Q: Erratic RPMs, 1995 BMW 318is

asked by on August 26, 2016

Lately, the RPMs have been fluctuating and I'm not sure why. I had some worn hoses replaced. The throttle body has been cleaned along with the idle control valve. Still, there RPMs keep increasing and decreasing erratically. What might be the cause?

Hello there, there are a few possible causes for your 1995 BMW 318is to have a fluctuation in the RPM’s. The most common are a vacuum leak, oxygen sensor, throttle sensor, exhaust leak, or the fuel pump. I recommend have each of these items checked in order to scope out the cause of the erratic RPMs. If you need help with this, a certified technician from YourMechanic can come to your car’s location to inspect the idle and let you know what should be done.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

What others are asking

1999 toyota corolla smog fail due to high emissions

Hi there. High emissions for HC and CO can be caused by more than 12 individual emissions sensors or fuel systems, ranging from your O2 sensors, catalytic converter, EGR Valve and more. As such, giving you the right repair advice...

RPM not increasing Yanmar 6LY2A -STP

Hi there - there are a couple of possibilities here for the "won't get to engine max revs" condition. This engine has a governor, set at 3,000, and a malfunction of the governor could be limiting RPM. It's also possible...

Leaking coolant, visible from reservoir. Has crack in reservoir.

Replacing the reservoir and hoses since they are cracked is the first step. The second step is to figure out why the coolant is creating too much pressure in the tank. This may be caused by a variety of reasons...

Car dies under acceleration

Hello there, many common faults will cause your 2001 Toyota Corolla to have a loss of power. Replacing the spark plugs is a great place to start as this is one of the causes. Other potential faults are the the...

Car stopped accelerating and started smoking while driving on the highway

Hi There, It depends on the color of the smoke you are referring to as the color of the smoke will mean a few different things. White smoke indicates that you may have an internal engine problem, such as a...

Can a faulty transmission shifter clip cause the transmission speed sensor to go bad?

The recall has doesn't involve the speed sensor. The recall is to replace a clip on the shift linkage to keep it from coming off and possibly allowing the vehicle to come out of gear and roll if the parking...

Tried pressing the clutch pedal and it just flew to the floor. It wouldn't come back until I brought it up myself.

Hi. The most likely cause of this problem is the clutch master cylinder has a leak or has just completely failed. The clutch master cylinder gives your clutch pedal the proper pressure to engage the clutch so the transmission can...

Oil mixing in with coolant, No overheating. Car performs fine.

If you are seeing oil in the water it could indicate a blown head gasket and should be looked at by a technician. I would not drive the car until you fix the problem because a blown head gasket could...

slip indicator light staying solid

The solid illumination of the slip indicator warning light signifies a malfunction in the Vehicle Dynamic Control (VDC) system. VDC is a version of "electronic stability control" and is a very useful safety feature. Occasionally, the slip indicator light comes...

Related articles

Symptoms of a Bad or Failing Connector Hose Heater Control Valve
If your car's AC stops being able to blow warm air and you find coolant leaks, you may need to replace the connector hose heater control valve.
What Do Hose Clamps Do?
Hoses Hoses are used throughout the engine, any time there’s a need to transport fluid from one point to another. Your radiator uses hoses, your heater uses hoses (it’s technically part of the coolant system). Your power steering system uses...
How Serious Is It When a Hose Is Leaking?
A leaking hose in your car could indicate different problems. Some leaking hoses are more serious than others, but all should be checked and repaired.