Jetta - Volkswagen :: 2006 - Engine Randomly Misfires Causing Stutter Or Stammer

I have a 2006 Jetta with a 5 speed manual transmission and 35,000 miles. The engine randomly misfires causing it to stutter or stammer. The check engine light is on and has been for several weeks. Occasionally the check engine light flashes. I took it to a local mechanic who ran a series of diagnostic tests (no vacuum leaks) and they recommended having all the ignition coils replaced for all 4 cylinders. They also replaced the fuel filter. I did so but the problem soon returned to which they referred me to the dealer.

I decided to take it to a VW specialist in town and they replaced the spark plugs for all 4 cylinders. They noticed that some of the plugs were black with a buildup and some were clean. The problem soon returned. The VW specialist also recommended that I take it to the dealership as they too had no clear idea as to what the problem is.

The car did suffer rodent damage in 2007 but was still under warranty so all the wiring that had been chewed on was replaced. I experimented using premium gas and regular gas. Premium gas seems to make the problem worse. Also, the misfires seem to lessen as the weather gets warmer. I would like to fix the problem to avoid any catastrophic failure but am trying to avoid throwing money away on any more guess work.

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Ford Super Duty (1999-2016) :: 2006 F250 5.4 - Engine Misfires?

Ok I rebuilt the engine in my f250 5.4 3v. Timing set cam phasers and oil control valves are new. The problem I'm having that just started after 5k miles on a new engine is all of a sudden i will start getting misfires 1st time it happened said #6 i changed coil same problem came back this time said multiple misfires now I'm just getting #4. When the misfires happen if i hold throttle where it is it will misfire as long as i hold it there if I let off gas then apply right back misfires stop for several miles then will happen again. I have changed fuel pump and fuel pump driver module same problem exist.

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Lexus GS 2013+ :: Burning Oil / Misfires?

Having burning oil problems or misfires again like in the 2006 GS.. I don't want to buy this thing and then have to deal with that problem a second time. I will move on to a acura RLX sport hybrid or something.

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Sonata NF (2006-10) :: Code P0300 - Multiple Misfires On 2009 V6 3.3l

I am trying to get a 2009 Sonata NF with a 3.3L V6 to run correctly and i have tried everything that i can find and still get the problem. The car runs very rich with a strong gas smell. The engine runs rough but doesn't stall. The car has has period where it runs fine and then the issue returns but is in more frequent and steady now. The car will run for the first 5 minutes great if it is cold and it also runs good at full throttle and the check engine light went off during hard acceleration which seems consistent with getting too much fuel. I bought a BlueDriver to read the codes and I love the data it provides but I am learning all the features.

For a little history the car has 95,250 miles. At 81157 miles the check engine light came on and an independent shop replaced the downstream O2 sensor and the light has been off for 2 years until coming back on recently. The code showing was a P0300. The shop replaced spark plugs and the manifold gasket with and oil change for $775. The check engine light stayed off for about a month and 550 miles. The car was taken back to the shop and they replaced the rear O2 sensor for $429 . The check engine light was off for a couple of days and then returned with the P0300. It might go a couple of days without a problem and then it would return.

This is when I got the car and started reading all the forums i could for possible causes. I saw the Tech Bulletin on the Variable Valve Timing Oil Control Solenoids so i replaced both valves. The check engine light returned with a P0303 for cylinder 3 misfire so i figured it was a coil so i replaced all the coils. The P0300 code returned. I check fuel pressure after seeing a post about fuel pressure regulators causing the problem but the pressure was correct. I changed the Mass Flow Sensor figuring it was getting too much gas but no improvement. I bought the BlueDriver so I could see more than just the codes. The O2 sensor looked erratic so i changed the front upper O2 sensor.

