Motor Vehicle Maintenance & Repair Stack Exchange
Motor Vehicle Maintenance & Repair Stack Exchange

Questions tagged [carbon]

15 questions
7
votes
4 answers

The Mystery of the Misfiring MINI

It's me again. 2008 MINI Cooper S w/ dealer-installed JCW package (chip tune, larger air intake, larger cat-back exhaust). I thought everything was fine after resetting my ECU last week, but had bad misfiring at idle again this morning which set the…
Spivonious
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7
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1 answer

What does a wet intake port (direct injection) mean?

Car: Audi S5 4.2L V8 FSI I have my intake manifold out to clean carbon of the intake ports. When I was removing the port separators, I noticed some were really dry (light grey carbon), others were dark black (but not shiny). But I noticed two…
tgun926
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6
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3 answers

Lack of power when cold under load

EDIT 8: Final update, I think. Using an OBD scan tool, I saw that the fuel trims were still very low to adjust for the vacuum leak. I reset the ECU and the trims went back to around 0, and the engine is running much more smoothly. I think we can…
Spivonious
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5
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2 answers

I have a Vauxhall zafira diesel 1.7 what happens if the EGR valve and inlet manifold get blocked with carbon

What happens if the EGR valve and the inlet manifold get completely blocked
Steven White
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5
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1 answer

New to mechanical work. Is this a safe way to clean oxygen sensor, or any similar part

https://www.youtube.com/watch?v=tD9KXAukO9M So I found this video of a guy cleaning their oxygen sensor out with an ultrasound cleaner. I presume what it is doing is breaking up the carbon build up in the device. Is this safe? It seemed pretty…
user1428649
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4
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Can carbon buildup on a valve seat cause idle surging?

I've got a 1994 BMW 325iC that won't pass smog (for more details, see this thread). I took it to a shop to get both a leak-down and compression test done with some interesting numbers: Cylinder 1 2 3 4 5 6 Compression 180 210 160 210…
Hari
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3
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1 answer

Diesel Injector Well full of Carbon

While looking over my friend's 08 Kia Carnival J3 2.9L Turbo Diesel, I noticed a strange huffing noise. After removing the decorative engine cover I discovered this: This injector well is filled with a hard carbon deposit, while the other three…
Robert S. Barnes
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3
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Advice for cleaning an electrically actuated EGR valve

Intro - skip to TL;DR for the main part of the question... I keep getting P0402 errors indicating EGR excessive flow on a VW Golf IV Variant, 1.6 l, 16V, engine code AZD. When warm, the engine has a bit of a rough idle. Being aware that EGR errors…
zebonaut
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2
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1 answer

Car consuming oil, leaving soot on ground

I have a 2010 Hyundai i30cw. It's the FD, 2.0L Petrol Engine variant, Automatic Transmission. Around five or six months ago I took it to the dealer for a service - they didn't call out any issues, but since I got it back I've already had to refill…
James D
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2
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3 answers

Will dislodging carbon deposits harm the catalytic converter?

If I use an intake valve cleaner that dislodges chunks of carbon from the intake valves or piston head, and they flow through to the exhaust, could they harm the catalytic converter? I'm interested in testing the efficacy of intake valve cleaners by…
Craig Younkins
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1 answer

High crankcase pressure, no flow through PCV valve

I have a 2011 Acura RDX with 385000km on it. When I remove the oil filler cap with engine running, the air blowing out the filler hole is substantial. With engine running I unplugged the output side of the PCV and no air is coming out. Since the…
TSG
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1
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Honda Interceptor 1987 Spark Plugs getting carbon fouled within seconds. Vehicle idling louder than usual

I recently installed a new engine on my Interceptor. After riding for about half an hour the bike petered out. I left in in the garage for about 7 months before installing new spark plugs. This got it running again, but it idles extremely loud, as…
Griffin Hines
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1 answer

CO and Lambda fail after cleaner, air filter and throttle body clean

Went for an MOT, first test failed on high CO AND HC but normal lambda. Got new air filter, cleaned EGR and throttle body and added a cat cleaner into petrol tank. Second MOT failed due to high CO (nearly x2 as last time) and high lambda (1.037,…
LionLeon
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0
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1 answer

Do carburetors protect intake valves from carbon deposits?

For a long time, most car engines were using multi-point port injection that sprays fuel directly at the intake valves. Today, engines are increasingly commonly direct injected. A problem of direct injection engines is that the intake valves often…
juhist
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Does driving a car economically damage the engine?

I have a Honda Vezel, which is available only in Japan. The closest (very close) equivalent is the 2016 Honda HRV. It has a 1.5 i-VTEC engine (whatever that means) and a CVT gearbox. The shift has three forward positions: L, S and D. I get an…
u936293
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