engine cranking but wont start intermitently

[TonyBelvedere]

hi i have a bclass 2006 model automatic transmission and over the last couple of weeks it wont start although it is cranking ,this happens intermitently and we have had 2 garages look at it and nobody can detect an issue as it has started for them and only once has it not turned over but the AA have mentioned fuel pipe problem and brake light switch problem,aa told us we shudnt be able to start without putting foot on the brake but garages have said this is not the case with this model, any ideas on what could be the problem as its looking very much looking like we have been sold a dud ty

 

[mattkh]

What did AA engineer say about the fuel pipe???

 

[mioba]

Everything can repaired in the right hands, find yourself a competent merc indy who can run a diagnostic on the car and pinpint the issue.

 

[M80]

The AA man is off track with the brake bit.
A fuel pipe issue would, imo, give other symptoms while running.

It could be a thousand things, a Star diagnostic might point to the issue.
As a simple try I would replace the engine management relay. I couldn't tell you which it is on yours.

 

[TonyBelvedere]

What did AA engineer say about the fuel pipe???

not much it had an advisory stating pipe corroding and will eventually need replacing but been advised this is not leaking so wouldnt affect the start

 

[TonyBelvedere]

Everything can repaired in the right hands, find yourself a competent merc indy who can run a diagnostic on the car and pinpint the issue.

im guessing the AA are competent and so far 2 garages have not found the problem

 

[TonyBelvedere]

The AA man is off track with the brake bit.
A fuel pipe issue would, imo, give other symptoms while running.

It could be a thousand things, a Star diagnostic might point to the issue.
As a simple try I would replace the engine management relay. I couldn't tell you which it is on yours.

would a bog standard garage know to check the relay as they have the car and are still baffled? and im assuming both garages have run diagnostics is the star one a specialist tool?

 

[Arv]

Pl read this thread. I just had the same problem & fixed it.

1994 C280 - Consistent Engine Cutoff after 20+ mins & Crank No Start after that till car cools overnight. Warm Engine "Crank NO Start"

Hello, 1994 C280 Consistent Engine Cutoff after 20+ mins at any speed & idle & Crank No Start after that till car cools overnight. Warm Engine "Crank NO Start" NO Engine Light on. When "Crank No Start" happens, 1. Tested Fuel Relays on the table by applying voltage & they work as expected...

forums.mercedesclub.org.uk

 

[TonyBelvedere]

Pl read this thread. I just had the same problem & fixed it.

1994 C280 - Consistent Engine Cutoff after 20+ mins & Crank No Start after that till car cools overnight. Warm Engine "Crank NO Start"

Hello, 1994 C280 Consistent Engine Cutoff after 20+ mins at any speed & idle & Crank No Start after that till car cools overnight. Warm Engine "Crank NO Start" NO Engine Light on. When "Crank No Start" happens, 1. Tested Fuel Relays on the table by applying voltage & they work as expected...

forums.mercedesclub.org.uk

have passed this on to garage hopefully will have an update later ty

 

[mioba]

im guessing the AA are competent and so far 2 garages have not found the problem

You answered the competence with respect to the AA above, that they pointed to something unrelated.

AA and RAC have gone downhill depending on your package, their aim is to get you off the road and home and wash thier hands.

The reason I sugest an MB Indy is they have the better diagnostic readers and are knowledgeable about the brand and the pitfalls on many models.

Good luck and hope you get sorted soon.

 

[LostKiwi]

im guessing the AA are competent and so far 2 garages have not found the problem

No one can be competent on all cars to the level that a Mercedes specialist can be. If all you do day in and day out is Mercedes cars you will acquire far more knowledge about them than an AA man who sees them relatively infrequently and only for a few minutes each time.
Ditto a general garage.

would a bog standard garage know to check the relay as they have the car and are still baffled? and im assuming both garages have run diagnostics is the star one a specialist tool?

Star aka Xentry on later cars is the Mercedes dealer level diagnostic equipment designed solely to help fix Mercedes cars. A general reader may give some information but not the additional information available in Star/Xentry.