Hot start issues v8-5.6l mercedes-benz 560sec 1987

Q: Hot start issues

asked by on October 20, 2017

Car starts up fine when cold but when hot it’s cranks for awhile then starts rough new spark plugs ignition switch and starter u don’t what else to test what should I do next

My car has 131000 miles.
My car has an automatic transmission.

The air fuel ratio is off on your hot starts probably due to sensors or controls operating out of range or perhaps due to a stuck open EGR valve. Heat affects ignition coils and can also adversely affect sensors such as the crankshaft position sensor and so those are two additional ignition system related possibilities. What a mechanic would do is methodically test all those components which potentially affect the air/fuel ratio such as the idle air control valve, coolant temperature sensor, injector operation, crank sensor output and so forth. Of course, the ignition system has to be considered as well (even with the correct air fuel ratio, you still need ignition). If you want the required diagnostic steps performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a hard starting diagnostic and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Was this answer helpful?
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

Get a quote

What others are asking

loud hum coming from the front tires when driving on highway

Hello. The brake caliper hanging up can cause the noise you are hearing. If the caliper is causing the brake pads to drag, this will occur. It can also be caused by a bearing failing, which will cause the noise...

Car vibration, engine shuddering at idle

Hello. It sounds like the torque convertor is malfunctioning causing the car to vibrate and shudder. It is also possible that there is a problem with the drive shaft being out of balance. One more possibility is that the transmission...

2003 Mercedes-Benz C230 turn signal switch problems

Then turn signal switch internal parts hold it in one direction or the other normally until the steering shaft contacts the lever mechanism and returns it to center. You have a defective turn signal switch and need to replace it....

Related articles

A Buyer’s Guide to the 2012 Mercedes Benz S400 Hybrid
When When you expect your vehicle to show everyone that you have truly arrived, while being greener than some of the other luxury options, the 2012 Mercedes Benz S400 Hybrid needs to be on your list. Add in the fact...
The Best Used Cars to Buy If You're a Dog Trainer
If If you are a dog trainer, you expect a lot from your vehicle. You want a ride that is safe, roomy, and of course, dog friendly, since your training operation will often mean that you need to transport the...
How to Get Mercedes-Benz Dealership Certified
Mercedes Benz dealerships offer automotive technician jobs to those certified through Mercedes-Benz's Automotive Systems Technical & ELITE programs.