Passat (B5) :: Very Rough Idle When Cold
Jul 13, 2007
My 1.8t is very rough at idle when cold, smooths out when over 1000 rpm and when at normal operating temperature. Code reader says 171 and misfires.
View 6 RepliesMy 1.8t is very rough at idle when cold, smooths out when over 1000 rpm and when at normal operating temperature. Code reader says 171 and misfires.
View 6 RepliesI got the fuel pump and fuel pump control module replaced. Now I am still getting a cold start delay (5-10 seconds to start) and it has a rough idle sounding like its misfiring. This happened when i picked it up at the dealership after a new fuel pump BUT! keep in mind it has been doing this for a while so i figured it was the fuel pump.
New oem plugs and the coils were replaced when i bought the car because the coils failed during a test drive I need to scan the codes but i will post. Also this only happens during a cold start. if the car is warm and i go into target or something then start it shortly after its fine.
TSB'S I think will fix this. [URL] .....
I've got an "on- and off-going" problem with my '92 S10 Blazer.
Car specs:
Year 1992
Blazer S10 4.3 Tbi
4- doors 4WD
Mileage 200k miles
Symptoms:
As cold, every now and then it will start right up, but the idle is wery rough, and seems like its running on less than 6 cylinders. When giving gas, it revs up, but runs roughly and still seems to be running on less than 6. Won't stall though.
When engine warms up after a couple of minutes, the idle gets smooth and no issues what ever when driving.
So just to be clear, this issue is so far only happening when staring cold.
Parts (new off course) changed recently (less than 500miles on them):
Distributor
Spark plugs + wires
Alternator
Battery
IAC valve
Fuel filter
This symptom came up now and then before changing any parts. I am quite handy with cars (pure amateur though), but can't really afford solving the proble by changing loads of parts with no effect..
If my car's been sitting - say monday morning after sitting all weekend in the garage- it runs rough for a little while. Sometimes only for a few seconds, sometimes for a little while after the idle drops. The colder the car is, the longer and worse the condition. It feels like a cylinder isn't firing.
After a particularly cold and wet spell (I had the car outside) it ran so badly it threw a code for one of the cam position sensors and #4 misfire. I replaced both of the sensors. That worked a little.
Since I was due for 80k service and saw a misfire when damp, I replaced the ignition coils along with the spark plugs. That worked a little more. But, it still does it. What else could it be if not ignition? Sticky valve? something else?
I have a 2007 SF 2.7L V6 with 55000km.
Recently we have noticed that from a cold start the engine idles roughly few a short time and especially bad if put into gear only moments after starting.
Do we need to let it warm up for longer?
I have a 99 silverado with the 4.8 w/186k on the clock. I am having an issue with rough idle and hesitation on cold start up. Once the truck warms up the idle and hesitation go away. I have replaced the PCV valve hoping this fixed it, but it did not. I have also cleaned the TB and the MAF.
View 2 RepliesI have a 99 lesabre cold start rough idle but smooths out . Warm no start. Trouble codes P0171, P0300, P0336. Had plennum replaced 2 years ago but I'm seeing coolant around the base of the plennum so I'm going to have to do that again but I don't think that has anything to do with the warm no start.
View 14 RepliesMy 2007 TrailBlazer with 84K stumbles for 25 seconds when I start up cold. After 25 seconds I hear a click and then it runs perfect. No engine codes present. Have new plugs, new O2 sensor, new thermostat.
View 5 RepliesSince my V6s very rough ride only occurred on cold mornings (fixed with a new driveshaft early this year), I wonder if some of the newer owners will be complaining of this problem soon, now that we're embarking on fall.
The symptom was strange. On cold mornings, between 30 and 50, the Touareg would feel as though it was riding on extremely rough pavement.... over 50 it was fine, and then, after about ten minutes of driving, it went away at all speeds.
I have 114,00 miles on my car. Plugs changed and decarbonization done at 99,000 as well as ECM reprogram or update ($99). Anyway, when my car sits overnight and starts it is getting a rough high idle until I feather the pedal or give it a minute or 2 and it is fine. It is warm now in the 70's and this just started. I had it to the dealer for oil change and they looked at it. There are no codes, they recommended changing the plugs and doing a decarb again. So I told them if I need plugs there is something wrong, Iridium OEM were installed.
Anyway, they suggested changing the throttle body since it has new sensors. I have have the TPS replaced before when engine was surging. They told me there are 2 sensors and one could be bad in throttle body. I don't get it, I use Hyundai air filter now and change every 15,000 miles and get oil changes regularly and they use Quaker State Synthetic blend. I am wondering if maybe I have a faulty PCV? I don't think that has been changed. Don't even know what the interval is. Previously I was told there was none, but I disagree.
What would cause me to get carbon build up like they keep telling me? I don't want trial and error and throw parts and money at it since there are no codes. I was going to drive it til it throws a code. I do highway driving in suburban area, mostly 65 mph. The car runs good, still the intermittent hard downshift when slowing down but nothing like before the tranny was replaced.
It levels off and idles fine after about 10-15 seconds but sometimes it idles so rough I think it's going to stall.
View 14 RepliesI have a 1994 Volvo 940 and have previously owned a 740 for many years. I've only owned this car for about 1 month. The car appears to have been well cared for. Doesn't leak a drop of any fluids, everything works, and mostly a really nice old car. What happens is that it idles rough when it's cold. In fact, I have to pump the gas pedal to keep it going. When I first start off, the performance is less than what it should be too. Once it get warm, it mostly runs fine.
