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Rough idle, loss of power on accelleration, IMS?


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I have a major issue with my 2003 Boxster S which i'm hoping someone here can give a clearer picture of whats happening. I've researched the IMS failure and can't really seem to find any description of symptoms other than "you'll hear a crunch and your engine will stop".

Car Info:

2003 Boxster S 6-speed

74,000 miles

Oil changed 1000 miles ago with M1 5w30

Drive it conservatively (i'll push it to 6k in 2nd once a month :D )

all fluids fine, full tank of gas

Symptoms:

75mph and suddenly i get a flashing Check Engine. Engine cuts power by half.

Idles very rough and will slowly idle lower and lower till it dies (~5 seconds)

Take alot of throttle input to bring it above 3000rpm

Smooths out above 3000 rpm

clutch works fine (but since there is a lack of power under 3000, i need to launch at 3000+)

"ting" sound occurs 2 per second at idle

Any Ideas? I really hope it's not an IMS, and if it is, hopefully i caught it in time before destroying the engine.

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I have a major issue with my 2003 Boxster S which i'm hoping someone here can give a clearer picture of whats happening. I've researched the IMS failure and can't really seem to find any description of symptoms other than "you'll hear a crunch and your engine will stop".

Car Info:

2003 Boxster S 6-speed

74,000 miles

Oil changed 1000 miles ago with M1 5w30

Drive it conservatively (i'll push it to 6k in 2nd once a month :D )

all fluids fine, full tank of gas

Symptoms:

75mph and suddenly i get a flashing Check Engine. Engine cuts power by half.

Idles very rough and will slowly idle lower and lower till it dies (~5 seconds)

Take alot of throttle input to bring it above 3000rpm

Smooths out above 3000 rpm

clutch works fine (but since there is a lack of power under 3000, i need to launch at 3000+)

"ting" sound occurs 2 per second at idle

Any Ideas? I really hope it's not an IMS, and if it is, hopefully i caught it in time before destroying the engine.

Usually is an IMS failure is big event and the engine may drop all of its oil but it will not run with an IMS failure.

A flashing CEL means there is a severe emissions problem that can damage the catalytic converters.

If the CEL is still flashing do not drive the car.

Find a shop with the Durametric software, a Porsche PST2, or Porsche PIWIS tester and find out what the fault codes are.

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I have a major issue with my 2003 Boxster S which i'm hoping someone here can give a clearer picture of whats happening. I've researched the IMS failure and can't really seem to find any description of symptoms other than "you'll hear a crunch and your engine will stop".

Car Info:

2003 Boxster S 6-speed

74,000 miles

Oil changed 1000 miles ago with M1 5w30

Drive it conservatively (i'll push it to 6k in 2nd once a month :D )

all fluids fine, full tank of gas

Symptoms:

75mph and suddenly i get a flashing Check Engine. Engine cuts power by half.

Idles very rough and will slowly idle lower and lower till it dies (~5 seconds)

Take alot of throttle input to bring it above 3000rpm

Smooths out above 3000 rpm

clutch works fine (but since there is a lack of power under 3000, i need to launch at 3000+)

"ting" sound occurs 2 per second at idle

Any Ideas? I really hope it's not an IMS, and if it is, hopefully i caught it in time before destroying the engine.

What are the engine codes?

Could have lost timing -- I would not drive it or even run it.

many possible causes -- but basically timing chain jump could give you these symptoms.

Power loss is due to compression loss out an open/bent valve?

Could also have suffered a broken valve spring, and the valve stuck open

and hit piston.

ting -- could be valves hitting piston.

Mike

Edited by txhokie4life
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Definitely find a Durametric code reader to see what codes are coming up. Since the CEL light is up it could be a sensor of some type and since the idle is rough it could be related to a sensor that works with the throtle body, maybe MAF or a sensor control to do with idle, also I would check lines connected to the throtle body for air leaks and I would check spark plug wires, coil packs etc. My last thought is it might be your ECU, but again get a Durametric and scan for codes. Hope this helps.

