99 Boxster Engine Failure

[Dan Hinkebein]

Well it finally happened after 94,000 basically trouble free miles from my 99 Boxster, I’ve had my first major problem and it’s a biggie. I was driving to work Monday, sitting at a stoplight when my check engine light flashed several times then stayed on. When I pulled away from the light, the engine was missing and had a loss of power. I was only a couple of miles from my local dealer so I drove into the service bay. The initial thought of the service tech was that there was a vacuum leak since the car was not knocking, smoking or anything. My first thought was that a coil pack had gone bad. Neither of which I would consider a major problem. I left the car so that they could diagnose it. They called me yesterday and said that it was showing a misfire on the #6 cylinder. They wanted to do a compression check next to see what was up. The good news was that the #6 cylinder held great compression the bad news was that #5 did not. All other cylinders are fine. That’s right the computer was indicating a problem on #6 when the problem was actually on #5. They did a leak down check and determined that the air was pushing into the exhaust. At this point they’re not sure if the problem is a bad ring, bent valve, bent rod or crank. Not sure how this would have occurred since the car was idling when it happened. They did verify that my block is not one of the ones that were sleeved from the factory. Now comes my dilemma, they’re telling me it will be a minimum of $9,000 to rebuild the engine or $14,000 for a factory crate motor. I’m not sure if I want to spend that on the car. I would like to find a good used motor as a replacement. Does anyone know of a good 2.5 non-egas motor for a reasonable price?

Thanks,

Dan

[mikefocke]

A list of wrecking yards

is here

[Dan Hinkebein]

Thanks Mike. I have tried a few of these already. I'll try the others you've listed tomorrow.

Dan

[pk2]

I'd have them pull the head off and have a look before you buy a new motor. Sounds to me like a valve problem. That is really the only way air could leak into the exhaust manifold. You could breal the crank in half and if the vavle is seated correctly, no air would get through to exhaust manifold. You might well get away with a new head or maybe just a valve.

If you have to ditch the motor, why not shop around for a 3.4L...

Regards, PK

[rsfeller]

wow a crate engine that costs as much as the car!! Is that quote installed?

[Dan Hinkebein]

Yes, that is installed.

[dpwell]

I think the piston is broken or there is a problem with the valves. If the bleed down test consists of pressurizng the cylinder on tdc of the compression stroke, and air is escaping into the exhaust, that would seem to indicate an exhaust valve. pk2's response seems like the correct course of action. Even if the engine has to come out to do the repairs, I would rather fix my engine than take chances with a wrecking yard one. good luck mike

Well it finally happened after 94,000 basically trouble free miles from my 99 Boxster, I’ve had my first major problem and it’s a biggie. I was driving to work Monday, sitting at a stoplight when my check engine light flashed several times then stayed on. When I pulled away from the light, the engine was missing and had a loss of power. I was only a couple of miles from my local dealer so I drove into the service bay. The initial thought of the service tech was that there was a vacuum leak since the car was not knocking, smoking or anything. My first thought was that a coil pack had gone bad. Neither of which I would consider a major problem. I left the car so that they could diagnose it. They called me yesterday and said that it was showing a misfire on the #6 cylinder. They wanted to do a compression check next to see what was up. The good news was that the #6 cylinder held great compression the bad news was that #5 did not. All other cylinders are fine. That’s right the computer was indicating a problem on #6 when the problem was actually on #5. They did a leak down check and determined that the air was pushing into the exhaust. At this point they’re not sure if the problem is a bad ring, bent valve, bent rod or crank. Not sure how this would have occurred since the car was idling when it happened. They did verify that my block is not one of the ones that were sleeved from the factory. Now comes my dilemma, they’re telling me it will be a minimum of $9,000 to rebuild the engine or $14,000 for a factory crate motor. I’m not sure if I want to spend that on the car. I would like to find a good used motor as a replaceme goo Does anyone know of a good 2.5 non-egas motor for a reasonable price?

Thanks,

Dan

[Glyn]

I dont believe any of the diagnosis so far, though i must conceed the valve problem does seem to be on the right track.

You describe everything as normal up to the stop at the lights, no knocking, smoking, and you have not identified any tell tale signs in the run up to this in the preceeding few weeks - engines dont just let go at idle.

If a valve was bent it could only get bent by the piston comming into contact with the valve and that is only possible if the big end shells fell out - which they cant, to contact a valve either the valve has to stay open when the piston rises or the travell of the piston needs to be further - like taking a big end shell out of the housing so the con rod pushes further, or you have reved the engine so high that the valves bagan to bounce - you would know if you have done this and probably have heard this happen - So i would discount that theory.

The car has done 94000 miles, so my guess would be that carbon build up on a piston has become dislodged and has jammed itself around the exhaust valve leaving the valve poorly sealing, this would cause the misfire though i dont believe this would trigger the CEL, but perhaps it would as a poor seal would affect induction and ignition and perhaps this would be noticable to the oxygen sensors in the exhaust (others may be able to confirm this)

Personally i would simply remove the head on that bank and have a poke around, after all you've nothing to loose as currently you have a knackered engine, take it apart and find nothing and you still have a knackered engine so you loose just a little time.