I have so far replaced, the Plugs, Wires, Cap & Rotor. All the vacuum lines, crank position sensor, Air Mass Meter and the fuel filter and most all the fuel lines too. The Fuel Pump Relay was replaced but I removed it and saw a few cold solders and fixed those but no changes in performance. Before I replaced the Air Mass Meter I brought it to local shop and they returned a readout of 2-3-2 which I'm understanding means running too lean. That's why I replaced the Air Mass Meter. (I did notice a big improvement once I replaced the Air Mass Meter too.) It was interesting that when I replaced the Distributor Cap, I noticed like black carbon in there and I'm not sure what could cause that. Although, I did find the previous plugs were not all the same. Three of them were high spark performance plugs and one was just normal
I pulled the Idle Air Control Valve and plugged one side to ground and the other side to 12V and noticed the flapper moving when powered on/off. The previous owner told me he replaced both fuel pumps about two years ago. It also looks like the fuel regulator valve is mostly new.
I'm guessing now that I have a problem with the Idle Air Control Valve or perhaps the Fuel Temp Sensor under the intake manifold. I purchased the Fuel Temp Sensor and just have not installed it yet. I really don't want to remove the intake manifold but I know it's not going to be that bad. I know that it could be carbon build up on the intake valves but I'm not quite convinced yet. I put some fuel cleaner in the tank to see if that works and so far nothing yet. The car only has 150K on it and I was told that during the owner before me did do highway driving.
When it's warm, the car does run very very well. The idle is still a bit quirky even when warm. For instance, when I power on the A/C, the idle RPM doesn't increase like I expect that it should. (It did on my 740) ... I'm still thinking maybe it's the Idle Air Control Valve too. Perhaps it's intermittent or do I understand that they can gradually open and gradually close?
2000 Sierra 1500, 5.3L engine. When he starts it in the cold (below 40 degrees) at first hits 1000rpm, then immediately drops to 400-500rpm. The idle is rough and wants to die if he tries to drive it. However after 10-15 minutes and the eng warms up, its fine no problems at all. There is no codes, so the scanner we had didn't tell us anything. He had cleaned the TB and intake system with cleaner, no dice. He also disconnected the IAC while it was idling rough, that didn't change the way it ran at all. We would like to toubleshoot it more before we start throwing parts at it.
View 1 RepliesI have a 2003 Camry 4 cylinder. The problem we are having is the car has a slight rough idle only at cold start. After she warms up she is smooth as glass. What would cause this?
View 14 RepliesI have a 2003 Camry 4cylinder. On first start of the day the engine shakes a little untill it warms up and is driven for about 2 blocks. After that it is smooth. I cleaned what I could of the throttle body on the car, changed spark plugs and PCV. All that worked but cold start shake still there.
View 9 RepliesOwner of a 2014 350 fsport here.... 15,000 miles ... I noticed on cold starts a slightly rough idle since its gotten colder here recently. After starting the car it'll start fine and everything but then as its warming up the needle sometimes jumps 75-100 rpm. its like someone tapped their foot on the accelerator and let off. no lights or anything and the car runs fine.
Heres the catch... i have a joe z catback and joe z intake with fsport filter, could this possibly be why? because of the airflow ? i also have been using Lucas fuel injector cleaner and lubricant.
Also when i put the car in park after driving, i notice the needle isn't steady, it does move a little maybe 20-50rpm, not sure if this is normal or not because i never really paid attention until now.
I'm having this cold start issue with my 2001 SF, but it doesn't seem to be fuel related like as the car starts fine but after about literally 1-2seconds the RPMs drop below 1k and the car will stall if I don't put my foot on the accelerator and keep it around 1000-2000 RPMs. But if I happen to make the revs go too high and let them drop again it seems like it wants to stall even easier. After about 30 seconds it smoothens out and drives almost perfectly except for a slight lack of power than normal going uphill (A.T drops to 2nd gear, sometimes 1st depending on the incline). We have had the coolant temp sensor and the fuel pressure sensor replaced. Could it be the MAF? We did clean it one time but it didn't seem to work much at all. Recently out of curiosity, I disconnected the MAF sensor and started the car it being started for a few days. No issue with idling whatsoever!.. ??
View 4 RepliesMy moms has a 2010 Elantra with 30,000kms on the clock, and we have noticed since new when the vehicle is started cold in the morning it seems to run rough for about 30-60 seconds then stabilizes.
It's almost like it has a slight misfire, or slight fuel flooded from sitting overnight. Now if course we have taken it to the dealership twice for this issue and dropped it off overnight for a cold start, and both times they cannot re-produce the problem.......surprise.
I bought my 2012 Accent a few months ago. I have been noticing that when its cold it has a bit of a rough idle. Nothing bad, no reving, but just a general mild shaking. No check engine light either. It happens in park, reverse, neutral, and drive. It stops and runs smooth after a few mins of driving. Since I bought it I have been using Top Tier gas and a bottle of gumout at oil change. Could it be just the way the engine is, since it is a small 4cyl? Like I said its not bad or affecting the way it drives, just seems strange to me.
View 6 RepliesMy idle seems to always be somewhat rough whenever I put the heat on in cold weather. While in drive I'll come to a red light, heat will be on and I'll stop. The. my idle will bounce down then back up. I shut heat off to test and it only does it while heats on.
View 5 RepliesI understand there is not much adjustable on my 98 Ranger (2.5L) as far as idle speed and mixture. It runs rough when started cold. Is this a sign to replace spark plugs?
View 2 Replies