I found the Tech Bulletin about the O2 sensors fuel trim readings and realized there was an upper sensor on the back manifold and it was reading -18% so i changed it and now I don't know which way to go. I currently have the P0303 code confirmed and P0300 pending. With the live data the items that looked strange at idle were O2 Sensor Bank 1 Sensor 2 steady at 99.2% and Calculated Engine Load a 21.6%. The freeze frame data from when the light came on has all the short fuel trim at 0.0% and long term at -0.8% for both banks. Calculated Engine Load was 45.9% even though I was trying to drive slowly at 29 mph. Mass Air was 21.71 g/s, I had been running 3 minutes from a slightly warm start, Absolute engine load was 44.3%. Anything else to check or data I should look at?

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Accent MC (2006-11) :: CEL Code P0171 - Misfires With Full Throttle

My accent 2006 has the check engine code p0171. AT mornings I have to start the car like 5 times until it revs up and do not stall. Also when the car is running, If I press the gas too much it starts misfiring and have really slow acceleration. I have already change the 02 Sensor, spark plugs, TPS and maf sensor, and PSV valve, cleaner the throttle. I really don't know what else to look for.

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F Series :: F150 V6 4.2L Hard To Diagnose Engine Misfires?

Been a common problem for years and recently got one in the shop for the concern with the EGR port plugging up and then dumping all the egr into the one cylinder that is not plugged causing a misfire off idle. Many know of this concern but I have yet to see a good example of it. I show you some easy diagnosis before you pull the upper plenum to inspect the ports.

This video is hosted at YouTube . If the video does not play, wait a minute or try again later.

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S-10 :: 4.3L Engine Misfires Or Hesitates At Constant Speed On Highway

My fathers truck starts, runs, idles fine but once on the highway at constant speed, the engine misfires or hesitates causing a small buck or jerk but continues on down the road. The SES light is on. He took it to O'Reilly and they put some kind of computer on it and (I think) it said misfire in a cylinder. He replaced one of four O2 sensors, pickup in the distributor (not sure what this is called), wires, and plugs with no cure. This problem is very strange as again, it only does it a constant speed; truck runs fine at idle, acceleration, deceleration, startup, etc. There may be a slight sulfur smell during idle and there is a decrease in gas mileage.

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Golf/GTI VI :: Random Engine Misfires All Day / Vacuum Leak

Car: 2011 VW GTI MkVI
Mileage: 79k
Configuration: Stock
Warranty/Coverage: None

So I started my car last Monday and the check engine light was on. Didn't think much of it because the car ran fine and there were no immediate symptoms. I was busy with work this week, but noticed some changes in the car's performance over time so I waited till Thursday to have it scanned at AutoZone, which threw the following codes:

P 300 Definition: Random Engine Misfire
Explanation: Lean air/fuel ratio
Probable Cause: Ignition system misfire condition, Fuel injector fault, Engine mechanical condition

P 302 Definition: Cylinder 2 Misfire
Explanation: Vacuum leak on engine
Probable Cause: Ignition system misfire condition, Fuel injector fault, Engine mechanical condition

P 303 Definition: Cylinder 3 Misfire
Explanation: Vacuum leak on engine
Probable Cause: Ignition system misfire condition, Fuel injector fault, Engine mechanical condition

Prior to making any purchases I noticed that I started losing some pickup, primarily in lower gears between 2-3k RPM's. Praying that it was somehow just the coils/plugs I bought the R8 pack for both and replaced them this evening. Engine starts up and continues to misfire. I have not had a chance to have it scanned but it would appear it isn't the plugs or coils.

When the plugs were removed, there was an 'oily' substance on the threads, which also seemed like it could have been burnt off fuel or oil pushed up from the cylinder. Also 2 of the plugs seemed looser than the others and didn't feel properly sealed. New R8 install included proper plugs for STOCK application, as I do not run any tuning, and i installed with the appropriate plug grease added lightly to the threads.

I took the car for a spin with the R8 coils/plugs installed to compare it to how the car was doing prior the install. Car misfires and seems fine (relatively) at idle and revving to 2-3k rpm yields NO change. It is almost unable to accelerate up a hill, or go past 30 MPH without the car shaking and any gear higher than 3rd seems not drivable. I feel these are my potential diagnoses before i bring it somewhere and have it looked at.

