S320CDi Diesel Leak

[RobWheatley]

Hi All
Had a look around but cannot find any info on my problem.

2002 S320CDi, when starting from cold the High Pressure pump at the front of the engine leaks (at a fair rate onto the belts etc), when it warms up the leak seems to stop, its leaking from the very top plate (at the mating surface) is this something that can be repaired or is it a new pump?
If it can be repaired are there seals/gaskets that are needed or can it be done any other way?
Is it easy to remove to replace/repair it?

Thanks
Rob

 

[Silver_Star]

Are you sure it is the H/P pump leaking rather than the low pressure fuel lines going into it?

If it is the H/P pump you can buy the repair kits for the H/P pump either from a Specialist Diesel form or Bosch service centre I believe. I also believe you can get the repair kit from MB.

The other option is to either buy a replacement pump or send yours off to be refurbed.

I am not sure on the prices but this has been covered a few times so a search should bring something up for you.

 

[RobWheatley]

Are you sure it is the H/P pump leaking rather than the low pressure fuel lines going into it?

If it is the H/P pump you can buy the repair kits for the H/P pump either from a Specialist Diesel form or Bosch service centre I believe. I also believe you can get the repair kit from MB.

The other option is to either buy a replacement pump or send yours off to be refurbed.

I am not sure on the prices but this has been covered a few times so a search should bring something up for you.

Hi, thanks for the reply.
Yes its definatly the pump, I can see the diesel leaking between the top plate and the body of the pump, its also above the pipes in/out of the pump.
Rob

 

[flyinyam]

Rob,

Don't know if it will help but take a quick look at this, put in; 'W203 Diesel' Then look at

'W203 - C220 CDI - Fuel Pump & Pipe Leaks Help'

If nothing else, it will give you better idea of pump assembly.

Cheers

Russell

 

[Parrot of Doom]

An MB dealer will tell you that you need a new pump at a cost of 53 thousand pounds, but I've always taken the view that somebody in a factory put these together. I'd be very surprised if you couldn't order from Bosch a new set of seals, washers, bolts, etc. It may be a specialist job but there are plenty of diesel injection specialists around the country who could service your pump.

 

[RobWheatley]

I have spoken to a bosch service center and they are telling me that a seal kit is not available for the pump but "they" can repair it for me at a cost of £200 plus parts and will take 4 days!!!!!!

Been in contact with a local diesel place and he has the kits for £30 so I'm going to get one but would really like an exploded diagram of the pump as he says there are lots of springs/wahsers and shims in there. Don't want to take the valve plate off and not know where everything goes back.

I'm going to take the pump off to do the repairs so nothing gets dropped or lost.

Can anyone help with the diagrams please????
Rob

 

[Alex Crow]

changing the seals is not too bad a job, cleanliness is the key here. disassembly is easy enough, and you only need to undo the caps to change the seals in the kit - which is also available from MB btw. there are no suicidal springs to negotiate, just take time and notes when taking it apart and clean up all mating faces before reassembly - good luck!

 

[PARESH]

This would make a good "How To". Please take some photographs of the procedure when you replace the seals on the HP pump. This would be helpful to other forum members.

 

[Xtractorfan]

Some info here on pumps and kits have a read...
http://www.benzworld.org/forums/w901-905-sprinter/1306394-fuel-leaking-high-pressure-pump.html

 

[haith]

Leak around High Pressure Pump area - also on a S320 CDI (2003)

I'm also experiencing some issues at the moment with my 2003 S320 CDI. There are diesel fumes coming from around the front of the engine (common rail pump area) and it's actually possible to see diesel vapour / smoke when the engine is being revved quite hard (pump running at higher pressure). At lower revs the smoke / vapour tends to be much reduced.

I think there must be a small leak on the pump that is spraying small volumes of diesel under higher revs / pressures onto hot metal and hence I'm going to remove the pump and send away for reconditioning (new seals etc). Can anyone advise how best to remove the pump please from a W220 with this engine (straight six 3.2 cdi)

- which bolts do I remove? The countersunk bolts or the smaller non counter-sunk? I think there are 3 of each from memory?

