Golf/GTI VI :: Random Engine Misfires All Day / Vacuum Leak
Nov 12, 2015
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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I am getting random misfires on cylinders 4, 5, and 6. Mostly on 6, less on 5, and even less on 4. Cylinders 1-2-3 show ZERO misfires. I am using vag-com to monitor these. Mostly doing it on idle, cruise seems fine but occasionally when shifting I feel it when engaging the next gear. It doesn't buck but I feel a little hesitation. Cruising and accelerating I do not feel it. Its very strange. A couple times during extended idling I have even gotten a flashing CEL. Fuel mileage has been pretty bad ever since I got the car in December. Average tank gets me 250-270.
I tried swapping coils with 123, and the problem stayed on 456. Coils are all new since I got the car. Plugs are fairly new (under 5K) and I pulled a couple to check, they looked fine and gap was about .028. I might try a new set but my gut is telling me the problem is some where else. I would like to verify/test grounds but I don't know where the harness grounds out.
I also want to get a vacuum gauge on the FPR, or check fuel pressure at idle. I replaced one cracked vacuum line, i am thinning there might be others since there seems to be miles of vacuum line on MK4's. Also have a new fuel filter to install, mine appears to be OEM and the car has 97K.
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It all started a few months ago.... I started my car, and it started noticeably misfiring, CEL flashing and everything. I scanned it with my vagcom and it came up Cylinder 1 Misfire and Random Multiple misfire. I popped the hood, made sure everything was seated correctly, and shrugged.
Ordered some new wires for it, since it had 80k miles on it with original wires, I figured why not. The misfire didn't come back.
A few weeks later, same thing happened. Misfires, flashing CEL, same codes. I ended up driving it the 5 minutes to work anyways and figured I'd look at it later after I got off.
8 hours later I started it up again, ran like a champ, no CEL on. The problem didn't come up again for 3-4 weeks.
So now, without fail, every month or so, I'll get the same issue. It doesn't matter if it's raining or sunny or cold or warm. But if I let it sit for a few hours, it'll act like it never happened.
Now, I haven't replaced the coil pack yet, simply because it doesn't sound like a coil problem, but I might do it just for the hell of it. New plugs and wires have already been done.
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2000 Jetta MKIV ... 2.0L GL
I've been dealing with random misfire codes on my Jetta (P0300, P0301-P0304). I've since replaced the spark plugs, wires, fuel filter, MAF senor, & camshaft positioning sensor but the problem still persists. The misfires occur right on start-up and don't stop which is leading me to the coil pack being bad.
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So I picked up this 24v vr6 in florida and it has the folowing codes:
p2181 malfunction in cooling system
p0303 misfire in cylinder 3
p0305 misfire in cylinder 5
p0300 random multiple misfires detected
p1570 engine control module disabled
I am thinking the ecu is fried? otherwise why else would that last code pop up. misfire codes im assuming are related to the ecu because theres new COP on each cylinder, newer starter, newer alternator, new spark plugs. Cooling system malfunction im thinking could be the ECT sensor, apparently the water pump was replaced a little while back.
If the ecu is fried can I buy a new one chipped from like APR or do they need the existing ecu and then they modify it?
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I have a mk4 1.8t Gti. Recently I have been having issues with idle and boost. I read the codes and multiple random misfires in all 4 cylinders came up, idle control and the crank, knock, and o2 sensor came up. Shows that system is running to lean as well. I changed the spark plugs and wires, check the coil packs they where done about 1k miles so I expect them to be perfectly fine. When I clear the codes it idles below 9-8k rpms. I also noticed the breather hose coming out of the valve cover into the EGT has a hole melted into it, could this cause any of my issues?
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I suspected I had a vacuum leak somewhere, was told it wasn't likely. Just installed a tune in the evening drove it 15 miles was pretty sure I had one.
Installed Forge DV the next morning it was evident I had one by the sound the DV was Making. I checked the car head to toe and found two lines had broken apart. I replaced them will silicone lines and it appeared to be fixed.
Drove it 5 miles and the 'turkey sound' came back. (This is the sound that I originally heard and confirmed I had a vacuum leak somewhere)
I searched all over there car, had a second set of eyes that was mechanically inclined and we found nothing obviously causing a problem. We ended up just taking off the Forge DV and testing it by hand it held up and re installing it and securing it.