In Order of Most Likely:

1) Fuel Injectors
2) Air Intake
3) High Pressure Fuel Pump
4) Electronic Leads for the Coils
5) Battery Needs Changed
6) Chain Tensioner Failure
7) Coils and Sparks are all Bad, and I am an idiot

I would prefer to do this work myself and can afford the parts. I just didn't want to be fooling around all month without a mode of transportation to get to and from work.

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Ford - Escape :: 2001 - Engine Misfires Under High Load And Low RPM

I have an 2001 Ford Escape V6 3.0, about 130,000 miles. When the engine gets under high load and low RPM, before downshifting, it will shudder (misfire?). Local shop couldn't reproduce it, but they thought it might have to do with slightly cracked vaccume hose, which they gouged me to replace. No improvement. Next they wanted $700 to replace Valve Cover Gaskets. I decided to become a mechanic and learn how to do that one myself. Sure enough, there was a little oil dripping onto one plug. I replaced the gaskets and all 6 spark plugs successfully. Still didn't fix the problem though.

Symptoms will occur reliably when driving at 45-50 MPH with the transmission in overdrive (1500 RPM), and I begin a slight incline. The vehicle will kind of chug forward (feels like sporatic misfires) in overdrive, getting down to 1200 RPM before deciding to downshift. Generally, I can just give a little more gas to force downshift and avoid the nasty-feeling misfires. Some days, however, it is much worse, and will misfire at idle, and make me feel like I have to treat the gas as an on/off switch to keep the engine from dying. (It has never actually died.)

During a really bad day, I got a flashing check engine light. I did not check codes in time - they've all cleared.

I now have an ODB2 reader logging real-time data. All I can do is prove the conditions that cause the symptom: high engine load at low RPM is the recipe. Nothing seems to show a cause... I may just not know what I'm looking at :-/ . I haven't monitored long enough to record a 'bad' day.

I've read about ignition coil issues on this engine, and weather might explain why this is worse some times than others. However, I wouldn't expect that to be load dependant.

Most of the time it feels like the transmission just isn't shifting when it's supposed to, but on the bad days it seems more than transmission related. When stopped at a light in Drive, this can still occur.

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Passat (B5) :: 2003 1.8T - Check Engine Light On / Multiple Misfires

My daughter has a 2003 Passat Turbo. Two weeks ago it started to run like crap with a check engine light on. I pulled the codes and it said multiple misfires. My buddy owns his own shop and said bring it down. He pulled the plugs and the spark plug holes were filled with oil. He changed the valve cover gaskets and replaced the plugs. Still ran rough with low fuel pressure so he replace the fuel pump and injectors. Still runs rough, when he pulled the air intake off there was oil in it. Could this have happened do to the valve cover gasket? The codes still read misfires. He said the turbo was full of oil also. Could the turbo be bad causing it to run like crap? Can it be rebuilt? I really don't want to go to the dealer.

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Avalon 2005-12 :: Engine Control Malfunction - Multiple Misfires

Had codes come up for ignition Coils twice. Car shook for all the way home. Replaced that coil 2. Second time shook for just a little bit. Codes for coil 2 snd 4. replaced all the Rear ones and the one front one that thru other code and all spark plugs. 2 weeks later I get Engine control malfunction, multiple misfires? Wife said happened when driving and didn't feel anything. Ignition control box bad?

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Camry :: 2002 4cyl Ride Rough And Die On Idle - Engine Misfires

After a long trip from Houston to Dallas, my vehicle started to ride rough and eventually die on idle. It seems to idle fine, but then die after the first minute. I am getting code P306 and others all dealing with random misfires and misfires on ALL cylinders. The troubleshooting steps I have taken so far to no avail are:

(1) Replaced spark plugs with pre-gapped iridium
(2) Checked ignition coils
(2) Checked all vacuum hoses and air intake leaks
(3) Changed air filter(not a big deal)
(4) Removed and cleaned the throttle body with carb cleaner thoroughly
(5) Checked the intake manifold for leaks and did not find any.
(6) Computer PCM checked for updates and issues at dealer

The dealer said it needed new fuel injectors, which seemed kind of fishy due to the following symptom:

The car runs GREAT at highway speeds, but it is unable to maintain an idle for an extended period of time and dies due to misfires. I hear a chugging in the engine sometimes.

