Rough Idle on warm startup.

[BlackLS06]

Lately ive been having a rough idle if the car has been driven a bit and i try to start it...enough of a rough idle that it wants to stall. I can drive to work and back just fine whens its cooler out but once the car is warm the issue repeats.

Was gonna order some coils but just want to make sure this is the issue before i go further. Plugs were done less than 5K miles ago.

I do have a cel but it doesnt flash just stays on...havent had codes scanned yet.

 

[mlara1129]

what coils are you, or would you be, going with?

 

[BlackLS06]

The visteon coils on ebay.

Im pretty sure i have factory coils right now.

 

[G-RELL]

could be several things but other than just listing them, start with the code, see what that says

 

[BlackLS06]

Well as of right now i cant even drive anywhere because it will stall. i thought it could be the maf as well but i would think coils more likely.

 

[G-RELL]

probably... but cleaning the MAF couldn't hurt (unless you do it wrong LOL)... or if you've got a bad cat or something...doubtful though

 

[BlackLS06]

A bad cat can cause rough idle??

If so that makes sense because i can hear the right side exhaust backfire a bit when i turn it on and the tip is covered in grime versus the left tip which is much cleaner.

My old car only had one cat that went bad and it ran fine.

 

[G-RELL]

well if its bad enough it can by pluging up the flow... dodge trucks are notorious for it...

 

[reaper76]

well if its bad enough it can by pluging up the flow... dodge trucks are notorious for it...

Thats a true story. I had two cats go bad on my doge truck when I had it! Caused it to stall the first time and the second time it would stay running but had no power at all.

 

[joegr]

A bad cat can cause rough idle??

If so that makes sense because i can hear the right side exhaust backfire a bit when i turn it on and the tip is covered in grime versus the left tip which is much cleaner.

My old car only had one cat that went bad and it ran fine.

A plugged cat should cause loss of power long before it ever gets bad enough to cause idling problems. However, rough idle due to bad coil(s) will lead to clogged cats.

If you think that it might be the MAF instead, you can unplug it and see if the cures the stalling problem. The catch is that it will add more OBDII codes and could confuse your diagnosis. You can borrow a scan tool (for a refundable deposit) from some auto stores, if you have another way to get to the store.

 

[mlara1129]

You can borrow a scan tool (for a refundable deposit) from some auto stores, if you have another way to get to the store.

Or buy an Xcal tuner with Torrie tunes and enjoy the added performance as well

By the way i'm going with Visteon coils too.

 

[BlackLS06]

Will the scan show a bad maf??

Can i unplug the maf while the vehicle is running???

 

[joegr]

Will the scan show a bad maf??

Can i unplug the maf while the vehicle is running???

1. It should.

2. Of course you can, but I wouldn't. I think that doing so is risking damage to the MAF and maybe even the PCM.

 

[G-RELL]

you would think he'd have the problem more frequently if it was MAF related.... the temp related to rough idle is the interesting part.... get the code checked.

 

[BlackLS06]

It could just be coincidence...but it hasnt happened when its been cooler.

Will go to autozone tomorrow and see what pops up. Hopefully it is the maf because thats a cheap fix with no labor.

 

[05 LS8]

Black, sounds like a coil. Doesn't your car have under 100k? Drop it off to the dealership and have them take care of it.

 

[joegr]

Black, sounds like a coil. Doesn't your car have under 100k? Drop it off to the dealership and have them take care of it.

2006 is not covered by the 100K extended coil warranty. It only applies to 2003 to 2005.

 

[BlackLS06]

And sometimes even when its warm out it wont do it.

Its a very random occurrence....if it is a coil i dont think all are bad but i will replace all for peace of mind.

 

[M4rk]

I had a similar issue which turned out to be a coil (#8). It never stalled, but was very close to. Only happened when warm, and intermittently as well.

 

[BlackLS06]

Ok that convinces me enough to order the coils.

Have you had any issues since? This is my only car right now.

 

[joegr]

Ok that convinces me enough to order the coils.

Have you had any issues since? This is my only car right now.

I hate to tell you, but you really need to order spark plugs too. It takes way less than 5K miles with a bad coil to damage them.

 

[M4rk]

A rattle in the exhaust area during WOT/heavy acceleration. There's a big thread on it somewhere.. a member found some loose metal pieces holding the heat shield in place, or something along those lines, and fixed the issue by removing them.

I also had a slight vibration at idle present at all times since then. A few WOT runs from 0-100km/h fixed it. I guess it was a dirty injector..

Good luck.

 

[BlackLS06]

I hate to tell you, but you really need to order spark plugs too. It takes way less than 5K miles with a bad coil to damage them.

I have a good mechanic he can tell me if the plugs are bad while he's in there.

A rattle in the exhaust area during WOT/heavy acceleration. There's a big thread on it somewhere.. a member found some loose metal pieces holding the heat shield in place, or something along those lines, and fixed the issue by removing them.

I also had a slight vibration at idle present at all times since then. A few WOT runs from 0-100km/h fixed it. I guess it was a dirty injector..

Good luck.

I meant startup issues.

I love this car and hate it at the same time.

 

[joegr]

I have a good mechanic he can tell me if the plugs are bad while he's in there....

You realize that you'll pay as much in labor for him to remove, truly inspect and test, and reinstall your old plugs as it would cost to remove the old plugs and install the new ones? Or is he just going to claim that he inspected and tested them magically without removing them?

 

[BlackLS06]

You realize that you'll pay as much in labor for him to remove, truly inspect and test, and reinstall your old plugs as it would cost to remove the old plugs and install the new ones? Or is he just going to claim that he inspected and tested them magically without removing them?

Its my uncle...he charges me very little for labor.

ASE certified works on all of our vehicles. He did my brakes for a quarter of what the dealer would charge.