M987-TTP

Dear friends,

I have a 987 Boxster S in which I installed through TTP a brand new 3.8 X51 engine and several other mods (gt3 brakes, Bilstein PASM dampers and springs, quaifelsd etc). I have also chipped it and with the custom exhaust I managed 402hp (flywheel). I have only done 4.000km with the engine, from which the first 1.500 were not pressed at all as the engine was newThe car is trully fast and I absolutely love it but last week I am facing some weird issues. :

The engine is misfiring (all cylinders) every now and then. I might go for a ride and for 20 km it is ok and then it might start missfiring. Usually I leave the throttle and after two - three seconds it is ok and normal again. The revs which it usually are not stable, it can be at idle or at 3.000 rpm or at 2.000 etc. Furthermore, sometimes when it is misfiring I can hear the push rods knocking(I do not know if I use the correct term, I mean the unit that is being pressed among the camshafts and the valves). Then again after 1 or 2 minutes everything is back to normal again. The issue is that I changed all spark plugs and coils along with the MAP sensoro and it still does it. I repeat that it does it occasionaly, it might even not do it at all. I also fell like I have lost some power.

From the above it is obvious that the problem is the oil pressure. For some reason the oil pressure occasionally drops and the engine misfires and sometimes the push rods knock. Can anybody explain me why or give possible reasons? I also want to point out that the rev-limiter is being set to 7.600rpm. Has anybody faced any similiar problems before? Somebody told me that the rev-limiter it too high for this engine and I might have damaged a crankshaft bearing? Is that logical?
Please if somebody has had a similar experience or knows why it happens suggest me a solution. The porsche dealer in Greece cannot understand why this happens and he says that we have to open the engine and see. I will eventually have to send the car from Greece to Germany to TTP to find what is wrong, but I really want to avoid this whole procedure.
Does anybody have any clue???

Thanks in advance, I am desperate for a solution
Best regards, Michael

gpjli2

If the oil pressure is dropping you should see it on the gauge. Do you? I would think electrical or fuel first. Drop in oil pressure will kill the engine but you will not feel missfire. "Knock" could be caused by timing problem or gas. Do you get check engine light? On Board Diagnostics should be telling you whats wrong if it is hooked up right. This is a great idea for a swap but the opportunity for problems is high. You need a good technician not a message board. Good luck. Must be a great car. Gerry

MJones

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M987-TTP

It is not the fuel, I burnt the first fuel and now refuelled. When it misfires the check engine is blimping all the time. Then once it stops misfiring I shut down the engine and when I turn it on again everything is normal (!!!). Unfortunately I do not have the 911 Gt3 instruments, so I cannot see the oil pressure(I have only added an oil temperature gauge). The enginner told me that this is the problem without knowing what actually causes it!

Indeed, it is a fantastic car, I absolutely love it and go crazy about it. My nerves trully cannot handle the way it attacks on twisty roads (I have cup tires) but as you said all good staff has its bad aspect as well..

If the porsche dealer in Greece does not find a solution without opening the engine on Monday then on Tuesday the car will leave for Germany where TTP will find whatever it is. I just wished I could avoid this procedure, it will take a month!

gpjli2

Have someone read the error codes, or am I missing something?

dndodd

Go back to stock on the chip first and see if that solves the problem.

The cars don't have push rods. Pinging(timing issue or gas) is probably what your hearing. The chips timing may not be right.

gpjli2

Let me just repeat this fwiw When there is a CEL (check engine light) a code is stored in thr OBC (on board computer) This can be read with a diagnostic tool and will tell you what the malfunction is (with any luck) This does not require anything other than plugging it into the port Your dealer(?) should do this before your car goes anywhere.

TX996

I would really have someone do a scan on the DME and read the codes. On custom work like that I would have to think that it maybe electric. We had a boxster we did a regular 3.2 swap on and all in, everything fine, nada.

We checked and re-checked everything. After discussion to jump into the abyss is was the damn imobilizer (probably) on the engine harness. A firm re-connection after a removal and cleaning saw it fire right up.

Things can get streched, pinched. Consider a wiggle and connection session (granted not easy on a Boxster, belive me we know) and a code reading.

It is your best place to start IMHO, intermittent screams of electronic to me.

For what it is worth and best of luck man... I bet that car just screams...

JFScheck

OK - for the record I have heard of none of us with the X-51 engine package from Porsche ever have such issues...

Now the Troubleshooting side of me with this new install tells you to first take it to the folks who did the work as this is not your headache - and second tell them to check the harnesses for pinch/short or loose connections.

If it works sometimes and not others - such "phantom gripes" are wiring or sensors - be it corrosion shorts or opens. The computer may be able to help them troubleshot to a specific sensor or harness - again this needs to be cleared up by them.

Should be a pretty neat setup once these bugs get smashed!

awilks

I would agree with a few of the others...first, I assume you must have paid a decent sum to have all of that work done. Any shop concerned about reputation, and customer service (shouldn't they all be?) would be voluntarily taking your car back for immediate repairs which it sounds like is the case so that's a good start. This sounds electrical like a mapping problem with your ECU, or malfunction in the new wiring when installing new engine. Good luck and let us know how it goes.

M987-TTP

The Porsched dealer here has already plugged the tester and he saw only that it missfires all cylinders and that there is an oil error code too.
In any case the car is leaving for the mechanic who built it in the first place, so the error will be found and repaired but it will take some time. He gave me two year guarantee.
I do not believe it is a problem that has to do with the swap, I think it is something from the engine as an engine, that is why I posted here.
Tell me something else : is it safe to have the rev-limiter to 7.600? What do you guys in America do?
Thank you all guys for your help, I just wished it was something more easy to be diagnosed.

stv951

Michali, distixws den mporesa na sou steilw email, giati den exeis energopoiisei afti tin dinatotita.

Ama theleis epikoinwnise ,mazi mou

GREEK-TURBO-RACER

Michali, i maxani enai kenouria ? Opos to vlepo. tha enai provlima me to software y mpori na enai kati me kalodia and connectors.

Gamiseta, se katalaveno me tetia diskoli epothesi.


Theo

M987-TTP

Theo itan olokainourgia, se kouta apo to ergostasio irthe...! As ta na pane

GREEK-TURBO-RACER

Akouseme kala. Prepi na se voithisi o mexanicos se afto to thema. Elpiso exai xronia pou doulevi me Porsches ? TTP enai stin Ellada ? Den to csero afto. Vale fotia manga !! Exeis ksodepsi polla lefta na min trexi to caro. Sta 20 xronia pou doulevo se aftin tin doula, den mborousa na afiso pelati etsi.

Theo