Engine Surging – Engine Looses (RPM), Then, Suddenly Regains It

Engine Surging - Engine Looses (RPM), Then, Suddenly Regains It
Engine Surging - Engine Looses (RPM), Then, Suddenly Regains It

Engine surging, will cause the engine to momentarily lose (rpms), but then, suddenly regains normal engine speed.

Engine surging, can affect drivability but, can also cause error codes to appear in your, OBD-II system.

Furthermore, these codes can cause you to fail your local vehicle inspection; or at the very least can result in that very annoying, Check Engine Light coming on.

So, to avoid engine surging, performing maintenance tasks on time is very important.

Many common tasks include:

  • Replacing worn spark plugs
  • Inspecting plug wires
  • Replacing an old partially clogged fuel filter
  • Any one of these can make a huge difference, in how well your engine is running.

However, engine surging will usually re-appear; either under specific operating conditions, or randomly. Therefore, a engine misfire code may occur; when your engine is idling, causing a rough or uneven idle. So, having an engine that performs well, can save you a bundle of money.

P0300 Random Misfire Code Displayed On Code Reader
P0300 Random Misfire Code Displayed On Code Reader

Consequently, even one hour of diagnostic time at your local repair shop; can put a large hole in your wallet. So, the list of possible causes below; should give you a better idea of what’s causing, your engine surging or misfire.

Possible Engine Codes For, Engine Surging Or Engine Misfire

So, if you see a symptom that looks familiar, read on to find out what a possible fix can be:

  • P0300       Random/Multiple Cylinder Misfire Detected
  • P0301       Cylinder 1 Misfire Detected
  • P0302       Cylinder 2 Misfire Detected
  • P0303       Cylinder 3 Misfire Detected
  • P0304       Cylinder 4 Misfire Detected
  • P0305       Cylinder 5 Misfire Detected
  • P0306       Cylinder 6 Misfire Detected
  • P0307       Cylinder 7 Misfire Detected
  • P0308       Cylinder 8 Misfire Detected
  • P0309       Cylinder 9 Misfire Detected
  • P0310       Cylinder 10 Misfire Detected
  • P0311       Cylinder 11 Misfire Detected
  • P0312       Cylinder 12 Misfire Detected
Engine Surging
Engine Surging

Symptoms And Causes:


While you are moving the engine is surging or misfiring. But, the engine seems to start fine and will normally accelerate fine. While driving at a steady speed, the engine seems to “speed up” slightly or it seems to miss and buck.

So, any of these could be possible cause of engine surging:

If you have a carburetor, the choke may not be set properly.

  • Check the choke plate and make sure it is, opening completely.

The engine may be running, too hot.

The fuel pressure regulator may be operating at, low pressure.

Your ignition timing may be set incorrectly.

  • Check and adjust, ignition timing.

Ignition system problem causing a, weak spark.

  • So, if your engine has a distributor; check and replace distributor cap, rotor, ignition wires and spark plugs. And, you should also have the coil packs checked. Furthermore, there may be a fault in the computerized engine control system. In addition, check engine control systems with a scan tool. Finally, test circuits and repair or replace components as required.

The fuel filter may be partially, clogged. A common cause of engine surging.

  • Consequently, this is a easy and cheap fix. Replace, the fuel filter.

Torque converter (automatic transmission only) may not be locking at the right time, or it may be slipping.

  • Check the lock up circuit or replace torque converter.

There may be a, vacuum leak, a common cause of engine surging.

Leaking Vacuum Hose
Leaking Vacuum Hose
  • Check for vacuum leaks. Above all, this must include the intake manifold. Also, check and replace vacuum lines as required.

Possible internal engine problems.

The (EGR) valve could be, stuck open.

You may have loose or worn drive axles.

  • Check and replace CV/universal joints as required.

The fuel injectors may be, dirty.


So, some symptoms may vary from vehicle to vehicle, due to varying device designs. But, generally these symptoms apply. Consequently, engine Surging, Hesitation or Misfiring, could be just the start of your problems. Finally, having an engine that performs well will save you money.

Thank You !