[m80theWolf]

Dropped my car off for warrantied maintenance yesterday. I asked the advisor if bmw had officially come up with recommended preventative maintenance to prevent cbu. SA says they recommend the "injector service" every 15k miles. Cost = $250, not covered by the extra maintenance warranty. Anyone done this service at the dealership, or know if it's a waste of $$ ?

[kbsilver]

Originally Posted by m80theWolf

Dropped my car off for warrantied maintenance yesterday. I asked the advisor if bmw had officially come up with recommended preventative maintenance to prevent cbu. SA says they recommend the "injector service" every 15k miles. Cost = $250, not covered by the extra maintenance warranty. Anyone done this service at the dealership, or know if it's a waste of $$ ?

CBU occurs in the intake part of the engine. The injector is past this point directly in the cylinder. Injector cleaning will have absolutely ZERO impact on preventing CBU. As the manual is very clear on not using additives in the fuel, I believe the injector service is exactly that, putting an additive in the system. This is violating the manufacturer recommendation.

I would be willing to bet there is NO Diesel injector service, and the SA was thinking of a gasoline engine. If using poor quality (weak additives) gasoline there may be some benefit to injector service for gasoline engines.

Even if it did work (which it won't) - Let see $250 every 15000 miles. At 60K miles (average CBU point) you will have spent $1000. This is about what CBU cleaning will run if I'm not mistaken.

[taibanl]

Try BG 244 as an alternative

[Pierre Louis]

Originally Posted by taibanl

Try BG 244 as an alternative

It would be interesting to hear from anyone that has tried this.

PL

[m80theWolf]

Originally Posted by kbsilver

CBU occurs in the intake part of the engine. The injector is past this point directly in the cylinder. Injector cleaning will have absolutely ZERO impact on preventing CBU. As the manual is very clear on not using additives in the fuel, I believe the injector service is exactly that, putting an additive in the system. This is violating the manufacturer recommendation.

I would be willing to bet there is NO Diesel injector service, and the SA was thinking of a gasoline engine. If using poor quality (weak additives) gasoline there may be some benefit to injector service for gasoline engines.

Even if it did work (which it won't) - Let see $250 every 15000 miles. At 60K miles (average CBU point) you will have spent $1000. This is about what CBU cleaning will run if I'm not mistaken.

That's what I was thinking... Plus since I'm currently at 32k miles, covered by maintenance warranty and cpo till 100k miles, I might as well just wait until they find a fouled injector or worse... They've already replaced an injector or 2 in the year I've owned it. It was at least nice to hear my SA acknowledge that he'd heard of cbu being an issue on 335d's. has anyone asked their SA about 'recommended preventative maintenance' for cbu?

[Pierre Louis]

The only thing my SA told me was to drive it briskly. The mechanic's mother drove a 335d and she wasn't bashful on the road, having no problems at that time.

Mine gets a little better with an occasional hard downshift that would normally cause a black plume of smoke going out the back in my previously owned non-DPF DI diesels.

PL

[kbsilver]

Originally Posted by m80theWolf

That's what I was thinking... Plus since I'm currently at 32k miles, covered by maintenance warranty and cpo till 100k miles, I might as well just wait until they find a fouled injector or worse... They've already replaced an injector or 2 in the year I've owned it. It was at least nice to hear my SA acknowledge that he'd heard of cbu being an issue on 335d's. has anyone asked their SA about 'recommended preventative maintenance' for cbu?

I just went thru the CBU cleaning at 53K miles. The SES was for an injector but no injectors were replaced. In the past I think they were sometimes changing injectors that had nothing wrong with them, it was the DDE program than needed to be changed. After the cleaning the car runs great and MPG has returned.