Missfire number 3
12-24-2023, 09:54 AM
#1
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Missfire number 3
Hi all
new to the group but have used it for research I have a 2001 996 3.6, it has a misfire on cylinder 3 so far I have swapped coils,new plugs, new injector, checked the wiring done a compression test carried out a leak down test changed the oil (twice) and also swapped the cam actuators but still have a misfire at idle only even placed a Noid tester on the injector
if I thrash it down the road all is good for around 15 miles or so at idle then randomly it will start again
any ideas now would be great thanks in advance
new to the group but have used it for research I have a 2001 996 3.6, it has a misfire on cylinder 3 so far I have swapped coils,new plugs, new injector, checked the wiring done a compression test carried out a leak down test changed the oil (twice) and also swapped the cam actuators but still have a misfire at idle only even placed a Noid tester on the injector
if I thrash it down the road all is good for around 15 miles or so at idle then randomly it will start again
any ideas now would be great thanks in advance
12-24-2023, 10:52 AM
#2
Hi all
new to the group but have used it for research I have a 2001 996 3.6, it has a misfire on cylinder 3 so far I have swapped coils,new plugs, new injector, checked the wiring done a compression test carried out a leak down test changed the oil (twice) and also swapped the cam actuators but still have a misfire at idle only even placed a Noid tester on the injector
if I thrash it down the road all is good for around 15 miles or so at idle then randomly it will start again
any ideas now would be great thanks in advance
new to the group but have used it for research I have a 2001 996 3.6, it has a misfire on cylinder 3 so far I have swapped coils,new plugs, new injector, checked the wiring done a compression test carried out a leak down test changed the oil (twice) and also swapped the cam actuators but still have a misfire at idle only even placed a Noid tester on the injector
if I thrash it down the road all is good for around 15 miles or so at idle then randomly it will start again
any ideas now would be great thanks in advance
.
Well, what car do you have..?, a 2001 996 is a 3.4, 5 chain not a 3.6, 3 chain as you stated above. Unless you have a Turbo or GT..?
Seems you've done all the normal stuff to solve a misfire, unfortunately with no luck.
Have you got the exact fault codes, they might help shed some light on your problem..?
jmo
12-24-2023, 11:23 AM
#3
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Mine is a late 2001 first of the 3.6 engines I get p0300 and p0303 fault codes
I must also add the IMS was done 10k ago with a modified oil feed
I must also add the IMS was done 10k ago with a modified oil feed
Last edited by Ian338; 12-24-2023 at 11:25 AM.
12-24-2023, 01:53 PM
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hi 124k
full history
only done 10k since 2014 when the IMS was done and other than service not much I can see only just bought it so go stitched up as it happened about a day after I got it as I say give it a good thrash it clears then all good for 15-20 miles
full history
only done 10k since 2014 when the IMS was done and other than service not much I can see only just bought it so go stitched up as it happened about a day after I got it as I say give it a good thrash it clears then all good for 15-20 miles
12-24-2023, 01:54 PM
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hi 124k
full history
only done 10k since 2014 when the IMS was done and other than service not much I can see only just bought it so go stitched up as it happened about a day after I got it as I say give it a good thrash it clears then all good for 15-20 miles
may just break it as I’m done really it’s taken the fun out of owning one
full history
only done 10k since 2014 when the IMS was done and other than service not much I can see only just bought it so go stitched up as it happened about a day after I got it as I say give it a good thrash it clears then all good for 15-20 miles
may just break it as I’m done really it’s taken the fun out of owning one
12-24-2023, 02:15 PM
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So, what exactly is a “modified oil feed”? Do you mean a feed to the IMS bearing? If so, that shouldn’t have any relation to a misfire… Misfire should only be related to fuel, spark (maybe a bad wire/connection to ecu), or too much oil in the cylinder (fouled plug…). Good luck!
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12-24-2023, 02:41 PM
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So, what exactly is a “modified oil feed”? Do you mean a feed to the IMS bearing? If so, that shouldn’t have any relation to a misfire… Misfire should only be related to fuel, spark (maybe a bad wire/connection to ecu), or too much oil in the cylinder (fouled plug…). Good luck!
12-24-2023, 03:55 PM
#9
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You forget compression. Often times when a misfire needs to get troubleshot to the end of the line, a cracked head, block or damage to the head gasket are the culprit. These can often be hard to find as the effects are often temp dependent.
12-24-2023, 04:03 PM
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12-24-2023, 05:08 PM
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12-24-2023, 07:36 PM
#12
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The 3.6 M96/03 engine is well known ( by people who specialize in 996 engines) for misfires caused by sticking two-stage lifters. The intake lifters on the M96/03 engines are the vario-cam + type with a high lift and low lift, there is a pin that switches the high-low, that is operated by oil pressure ( and controlled by the DME+ an electric solenoid)
When you have a single cylinder misfire (#3 on yours) and all other possibilities have been eliminated ( archaic process of elimination) , then the only thing left to do is replace the intake lifters on #3 cylinder..
A lot of times when you have the lifters out in your hand, you can operate them by hand and actually feel the sticking .
Good luck..I know that is not what you wanted to hear, but is the way it is in the world of the Porsche Gods ..
When you have a single cylinder misfire (#3 on yours) and all other possibilities have been eliminated ( archaic process of elimination) , then the only thing left to do is replace the intake lifters on #3 cylinder..
A lot of times when you have the lifters out in your hand, you can operate them by hand and actually feel the sticking .
Good luck..I know that is not what you wanted to hear, but is the way it is in the world of the Porsche Gods ..
12-25-2023, 03:00 AM
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The 3.6 M96/03 engine is well known ( by people who specialize in 996 engines) for misfires caused by sticking two-stage lifters. The intake lifters on the M96/03 engines are the vario-cam + type with a high lift and low lift, there is a pin that switches the high-low, that is operated by oil pressure ( and controlled by the DME+ an electric solenoid)
When you have a single cylinder misfire (#3 on yours) and all other possibilities have been eliminated ( archaic process of elimination) , then the only thing left to do is replace the intake lifters on #3 cylinder..
A lot of times when you have the lifters out in your hand, you can operate them by hand and actually feel the sticking .
Good luck..I know that is not what you wanted to hear, but is the way it is in the world of the Porsche Gods ..
When you have a single cylinder misfire (#3 on yours) and all other possibilities have been eliminated ( archaic process of elimination) , then the only thing left to do is replace the intake lifters on #3 cylinder..
A lot of times when you have the lifters out in your hand, you can operate them by hand and actually feel the sticking .
Good luck..I know that is not what you wanted to hear, but is the way it is in the world of the Porsche Gods ..
this is the conclusion I had sort of got too but was hoping someone would put this forward, im an ex Ferrari tech albeit a while ago so not a complete novice, not knowing the product entirely and how it all works is a big disadvantage
12-25-2023, 11:36 AM
#14
I had one of those lifters bugging me also, after a drive when idling the CEL started blinking. Stopped blinking when I raised the RPMs.
Was also very audible if the car had been sitting for long.
Pretty pricey things are those intake side lifters on these 996.2 cars, huh...
Was also very audible if the car had been sitting for long.
Pretty pricey things are those intake side lifters on these 996.2 cars, huh...
12-25-2023, 11:41 AM
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I had one of those lifters bugging me also, after a drive when idling the CEL started blinking. Stopped blinking when I raised the RPMs.
Was also very audible if the car had been sitting for long.
Pretty pricey things are those intake side lifters on these 996.2 cars, huh...
Was also very audible if the car had been sitting for long.
Pretty pricey things are those intake side lifters on these 996.2 cars, huh...