?

I had an axle replaced recently, the CV boot went without my noticing and they said that's where the noise was coming from. I thought I had a ball joint issue because I was getting s light clunk. With the new axle I certainly have a clunk, either it cured nothing or made it worse. But if it were that then the vibration would be speed related.

I wonder if it's just that 200 miles after the new MAF it hasn't quite got things dialed in yet? But the fuel economy is back down to the previous crappy levels. So I expect the mixture is back to being right.

So... engine mechanical issue? Could it be a failing harmonic balancer/damper? No miss fires but I am going to change back from Bosch Platinum 4s to NGKs which I bought from ECS when I ordered the MAF.

The PAS pump is moaning too, so that will be replaced with the next timing belt which I guess I'll do in the next few months. Maybe I'll change the alternator while I am there, just to hit all the major points. That will only leave the A/C compressor.

Any suggestions?
 

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Sounds like a snub mount, especially if there is a clunk and vibration during acceleration.

I would check all mounts while you're down there. My Snub went to pieces after 80K, but then again, I accelerate pretty hard.

Fix it fast before you have flex joint issues from engine rock.

You can pop your hood, pull emergency brake, and look under the hood as you push slightly on the gas to check for engine movement. forward and back would be the snub.

Could possibly be axle or TRE or CAs also. But my guess is the snub (and it's a cheap/easy $40 fix DIY).
 

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Discussion Starter · #4 ·
OK then, I'll add a snub mount to the list for the timing belt change. Cheap fix really. Perhaps I'll swap out the engine mount too.

I am suspicious of the 'new' axle, I'll check that too when I change the oil tonight.
 
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