Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. How Long Does an Automatic Timing Advance Unit Last?

How Long Does an Automatic Timing Advance Unit Last?

timing advance unit

The automatic timing advance unit is a component in vehicles with diesel engines. Of course gas and diesel engines both work on the internal combustion principle, but they are quite different, and require different means of controlling the flow of fuel during operation.

Gas combusts much more quickly than diesel. With diesel fuel, combustion can take place long after the timing reaches TDC (top dead center). When this happens, lag occurs and adversely affects performance. To prevent lag, the diesel fuel has to be injected before TDC. This is the function of that automatic timing advance unit – basically, it makes sure that no matter what the engine speed, the fuel is delivered in time for combustion to take place before TDC. The unit is located on the fuel pump, and operated by means of the primary drive gear on the engine.

Whenever you are driving your diesel vehicle, the automatic timing advance unit has to do its job. If it doesn’t, the engine will not get a consistent fuel supply. There is no specific point at which you should replace the automatic timing advance unit – essentially, it lasts as long as it lasts. It could last the life of your vehicle, or it could start to go bad, or even fail entirely with little warning. Signs that your automatic timing advance unit needs to be replaced include:

  • Sluggish engine
  • More black smoke from exhaust than is usual with diesel operation
  • White exhaust smoke
  • Engine knock

Performance issues can make for dangerous driving, so if you think that your automatic timing advance unit is failing or has failed, consult a qualified mechanic to further assist you in replacing the failing part.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance...

Related questions

Q: Q: P0171

The code P0171 is due to the left bank of the engine running lean and has reached the rich limit for the ECM. Try to have the injectors cleaned and run only high quality fuel that has cleaning additives. This...

Q: White smoke while idling

White smoke while idling is normally reason to believe that your BMW may need the valve stems replaced, however this can also be the sign of bad Crankcase Ventilation (CCV) gaskets. On top of those possibilities, there are many things...

Q: Cambelt or Chain driven?

Hi there. Look at the engine and see if there is a plastic cover on the front or an aluminum cover on the front. If there is a plastic cover then the engine is driven by a timing belt. If...