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got back from the mechanic.

air filter is clean. MAS sensor is fine. Clanking noise coming from transmission with stethescope. At first he wasn't able to pull any codes. but eventually found a misfire in 1,5,6. Pulling plugs for 1,5,6 found them to be wet.

He suspects a crankshaft bearing failure, causing wobble and slack in the timing chain. Can't just replace the bearings becuase that would need a rebuild of the entire engine. It's possible an IMS caused metal shaving in the oil to foul the crankshaft bearings. Replacement engine is recommended. :(

I think this will be my last Porsche for a while. I've lost faith.

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got back from the mechanic.

air filter is clean. MAS sensor is fine. Clanking noise coming from transmission with stethescope. At first he wasn't able to pull any codes. but eventually found a misfire in 1,5,6. Pulling plugs for 1,5,6 found them to be wet.

He suspects a crankshaft bearing failure, causing wobble and slack in the timing chain. Can't just replace the bearings becuase that would need a rebuild of the entire engine. It's possible an IMS caused metal shaving in the oil to foul the crankshaft bearings. Replacement engine is recommended. :(

I think this will be my last Porsche for a while. I've lost faith.

I would get a second opinion.

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got back from the mechanic.

air filter is clean. MAS sensor is fine. Clanking noise coming from transmission with stethescope. At first he wasn't able to pull any codes. but eventually found a misfire in 1,5,6. Pulling plugs for 1,5,6 found them to be wet.

He suspects a crankshaft bearing failure, causing wobble and slack in the timing chain. Can't just replace the bearings becuase that would need a rebuild of the entire engine. It's possible an IMS caused metal shaving in the oil to foul the crankshaft bearings. Replacement engine is recommended. :(

I think this will be my last Porsche for a while. I've lost faith.

I would get a second opinion.

compression test?

boroscope?

Check oil filter, oil, coolant?

If the IMS were to fail -- you'd have carnage.

Or at least you would have lost timing -- did this get checked?

I agree with Loren -- get a second opinion.

mike

Edited by txhokie4life
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got back from the mechanic.

air filter is clean. MAS sensor is fine. Clanking noise coming from transmission with stethescope. At first he wasn't able to pull any codes. but eventually found a misfire in 1,5,6. Pulling plugs for 1,5,6 found them to be wet.

He suspects a crankshaft bearing failure, causing wobble and slack in the timing chain. Can't just replace the bearings becuase that would need a rebuild of the entire engine. It's possible an IMS caused metal shaving in the oil to foul the crankshaft bearings. Replacement engine is recommended. :(

I think this will be my last Porsche for a while. I've lost faith.

I would get a second opinion.

A crankshaft bearing failure would be pretty unusual in this car. An intermediate shaft bearing is more common but those are usually catastrophic.

If it were my car I would still get a second opinion.

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got back from the mechanic.

air filter is clean. MAS sensor is fine. Clanking noise coming from transmission with stethescope. At first he wasn't able to pull any codes. but eventually found a misfire in 1,5,6. Pulling plugs for 1,5,6 found them to be wet.

He suspects a crankshaft bearing failure, causing wobble and slack in the timing chain. Can't just replace the bearings becuase that would need a rebuild of the entire engine. It's possible an IMS caused metal shaving in the oil to foul the crankshaft bearings. Replacement engine is recommended. :(

I think this will be my last Porsche for a while. I've lost faith.

I realise your mechanic is a friend, but this is a most peculiar diagnosis. I agree with Loren that you should get a second opinion from a Porsche specialist.

You really need to get a proper diagnostic check with a Porsche Tester. Get the fault code numbers, and post them here.

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porsche dealer or porsche independant? which one is the cheaper option and which one is the most knowledgeable option?

The dealer will invariably be more expensive.