Alternatively, the diagnosis for cylinder 6, i dont believe the problem then could shift to num 5, I suspect a coil problem with cylinder 6 (try swapping coil 5 and 6 over to see what the diagnosis then indicates) with a sticking valve on 5, i think your problem is minor and you dont need a new engine - though obviously for the garage its very profitable to fit one.

The coil on six with a lower compression of 5 probably identified the problem, indeed you may have had a low compression for some time but failed to notice it and only when cylinder 6 was taken out as well did it become obvious.

Whatever you find do tell us all

Glyn

[Dan Hinkebein]

Glyn,

Thanks for your thoughts. I had the same thought over the weekend re carbon blocking one of the valve from fully closing. The Boxster is my daily driver and I spend 1.5 to 2 hours per day sitting in traffic. I have not gone out and opened the car up is several months so it's very plausible that there would be some carbon on the valves and or pistons. The dealer did check the coil packs and they were fine. There had been no other signs of engine issues. I do get the occasional puff of smoke on startup after the car has sat over night, which is not uncommon for a boxer type engine. I picked the car up from the dealer Friday evening and drove it home, in traffic, with no problems other then power loss. I’ll report back once I have time to further investigate.

Dan

[Glyn]

Dan, best of luck.

If you have the Durametric software you could hook it up to the car and it will tell what triggered the CEL.

You can also switch of individual injectors so you will be able to track down the offending cylinder.

The car would not run so well if there was anything seriously wrong, This just a minor thing, though when you go on forums there are so many people without a clue about an engine they simply grab at anything so it always sounds very serious as you dont know their level of expertise.

Im not having a go at those without a clue its just that their input clouds the issues.

[tatios]

Just wanted to throw in my two cents. I am a professional mechanic and I priced out a complete 02 Boxster S motor today from Porsche and list price is $10,039 with a $2181.00 core. I think you might want to check the price again. I don't know where you live but maybe they are artificially inflating the price. I don't know the price for a standard Boxster engine but I doubt it is more than the S.

Ed

Edited April 18, 2008 by tatios

[HJK]

few months gone since, but I'm just curious, what was the problem and how was it solved?

H

[Glyn]

Me too.

Would like to know how the problem was resolved and i am convinced the problem was minor, do give us an update

[seafeye]

Me too.

Would like to know how the problem was resolved and i am convinced the problem was minor, do give us an update

My buddy just bought a 97 with a blown motor and we have been toying the idea with a bigger motor.

But for now to get it running i think we are going to get a 2.5l and go from there.

www.car-part.com has a great network. Just a 2.5l longblock you can get for $1000.00. Cheap. If you just

want to get the car going again. Don't expect a warranty.

Aside from that any idea on how a piston breaks like this one?

Edited June 18, 2008 by seafeye

[KevinC]

I'm afraid that Dan might have an intermediate shaft failure. My car is throwing the same kind of misfire codes (also a "signal implausible" code for the camshaft position sensor).

One of the first things my mechanic checked was the oil filter. He found lots of metal in the oil and his experience told him the problem was most likely the IMS failure. My car is now at the dealer to get their diagnosis and then to see if Porsche will help me out with a new engine.

kc

few months gone since, but I'm just curious, what was the problem and how was it solved?

H

[juniinc]

Hey Kevin

whats the mileage on your 2000 S? around 30,000

I'm afraid that Dan might have an intermediate shaft failure. My car is throwing the same kind of misfire codes (also a "signal implausible" code for the camshaft position sensor).

One of the first things my mechanic checked was the oil filter. He found lots of metal in the oil and his experience told him the problem was most likely the IMS failure. My car is now at the dealer to get their diagnosis and then to see if Porsche will help me out with a new engine.

kc

few months gone since, but I'm just curious, what was the problem and how was it solved?

H

[KevinC]

The car has 90K. The engine has 40K.

kc

Hey Kevin

whats the mileage on your 2000 S? around 30,000

[Dan Hinkebein]

I wanted to give everyone an update. I've just turned 100k on what was suppose to be a blown engine. The SeaFoam did the trick for me. I've had no other issues with my engine. 6,000 miles after I was told I needed a new engine and it's still running strong. No CEL faults and after 100k My gas milage has only dropped 1 mile per gallon (27.2) during normal highway driving. Even on a 2 hour spirited drive through the twisty backroads this past weekend, I averaged 24.9 mpg's.

Dan

[rsfeller]

I wanted to give everyone an update. I've just turned 100k on what was suppose to be a blown engine. The SeaFoam did the trick for me. I've had no other issues with my engine. 6,000 miles after I was told I needed a new engine and it's still running strong. No CEL faults and after 100k My gas milage has only dropped 1 mile per gallon (27.2) during normal highway driving. Even on a 2 hour spirited drive through the twisty backroads this past weekend, I averaged 24.9 mpg's.

Dan

What do you mean "seafoam"?!?!? I re-read the posts and must be missing something!

[psng]

What do you mean "seafoam"?!?!? I re-read the posts and must be missing something!

Fuel/injector/carbon cleaner Seafoam About $6 a bottle.

Worked out great on my 300K 83 BMW.

Peter