Please help, Engine vibration .... - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Sideways Steve · 03-15-2010, 12:55 AM

Good Morning Everyone,

Apologies in advance for this being my first post however I only just bought myself a nice tidy 2000 Boxster 2.7 over the weekend.

On driving her the 400 miles home I seem to have encountered a problem !

Once on the open road I opened her up a little and all was well but as the revs passed 5,500 rpm I noticed what can only be described as heavy engine vibration followed by the check engine light flashing at me.

I backed off and the vibration went away and the light went off.

I drove sensible the rest of the way home then yesterday took her for a spin to see what she done. Again above 5,500 rpm the vibration started and the light came on again, this time on bacing off the vibration went but the light stayed on.

Low down the revs etc she drives fine even though the light is still on but any time you go above 5,500 ish it shudders quite a bit and feels really nasty. At that point the light goes from solid to flashing again until you back off.

Now last night an additional issue has come to light, she seems to be dripping some oil when parked after a drive now too. Not much but enough to be concerned about !

Ive not had a chance to look and see where the oil is coming from yet but im thinking the vibration has damaged something and caused the leak.

What could be causing the vibrations ?

Just to add, I have owned many performance cars but generally stuck to japanese stuff, last car a Skyline GTR with over 600bhp. I do all my own work on cars etc and also can get access to a fault code reader to check why the light come on, but something really does feel mechanically wrong here

eightsandaces · 03-15-2010, 03:58 AM

SS, This car doesn't sound tidy at all, it sounds like it has any one of many possible serious, expensive, internal engine problems, that theory being fortified by the oil leak. Is there any way to approach the PO for a refund or force them by law to repair it?

If not, your cheapest option might be a used engine.

idheaton · 03-15-2010, 06:02 AM

Not sure what your problem might be but do not drive the car if the CEL is flashing, if it's solid that's okay but flashing is an indication of something very bad and driving the car could cause major damage.

Steve Tinker · 03-15-2010, 05:46 PM

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 · 03-20-2010, 01:16 PM

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 · 03-20-2010, 03:22 PM

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

Steve Tinker · 03-20-2010, 09:14 PM

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 · 03-22-2010, 01:05 AM

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 · 03-22-2010, 02:56 AM

Quote:

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 · 03-22-2010, 07:01 AM

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..

Steve Tinker · 03-22-2010, 02:45 PM

SS
Just be very aware that these M96 engines are very complex pieces of kit - more so than the straight 6 Nissan units.
Before embarking on a teardown, I would suggest you obtain as much info as you can on the complexities / costs / tools etc you are going to need campared to (say) going to Porsch specialists like Hartech or Autofarm for advice.
Whichever way you go, best of luck & keep us informed of the results.....

Sideways Steve · 03-23-2010, 02:08 AM

Cheers Steve,

I'm aware there complex but not as complex as some of the stuff I have rebuilt

Rebuilt some Rotarys along with upgrades at the same time also done a Mitsi V6 Mivec engine recently and I have rebuilt gas turbines and various other mechanical/electrical systems through my line of work too so the wee boxxer engine is a piece of cake in comparison

Plus I also have the full workshop manual to hand too

Also have all tools that I will need which I have collected over the last few years of messing about with all manner of engines/vehicles.

There was me thinking now that Im an Instrument Tech to trade I would no longer be getting my hands oily ! grrrr LOL

Dont have any comeback with the seller as it was a private sale and sold as seen. On the test drive the car drove fine, although I didnt give it quite as much abuse as I probably should have !!!

My own fault though, and to be honest I actually believe the seller had no idea there were any issues as he was the type of guy who would probably only ever drive below 4000 rpm !!! LOL

eightsandaces · 03-23-2010, 02:51 AM

SS you're a saint, why? Well I for one think the PO knew exactly what was wrong with that automobile. Sounds like you have an impressive resume to tear down a m96. I would however, heed Steve Tinker's advise as I have read where even full-time mechanics would have a hard time with the M96. Good luck, we will certainly be pulling for you to resurrect the Boxster.