- do I need to remove the radiator fan assembly in order to withdraw the pump from the cylinder head?

Any other advice concerning my problem and removing the pump would be much appreciated.

Many thanks.

 

[Oarsman]

Before you start removing the pump, check the two braided hoses that run to it. They can perish and start to leak under pressure.

I had a similar problem last year, with slight amounts of diesel spraying across the engine. After the pipes were renewed the problem disappeared.

Much cheaper than replacing the pump or even having it rebuilt.

 

[haith]

Many thanks for your point concerning the hoses. I should have mentioned that I've already replaced the two fuel hoses that attach to the pump body - hence I'm fairly sure it must be the pump itself.

If those who have removed high pressure pumps on this engine / model can provide any advice on removal, it would be much appreciated.

 

[curious]

Hi, thanks for the reply.
Yes its definatly the pump, I can see the diesel leaking between the top plate and the body of the pump, its also above the pipes in/out of the pump.
Rob

Just repaired mine today. Exactly the problem you describe.
I obtained a service kit from Bosch and job done in an hour (including taking the pump off and back on the car).

If it's weeping between the back plate and pump body then it's only a question of replacing the 'O' rings between the mating surfaces. You don't need any special tools just torx sockets to get the pump off and torx bits to take the back plate off. The advice I was given (Bosch service centre) was to only touch the 'O' rings between the two parts I've mentioned, don't go pulling the whole pump apart to use up all the other 'O' rings in the service kit!

 

[sam79]

Hi All
Had a look around but cannot find any info on my problem.

2002 S320CDi, when starting from cold the High Pressure pump at the front of the engine leaks (at a fair rate onto the belts etc), when it warms up the leak seems to stop, its leaking from the very top plate (at the mating surface) is this something that can be repaired or is it a new pump?
If it can be repaired are there seals/gaskets that are needed or can it be done any other way?
Is it easy to remove to replace/repair it?

Thanks
Rob

Hi All

2002 S320CDi, when starting from cold the High Pressure pump at the front of the engine leaks (at a fair rate onto the belts etc), when it warms up the leak seems to stop, its leaking from the very top plate (at the mating surface)
and when i accelerate the engine cuts off showing ECP fault !!!! is that happinig because of the diesel leak
any one can help !! i been told to replace the MAF sensor and i done it but still have the same problem the engine keep cutting of
thanks alot

 

[Taffy7hfa]

You have a cold weather diesel leak. Likely to be either be "O" rings or the pump itself leaking, ECU will shut down the engine if pressure in the rail is too low.

 

[om613]

Try the o-rings and the fuel filter (if not new), both easy cheap DIY jobs.

I sell the o-rings, posted cheaply, if you need them.

 

[mersum1es]

o-ring leak may be mixed up with lower piston plate leak but if it clearly comes between pump body and top plate, it is pump seal leak. Often is also tighten when warming (mine OM613 pump did the same) until it escalates. O-rings must be chaged anyway when removing hoses, hardened seals loose their sealing capability if there is any left.

MAF does not cause engine to cut off, low fuel pressure does. There are good pictorial repair threads on this and 'other' forum.

 

[sam79]

You have a cold weather diesel leak. Likely to be either be "O" rings or the pump itself leaking, ECU will shut down the engine if pressure in the rail is too low.

Thank you very much

 

[sam79]

Hi All

2002 S320CDi, when starting from cold the High Pressure pump at the front of the engine leaks (at a fair rate onto the belts etc), when it warms up the leak seems to stop, its leaking from the very top plate (at the mating surface)
and when i accelerate the engine cuts off showing ECP fault !!!! is that happinig because of the diesel leak
any one can help !! i been told to replace the MAF sensor and i done it but still have the same problem the engine keep cutting of
thanks alot

 

[sam79]

Hello there
I need help. My merc s320 w220 year 2002 , there is no power to the climate control unit , its of completely there is no lights at all and the cooling fan always on when i start the Engine
It looks like a fuse blowed
Anyone knows which fuse number for the climate control unit
Thanks