Due to these symptoms, I self diagnosed this as a fuel regulator?

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Subaru - Forester :: Rough Engine - Power Is Low / Surges And Misfires When Cold

We're talking about a 2002 Subaru Forester with only 80,000 miles on it.

This winter, the cold seems to have taken its toll. The fuel economy is bouncing around between 16 and 24 MPG and the car runs a bit roughly. Especially when it's colder (<30 F) there is often a lack of power/RPM when depressing the gas pedal. The problem is worst in city driving, but exists on the highway also. It doesn't go away during my 15-20 minute commute. For a period of a couple weeks, it was even easy to induce misfires (I think that's what they were; quiet pffft pffft pffft sounds during severe lack of power) by fully depressing the gas. But even if you half-depress and hold the pedal steady, the car will accelerate weakly and then sometimes surge forward. Other times it seems to be idling strong and running rich. Now that it's warmer (>40 F) the problem has lessened, but I've also started feeding it 93 octane gas and the car feels rougher than normal.

A year or two ago, I replaced the front oxygen sensor and spark plugs (prior to problem). This winter, I took it to a mechanic who couldn't explain the problem and replaced the spark plug wires.

Based on my reading, it seems like the only other most likely culprit is the manifold air pressure (MAP) sensor that's mounted on the intake manifold. I haven't worked up the effort (and can't find my multimeter) to do an electrical test of the MAP sensor's output itself. I'm also not keen on just buying a $270 part without sound evidence, nor paying for ill-informed guessing by lesser mechanics (than yourselves, of course!). I also have a sneaking suspicion that the automatic transmission could be slipping -- when I drive with 2 adults and two kids in the car up a hill, it seems more underpowered than days of old.

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Jeep - Cherokee :: 2000 - Misfires / Check Engine Light Keeps Coming On

I have a 2000, Jeep Cherokee 4.0L. The check engine light, keeps coming on, and the scan tool, shows P0300, P0301, P0302, P0303. Misfires in #1, 2 & 3 cylinder.

I replaced the Coil Pack & all spark plugs with genuine jeep parts from the dealer. What might be wrong or other things to check?

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Jeep - Cherokee :: 1993 - Engine Softly Stutters And Misfires While Driving And CEL Came On

My inline 6 engine softly stutters and misfires while driving and has the check engine light on whenever this happens. It's becoming more frequent now - 20% of the time I'm driving I'd say. The codes are 11, 12, 27, 34. I've looked up the meanings of the codes and I'm leaning towards its bad fuel injectors or a bad connector leading to the fuel rail. I have lots of bad wiring on my 93 Cherokee haha. I've fixed so far: a bad head light connector, and an exposed wire that connects to my distributor - it would swing and touch my engine block causing the engine to die.

But now I am struggling on how to fix my small stuttering engine problem. So the problem only occurs after I make a strong left hand turn such as a 90 degree or a uturn so that means a connection is being pulled to the right. It doesn't have an issue turning to the right though. I don't have sway bars on my 6" lift so there's a reasonable amount of body roll to pull on the wires etc. When I open the hood with the engine running smoothly I can touch and wiggle the front fuel injectors and sometimes I hear it softly misfire or sputter. What connectors lead up to the fuel rail?

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Ford Escape / Hybrid :: 2001 - Engine Light Blinking And Misfires

I have a 2001 ford escape. Today it starts to miss and the engine lights starts flashing. It is never the same amount of flashes. Sometimes its 8 or 10 flashes. I counted up to 25 flashes one or twice It just shakes bad and that's when the flashing starts. When it starts to miss and vibrate, I can accelerate in passing gear and it smooths out. When you hold it at a constant speed it starts missing again. Cannot get a code with my reader. Someone told me a flashing light indicates a misfire. What may be causing this problem?

