Skip the auto shop - Our mechanics make house calls

Q: Will not always start

asked by on

Will not always start. Just had a new starter put in. Battery good Does it in cold condition or after it has been running awhile. The sits sits in a garage all week. Only used on weekends

My car has 169000 miles.
My car has an automatic transmission.

With an old diesel like yours, everything has to be right to start it up cold. First of all, all the glow plugs need to be working. I usually test the glow plugs by measuring the current draw with an inductive ammeter. A functioning glow plug will draw about 12-15 amps. If all your glow plugs are working, but you are still not starting, you need to check the compression. Compression on a diesel needs to be around 350 PSI or the engine will be very hard to start. If the compression is good and the glow plugs are good, you need to check the fuel delivery. That will be easy to see since you have the injectors out for the compression test, but it gets messy. Fuel delivery is not a problem as often as is fuel contamination. You may want to take a sample of fuel from the car and check it for water. All of this is pretty messy business, as is any work involving old diesels. If you decide to get some help with this, you can contact Your Mechanic to have a technician come to your home or office to ’check out your stubborn Mercedes and let you know what needs to be done.

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: Do you work on Old Mercedes Benz?

It will depend on what kind of work you will be needing. Most maintenance like brakes, filters, belts or most window or body electrical repairs can be done by most mechanics. If you need diesel engine repairs then it will...

Q: Cost to replace turbo? 1987 Mercedes 300SDL

Hi there - unfortunately, this is not a service YourMechanic can offer at this time. Thanks for thinking of us though!

Q: ATF oil leaks lights

The vehicle will need to have a complete inspection done to determine the mechanical and electrical condition. A complete fault survey should be done to see if there are any electro-mechanical issues both with the engine and/or transmission. Fluid levels...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...