Posts Tagged: rough idle
P0172 trouble code and fuel in oil plus rough idle and engine run-on
GM has a fix for a P0172 trouble code and fuel in oil, rough idle, and engine run-on GM has issued a service bulletin #PIP4783B to address a P0172 trouble code and fuel in oil, rough idle, and engine run-on the GM vehicles listed below. Before you perform any diagnostic tests, pull the engine oil dipstick, and check for the presence of fuel. GM has determined that a P0172 System Too Rich (Bank 1) may be caused by a defective high-pressure fuel pump that’s leaking fuel into the crankcase when … Read More
What is an idle air control valve and how does it work
Learn how an idle air control valve works An idle air control valve bypasses air around a closed throttle plate so the engine can get air at idle. Because it bypasses air, it’s also called an air bypass valve. Back in the days of carburetors, idle speed was adjusted by way of an idle speed screw that forced the throttle plates open by a crack. In fact, on many carburetors, there were two idle speed adjustment screws; one for hot idle and another for cold. Turning the screw inwards prevented … Read More
Transmission slips – GMC Safari
Transmission slips – GMC Safari Rough engine and slipping transmission on 2004 GMC Safari van with the 4.3L V-6 engine. Before you even think of adding anything to your engine or transmission, clean your mass airflow sensor (MAF) sensor. It’s one of the known causes of engine and transmission issues. The MAF sensor is located in the air duct between the air filter box and the throttle body. The sensor contains heated wire elements that are cooled by the inrush of fresh air. The sensor measures how much power is … Read More
Rough idle Mazda 3
Rough idle Mazda 3 Rough idle, bad gas mileage on Mazda 3 with the 2.0-litre engine A vacuum leak can cause both a rough idle and poor gas mileage. And on this vehicle the positive crankcase ventilation (PCV) valve hose can leak and be very hard to diagnose. Even professional shops with smoke machines have a hard time finding this one. The hose is located under the intake manifold. Since new hose is cheap, try replacing it and the PCV valve and see if the condition improves. I’m betting it … Read More
Why Your Engine Has a Rough Idle and How to Fix It for Good
The Real Causes of Rough Idle and High Idle Quick Summary The root cause of a rough idle or high idle is almost always extra air getting into the engine or the computer losing control of airflow at idle. Vacuum leaks, carbon buildup in the throttle body, and idle air control problems account for the vast majority of rough idle and high idle complaints. Fixing the airflow problem first saves time, money, and frustration. Article Rough Idle or High Idle? How to Diagnose and Fix Both Problems the Right Way … Read More