Intermittent rough idle... kind of like a "hiccup"
Mar 11, 2007, 04:08 PM
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Intermittent rough idle... kind of like a "hiccup"
I did several searches, and couldn't get a definitive answer. Hope someone here can chime in (and I do sincerely apologize if this question has been asked before, I'm just unable to locate it).
I have a brand new 2006 EVO MR. I notice that the idle can sometimes become a tad rough... in other words, it will idle smoothly at a stop light, but every once and awhile the engine seems to hiccup. I don't notice the tachometer surging when this occurs, but the feeling is definitely noticeable. Otherwise, power delivery through the RPM band is fine, and the engine pulls strong. No SEL lights or any other indicator of a problem issue is present.
Is this normal behaviour for this engine? The car I traded in for the MR was a 2005 BMW M3. The S54 mill is incredibly smooth at idle, so this is what I'm basing my experiences on. This is also my first forced-induction vehicle, so please be patient with me. I'm learning!
Oh.. one last thing (and from this, you'll understand just how much of a n00b I am when it comes to the EVO), but I notice quite a lot of torque steer on dry pavement. Coming from RWD only vehicles, this is taking me some time to get used too. Is the torque-split on the EVO 50/50, or is it front biased or rear biased?
Thanks in advance for your time and assistance.
Edit: now that I think about it, perhaps it's not an idle issue. The best way I can describe the situation is this: sitting at a stop light, engine idles smoothly at 900rpm. Perhaps 6-10 seconds later, a very mild vibration or shudder occurs. It's only a split second. As if the idle dropped to about 500 quickly, then stabilized. It occurs intermittently, with no obvious pattern. The tachometer doesn't register a change. The A/C is off, along with other electrical components. Is this normal, and perhaps the engine vibrations just aren't isolated as well as the S54 in my M3?
Another thing, after doing a few more searches.. some people have said the EVO has a "lumpy idle" even when stock. Could this be what I'm feeling, and is completely normal??
I have a brand new 2006 EVO MR. I notice that the idle can sometimes become a tad rough... in other words, it will idle smoothly at a stop light, but every once and awhile the engine seems to hiccup. I don't notice the tachometer surging when this occurs, but the feeling is definitely noticeable. Otherwise, power delivery through the RPM band is fine, and the engine pulls strong. No SEL lights or any other indicator of a problem issue is present.
Is this normal behaviour for this engine? The car I traded in for the MR was a 2005 BMW M3. The S54 mill is incredibly smooth at idle, so this is what I'm basing my experiences on. This is also my first forced-induction vehicle, so please be patient with me. I'm learning!
Oh.. one last thing (and from this, you'll understand just how much of a n00b I am when it comes to the EVO), but I notice quite a lot of torque steer on dry pavement. Coming from RWD only vehicles, this is taking me some time to get used too. Is the torque-split on the EVO 50/50, or is it front biased or rear biased?
Thanks in advance for your time and assistance.
Edit: now that I think about it, perhaps it's not an idle issue. The best way I can describe the situation is this: sitting at a stop light, engine idles smoothly at 900rpm. Perhaps 6-10 seconds later, a very mild vibration or shudder occurs. It's only a split second. As if the idle dropped to about 500 quickly, then stabilized. It occurs intermittently, with no obvious pattern. The tachometer doesn't register a change. The A/C is off, along with other electrical components. Is this normal, and perhaps the engine vibrations just aren't isolated as well as the S54 in my M3?
Another thing, after doing a few more searches.. some people have said the EVO has a "lumpy idle" even when stock. Could this be what I'm feeling, and is completely normal??
Last edited by amstel78; Mar 12, 2007 at 07:04 PM. Reason: Grammar error
Mar 11, 2007, 10:03 PM
#7
I've wondered about the idle too. I've checked for boost leaks and intake piping leaks, changed plugs and wires and have not found anything wrong. When I was doing all of this I was actually trying to fix a different issue but thought that the rough idle might be connected to the other issues I was having. It wasnt.
I've logged this and the idle rpm does fluctuate a little although its not very drastic that's why you dont see it on your tach. Essentially I think the problem comes from the MAF Scaling that the ECU uses - I dont think its very accurate at low airflow.
I've logged this and the idle rpm does fluctuate a little although its not very drastic that's why you dont see it on your tach. Essentially I think the problem comes from the MAF Scaling that the ECU uses - I dont think its very accurate at low airflow.
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Mar 11, 2007, 10:06 PM
#8
its your caligula pin...
seriously though
my 06MR does it when its cold
then its fine
most likely the cold start function
i also read somewhere to check if the MAF might be dirty
i am going to buy a cleaner and spray mine down as i had a K@N air filter
and it might have dirtied the MAF a bit
or at least oiled it somewhat
seriously though
my 06MR does it when its cold
then its fine
most likely the cold start function
i also read somewhere to check if the MAF might be dirty
i am going to buy a cleaner and spray mine down as i had a K@N air filter
and it might have dirtied the MAF a bit
or at least oiled it somewhat
Mar 12, 2007, 11:15 AM
#9
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its your caligula pin...
seriously though
my 06MR does it when its cold
then its fine
most likely the cold start function
i also read somewhere to check if the MAF might be dirty
i am going to buy a cleaner and spray mine down as i had a K@N air filter
and it might have dirtied the MAF a bit
or at least oiled it somewhat
seriously though
my 06MR does it when its cold
then its fine
most likely the cold start function
i also read somewhere to check if the MAF might be dirty
i am going to buy a cleaner and spray mine down as i had a K@N air filter
and it might have dirtied the MAF a bit
or at least oiled it somewhat
When idling at 900, the engine doesn't sound "smooth." Every once in awhile, it will "hiccup", causing a slight, split-second vibration. Exhaust note dips as well. Mind you, that this only happens in a fraction of a second. I suppose the best way I could describe it, is it sounds like the engine had a very mild misfire. Other than that, the engine idles fine. These little blips or glitches, however you want to call them are sporadic.
