You are excited that you found a place that is actually able to clean and flow test your BMW Piezoelectric Injectors at the actual high pressure! This is going to save me like $1600! Awesome! Sign me up!
Not so fast. Let’s slow down and discuss this a little more. Your expectations should not exceed what the results could possibly be. First off, please understand this service is for Index 11 and Index 12 Injectors. It really is only for Index 12. However, there is a decent enough success rate with Index 11 that we have been lumping them in with the Index 12’s. ANY other index below 11 (10 and under) we do not recommend even attempting this service. That being said, we will attempt it if you are paying for it. Just know, we warned you. The success rate is extremely low. Understand this is coming from a company in business to make money. We would rather see you put that money towards newer Index 12’s than to gamble on this cleaning or Piezo Stack Regeneration working for you.
Lower Index Injectors
BMW Piezoelectric fuel injectors under an Index 12 were revised for a reason. The revisions weren’t just for the hell of it. Our Cleaning and Flow Testing Service for N54 N63 and N74 Fuel Injectors does not bring them up to Index 12 Specs. Earlier Indexes were very prone to leaking. Either major leaks or leaking resulting in higher flowing injector. This is a design flaw. It is not something cleaning can fix.
Piezo stacks on earlier Index fuel injectors often benefit greatly from the regeneration process. That being said, it only matters on an injector that is working properly and not leaking. In addition, regenerating the Piezo Stack can also cause an injector that is not leaking to form a leak sooner than would have. So, it is a trade off. You are reminding the injector what it is capable of doing. At the same time, you are allowing it to operate in ranges it hasn’t done in years. I would equate it to reminding an older person how fun climbing a tree is and giving them pain pills. I’d be willing to bet if they feel well enough to go climb that tree, it probably isn’t going to end well.
Index 12 Results
So you have Index 12 Siemens VDO fuel injectors for a BMW N54, N63, or N74 and need them cleaned. A set of Siemens VDO 1353-7585261-12 Fuel Injectors. We can help. That being said, please follow along with some more info on this process. Index 12 fuel injectors still have issues. Just because they are Index 12 doesn’t mean you are in the clear. Piezoelectric injectors are sorta one of those things you could say is ahead of it’s time. Always has been and always will be. The theory and technology behind them is amazing, but over a decade later still doesn’t work 100% and they fail more often than they should.
The success rate of cleaning standard port injection injectors has had an impact on the expectation with Piezo fuel injectors. With standard port injection fuel injectors, you are just about guaranteed we can get them back to life again. Obviously there are exceptions, but it is probably somewhere near 99.5% success rate. With the Piezoelectric, the success rate is probably closer to 75% – 80%. Translate that into a set of 6 injectors being sent in means there is a very good chance about 2 of them are not going to be in spec even after cleaning.
Now lets discuss what “In Spec” means. First off all, it does not mean the injector does not work. It means the injector flows outside a hard limit or minimum. Siemens VDO provides us with these limits. This is what every New in the Box Index 12 fuel injector “Should” flow. I can 100% tell you we have seen dozens upon dozens of New fuel injectors fail this test. Not by much, but it does happen. We do not alter any test plan minimums or limits to force an injector to be within spec. It can have a limit for just say 33.5 mm3/STRK. Results on that plan come back at 33.6 and the injector has failed. Again, this does not mean it does not work. It may perform like a rockstar, but the test results will show it is out of spec.
Often times with Piezoelectric fuel injectors, an injector can pass all test plans on the Before Cleaning test. After cleaning, it is often possible they fail a test result or two or 3. The normal results to see are an injector flowing more after cleaning. This is common on pretty much every type of fuel injector, but more so on Piezoelectric fuel injectors. Port injection, CPI, SCPI, Throttle Body, and even GDI fuel injectors can often fail as flowing higher than they should, and flow less after cleaning. On Piezo, I can probably count on one hand how many times this has been the case.
Be ready for the results
Just be aware of these things when choosing to have yours fuel injectors cleaned. We don’t have some magic solution and don’t want to portray this is the case. We want to be as upfront with customers as possible. You may wonder why anyone would do it if it is not guaranteed. It’s because it will still save you money. Just because test results may show an injector “failing”, does not mean the injector is garbage. BUT Speaking of garbage, understand that under an Index 11, we recommend putting the money you would have spent on cleaning towards new injectors.
We wish you the best with your issues with Piezoelectric fuel injectors and feel your pain. These things are very expensive and it hurts the wallet when they fail on you. If we can give one other word of advice it would be about having them tested by a company that uses port injection machines. If the company is touting “spray pattern” or measuring volume in cc/min or lb/hour, run. I am willing to bet they have a much better “Success Rate” than us. We would have that same “Success Rate” if we used the wrong equipment and tested at no more than 10 Bar of pressure too. They literally can tell you no relevant info about the health of your Piezoelectric injector. These ASNU machines are great for port injection, but adapting them to be able to drive a Piezoelectric is deceiving.