Was stopped at the traffic lights last night when all of a sudden the car shook and smoke began to rise out from under the bonnet. I switched the engine off, opened the bonnet only to find an injector on my 6cyl Mercedes S320cdi had shot 6" out the top of the engine.

 

Firstly, what can cause this to happen?

 

And what work is involved in having it repaired as it was recovered back to Mercedes main dealer at 4am this morning & am begining to get fed of spending money there.

 

Thanks guys, Dan

Blocked injector and some serious fuel pressure built up will do that :).

I think on the cdi's they have something in excess of 50 psi fuel pressure, best check with Paul C as he's a merc specalist mechanic.

Blocked injector and some serious fuel pressure built up will do that :).

I think on the cdi's they have something in excess of 50 psi fuel pressure, best check with Paul C as he's a merc specalist mechanic.

Times that pressure by about 32 they reach a maximum of a massive 1600 bar. Hard to believe but its true, because of the fine jet of fuel the Piezo's have been known to cut through the heads.

 

Quote from Merc

 

Moreover, piezo injectors are considerably lighter and operate at twice the speed of conventional solenoid valves. With a response time of only 0.1 milliseconds, the fuel injection process can be even more precisely suited to the current load and engine speed situation, with favourable effects on emissions, fuel consumption and combustion noise.

Five fuel injections per power stroke at a peak pressure of up to 1600 bar are possible thanks to this piezo-ceramic technology.

 

HTH

Mike