Vibration problems.

[LiquidOC]

Alright, since noone seems to be able to tell me how to fix this....or how to check this, I'm going to ask one more time (and hopefully recieve an answer) before I give up and take it to satan.

How can I tell without ripping my timing belt cover off if my balance shafts are out of phase or if my timing is off by a tooth? I have a massive vibration coming from my engine above 4000 RPM's, it starts getting progressively worse at somewhere above 3300 (very close to it) and I haven't gone above 4200 to see if it stops at any point above that. I can only cruise on the highway at 70 MPH (Which is kinda annoying on those long trips through west virginia where the speed limit is 75) Also, my car shakes pretty bad at idle, in addition to making a horrible squealing noise (Now that it's been colder outside....the squealing isn't there, oddly enough.) and it also takes a good 5 turns (audible turns) of the engine for it to crank, sometimes more, sometimes it catches on the first one. If anyone could help me here, I'd greatly appreciate it.

Some background info:

Recently slipped my timing belt (end of august, or around there) and took it into a mechanic for him to rebuild the head (bent all 8 exhaust valves) and got all new timing components put on, new waterpump, and had the oil pump replaced. (dunno if it was a rebuilt one, or a brand new one, I can call him and ask though) and it's been doing this since I got it back. It also has a fuel cut problem around 4200 RPM's, but it only occurs when at WOT. The vibration does not seem so apparent at WOT, but if I am slowly climbing through the revs, it gets really bad.

 

[Slipstream]

Sounds like you're on the right track...but afaik there isn't a way to be 100% certain without pulling the cover. But before taking it to satan take it back to the mechanic (who should back up his work) and ask him if it's possible he got them wrong. A good mechanic will say..."ahh hell ya know what, I might have, let me check it for you."

If he is 100% certain he did them right and won't take a look at it make a bet with him. "If I'm right and I go to the dealer and they say it's wrong and fix it you eat the bill. If I take it to the dealer and I'm wrong I'll buy you a case of whatever poison you prefer and I'll send everyone I know in here to the best mechanic in the world." :laugh:

Now on another note, are you absolutely, positively certain that it is rpm related and not speed related? I know when I drive I typically hit the same speeds in the same gears at the same rpm points...it's the way it works. But if you're in neutral and rev it up does the vibration still appear?

 

[CMB12]

OK, bad shuttering or vibrations when accelerating more than likely is one of two things.
1. Timing. Crack that cover off, and check it out. Thats the only way to be 100% sure. Its not that tough anyway if you got a jack. If your balance shaft was out, it would definetly shake things up.
2. Rear diff. This is what i'm gonna lean towards. i only know this cause our shop car is a 95 tsi awd and has this problem(probly cause we beat the hell out of it). It displays the exzact same type of vibration you are talking about. its the worst in 4th gear.

So check the timing first, if everything is cool, its the rear differential.

 

[Defiant]

It started when you got it back from a belt replacement job. How much more obvious can it be? He missed on the rear balance shaft, and if he did that then it's also possible he missed a cog on the exhaust cam.

Make sure your transmission bolts and engine mounts haven't wandered loose, too.

 

[LiquidOC]

it's definetely RPM dependent, as it does it when I rev it in idle. I will be taking it back to him on my next day off....Hopefully this monday. I will report back my findings when I do figure out what the **** is wrong with it.

EDIT: Would it be easier for me to just get them removed and see if that solves the problem? (The balance shafts, that is.)

 

[Slipstream]

It started when you got it back from a belt replacement job. How much more obvious can it be? He missed on the rear balance shaft, and if he did that then it's also possible he missed a cog on the exhaust cam.

Make sure your transmission bolts and engine mounts haven't wandered loose, too.

With his last post I completely agree with you.

However, I was had a thought that with a broken belt it got towed to the shop...and as we all know with the awd if done inproperly it can do bad things.

 

[LiquidOC]

No, I was very straightforward with them about it. I watched them tow it to both garages, and I said that if they even thought about bring a regular towtruck instead of a flatbed, I would have their asses before they got within 10 feet of the car.

 

[rtp03]

I have a similar problem. My car has a resonating vibration at cruising speeds between 3K and 4.5K in 4th or 5th gear. Mechanics have checked over everything but have not pulled apart the rear diff. Would that be the problem???