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Suburban :: 1999 - While Driving After Engine Warm-up Misfires On Cylinder 2 Under Slight Load

1999 Suburban 5.7L Vortec

Symptoms: While driving after engine warm-up the engine misfires on cylinder 2 under slight load (basically whenever maintaining speed, and slight acceleration) between 1500-3000 rpm's. Backfires through exhaust when this is happening. Misfire counts on Cyl. 2 collect rapidly and only a few on Cyl. 1 but no P0301.

History: Purchased vehicle with a blown engine (intake gasket leaked coolant into engine and was hydro-locked) with the intention of using it to pull a boat or camper but never did buy either one. Replaced the engine with a new Goodwrench engine and rebuilt the tranny figuring I would drive it till the body rusted off of it. I honestly never felt that the truck ran as strong as it should have with a brand new engine but just attributed it to being as big as a cruise ship. A couple of years later started receiving multiple codes (don't remember what they were at this time) found the distributor very corroded inside due to the ear on the distributor being broken off.

Replaced the distributor, cap,rotor,plugs and wires and fixed it. About a year later, only in the summer I would start to receive the P0302 sometimes, would not happen in the winter. Did the usual plug swap, wire swap, checked spark to rule out ignition with no change. After a while the catalytic converter failed (big surprise with a missing engine) and replaced it as well as both O2 sensors on the rear bank and one on the front bank. P0302 did not change. Last year the fuel pump failed so I replaced it. This April I took the truck on a road trip to visit relatives, about 80 miles out it started backfiring through the exhaust whenever I got over 70 mph and the CEL would flash. Finished the trip babying it the whole way but now it does this all the time when warm.

Repair attempts:
* Distributor, cap, rotor, wires, plugs. (Due to distributor failure mentioned above.)
* Fuel pump and filter. (Due to pump failure mentioned above.)
* Upgraded fuel injection spider. (Because of GM bulletin regarding misfires and multiple failures found on the internet.)
* Repeated valve and fuel system cleanings. (Grasping at straws.)
* Removed rear bank cylinder head and sent to machine shop, All checked good. (After ruling out ignition and fuel figured it had to mechanical. Compression was good, cylinder leak down test was good. The problem seems to be temperature related so thought maybe the exhaust guide was mis-manufactured too tight causing it to drag when warmed up.)
* Crank sensor with a used one from a u-pull it place, I got too much money wrapped up in this. (Found a reference to this repairing a similar problem on another vehicle.)

One final note: After replacing the fuel injection spider the truck ran extremely well, this only lasted a few days and the problem came back. After replacing the crank sensor the truck again ran extremely well, but only for 1-2 days. What is the connection between the injection spider and the cranks sensor? The only other thing that I can think of that would create a misfire on one cylinder only is the PCM but that gets misdiagnosed so much that I don't want to jump to it unless all other options have been checked out.

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Tiguan :: 2.0 VW Engine - Breather Valve Stuck Causing Oil To Enter The Cylinder / Misfires

We have a 2009 2.0 Tiguan with approximately 60,000 miles. About 6 months ago, the check engine light came on so we took it in and found out the breather valve was stuck causing oil to enter the cylinder and causing misfires. Had this fixed an about a week later, the car acted up again. Took it in and removed & reinstalled the intake manifold. Both pricey fixes. The dealership said it was a problem with the 2.0 engine design. Now we have taken it in again to a local shop who is now informing us we will need to replace the intake manifold. He said the same thing about the engine design. Our concern is that this problem will need to be fixed on a fairly regular basis. We really love the vehicle but cannot afford the cost of this maintenance if it becomes routine and are considering trading it in for a Passat.

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Sebring - Chrysler :: Rough Idle And Engine Light Comes On / Codes Read Misfires On 1, 3 And 5 Cylinders

I have a 2006 Chrysler Sebring Convertible 2.7L engine. Replaced water pump and spark plugs. We triple checked the alignment on the chain and are sure the timing is fine. Car started right up. Now running rough idle and engine light comes on. Codes read misfires on 1, 3, and 5 cylinders.

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