The level of knowledge and competence among indies varies greatly.

Ask around for a Porsche indie in your area with an established reputation and get your second opinion. The PCA chapter in your area might be a good place to start.

Regards, Maurice.

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I'm in Hayward, CA. Any Porsche indie recommendations?

There is a German Auto Kraft and German Motor Care in Belmont, CA. I pass by them all the time.

Thanks Elucidus. My porsche is in santa clara so that'll help with towing.

Edited by BrianH
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  • 7 years later...

Hi Everyone, I'm new to the post and need to resurrect this old thread as I have exactly the same issue. Brian H, if you are still around did you get to the bottom it with your car? I also have a 2001 Boxster S that just went down the same way this weekend. 

 

I would appreciate any information anyone can provide!

 

Thanks in advance,

Morrissey

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43 minutes ago, Morissey said:

BTW, fault codes are P0300, P0301, P0306, P0305. In that order

 

Start with obvious. Your car is 16 years old.

Check the spark plugs on each of those cylinders - tight not cracked - and less than 30,000 miles.

Check the spark plug connector with an ohm meter - it should be about 2k ohms.

Check the coil packs with an ohm meter - Resistance between terminal 1 and terminal 15 at 20°C: 0.3 - 0.7 ohms.

Of course look for corrosion or damaged spark plug wires.

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Agree with the deferred maintenance diagnosis .If the plugs,seal,coils are old - it is prudent to replace all in my experience.It will eliminate all those issues from any future diagnosis.

Seems you have misfire on cyls. 1,5,6. So both Banks are affected. Are you sure the 6 was not a 3 ? I ask because that would have limited the diagnosis to Bank 1. In turn that would have suggested a need to check the static timing (the green plugs job).

Were the plugs tips wet with gasoline or oil ?  Was the body of the plug wet with oil(seal leakage)?

Once you've done the parts replacement work let us know what codes you get?

A good idea to poke around looking for vacuum leaks. For example the AOS hoses and their brittle connectors and missing seals?

Edited by Schnell Gelb
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2 hours ago, Schnell Gelb said:

Agree with the deferred maintenance diagnosis .If the plugs,seal,coils are old - it is prudent to replace all in my experience.It will eliminate all those issues from any future diagnosis.

Seems you have misfire on cyls. 1,5,6. So both Banks are affected. Are you sure the 6 was not a 3 ? I ask because that would have limited the diagnosis to Bank 1. In turn that would have suggested a need to check the static timing (the green plugs job).

Were the plugs tips wet with gasoline or oil ?  Was the body of the plug wet with oil(seal leakage)?

Once you've done the parts replacement work let us know what codes you get?

A good idea to poke around looking for vacuum leaks

I have yet to get into the inspection and diag process. I plan to check everything with air, fuel and ignition, starting with ignition.

I am certain about codes 1,5 and 6. I understand our question and double-checked the codes. Indeed very odd.

While I do the discovery...Someone suggested the symptoms seem more timing related than ignition, arguing that 3 random cyls could not begin misfiring at the same time...thoughts?

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Just now, Morissey said:

I have yet to get into the inspection and diag process. I plan to check everything with air, fuel and ignition, starting with ignition.

I am certain about codes 1,5 and 6. I understand our question and double-checked the codes. Indeed very odd.

While I do the discovery...Someone suggested the symptoms seem more timing related than ignition, arguing that 3 random cyls could not begin misfiring at the same time...thoughts?

Sorry about the typo. Meant 'your' question.

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Cam Timing - maybe, but it would have to be a common component to both Banks if 1,5=Bank 1 & 6=Bank 2 are causing the codes.

That is why I suggested the basic cam timing check by removing the green plugs.

Vacuum leak  is still a possibility if the misfire is caused by an excessively lean condition in those cylinders.

The plug color may give clues?

My speculation is not authoritative so best for you to gather evidence and let the smarter guys comment.

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