Passat (B7) :: 2012 3.6 SE - Hard Startup Due To Excessive Carbon Build Up
Last week when we were in the single digits outside my 3.6 SE took about 15-20 sec of cranking to start (garage kept). Then the check engine light came on (2nd time in 10 months). I drive a lot (80 miles a day), and have put 19,900 miles on since I purchased it in March of 2012. The light turned off after three cycles, but I just so happen to have my 20,000 mile service scheduled so I took the car in. The hard start still is happening every few start ups.
The dealer told me the hard start issues I have been experiencing was due to excessive carbon build up on the valves. The dealer said they haven't seen many "high mileage" 2012 3.6 come through, so they could not tell me if this is common.
I use Shell 93 octane for every fill up. Is there something else I should be doing to prevent this carbon build up? Any others seen this with their higher mileage 2012 3.6? BTW they also had to replace the right rear control arm due to one of the bushings being worn out!
Passat - Volkswagen :: Misfiring On Cylinder 3 - Carbon Build Up On Intake Manifold
I recently took my 2007 VW Passat 2.0T in b/c the check engine light was on. They initially replaced a leaking valve and a bad ignition coil, but the car was still misfiring on cylinder 3. They took off the intake manifold and found that there was significant carbon build up. The service writer said it was from "low-quality" gas. The car requires 91 octane. I've used 93 octane since 2007 but started using 89 octane around 6 months ago when the gas prices spiked again. Could 6 months of 89 octane cause significant carbon build up to the point it would trip the check engine light? Or could something else have caused it that I need to watch out for?
View 4 RepliesFord :: How To Prevent Carbon Build Up
My commute is only 11.5 miles. 6 miles of it I can run 55-65. Am I building a carbon nightmare?
View 11 RepliesAcura - Integra :: Removing Carbon Build Up On Pistons?
My 87 Acura Integra with 170k gave SMOG reading in CA as below:
NOSpeed Max Meas15 760 87525 542 535
A m/c tells me it is the result of carbon build up on pistons.
Incidentally it gave the following in 2010 - upon retesting without any repair it passed:
NOSpeed Max Meas15 760 65625 542 678
Note: Recent oil change (Mobil 1 High Mileage), tune up, Thermostat, new PCV valve, NGK Plat spark
It is for "NO" - Nitrous Oxide
Sonata I45 (YF - 2011+) :: Valve Rattle Under Acceleration - Carbon Build Up
I have a 2014 Sonata with 22k miles. I love this car but lately I've noticed valve rattle under acceleration. Brought this up with service tech and he said I'm not driving the car on long enough trips to keep it cleaned off. When I researched the GDI very little info comes up for Hyundai mainly vw and BMW. I guess what I'm asking is is the only fix for the carbon build up removing the intake and cleaning the valves manually or is there another way.
View 56 RepliesHonda - Accord :: 1996 - Check Engine Light On / Carbon Build Up In Suction Side
Been told my EGR valve is ok on my 96 accord . But I may have carbon build up in my suction side . I used deep creep for week to loosen up the build up. What else can I do?
View 5 RepliesVolvo :: 740 Engine - Rough Idle / Fair Amount Of Carbon At Exhaust Pipe
I've got an '88 Volvo 740 Turbo Wagon: 5-speed, 225K miles, that's been acting up over the last year. She doesn't burn oil (qt in 1500 typical) and appears to still be tight. The Turbo works and bearings make no noise. The engine service light does NOT glow (but I admit I haven't checked the bulb). I do have a Haynes manual and have been using it to assist with some results (see replaced items), but I'm not trained on this car and this manual is woefully lacking in good diags for some obvious things. (IMG: [URL] .....)
Symptoms: She cold starts OK, but try to restart warmed at all and she usually has to sit at least an hour or no go. Outside temp seems to make little difference. There's a gassy smell while cranking warm and it's very much like a flooded carburetor engine. Often, the engine will finally catch with the pedal floored after a long crank. Also, after warming and driving a few minutes, the idle erratically will not return to normal, sitting up at 1800-2700 RPM for a bit before finally calming down. It was also running a little rough. There's a fair amount of carbon at the exhaust pipe and MPG is only ~20 and I'm a light foot. The idle RPM varies a bit much moving around between 600-1100 RPM warm.