Sideways Steve · 03-23-2010, 03:04 AM

Quote:

Originally Posted by eightsandaces

SS you're a saint, why? Well I for one think the PO knew exactly what was wrong with that automobile. Sounds like you have an impressive resume to tear down a m96. I would however, heed Steve Tinker's advise as I have read where even full-time mechanics would have a hard time with the M96. Good luck, we will certainly be pulling for you to resurrect the Boxster.

Cheers dude,

I do genuinely believe the guy I got the car from was unaware, believe me I have bought some seriously rough cars in the past deliberatly to fix up and sell on as I enjoy doing so and you can get a feel for people. This guy was 100% clueless about cars other than that he knew how to drive one LOL There are even receipts for having a wiper blade replaced so basically anytime this car needed something done, it went off to a garage and he payed silly amounts for it to be put right.

Thats aside though, theres no point in being angry about it, At the end of the day I have bought a well optioned boxster for about £3000 less than the current UK market value, so even at worst if I did source a full engine and drop that In I still theoretically wont be out of pocket other than for my time involved to sort it.

But that would be the easy way out ! I never jump to replacing a full engine until I know exactly what failed.

I once bought a car which had a suspected blown engine which on full investigation turned out to be some bad wiring and a small oil leak !

Cost to fix ----- £10 whereas anyone else would have replaced the engine and it would have cost ££££'s

This M96 failure though is a bit of a special one from what I can see so far, in that the failure has not been noted before anywhere I can see online. I have been in contact with flat6innovations and Jake is keen for me to keep him updated on my findings as he has not even had one of these engines with these sort of symptoms.

on the plus side .... my IMS appears to be in perfect condition !! haha !

eightsandaces · 03-23-2010, 03:34 AM

Well SS, god bless you and your positivity, it's very refreshing. Besides, you have a failed engine that isn't because of an IMS, we love you just for that!

Sideways Steve · 03-23-2010, 03:39 AM

Indeed, if i end up replacing the engine I may take the IMS from mine and retro fit it simply because I know its a good one ! LOL

Ach if you dont laugh you will only cry so its good to just be positive. At the end of the day its all nuts and bolts and It will get fixed, just a matter of when as its happened at a really bad time for me ! Im moving house at the weekend and start a new job in 2 weeks so its all come at once !

jmatta · 03-23-2010, 05:55 AM

Keep us posted, Steve...your attitude is very refreshing. Instead of pointing fingers and "poor me" ramblings, you are attacking the problem head on and, hopefully, we'll all learn from your experience.

I have no where near the talent you possess, but I did sleep at a Holiday Inn Express recently (American joke).

Sideways Steve · 03-23-2010, 06:55 AM

Thanks all for the kind words, its nice to feel like I have some support and it makes me all the more determined to get this sorted ASAP so that I can start enjoying the car

I have already decided I will be keeping this one for 8 - 12 months then moving up to a boxster S for a bit before finally moving onwards to a nice 911 as I have ALWAYS wanted one !!

eightsandaces · 03-23-2010, 07:48 AM

Quote:

Originally Posted by Sideways Steve

Thanks all for the kind words, its nice to feel like I have some support and it makes me all the more determined to get this sorted ASAP so that I can start enjoying the car

I have already decided I will be keeping this one for 8 - 12 months then moving up to a boxster S for a bit before finally moving onwards to a nice 911 as I have ALWAYS wanted one !!

Don't be surprised if you like the Box S better, personally, I'd take a Cayman S over a 911 unless said 911 was a gt3rs.

Sideways Steve · 03-29-2010, 03:29 AM

Well,

after a busy Saturday the engine is out and mostly stripped back, but again I only had 1 day and ran out of time.

I clocked the crank and its showing 0.45mm of runout at the flywheel end which is a fair whack more than the Porsche tolerance of 0.04mm !!!

It appears that indeed I have somehow got a bent crankshaft ! its not broken but is definately bent.

Its also not the bearings causing the runout as theres not metallic residue in the oil etc either.

It does sound impossible to have bent such a tough piece of steel but the proof is now here that it can be done !

I have a new crankshaft and cradle on my watch list on eBay so hopefully will have her running sweet again very soon