knock, knock, knocking on...

[fatality]

Hey guys,
so there is this knocking coming from the nose area of my friend's 7MGTE. he pulled it hard in fourth all the way up to 6k rpm, then again in fifth to about 5500 rpm. the retard left the AC on full blast. he pulled over and noticed the main crank pulley was wobbling. upon getting it home very gently, and letting it cool down, he noticed the main bolt was plain loose (he hand tightened it about three turns). So he tightens is up completely, the knocking goes away for a couple of days. 3rd day, he ran the AC again, the knocking came back, even though car wasn't driven hard (no boosting). the pulley was wobbling again as well. he let it cool down and the bolt was still tight. any ideas?

 

[IJ.]

Shagged the inside of the Balancer and possibly the Key/Keyway and Crank snout!

 

[fatality]

Shagged the inside of the Balancer and possibly the Key/Keyway and Crank snout!

what shagged? more explanation please.
also the wobbling goes away with the knocking.

 

[IJ.]

If it's been run with a loose bolt it wears the inside of the balancer and in bad cases all of the other components I listed can be damaged as well.

"Tight" in this case is 197 ft/lbs

 

[rakkasan]

pray the crank isn't damaged.....

 

[johnathan1]

Tighten the bolt down to spec and see what happens...

 

[miggles]

when you say wobbling is it moving forwards and backwards? like to the front of the car and to the back? If so then it could be your thrustwashers worn out but it would seem like what was mentioned above.

 

[fatality]

no it wobbles from driver's side to passenger, but only if the AC is turned on. otherwise the car runs normally.

 

[Boss302]

so it's only wobbleing while the A/C is on?

 

[fatality]

so it's only wobbling while the A/C is on?

yeah only when the AC is turned on, and then it wobbles and a knocking sound shows up. after shutting it down have to tighten the bolt to specs again and it runs perfectly. You think I just need to replace the compressor?

 

[jdub]

yeah only when the AC is turned on, and then it wobbles and a knocking sound shows up. after shutting it down have to tighten the bolt to specs again and it runs perfectly. You think I just need to replace the compressor?

Dude...re-read what IJ and Rakkasan posted above...now focus and understand: YOUR CRANK PULLEY (harmonic dampener) IS DAMAGED...PRAY YOUR CRANKSHAFT/KEYWAY ISN'T DAMAGED TOO

:slap:

 

[rakkasan]

yeah only when the AC is turned on, and then it wobbles and a knocking sound shows up. after shutting it down have to tighten the bolt to specs again and it runs perfectly. You think I just need to replace the compressor?

How tight is your AC belt? Is it so tight you can play it like a banjo?

 

[Boss302]

what does the harmonic balancer wobbling have to do with the A/C being on the clutch isn't froze is it?

 

[Boss302]

How tight is your AC belt? Is it so tight you can play it like a banjo?

or that.

 

[rakkasan]

or that.

When you have the A/C belt too tight, it causes the rear passenger tire to lose its' balance & the vibration transfers through the unibody to the motor causing the harmonic balancer to come loose. :icon_conf

 

[johnathan1]

When you have the A/C belt too tight, it causes the rear passenger tire to lose its' balance & the vibration transfers through the unibody to the motor causing the harmonic balancer to come loose. :icon_conf

OMG!!!!! REALLY???????

 

[IJ.]

When you have the A/C belt too tight, it causes the rear passenger tire to lose its' balance & the vibration transfers through the unibody to the motor causing the harmonic balancer to come loose. :icon_conf

Bad man Mark baaaaad man
(LMAO here)

 

[Boss302]

quit yanking man. :icon_razz

 

[SublimeSupra]

Well what everyone is saying is generally the same.Probably your ac belt is on super tight,and when you turn on your ac the compressor puts even more parasitic drag/stress on the dampener/pulley and then causes the crank pulley to "walk."If you drove around like this for awhile it will eat the key on the outside of the crank/inside of the pulley/dampener.If it gets to bad then you have to find a new crank or get a new dampener/pulley and get the snout of the crank wielded with a new key which i dont recommend.

 

[IJ.]

Well what everyone is saying is generally the same.Probably your ac belt is on super tight,and when you turn on your ac the compressor puts even more parasitic drag/stress on the dampener/pulley and then causes the crank pulley to "walk."If you drove around like this for awhile it will eat the key on the outside of the crank/inside of the pulley/dampener.If it gets to bad then you have to find a new crank or get a new dampener/pulley and get the snout of the crank wielded with a new key which i dont recommend.

Sorry but I don't think anyone is saying a tight AirCon belt is the cause here.

NOT doing it up to 197 Ft/Lbs is the cause the effect is at best a damaged Dampener but by this time if he's kept driving it the Crank and Key are probably toast.....