Flushes as part of maintenance

[Zamba]

I don't see these flushes in the maintenance schedule, but the local dealer service employees recommended an injector flush and an emissions flush. My M35x is at 46k miles. Are these services just unnecessary upsells?

[qship96]

Depends on how long you plan to own the car. If you plan on trading at or before 100,000 miles or so, just follow the factory plan in your owners manual.If you plan to keep it 150-200-250-300 thousand miles, you must be aggressive and perform more strict proactive maintenance to prolong life of every component{change every fluid/filter every 30,000 miles,along with quarterly motor oil/filter changes} Transmission/differential/steering/brakes/radiator/traction control/ac compressor oil- regularly changing these fluids will double life of their components.

[Zamba]

I understand your point. However, let's consider the cost-benefit ratio of services like these that give the owner marginal advantages. Wouldn't it just be cheaper to replace the components every couple hundred-thousand miles instead of doing regular flushes?

[Q45tech]

Important to be clear in using terms. Technically a flush is using an EXTRA chemical to clean away residue compared to a normal simple fluid exchange , where an equal amount replaces what is drained.

Coolant systems often get flushed to remove corrosion build up from aluminum insides, as do oils, tramsmissions, etc. Differentials, ps, ac don't usually get flushed just replacements of lubricants....................not to say you cannot flush them.

[qship96]

I understand your point. However, let's consider the cost-benefit ratio of services like these that give the owner marginal advantages. Wouldn't it just be cheaper to replace the components every couple hundred-thousand miles instead of doing regular flushes?

Do the math- add up cost to replace every fluid at 30,000 mile intervals and double the life of their systems components VS not performing the fluid changes and purchasing a new transmission/differential/steering system/brake components/ac system- you will quickly see that the investment you make in regular fluid changes is significantly less expensive compared to early parts replacement.

For example, on the Q45 a transmission is $3,000, differential $2800, a/c compressor/evaporator/condensor job $2,000,and so on.

[maxnix]

It is always wise, especially when posting here, to detail what exactly is included in any service with a single name like "flush", "transmission service", "emissions flush", "injector service", etc.

Usually catch-all phrases mean different things at different dealers, and usually are just palliative in nature.

[Q451990]

Depends on how long you plan to own the car. If you plan on trading at or before 100,000 miles or so, just follow the factory plan in your owners manual.If you plan to keep it 150-200-250-300 thousand miles, you must be aggressive and perform more strict proactive maintenance to prolong life of every component{change every fluid/filter every 30,000 miles,along with quarterly motor oil/filter changes} Transmission/differential/steering/brakes/radiator/traction control/ac compressor oil- regularly changing these fluids will double life of their components.

Couldn't have said it better myself.

Heath

[fixer]

our retail price for an injector on an m35 is around $200 each and you have 6 of them. also the labor will be around $400-500 . compared to an injector flush that we recommend for around $160 every 30K. I think flushes cost alot less and will actually save a little gas during that 100k miles

[SteveTheTech]

The maintenance schedule in the owners manual outlines a rough estimate of fluid and component replacements. If you follow that closely your M should be fine.

Companies market these flush products for profit. With the independent shops loosing ground to the dealers the salesman have set their sights on the dealers. I personally do not believe in the benefits of many of these products for most cases. If a thorough inspection reveals the need for something than I can see the justification for recommending a service, but replacing an OE fluid with some generic replacement is not something I personally do on my old car. The bottom line on this is there is a market for these products, the claims they make I question though. My dealer has a contract with one of the large traveling fluid sales companies and after many years I am still a skeptic. Don't get me wrong if your car is old and uses old car technology they run less efficently than the modern VQ and require cleaning of things to stay alive. An emissions flush though what does that include? Are they cleaning the EVAP lines? and if so why? If you use high quality premium the need for fuel injection cleaner is arguable, and rarely shows any improvements in well maintained engines. If the injectors were getting as dirty as they used to they would still use an external filter that would require regular service.

It all comes down to a business.

[maxnix]

The maintenance schedule in the owners manual outlines a rough estimate of fluid and component replacements. If you follow that closely your M should be fine.

One has to realize that the OEM maintenance schedules are the minimum required to get the car beyond OEM or extended warranty so the failure of large systems are on the owner's dime, and not the OEM!

If you are not a leaser and are extracting full value from your purchase by keeping it past the initial warranty period, more aggressive maintenance will be rewarded on the long run by not only better longevity, but better performance during that extra life period.

For dealers, replacing worn out parts is a big profit center in their business. They have no interest in extending the life of components beyond warranty periods. Also, most owners are trying to get by on the cheapest path possible so are not amenable to the investment required in preventative maintenance. For them, even frequent OCI are something to be extended for a saved buck today vs. longer life after the warranty expires. Why one always verifies services on a pre-owned car.