Starting issues on a E270 CDI

[KLP 92]

My cousin has purchased a 2003 E270 CDI with 98k on the clock. The car suffers from a strange problem with regards to starting.

When the car is cold the car starts in the normal amount of time, approx 1-2 secs of engine crank. The problem arises after the car has been driven for a while, then parked up for 15-20 minutes. When you go to restart the car it keeps turning but doesn't fire up. It has the one flick start so the engine turns for approx 5-10 secs and then stops. If you try again it starts, with no puff of smoke from the exhaust. It will sometimes start on the first attempt but takes 5 seconds+

There are no fault codes on diagnostics.

Now with my limited knowledge of diesel engines i can presume the glow plugs are fine as it starts first time in the morning without any misfire/clatter. The car has been to a few garages to have the problem seen to but according to my cousin its a case of guessing games which we all know can turn into a serious expense.

Can anyone shed any light on this problem?

Thanks

 

[Ian B Walker]

Just a thought but is the immobaliser working correctly. What about the battery in the key?

 

[KLP 92]

Just a thought but is the immobaliser working correctly. What about the battery in the key?

Does the same with both keys. The symptoms only appear after the car has been driven a while and then parked for 15 minutes.

 

[Dieselman]

Start with the basics a compression test, then look for air in the fuel pipes and have the rail pressure tested.

It could be something like the rail pressure sensor or crank position sensor faulty.

If the CKP doesn't say the engine is turning the injectors wont inject fuel.

Thinking about it I'd probably fit a new CKP anyway as the symptoms sound right.

 

[Dieselman]

Just a thought but is the immobaliser working correctly. What about the battery in the key?

Doesn't need a battery, the key is powered from the ignition lock. Also if it wasn't working it wouldn't allow the key to attemp to start the car.

 

[fredfloggle]

Mine will turn over without firing in certain circumstances

 

[KLP 92]

Start with the basics a compression test, then look for air in the fuel pipes and have the rail pressure tested.

It could be something like the rail pressure sensor or crank position sensor faulty.

If the CKP doesn't say the engine is turning the injectors wont inject fuel.

Thinking about it I'd probably fit a new CKP anyway as the symptoms sound right.

My cousin will try the CKP sensor first as its the cheapest at £60. The rail pressure sensor is at £120

I reckon its the latter as i do remember clearing one fault when he had purchased the car under the common rail injection section, a small f stating excessive boost. Its not on there now but it may be that sensor playing up.

Well hopefully this should cure it, booked in on Tuesday so we shall see.

 

[BlackC55]

Have you thought about an injector fault?

 

[ckember]

have you checked the pressure in the rails? I had a leak in the pressure hoses on my c270 and the car had to build the pressure up before it would start, involved turning the engine over until it fired. Sometimes it was OK others not.

 

[Dieselman]

, a small f stating excessive boost. Its not on there now but it may be that sensor playing up.

Excessive boost relates to turbo boost.

 

[KLP 92]

Have you thought about an injector fault?

The car performs well, doesn't smoke and doesn't have any kind of injector knock noise either so i presumed they were ok.

 

[Carlo]

We've had a similar problem with a CLK-270 cdi.
In the stardiagnosis you can see if the synchronisation between the crankshaftsensor and the camshaftsensor is ok.If not , replace the 2 sensors.
Our'e problem was solved.

Greetings Carlo

 

[KLP 92]

Update

I went to GF yesterday with car to have the problem diagnosed. There were no fault codes at all on diagnostics, went into each system individually but nothing.

I spoke to George about changing the crankshaft sensor, but he wasn't convinced that it was. He said that the fact the car only does it once its warm and after leaving it 10-15 minutes wasn't typical symptoms of one failing. Normally it was non-starting (not guarenteed start second time round) and random intervals of the engine dying.

He basically said i could have it changed but its basically spending money for the sake of it. He reckoned it may be the fuel pump on the way out.

My cousin said he may just wait for the symptoms to get worse first before he starts the guessing game!

 

[Dieselman]

It could be the pump sucking in air but I would have expected it to be worse after an overnight stop as it will have had longer for the fuel to retreat.

It really needs a check of the rail pressure and injector dwell when the problem manifests itself.

 

[KLP 92]

It could be the pump sucking in air but I would have expected it to be worse after an overnight stop as it will have had longer for the fuel to retreat.

It really needs a check of the rail pressure and injector dwell when the problem manifests itself.

I think he meant that the fuel pump was struggling once it was hot. Another symptom which my cousin only told me yesterday was that the symptoms got worse if the car had less than 1/2 tank of diesel.

 

[Harley Man]

My W203 C220 had a problem like that, it was the o rings on the clear plastic pipes between the filter and the low pressure pump, I in fact changed all the pipes and the fault went away, it was not expensive, or difficult to do. May be worth a try

 

[KLP 92]

Well the problem has got alot worst. I beleive its temperature related (outside) as the car takes approx 30 seconds crank for it to start when warm and left for 10-15 minutes. The problem gets worse if you have under 1/2 tank of diesel.

Are these symptoms of a failing fuel pump? I have had the plessure of driving the car this weekend and its embarrasing when it doesn't start!! I'm in fear of the battery dying......

 

[KLP 92]

Start with the basics a compression test, then look for air in the fuel pipes and have the rail pressure tested.

It could be something like the rail pressure sensor or crank position sensor faulty.

If the CKP doesn't say the engine is turning the injectors wont inject fuel.

Thinking about it I'd probably fit a new CKP anyway as the symptoms sound right.

Still no joy on the starting issues. The car has had a new crankshaft position sensor and a new rail pressure sensor.

There are no air leaks into the diesel system and there are no visible leaks on the injectors. The injectors will be tested next week.

Any other ideas

 

[KLP 92]

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A slight update. Everytime the engine is hot and i floor the car the EPC warning light comes on and the car switches off. After restart the light goes away but will come back on full acceleration. The fault code comes up in diagnostics saying Excessive boost pressure (under the common rail injection section).

Any ideas whats the cause? Its definately temperature related and i feel that both these symptoms are related. If the car doesn't struggle to start then the EPC light won't come on. Both symptoms are worsened by engine temp.

 

[Dieselman]

The excessive boost bit must be turbo boost, unless it's rail pressure.
there must be a fault code as well.

If it's rail pressure maybe the pressure regulator has gone faulty so is leaking the pressure away when warm hence the no start, then it also sticks so produces too much pressure when under full chat.