Strange enough that fixed the problem (no other hoses were tampered with while we were inspecting)
Drove the car home about 15 miles and stopped in a drive through. At some point while sitting something happened. Cause when I left the drive through then I noticed the car seemed to be lacking at low end, turned down the music and I could hear the turkey call. I left the car alone for the night. Thought maybe heat jas a factor in this. Drove it this morning and it was just how I left it. I inspected the hoses and found no change. I took the DV off and inspected then re installed. I noticed the turkey call was not as predominant but still completely present.
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Recently bought a MKV R32. Already had a magnaflow cbe, k&n panel filter, and some emissions stuff taken out from under the hood. not sure if it has been flashed, waiting to get a vagcom. think it is pretty stock other than that. My problem is about 2 weeks after I got it, I started to notice an exhaust leak or vacuum leak or both at higher RPMs, like above 3 or 4k it starts. The exhaust has a nice deep rumble in normal driving but when the leak noises start that is all you hear, the exhaust note disappears completely. I have tightened the clamps on the cbe and still does it. Not sure what to look for.
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I have a vacuum leak on the driver side seal on the changeover rod in the intake manifold. It was replaced recently at the dealer and now has another hole in it. I was told this is caused by oil in the lines and my pcv valve is bad.
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I need replacement vacuum hose part for my GTI 337. The piece that is disconnected is the hose from the break booster to the intake manifold. It appears to be at a one way valve. I found a picture from a different DIY, that I have circled in green. The red arrow points to the place where it separated. I am not sure if this is a matter of me using a new clamp or buying a new piece of hose from advanced auto parts. The vacuum sets on ECS Tuning and it doesn't appear to be the correct set.
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Just bought my volvo several days ago. It was throwing check engine codes so I had it scanned and it came down to a vacuum leak. I found the spot where it was leaking which was a little piece to the left and slightly behind the exhaust manifold, slightly behind and beneath the thermostat housing. It went from a hard plastic vacuum line, to a 1.5 inch rubber vacuum line which plugged into a nipple on the exhaust manifold or something behind the manifold. the rubber section had 3 large holes in it, so i replaced it with more rubber vacuum line. same length and same inner diameter.
What I did notice when I replaced it was that it was too large for the plastic line, slid on way too easy, but i had to fight it onto the nipple. The check engine codes went away for 2 days(I drove about 150 miles over that time) but today, the check engine light came back on, went to auto zone, had them scan it, came back with vacuum leak. So when I got home, I popped the hood, sprayed some carb cleaner by the replacement vacuum job I did, and sure enough the idle changed. What the proper replacement hose is for that area?
[URL] ....
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Ever since I got my car about 5/6 months ago I noticed it's not getting full boost. when I first got it the stock boost was getting about 5-7 I don't know if that's normal I've read they normally get more. eventually I got my car tuned and it's supposed to peak at 22 psi but it only got to about 13-14 psi. slowly it's been getting worse and my car is getting 2 psi. I've had lots of people tell me it's a vacuum leak. also the bov makes a flutter noise if that has anything to do with it. my intake doesn't make a sucking in noise like most do. The car has been randomly backfiring usually between gears. I just ordered a turbo inlet pipe a breather hose kit and a boost hose kit.
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As title states, I scanned my gti and got P0420 (nothing new here) and P1136. I did some searching and looks like vacuum leak can cause this, however I also read that it'll affect my idle. I replaced MAF 2 years ago with a brand new OEM one, my idle is NOT rough, at all.
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Having problem on mrk 6, sounds almost like a high pitched vacuum leak but I can't find it.
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so i've had my 337 for a couple months now and when i first got it i found 2 broken vacuum hoses that were causing misfires. once i got those replaced my CEL went off and seemed to be running fine other than from time to time when i started it up my idle would be around 1.2k rpms and then after a couple miles itd settle down to 750-800 rpms but it wasn't rock solid, so obviously there is still something wrong.
on my drive home tonight from work i was in the mood for some spirited driving but when i'd hit the gas i could feel some hesitation through the powerband at wide open throttle. when i got home i turned it off, and started it back up to see if it was idling funny and when it ignited the rpms jumped to almost 2k and immediately fell back down to 1.2k.
My thoughts are its either a vacuum leak again, bad/dirty maf, dirty throttle body, or a boost leak.
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OK. I have a 2005 Passat 1.8t fwd. Tiptronic. 105k
The symptoms i am having is random cylinder misfires on all 4 cylinders. I have scanned with vagcom multiple times and get the same codes. However, I have cleared the codes, and wen fpd a 60 mile drive on the turnpike. Not a single code. So everything is perfect as long as the car dissent have a chance to idle.
I have also driven the car while logging misfires and only get misfires at idle. Never while driving.