What I've done this year: It had a broken thermostat (replaced), failing alternator (replaced), failed starter (replaced), failing fuel pump (replaced with filter), recent oil change (has turned black after 800 miles). Most grounds around engine and firewall and 12 volt ignition contacts cleaned. The bat cables were cleaned and terminals coated. Ohm tested the injectors OK (all exactly the same, on spec) and they all "click" in operation. I replaced a bad coil (low ohms by 20% for both primary and 2nd) and changed the carbon fouled plugs (which were also ill-gapped by some hamhand), both of which worked for the roughness considerably. The plug wires all came up roses well under 10k ohms. The battery was a suspect for testing low so much when resting, but the alternator seems to have slowly fixed that (and problems come when system is charging OK). However, the main warm start and idle problem persists. (IMG: [URL] ....)
My next good guess: An obvious rich condition exists and, having eliminated quite a few other things, a sticking "Air Control Valve" seems the likely suspect (some call it an idle control valve but I'm going by the manual). My specific observations of this device: after a warm no start, I pulled the ACV electrical lead and she fired right up and idled well at 16-1800 RPM. I plugged it back in and she chugged and nearly died before idling ~800 RPM. As it idled normally, I pulled the rubber hose from the upstream air connection to the ACV and it chugged and died within 5 seconds. I noted the vacuum was very strong. Putting the hose on, it wouldn't restart till I removed the electrical lead again. The ACV circuit has continuity at the device but I haven't ohm tested it yet. My best diag is the mechanical part of the ACV is gummed up or worn out. The Haynes manual was almost no way in arriving at this conclusion. (IMG: [URL] ....)
Ford F-150 (2004-2008) :: 2006 - Rough Idle / Throttle Plate Had Lot Of Carbon
I recently bought a 2006 that idles rough, not real bad, but bad enough for me (and my 9 year old kid!) to notice. I asked the dealer where I bought it and they put it on the computer and said everything checked out. He said "it's a characteristic of this motor." I've never heard of such a thing. The truck has 27,000 miles on it and the dealer flushed the fuel system. He said the throttle plate had a lot of carbon on it, but it still idles rough... 4.6 idle rough?
View 13 RepliesPassat (B5) :: 2000 V6 - Rough Starting And Sputter
Past few mornings, I had a bit of trouble starting my 2002 Passat V6 (60K miles); car would start, and sputter. After a few times of this, the car would eventually turn over, and would be a little rough once I put it in gear for the first few hundred feet or so.
Brought it up to North Penn VW in Colmar, and the service tech said it had to do with the ethanol in fuel settling to the bottom of the tank, and not being potent enough to fire the engine, and normal acceleration would be enough to burn this stuff out of the lines and/or where the gas and ethanol would mix.
Passat (B6) :: Knock Sensor Code After Valve Carbon Scrubbing Service
I have a '07 Passat Wagon 2.0T with 80K miles. I just had the carbon scrubbed off the valves (looked like black popcorn stuck in there!) and now I'm getting a "P0327 Knock Sensor 1" light. The motor seems to run just fine (actually much better now without the carbon build-up). I'll clear the code but it will show up again the next day.
What could cause the code? Could it be related to the recent scrubbing (fully removed and replaced the valve cover in the process), perhaps a chunk of carbon floating around in the tubes somewhere? I want to go back to the guys that performed the service but I want to have a good idea of what could be the problem and the fix before I get there.
Golf/GTI VII :: How To Get Carbon Off Exhaust Tips
I have tried a few solutions with minimal success. Any luck with anything? This is the first time I did not clean them in 2 months and can't get it off now...
