c270 cdi "03" diesel noise issues.Please help!!

[c76jon]

All

I need some guidance please.

C270cdi saloon auto.

I will try and give as much info as possible

116k miles with good history.

Car starts fine cold or hot.

In last 1k miles all injectors have been replaced as they were shot and I just changed the lot.

This issue was present prior to injector change.I had two leaking and others were worn when tested so I just bit the bullet!!

New MB seals and bolts.

New fuel filter.

New glow plugs.

I have no errors regards glow plugs ie coil remaining lit on cluster etc.

As stated car starts immediately

On initial start in morning the engine is noisy and by this I mean diesel clatter.

Once warm the engine is smooth as silk and very quiet especially for a diesel.This can take 10 miles plus.

MPG is fine. It will do high 50s on a run.

If I leave car for 3 or 4 hours and restart the engine is quiet and smooth.

Terrible noise when started again next morning.

Now I have noticed that the car takes an age to get to temp.

By this I mean will sit at 60 degrees or less for an eternity .To make this rise anymore you need to let it idle stationary and then it is fine.

If your journey was on a motorway immediately from starting it wouldn't move over 60 degrees if that makes sense.

Could the high pressure pump be at fault??

Is the thermostat shot and in turn wrong fueling info is being sent and causing diesel clatter??

This is driving me mad!!!!!!!!

The car idles perfectly.It does not miss at all.

Pulls strong

Can anybody give any advice through experience??

I want it sorted just need a direction to investigate.

Many thanks for any help you can give.

Any info anybody needs just state what and I will post it.

I have tried to mention anything relevant.

John

 

[C180_Driver]

I have the same problem with regards to the temperature not rising (C270 CDI 2005) and won't rise if I jumped straight onto the motorway. I've heard just by changing the thermostat, that can be fixed but its not always the case and can be due to further issues. But changing the thermostat should be your first port of call for that.
With regards to the noise i know when cold, mine is clattery and not the most refined sounding engines but this does pass as you say after a few miles and once all the oils get warm etc.

 

[panason1c]

First thing is to renew the thermostat, it is easy to change, normal running temp is circa 85/90 degrees. The 270 cdi engines are a bit noisy from cold but quieten down when hot

 

[c76jon]

Many thanks

I will try this and change thermostat.

Does the housing hold a temp sensor or is there a temp sensor for ecu that would sit in area that due to faulty thermostat be receiving and then sending duff info.??

By this I mean if my car is sitting at 60 degrees and a sensor is seeing 60 degrees would this inhibit warmed up info being sent ??

Many thanks for all input.

John

 

[ivandraganov]

Mine does the same,it's noisy in the morning and take ages for the heating-15 to 20 min.So probably it's normal.I've heard that even W204 are noisy when cold.Just put up with it.

 

[Buffers]

Just change the thermostat, the car should run at 85 degrees +. its a complete unit. just drops in. These engines are a bit agricultural and noisy when cold but are really strong units and capable of hugh milage.

 

[grumpyoldgit]

Hi John,
I've just checked in the 'well known' workshop manual to see if there are any pointers. Couple of extracts follow.........
Thermostat
If the engine seems to be taking a long time to warm up (based on heater output or temperature gauge operation), the thermostat is probably stuck open.
Equally, a lengthywarm-up period might suggest that the thermostat is missing - it may have been removed or inadvertently omitted by a previous owner or mechanic. Don't drive the vehicle without a thermostat - the engine management system's ECU will then stay in warm-up mode for longer than necessary, causing emissions and fuel economy to suffer.

Diesel Models
The coolant temperature sensor is located in the thermostat housing, on the left-hand side of the engine, at the front.

I seem to remember a link in one of the posts on here regarding thermostat replacement and I'm not sure if it said a new one came complete with the housing.

Thermostat opening commences @ 80ºC +/- 2ºC - Fully open 100ºC

 

[jay1983]

My 270 took an age to warm up when I got it. Changed the thermostat and now it's all good.
Got the thermostat from ECP. Comes as a whole unit - housing, thermostat and gasket. I just reused the sensor from old unit.
Another thing worth checking would be the tensioner and idler for the drive belt. These can produce a lot of noise.

 

[ccp]

Temperature symptoms are exactly those I saw with my C270. There's all the info you need to change it in this post: http://www.mbclub.co.uk/forums/engine/33395-ml270cdi-thermostat.html

 

[Dblock]

Deffo your thermostat. Had the same problem cleared up when thromostst was changed.