Need help Identifying violent engine rattle/vibration.

[Devicex]

About a month ago I began to notice a sound developing in the engine bay area under acceleration. Having had exhaust leaks in the past and after finding some carbon under the heat shield from the head/exhaust mani area I pulled the turbo and mani to replace the gasket. Turns out the turbo was fried after 1700 miles and ended up being rebuilt by PTE. As of last night the car is running again, exhaust mani gasket replaced, new plugs, and all seemed well. Although the car runs fine, the sound I was hearing before the car was down is still present, if not more so. To best explain it would to say that it's a violent rattle, accompanied by a good bit of vibration. It doesn't come on full force till about 3000 rpm and the intensity seems to be rpm dependant. It doesn't appear to be boost related as it will do it simply revving it up in neutral, the sound seems to be coming more from the timing belt side of the engine but that is just based on my quick observation. The car idles and runs fine, fuel trims are reasonable, and compression is 180 175 170 180, but this sound is killing me!!! Any input would be greatly appriciated.

 

[cfisher]

hmmmmmmmm. have you checked your motor mounts.

 

[Devicex]

I recently installed Front and rear inserts into the mounts, everything appears fine but I will check them when I get the chance.

 

[blue92laser]

Have you messed with your tranny lately? Like take it out or anything?

I know i forgot to tighten those bell housing bolts, i guess all the way down, but they work themselves loose fast due to those high engine vibrations/ during high RPM's. But anyways, i was driving and it felt like my car was gonna vibrate to peices evertyime it started to rev up over 2,000 rpm's, i thought it was the oil pump gear rotated 180 degrees but it was just the bell housing bolts.

 

[Devicex]

Tranny hasn't been touched since last October so I doubt thats the issue but at least something to consider, thanks. Its strange how well the car runs otherwise because it sounds like something is very wrong....

 

[Devicex]

Pulled the oil pan today....

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I wonder if that has anything to do with it?? This image doesn't come close to showing the amount of shavings I found in the pan

 

[Defiant]

Balance shaft bearing.

 

[papifry]

My tensioner pully for my timing belt came loose causing my timing to jump at the crank. Luckily it happened when I started the car, so I immediately shut her back off. Just ten minutes earlier I had had her cranked and was idling just fine. The sudden pull by the starter must have caused the slippage.
This is the seconed time this has happened and later I found out that it was due to the fact that whenever we retimed the motor in the past we never recompressed and pinned the plunger for the hydraulic tensioner in before tightening the tensioner pully, thus the tightness of the belt relied soley on the setting of the pully and had no help from the hydraulic cylander. I know that I am an idiot, but then again my Haynes manual mentioned nothing of that.
Moving right along...
When the motor jumped time, the slight piston valve touching was audible, but no damage was done.
After the motor was re-timed correctly, everything ran fine... it idled fine and at the correct rpm... accelerated smooth and with all the power it had before. However, when the motor reached about 4000 rpm the it started screaming like it was giving birth to a Lancer... a telltale sign that the balance shaft was misaligned. This is also a road Ive been down before, so I immediately checked the alignment of everything again. Everything was perfectly aligned. So then I misaligned the balance shaft by 180 degrees, tightened everything up again and cranked her up. Again the motor screamed like a chainsaw when it reached 4000 rpm. I then shut her down, pulled the timing belt off, and removed the balance shaft belt completely. I then retimed everthing again and fired her up. The motor revved up smooth althe way to red . Problem solved. My baby is back to running normal, but I cant help but wonder whether or not it is ok to run with the balance shaft simply disconnected. I know that there is a kit for removing it, but will it be ok as is until I can get the kit?

 

[Devicex]

Balance shaft bearing.

Thanks for the input, this was kinda what I was assuming but it gives me enough of an excuse to put the car down for a bit and work on a 6-bolt.

 

[Defiant]

The motor revved up smooth althe way to red . Problem solved. My baby is back to running normal, but I cant help but wonder whether or not it is ok to run with the balance shaft simply disconnected. I know that there is a kit for removing it, but will it be ok as is until I can get the kit?

Did you see the picture? You don't really want that stuff sloughing around inside the engine, being fed to whatever remaining bearings it has.

 

[projekz]

Wow...Thanks for the info. I'll look into that tomorrow. Bump for a 4 years old thread!