View 24 RepliesIntrigue :: GLS Hard Starting / Rough Idle
My wife's Intrigue has had a hard starting/rough idle/rough start issue for a little bit now. On a hunch this weekend I decided to clean out her throttle body. Turns out it was more full of soot than a chimney in February. Nasty black carbon buildup. Took a toothbrush and some throttle body cleaner and scrubbed it out best I could. Car runs great now, very smooth and responsive. Gas pedal use to stick, even fixed that. So I'm a hero, until we realize that her car is still starting hard. Turn the key and the engine turns over no problem, starter sounds good. Once the engine is running it purrs like a kitten. But sometimes you have to crank it for several seconds before it fires up.
View 14 RepliesTouareg :: Transition From Stopped To Starting Rough Sometimes?
Ever since I picked up my V8 Touareg I've noticed that the transition from stopped to starting can sometimes be rough, and that the shift from 1st to 2nd is often a fairly violent jerk. The worst transmission problem on my Touareg is experienced when I'm in stop-and-go traffic going around 5mpg in 1st gear then accelerate normally. The shift to 2nd is extremely rough.
I took my Touareg into the shop last week to fix this, and another problem I was having, and the car is still at the dealer. When I talked to my service advisor on Friday he said that this is a fairly common problem with later VIN cars. Evidently, they had to reprogram the transmission to meet some EPA regulation and that is causing rough shifting in the lower gears.
Silverado :: 2001 - Carbon Buildup In The Intake
I'm replacing my knock sensors and intake gaskets on a 2001 silverado and there is a lot of carbon buildup in the intake, what can i use to safely clean it with....
View 5 RepliesPrius (Gen 3) :: Intermittent Shaking / Rough Starting Sometimes After Car Sits For A While
I have a 2010 Prius III I bought used the other day and all of a sudden I'm getting intermittent shaking / rough starting sometimes after the car sits for a while. However, after that happens it seems to run and drive just fine. At first it didn't throw any codes or anything but now Check engine light on with 3 codes.
View 8 RepliesSubaru - Forester :: Rough Starting - Engine Is Misfiring
I've 2005 Subaru Forester automatic with 2.5L engine. It ran fine since I purchased it in 2005. However for the last 3 months it is behaving strangely. When it sits in the garage for 2 days or longer, it starts up very rough. It feels like the engine is misfiring. If I let it run for 10 to 15 minutes, it is back to normal!! The car has 80,000 miles. It was tuned up at 61,000 miles. I recently had a diagnostic check done. It showed no problems.
View 1 RepliesGolf V R32 :: Engine Rough Idle When Starting Cold
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 RepliesFord - E150 :: 1988 Not Starting And If Start Then Ran Rough?
1988 Ford E-Series Van ford van starting problems I have a 1988 ford van e150 302 that wont start. when it did start, it ran rough, then progress to needing start fluid to start. Now it cranks but wont start at all. it sat for almost a year with additves in gas but it does smell now unlike normal gas. it has sta-bil and gas line anti freeze as additives. A rail mount high pressure pump was put on two years ago. Could the hi-pres pump been installed backwards? Now it will not start even with starting fluid, just cranks and tries(pops and backfires a little sometimes). I towed in to a mechanic to get diagnosed.
In regards to the 1988 ford van start problems, the mechanics said that fuel is bad and needs drained, that in tank pumps seem to have pressure(low pressure pumps). the rail (high press pump) they say tests 15-20 psi only. the want to drain tanks, replace pump and "go from there". They also said a multitude of problems can happen from "bad gas" ranging from injectors needs cleaning to bent push rods, lifters and crank shaft can be damaged. All may need cleaned, fixed or replacing. does this seem a little fishy ? Could it need the timing set? Or injectors bad?
Camry :: Some Black Carbon Came Off While Removing Top Plastic Cover
I recently removed the top plastic cover on my '05 Camry LE V6 to pull a plug and inspect/decide if I was going to change them out. While I felt I was being careful handling the plastic cover, I grabbed it by the access hole for the oil filler cap. Walking back into the garage, some black carbon came off, and looking at the bits on the ground, and what was left on the inside of the cover, I'm not sure if there is supposed to be a gasket there.
Maybe it was just an accumulation of spilled oil over the years that has trapped and "cooked", or something put in place to capture spilled oil. I scraped the rest of the carbon off using a razor blade and cleaned it up before installing the cover.