So much has been done to the car that is so hard to decide where to start. Ill try to go in order of events.
All this in the past 4 weeks by the way.
Took car to very experienced VW tech. Found out.timing was off by 3 degrees. So new timing belt, water pump and all. Started car, still had misfires. Noticed wetness on head gasket. And did a compression test. Very bad results. (I can't remember the numbers but they were way off from each other) So he removed the head. He said there was a crazy amount of carbon buildup in the combustion chamber. Everything was cleaned, head inspected for bent valves and everything looked perfect after cleaning. (this car has NEVER overheated by the way) He said it is very rare for a head gasket to fail on 1.8t's . So he did a leakdown test and turned out the piston rings were shot. So engine was rebuilt. All components cleaned of carbon, replaced all parts, bearings with new OEM parts. Pickup tube cleaned along with other oil lines. Turbo was inspected, and I was told it is on its way out but still has life. So that was let go for now. All reassembled and all hoses checked, combi valve cleaned, new k&n filter in stock airbox. So he told me the car is finished after all that. I was excited! Drove the car home 15 min drive, ran great. Parked in my driveway, put it in park and misfires came right back. Called him the next day and brought the car back. He looked over it and replaced the fuel pressure regulator with new. He said it seemed like a fuel starvation issue. Tested fuel pump and it was towards the low end of the proper operation value. So I had a high flow pump sitting at home brand new and I brought it down and put it in. Still misfires but a lot less than before. Also fuel filter was replaced. So next he disconnected the cat And found it was clogged. Replaced with my old Audi one, and it ran fine. And this is the first time the car idled good enough to get all the monitors set for emissions testing. So he was convinced it was fixed. Room it for a test drive and came back, parked And began misfiring again. So I was so sick of this thing at this point, I told him to replace the Turbo with brand new OEM unit. And it still misfires.
He swapped a known good throttle body into it and no difference. He also said that he started going around and unplugging sensors and the more sensors he unplugged, the better the car ran. He was curious whether the ECU was faulty. So he put an ECU from his Audi in it which had a ko4 file in it. He said it ran amazing!! So he modified an ECU from a stock Audi and that's what I am driving with now. Still same symptoms. But not as often. Also brand new bosch mass air sensor was installed as well. So this is as far as we have gotten with it and I am so sick of this car right now. But we are both determined to get this thing fixed! And after all the money I have just spent, I can't even get rid of it or I will lose a lot of money. It really sucks because I love the car and so does my wife. And out of the three 1.8t's that I own, I have never had any major issues like this.
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I have a 2000 B5 . It has minor damage front and rear (cosmetic only). Also, the check engine light stays on due to a vacuum leak somewhere between the MAF and the intake manifold. It would need a full paint job at some point after the body work was completed.
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I have just replaced my vacuum lines after find a hole in the hose going the the vacuum reservoir. I have also recently replace the pcv hose. This seems to have created increased vacuum pressure and I am now hearing a hissing coming from the back center part of the engine.
Pulling codes P1411, P1423, P1138
Regarding photo - The area the hissing appears to come from is located in the rectangle area, more or less.
2.8 atq B5 Variant
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It has been since the 80's that I have attempted to do any work on a vehicle. How do I find a vacuum leak and where is my vacuum canister. I am assuming that it is a vacuum leak for anytime my engine has a load on it the air stops coming out of the dash vents and goes to the defrost vents. I have an 2000 F150 with the large engine with about 112,000 miles.
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4601 DBP, just under 35k on it. At idle, i hear a slight whistling almost like squeaking. I took it to my independent tech and he showed me that if he removed the dipstick for a second while idling, the noise stopped, due to lack of vaccuum, so he believes its in the pcv system. I am still under powertrain and obviously federal emissions 8yr 80,000. Go start your R and listen at idle inside the car for a whistle or squeaking noise that seems like its inside the passenger dash.
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I just bought a 05 1.8T Jetta 116,000miles. and need diagnosing it. It misses all the time. Has new plugs I tried two other sets of coils (from my 2.0 a4 and my dads passat) and it made no difference. The SAI was taken out but nothing is blocked off. Also the coil pack wiring harness has cracks on the big brown wire where it goes down along the block. I'm getting these codes on my vag-com.
16687 cylinder 3 misfire
16686 cylinder 2 misfire
16688 cylinder 4 misfire
17766 cylinder 2 open ignition circuit
17763 cylinder 1 open ignition circuit
17769 cylinder 3 open ignition circuit
17772 cylinder 4 open ignition circuit
So am I correct in thinking that it's from the cracked harness? An not a vac leak?
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