May have blown my motor, any other possibility? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

rezanourai · 04-04-2021, 09:35 PM

So I had taken the boxster s race car to the track this Saturday, even though I haven't installed the baffled deep sump yet (you can probably already guess where this is going

). It's sitting on my workbench in the garage waiting for my next oil change so I can just do it then....

Well, during a sustained high G corner, my engine started to make a bit of a weird sound. Then the car started running rough, then oil pressure light flashed on the dash and the car stalled right in the middle of the track. Luckily I was able to roll off the track onto the dirt. Had a hard time starting the car, but got it started and limped most of the way back into the paddock but it stalled again. Struggled to get it started, but then was able to stall barely back in. Engine sounded awful. I pushed it back onto the trailer and brought her home, but haven't started looking around. I ran codes and saw a combination of:

P0343 - camshaft sensor bank 1 exceeds limit value
P1397 - camshaft sensor bank 2
P0300 - misfire damaging to cat converter
P0306 - cylinder 6 misfire damaging to cat converter
P0303 - cylinder 3 misfire damaging to cat converter
P0305 - cylinder 5 misfire damaging to cat converter
P0301 - cylinder 1 misfire damaging to cat converter

I'm pretty sure I know the answer to be that I'm an idiot for waiting to install the baffled deep sump and should have just done it instead of starving the engine around a sweeper, but on the off chance that the issue could be anything other than a blown motor, what else might I check?

One thing that is giving me pause is that I just finished gutting electrical from the car, ripping out 25lbs+ of wiring. Any way a short somewhere could trip up the DME and cause this, or does the combo of codes + rough awful sounding motor + stalling + oil pressure light pretty much guarantee I need to start shopping for a replacement motor?

I knew this would eventually happen, was just hoping it wouldn't happen so soon on a new race car... was hoping to get a year of track days out of it first.

Thanks for any suggestions!

maytag · 04-05-2021, 07:03 AM

Sucks, for sure.
However, not all hope is lost. You don't mention any clouds. No oil smoke?

When you say the engine sounds terrible; what does that mean? Runs rough? or mechanical grinding and banging noises?

Very first thing you need to do is pull those plugs and do a compression check.

Honestly; on the surface, the symptoms sound more like IMS to me. (this from the guy who thinks the IMS issue is exaggerated).

But if you added lots of smoke to the symptoms, then my mind would shift to other ideas.

rezanourai · 04-05-2021, 07:32 AM

No smoke, sounds like really rough running engine with almost like a knocking/clunking sound as its running

ike84 · 04-05-2021, 06:47 PM

I agree with maytag, check compression (or bet yet leak down if you're able). If those are way off then we will all cry a bit for you. If they check out though it may not be as bad as you think.

With that said, a massive vacuum leak or malfunctioning TB can do this as well. I again agree with maytag that no smoke may be a good sign, and instead you may just have a catastrophic failure along your intake. It's a long shot, just trying to be optimistic for ya. You're obviously not going anywhere with it soon - it may be worth an hour of time to tear down the intake and look at the TB to make sure. It's not stuck open.

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subieworx · 04-05-2021, 07:57 PM

If you starved the engine of oil and killed a bearing you won't have smoke.

Homeoboxter · 04-05-2021, 08:52 PM

If it`s the IMS, then why did the pressure warning come up? If you indeed killed a bearing you should be able to find bearing material in the engine oil. Hopefully that`s not the case... If it`s an IMS failure you should be seeing metal debris in the oil anyways, so that`s what I`d look at first.

rezanourai · 04-05-2021, 09:19 PM

Here's a video of when it happened & the aftermath of me trying to limp my way back into the paddock. So dangerous, because the car stalled and coasted to a stop at the exit of a 100mph+ turn (turn 8 at thunderhill). Not where I wanted to be with a stalled car!!!! But luckily ended without incident.

https://www.youtube.com/watch?v=wyWh8TMzLHI

rezanourai · 04-05-2021, 09:20 PM

During that first turn in the video, you can start to hear the engine note change and the car slow down and then the light flashes red on the dash by the time I reach the uphill right hander (with

Boleador · 04-05-2021, 09:39 PM

Oh man...that sounds awful! Keep us posted. (Sorry I'd only be guessing if I tried to diagnose it, and I'm sure you have enough conjecture and hearsay to fill your head right now!)

Quadcammer · 04-06-2021, 05:49 AM

That motor is toast. Probably ims bearing.

pilot4fn · 04-06-2021, 10:11 AM

sounds awful-a-lot like there is something hitting the pistons

rezanourai · 04-06-2021, 11:26 AM

Thinking about how I could have avoided this, IMS retrofit & the deep sump w/ baffle were really the only things I had planned. Does it seem like whatever happened here was indeed an IMS or oil starvation issue or could it have been something entirely unrelated? Just wondering if there are other preventative measures I should take on the next motor besides IMS & baffled deep sump?

