Skip the auto shop - Our mechanics make house calls

Q: my engine cranks but does not start

asked by on

hi. ive got a mercedes E300 TD from 1999 and the issue is that the engine just turns and turns but does not start, i think it might be the fuel pump but im not sure, its been two months since the car drove last time.

My car has 343750 miles.
My car has an automatic transmission.

A: While it is natural to suspect a fuel pump ...

While it is natural to suspect a fuel pump right away when a car does not start, there is a good chance other issues could also be going on here. Diesel engines, like the one in your Mercedes, need two things to start up. The first is proper compression, the second is the correct amount of fuel being injected into the combustion chamber at the right time. If your engine has good compression, (meaning the vehicle is not losing compression in the cylinder head due to bad piston rings, bent valves, or a blown head gasket), then we can begin to suspect that a lack of fuel, a weak battery, or failing glow plugs are behind why your Mercedes Diesel engine is not starting.

However, to really know if your vehicle has good compression, it is highly recommend to enlist the assistance of a certified technician to stop by and go over your Mercedes with you in person. They will have the experience and tools needed to accurately check both the charging system and the fuel pressure and determine why your Mercedes is not starting. From there, they can let you know exactly what repairs are needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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

Get a quote

What others are asking

Q: My car wont start

Hello. If your diesel engine stopped running in extremely cold weather, then I would check the glow plugs. If the glow plugs are bad, the motor will have trouble starting, especially in cold weather. In regards to your brake system...

Q: Engine not turning over

There are many reasons why a car won't start. Everything from a low battery, fuel pressure issues, to ignition system problems, crank and cam sensors, engine timing, etc. Because of all the variables and the limited information, it is very...

Q: The code p0102 shows up after cleaning the mass air flow sensor.

Hi and thanks for contacting Your Mechanic. The wiring harness to the mass air flow sensor (MAF) could have a break in the wires. Disconnect your battery and remove the harness to the MAF and your computer. Use a digital...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...