Hey. I just got comptech headers installed today, and they're amazing until i come to a stop. then my car drops to around 500 rpms and starts to vibrate and stutter. I dont remember it dropping to 500 rpms ever before so i'm guessing this is because of the headers. Is this some kind of temporary break-in thing or is something I should immediately have checked out.

Note: unlike the previous mentions about stuttering, mine doesnt occur at all once the car is moving. just at stops.

 

Mine does the same thing. It's gotten better over time, probably as the car became adjusted to it, but still happens once in a while.

I never really thought of the headers as the culprit, though... interesting point.

 

same here. I just take it as normal now.

 

i have stone headers and never any idle problems, to me that is strange and any vibration is not a good thing. no idea why it would happen.

 

It's almost like the engine is choking and almost stalling. It goes down to like 500 RPM, accompanied by vibrations typical of when an engine is about to stall out, then comes back up to normal idle RPM. I don't think it's the IACV, though.

 

Alright. I decided to listen to it in my driveway when I got home from class. It sounds more like someone's rattling. There was another thread about this happening to someone else on this forum. He, if i'm not mistake was completely stock, so I guess that eliminates the possibility of it being my mods, even though the rattling noise seems to be coming from the same point as my headers.

Although the likelyhood of it being the idle control valve is unlikely, I must say that while my car used to bounce from 750 to 1000rpms, usually staying between them, it no longer does that. It just drops to around 650-700, never higher, never lower. The noise occurs around 60% of the time the car is stopped in drive or reverse (more like 35% of the time in reverse, because it doesnt occur when the engine is cold and i'm backing out the driveway in the morning, but it was there today when I got home, looking for the sound throught each tranny position). The rattling noise DOES go away in Neutral. So...IF the idle control IS the problem, then why would the noise not occur while in Neutral. Since we pretty much ruled out the IAFC valve (and since I pretty much dont know what that is), maybe its a battery issue?

I'm in need of a new battery. I know this to be fact. And I plan on getting one this weekend. I've heard things about people replacing batteries/putting together grouding kits having a smoother idle. And so maybe this is a more reasonable solution than tampering with the mighty idle control valve that should never be messed with unless you're 100% certain. So thats where I am today. From what I hear, the best batteries are Optima's. I was wondering which was better--> Red top or Yellow top, and how do I know which one of each version to get?

Finally, while I was listening, I moved from D5 to N to R and I kept hearing this click click click click noise from my tranny which could possibly be related to the idle rattling that i've been having? I dont think its a real tranny issue because i'm not getting the problems that I had that showed bad signs on my last tranny. Nothing lately but one or two irregular 5th to 4th gear shifts (Isnt that random, and i'm not talking about it shifting from 5th to 4th because I wasnt going fast enough to be in 4th. I'm talking about 5th to 4th for the fun of it? Oh well... Somebody help me! (and thanks to those that have so far)

 

Mine did that when I had comptech headers.

AcAvenger there is a meet in Tysons Corner VA on the 4th of Feb. Check the meets section if you are interested.

 

Ah! Awesome, i'll check my sched and post on it tomorrow. Should be game, because I think I'm going up to jersey that weekend to watch the game, and that would make a very nice pitstop

 

never got any problems with my comptech headers

i have vibrations and rpm drop back and forth because my car is running low batt in an extreme cold start, but it was fine after a few runs to charge the battery

 

I wouldn't rule out the IACV. This situation was exactly how mine started, then it did start stalling. The service tech that fixed mine said there is an idle motor that adjusts itself based on how hard it is to keep the engine at idle, and it was at a step of 11 rather than 3 or 4 which is normal, and eventually the IACV was so plugged it couldn't do anything to keep the car from stalling. So your IACV may be somewhat functional right now, but its on its way to needing to be fixed, eventually. Mine still does it every once in a while, maybe 1 or 2 times a month rather than every stop light which it had been

 

i just installed my headers last night and it did that at first... and then it seems to have stoped doing that I drove it for about 40 miles or so... and let it sit in idle for about 20 min... and today i drove around 2 miles but didnt pay attention to it... ill do so when i take my lunch break. I didnt feel a big diffrence though with the install of the headers... did any of you have big diffrence? ill i got on it though is a CAI, lowered 2'' and now the headers... not to surprised

 

try unhooking the battery cables for about 15 to 30 mins with the engine cool. this might help to reset the computer to adjust for the new mods. usually its a good idea so the comp starts fresh. it also could be the IACV. so try it out . make sure you have the radio code handy too. good luck..

 

well since they are automatics..duh..you are putting a slight load on engine by switching it outta neutral. So i would have to make a guess that it changes how the IACV is working or you are running to lean...and ECU is trying to adjust.

What i dont get is the Rattle part?? unless that is because your engine is bogging down so much it has something to do with Tq convertor??

 

well my rpms being low went away... but i do notice i have to go back and tighten everything again..

 

Did anybody notice how the rattling goes away if you take the car out of gear? Hmm, maybe thats a clue? I think the rattling has to do with the way my headers are mounted on there, I never really paid close attention to the way they were installed until I was putting in my new optima yellow top on saturday. I'll try to take pictures tomorrow (if the sun will come out), since it looks like something that might rattle