E220d S213 engineclight on intermittent

[Zululander]

Hi,
Good to be back on the forum after a couple of years absent (not because of car brand change). I have this engine light coming on intermittent, when the car is cold all good and can be driven normally, temp registered 90c but when reaching r this temp and I switch off engine and restart, it will take about 1-2 minutes and the light is back on. Coll down and restart no light and the cycle starts again. Any advise please?

 

[AMGeed]

The normal culprit when a hot engine only restarts after cooling down is the crank position sensor (CPS).
I must admit I've had two Mercedes that have had a CPS issue and neither time did the check engine light come on.

Sounds like the car needs a diagnostic check with a Mercedes specialist with Star to diagnose the issue.

 

[Zululander]

Hi,
The engine starts and dives normally, the issue is when hot management light pops up as soon as parked for a while and cools back down, the light is off until the temperature raises again to around 80 - 90c. I had a diagnostic done ( pics attached) although a 2018 model the car has only clocked 28000 miles

 

[AMGeed]

^ Ah, right.
That has me stumped then.

 

[ajlsl600]

The normal culprit when a hot engine only restarts after cooling down is the crank position sensor (CPS).
I must admit I've had two Mercedes that have had a CPS issue and neither time did the check engine light come on.

Sounds like the car needs a diagnostic check with a Mercedes specialist with Star to diagnose the issue.

I hav some experience of faulty cps stopping restarts intermittently but not stopping a running motor. On some motors there are 2 cps.

 

[Zululander]

I hav some experience of faulty cps stopping restarts intermittently but not stopping a running motor. On some motors there are 2 cps.

Thanks guys for your input.
The issue has been tracked down to the addblue tank and pump. Expensive repair on the way

 

[w213probs]

Thanks guys for your input.
The issue has been tracked down to the addblue tank and pump. Expensive repair on the way

so what did you do then? the whole tank replace?

 

[mioba]

not uncommon and a well known failing of MB. There was a mention of it being cussed by crystals forming in the adblue, a solution was some kind of crystal diluent. No idea if that worked.

I do wonder if other car brands have the same problem.

 

[Srdl]

It doesn’t help that OP’s car has only done 28k miles since 2018 so not surprising that AdBlue is getting clogged up.

 

[w213probs]

Adblue system needs a lot research i think. It works, its just about taking care of it and knowing what can go wrong eg crystallisation, ecu fault, poor adblue quality, additive to prevent crystals and etc.

Im loving my journey of adblue scr system learning. Have a whole thread on it

 

[Srdl]

Adblue system needs a lot research i think. It works, it’s just about taking care of it and knowing what can go wrong eg crystallisation, ecu fault, poor adblue quality, additive to prevent crystals and etc.

But no one tells you that when you buy a Euro 6 diesel!

 

[Larkone]

But no one tells you that when you buy a Euro 6 diesel!

Best advice is don't buy a Euro 6 diesel (avoiding Euro 5 is also sensible)

 

[Srdl]

Best advice is don't buy a Euro 6 diesel (avoiding Euro 5 is also sensible)

Exactly - that’s why I bought petrol

 

[malcolm E53 AMG]

Best advice is don't buy a Euro 6 diesel (avoiding Euro 5 is also sensible)

Totally agree except that managed properly the EU5 diesel doesn’t cause too much trouble as long as you don’t use it as a shopping trolley - many were mis-sold unfortunately as were EU6 diesels. My son’s W213 covered 12-15k miles Pa over 75k miles without a hint of an ADBLUE problem that’s exactly the type of usage these vehicles require.

 

[w213probs]

get your point and things. but i am really enjoying the journey of learning more about the SCR system. really nice.

Moved on from fixing the adblue pump myself to now looking at diagnostic systems. got the icarsoft v3. didn't like it. now looking for better tools which can help me do the actuation tests and etc.

 

[Zululander]

so what did you do then? the whole tank replace?

Yes thank incl pump replaced, all back to normal