I took it to the dealer this morning, and they advised me to wait until after the break-in period to see if the idle smoothens out. They also told me that if it was a misfire or other serious problem, my CEL light would illuminate. Bear in mind though, that most of the guys I spoke too at that dealership don't inspire too much confidence.
It's really hard to describe this phenomenon with words. It would be alot easier if I could just show someone. I'm just hoping that the roughness of this motor is typical. Remember, I'm coming from an '05 M3 with a silky smooth S54. I have no experience with turbo 4's. And since this is my first EVO, I don't have anything to compare my vehicle against except the M3. I guess, I'm just hoping someone will tell me that this behaviour being exhibited is typical, and not to worry about it.
Last edited by amstel78; Mar 12, 2007 at 11:17 AM.
Mar 12, 2007, 11:44 AM
#11
The only time I notice any idle fluctuation is when the engine has warmed up to operating temp and the electric fans come in. It is noticeable to me as a exhaust note change and maybe a slight change in engine RPM ( 100 or 150 RPM) +. Also what king of gas do you use? Maybe you got a batch with some water in it causing a rough idle. Try a can of Heet or other fuel line dryer. Other then that I don't have to many suggestions. Good luck with the dealers.
Strange thing is... rpm doesn't really oscillate so to speak. Even when cold. This is what happens: start the car, engine idle speed increases to 1500. It stays like that for several minutes, then eventually drops to about 900 rpm.
When idling at 900, the engine doesn't sound "smooth." Every once in awhile, it will "hiccup", causing a slight, split-second vibration. Exhaust note dips as well. Mind you, that this only happens in a fraction of a second. I suppose the best way I could describe it, is it sounds like the engine had a very mild misfire. Other than that, the engine idles fine. These little blips or glitches, however you want to call them are sporadic.
I took it to the dealer this morning, and they advised me to wait until after the break-in period to see if the idle smoothens out. They also told me that if it was a misfire or other serious problem, my CEL light would illuminate. Bear in mind though, that most of the guys I spoke too at that dealership don't inspire too much confidence.
It's really hard to describe this phenomenon with words. It would be alot easier if I could just show someone. I'm just hoping that the roughness of this motor is typical. Remember, I'm coming from an '05 M3 with a silky smooth S54. I have no experience with turbo 4's. And since this is my first EVO, I don't have anything to compare my vehicle against except the M3. I guess, I'm just hoping someone will tell me that this behaviour being exhibited is typical, and not to worry about it.
When idling at 900, the engine doesn't sound "smooth." Every once in awhile, it will "hiccup", causing a slight, split-second vibration. Exhaust note dips as well. Mind you, that this only happens in a fraction of a second. I suppose the best way I could describe it, is it sounds like the engine had a very mild misfire. Other than that, the engine idles fine. These little blips or glitches, however you want to call them are sporadic.
I took it to the dealer this morning, and they advised me to wait until after the break-in period to see if the idle smoothens out. They also told me that if it was a misfire or other serious problem, my CEL light would illuminate. Bear in mind though, that most of the guys I spoke too at that dealership don't inspire too much confidence.
It's really hard to describe this phenomenon with words. It would be alot easier if I could just show someone. I'm just hoping that the roughness of this motor is typical. Remember, I'm coming from an '05 M3 with a silky smooth S54. I have no experience with turbo 4's. And since this is my first EVO, I don't have anything to compare my vehicle against except the M3. I guess, I'm just hoping someone will tell me that this behaviour being exhibited is typical, and not to worry about it.
Mar 12, 2007, 12:08 PM
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The only time I notice any idle fluctuation is when the engine has warmed up to operating temp and the electric fans come in. It is noticeable to me as a exhaust note change and maybe a slight change in engine RPM ( 100 or 150 RPM) +. Also what king of gas do you use? Maybe you got a batch with some water in it causing a rough idle. Try a can of Heet or other fuel line dryer. Other then that I don't have to many suggestions. Good luck with the dealers.
Mar 12, 2007, 01:42 PM
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I've got the same exact problem on my IX. I'm completely stock besides a K&N drop in. When I got my car dyno'd the problem became pretty bad. While the car was idling on the dyno the rpms would dip dramatically. We figured it was probably the lack of airflow. No CELs or other problems.
Mar 12, 2007, 07:02 PM
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OK.. did a few more searches. Some people say that the EVO is known for its "lumpy idle", almost as if it had mild cams in it. Could this be what I'm experiencing here???
Apart from this issue, the car drives fine.
Apart from this issue, the car drives fine.