strong clicking noise

[Boxsterspharm]

Hello everyone,

Yesterday on my way home, I started the car and while on first gear,I heard clicking coming from the back of the 2001 boxster S. Then shifted second gear, strong knocking with faster rhythm as I accelerated the car.The sound is like I am sitting in a metal container and an broken iron bar knocking on it (depending on the speed of the car, the knocking also goes faster); it is very loud. I can feel the vibration of the knocking when I sit my arm on arm rest in middle console. since I was heading home, I had to drive on highway and although the car reach a little over the speed limit with no problem, the knock was consistent as a loud fast noise. I took exit and the metal bar knocking get slower as I reduced speed and again it increase as I go from zero to higher speed.

I parked the car and next day I called tow truck and here she goes to my indy mechanic. He had not had chance to even drive it yet and I am going nuts to find what's wrong. I looked youtube for similar knocking noise to match my case here but nothing I can have my hand on.............I hope you guys can help with opinions or ideas about the problem.

[txhokie4life]

Could be a broken timing chain

Not sure if the '01 has a 5 or 3 chain system

But even the 3 chain has a essentially a dual chain . So one strand of the chain can break and the other holds time until

The broken side wrecks enough havoc to do things in.

Think if it as two bicycle chains side by side and fused together. One set of links breaks, but the other is still holding together.

We were able to spot one of these by sticking a boroscope into the whole of a pulled chain tensioner

After we locked things in place.

Mike

[VMax1]

Did your Check Engine Light come on?

My 2001 Boxster S did a similar thing to my wife about 6 months ago. It turns out that I had a valve seat drop out of one of my intake valves on cylinder #3. She drove it from Albuquerque to Santa Fe with it knocking. Luckily it didn't drop out far enough to cause piston damage so i could have gotten away with just having the head rebuilt but I took advantage of the opportunity and rebuilt the entire engine.

http://www.renntech.org/forums/topic/44613-possible-engine-failure-misfire-and-low-compression

It really sounds like a dropped valve/valve seat to me but a compression check will tell you a lot. Hopefully there hasn't been damage to the piston or cylinder.

Good luck!

Tom

[Boxsterspharm]

it turned out to be broken rear drive cv axle on to both sides (inner and outer). So, got axle assembly and problem solved, is this common though? ? ?

Edited January 17, 2014 by Boxsterspharm

[JFP in PA]

it turned out to be broken rear drive cv axle on to both sides (inner and outer). So, got axle assembly and problem solved, is this common though? ? ?

On an S Boxster, yes. The six speed cars have an exaggerated axle angle as the suspension moves up and down, which leads to early CV joint issues.

[HolmaN]

I had the same problem.

Was the bolts attaching the drive shaft to the engine. They were loose, causing that sound. Luckely, I notice it before it got free and could have smashed other parts.

Notice you found it before my rely tho. Just wanted you to know that you're not alone.