Please help, Engine vibration ....

[Steve Tinker]

The Boxster M96 engine is usually very smooth all the way up to redline - you definately have a problem. It could be anything from a coil pack failure @ high revs, an engine mount failing or an IMS bearing.

1) Read the fault codes before you do anything else....othrewise you are just guessing.
2) Get the car up on jackstand and determine where the oil is coming from - if its from the bottom of the bellhousing its either a RMS (rear main seal) or IMS (intermediate shaft) seal or bearing.

Let us know what the fault code(s) are, someone here will be able to point you in the right direction......

[Sideways Steve]

Multiple cylinder misfire on all cylinders apart from 3 and 6.

Had it all apart today and replaced the dual mass flywheel as that looked to be knackered, It was so knackered that it was actually wobbling that much it had managed to hit the bell housing on the gearbox and score it round its outer edge !!!!

Pics to follow when I get them off the camera. Luckily the box is not damaged and its only cosmetic which can only be seen with it removed from the car.

It was indeed the RMS causing my oil leak but it was only leaking at the point where the vibration happens.

I got hold of a brand new DMF and fitted my new RMS, got her all back together and guess what ..... still vibrations, still get the CEL light coming on past 5500 rpm then it stays solid until I plug in my OBD tool and pull the codes then reset them.

Again the codes are for multiple misfires on 1, 5, 2, 4 ....

And again when it vibrates the RMS starts leaking oil !

Im losing the plot with this car already as I cannot see why it would be doing this, it feels like something is imbalanced, Im begining to wonder if the damaged flywheel has cause my crankshaft to bend ? Surely not ?

Has anyone ever suffered a bent or warped crank on an M96 ??

Could a misfire cause this sort of vibration issue meaning it is just a case of replacing 4 coilpacks ?

I think its safe to say I now know why it was a good £3k below book price despite having full porsche and indy service history !

Any thoughts are welcome,

Tomorrow im going to pull the starter out and clock the flywheel while turning the engine by hand to see if its running true or if its warped in some way. Hopefully this will show if its an issue with the crank or not. Im hoping its not though

[Matt Fredrikson]

Pull the front mount and have a look could be your whole problem

[Steve Tinker]

SS + 1 as Matt says.... but,
1) The leaking new bearing seal so soon after replacement is a definate worry - how much is it leaking? Indeed a severely unbalanced flywheel could theoretically twist the end of the crankshaft, so clocking the flywheel is a good idea - I wish you luck as a bad result is going to hurt....

2) If you have muliple missfires on 4 out of 6 cylinders, surely it will also cause severe vibration at high revs - but do you get a power loss too? Changing the 4 coilpacks (or even moving two of them to the "good" cylinders to see if the problem swaps positions on the OBD tool) is a relatively cheap option.
Keep us informed.......

[Sideways Steve]

Well, bad news im afraid

Pulled her all apart again and the new seal is wrecked. The end of the crank appears to be bent, I cranked the engine over without the clutch fitted or the box on so I could watch the new flywheel and it wobbles like a buckled wheel

I rekon as you have said the damaged flywheel has damaged the crank, I just dont know how it has warped so easily being such a short crank.

Either way the engine is going to be pulled apart next weekend when I get a chance to investigate.

The front mount BTW was also shot, however looked quite new so I think its died due to the imbalance issue with the crank.

The way I see it now I have a few options,

1) Complete drop in replacement engine

2) Replace the bottom end as a complete unit using my heads etc

3) Tear down the engine and rplace the crank and bearings (assuming the bearing housings are still intact)

Im looking into quotes for the parts to progress so will keep you all informed.

I rekon im looking at about £1500 to sort this out. I just keep telling myself it will be worth it when its done !

Im just a bit miffed as I sold my 600bhp GTR to buy something "reliable" and now im in here pulling engines apart !!! LOL

[eightsandaces]

Originally Posted by Sideways Steve

Well, bad news im afraid

Pulled her all apart again and the new seal is wrecked. The end of the crank appears to be bent, I cranked the engine over without the clutch fitted or the box on so I could watch the new flywheel and it wobbles like a buckled wheel

I rekon as you have said the damaged flywheel has damaged the crank, I just dont know how it has warped so easily being such a short crank.

Either way the engine is going to be pulled apart next weekend when I get a chance to investigate.

The front mount BTW was also shot, however looked quite new so I think its died due to the imbalance issue with the crank.

The way I see it now I have a few options,

1) Complete drop in replacement engine

2) Replace the bottom end as a complete unit using my heads etc

3) Tear down the engine and rplace the crank and bearings (assuming the bearing housings are still intact)

Im looking into quotes for the parts to progress so will keep you all informed.

I rekon im looking at about £1500 to sort this out. I just keep telling myself it will be worth it when its done !

Im just a bit miffed as I sold my 600bhp GTR to buy something "reliable" and now im in here pulling engines apart !!! LOL

SS, The front engine mount tends to go early on the Boxster, my belief is that is do to excessive heat. Combined with whatever happen to the engine, it's no surprise it's shot. If I were you, I'd look for a used engine in good shape, it might be cheaper in the long run, good luck.

[vipola]

Damn this is very sad to read.. :/
Any way you can get back to the seller because he hidded something??

Tell yourself at least you have the advantage of having a good mecanic background and been able to do some work youself.. imagin the bill if you had it tow fo the dealer and pay them to investigate all that..