Bosch CRD Injectors - Cleaning, Replacement

Citroënbender · 17-12-2022, 11:16 PM

2007 M-B OM646 motor if it’s relevant, 350K, no start. Third party has diagnosed injectors as the reason, with a quote from Mercedes of almost $4K.

Are these practically rebuildable (outsourced) or is new the better choice? If rebuilt, do the rebuilders here typically generate a new correction code or not bother?

Franco Cozzo · 17-12-2022, 11:42 PM

At $4K they're not overly expensive to replace the set compared to other setups, go genuine and program the new set to the car, with how finicky and precise diesel injection stuff is I wouldn't be trusting some rebuild service on this stuff.

I'd be inclined to look upstream and make sure there's no contamination anywhere as well.

Maybe send the old set out for testing to a reputable place which does a proper report before you commit as well.

Citroënbender · 18-12-2022, 05:08 AM

I think it’s well possible to come under that $4K by chasing the OEM part numbers, rather than paying for the Mercedes box. Good suggestion on testing the old ones, struck me as odd that it apparently won’t start/run at all.

Previous owners were a “get in and drive” Level 2 electrical service who use a mobile mechanic for fleet service, I doubt it’s been on a hoist since the end of warranty.

Just looked and it seems the Snap-On Solus can do injector coding. Yay.

Franco Cozzo · 18-12-2022, 01:05 PM

Quote:

Originally Posted by Citroënbender

I think it’s well possible to come under that $4K by chasing the OEM part numbers, rather than paying for the Mercedes box. Good suggestion on testing the old ones, struck me as odd that it apparently won’t start/run at all.

Previous owners were a “get in and drive” Level 2 electrical service who use a mobile mechanic for fleet service, I doubt it’s been on a hoist since the end of warranty.

Just looked and it seems the Snap-On Solus can do injector coding. Yay.

I've got a bung injector on my Focus thats leaky, if you let the car sit for a week it'll start and carry on like a pork chop at idle until it clears up then it'll run like normal.

At $1100+ GST each injector + having to code them to the car I can't be ****ed spending money on it, but the car will still run.

Find it odd that the car won't run at all, unless there is some smarts there with the ECU that if it detects problems like a misfire scenario it won't run at all.

Thats why I'm curious about sending them off for testing, if they come back and they are operating then it means you've either got:

A) Electrical problem between injector and ECU
B) Faulty sensor/sensor out of range
C) Injection pump halal

If its C then RIP - viking funeral for car.

Something you'll need to be careful about the Bosch part numbers on the injector rather than just paying for the Mercedes box premium is if the Bosch part numbers just refer to the body/series of the injector, they can have different nozzles for flow rates and spray patterns depending on what an OEM wants, this is critical with diesel DI engines as the spray pattern is going to put it in a specific place above the piston.

You'll need to make sure that they are identical to suit that engine/car.

Citroënbender · 18-12-2022, 05:55 PM

This has been sitting for months, it may be possible to get it started but I’ve given all of two minutes to the job this far. My workshop colleague says he has seen the same series of motor with gummed-up injectors wedged in their bores, coke everywhere. I don’t want to get it dragged into the shop until we’ve a handle on costs, time, possibilities.

Re the injector ID, would have thought the last three of the Bosch part number to constitute a really specific unit. Once I know the three digit suffix for the motor it will be easier to check. The free VIN decoders don’t tell me this.

**GasoLane** · 18-12-2022, 06:13 PM

Quote:

Originally Posted by Citroënbender

This has been sitting for months, it may be possible to get it started but I’ve given all of two minutes to the job this far. My workshop colleague says he has seen the same series of motor with gummed-up injectors wedged in their bores, coke everywhere. I don’t want to get it dragged into the shop until we’ve a handle on costs, time, possibilities.

Re the injector ID, would have thought the last three of the Bosch part number to constitute a really specific unit. Once I know the three digit suffix for the motor it will be easier to check. The free VIN decoders don’t tell me this.

What's the vin, I'll have a dig.