Quadcammer · 04-06-2021, 12:22 PM

Quote:

Originally Posted by rezanourai

Thinking about how I could have avoided this, IMS retrofit & the deep sump w/ baffle were really the only things I had planned. Does it seem like whatever happened here was indeed an IMS or oil starvation issue or could it have been something entirely unrelated? Just wondering if there are other preventative measures I should take on the next motor besides IMS & baffled deep sump?

It could have been almost anything, but I don't see this as oil starvation. I see it as the ims bearing chunked, throwing a bunch of crap in the oil. When the bearing failed, cam timing went to hell and the junk in the oil clogged the variocam system resulting in misfires and difficulty starting.

Not much further you can do beyond running good oil (driven xp6 or 9), keeping the oil cool, and putting in a better ims bearing.

maytag · 04-06-2021, 05:15 PM

Quote:

Originally Posted by subieworx

If you starved the engine of oil and killed a bearing you won't have smoke.

Indeed. I was actually HOPING he'd seen smoke. A catastrophic moment with the AOS, filling the intake with 2 qts of liquid oil, can make everything seem really, really bad.... ask me how I know.
But now that we've seen the video, and heard the noises, I'm back to my original guess: IMS. I think quadcammer is right on the money.

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Homeoboxter · 04-06-2021, 05:27 PM

Wow, my condolences man, I`m really sorry for your loss...:ah:
Thanks for sharing the video, it`s very instructive... I`m looking forward to seeing what was causing this, so keep us posted. Once I had a rod bearing failure in my SAAB because the pickup screen got obstructed, that was making a very similar clunking noise like this. If this is an IMS failure it`s surprising to me that you were able to restart the engine twice - I would assume the valves would get bent in each of the cylinders making it impossible to restart. Nevertheless, a complete dissassembly will tell you more about how to prevent this to happen again. I`d drain the oil and see what`s in there.

Homeoboxter · 04-06-2021, 09:48 PM

Btw, do you know the condition of the small cam chain guides on the variocam actuator? I just thought a little more on this, and just wondering perhaps the same failure happened to your car that I had on mine. I rebuilt my 99 Boxster engine because the chain pads completely wore down, one fully came off and caused the timing to jump. This resulted in piston-to-valve contact but surprisingly did not destroy the entire engine, the bearings, pistons, even the valves survived. But for sure it was making a loud rattling. Perhaps the drop in oil pressure caused the chain pads to fly off? Or, conversely, the variocam fell apart and the resulting oil leak led to the loss of pressure?

truegearhead · 04-19-2021, 05:35 AM

If there is a track that is going to starve an engine of oil its that one, super long fast sweepers. Sorry about the engine, time for an upgrade!

rastta · 04-19-2021, 09:53 AM

Not sure what motor you're shopping for - but with these cars and the inherent issues, I'm not sure I'd trust a used motor. This is why my car has sat for a year (well that and Covid) waiting to get the engine rebuilt. The cost of the rebuild is going to cost me 2/3s the cost of the car since it's a 2005 3.6.

rezanourai · 04-19-2021, 10:29 AM

Quote:

Originally Posted by rastta

Not sure what motor you're shopping for - but with these cars and the inherent issues, I'm not sure I'd trust a used motor. This is why my car has sat for a year (well that and Covid) waiting to get the engine rebuilt. The cost of the rebuild is going to cost me 2/3s the cost of the car since it's a 2005 3.6.

I found a used motor with 66k miles for $3500. For a dedicated race car like this, I almost consider the motor as a consumable, but of course like any consumable you want to squeeze the most life out of each replacement as you can.

This time around, I'm doing the IMS retrofit and 2qt baffled deep sump kit before the new motor even goes into the car. I'm hoping I can extract a year or two (maybe 20-40 track days) from the motor, but we'll see. I'm also planning on doing a tear down of the old motor if I can to see what exactly happened and make sure I'm taking any reasonable precaution on the new one.

rezanourai · 04-19-2021, 10:40 AM

Quote:

Originally Posted by truegearhead

If there is a track that is going to starve an engine of oil its that one, super long fast sweepers. Sorry about the engine, time for an upgrade!

It's a fun track! I was just starting to get used to this car a bit and finding it's traction limits with my current set up before this happened. Here's a lap from the prior session before blowing the motor: https://www.youtube.com/watch?v=UdsNRz7GoCA. Had traction control stuck on (I wired it wrong when I stripped the wiring a few weeks ago, so need to fix it) which was crippling me on turn exits a lot as well as some traffic. Previously in this car (while it weighed 200lbs more than today) and traction control off I had gotten low 2:10s.

Car oversteers a touch too much, but otherwise very balanced. I need to dial out that oversteer just a hair and then get some more seat time after the new motor goes in. I think I can get an 2:05-2:07 at this track when dialed in. Pushing below 2:05 will take some more work but not impossible. Car probably has 2:01-2:03 in it with the right driver.