Carbon Buildup

2004 Toyota Sienna minivan maintained with regular oil changes over 74K miles. Dealer mechanic says I need EFI (I think – explained as chipping off carbon buildup.) Is this regular maintenance or is it profit enhancement?

This sounds like profit enhancement. I have never needed to do this on any car I have owned. Todays cars do not get carbon build up like they used to do. Better fuel and igniton systems coupled with better detergents in today’s gas make carbon build up a thing of the past. The only time something like this would be necessary is if your injectors were clogged(you would have a rough running engine if this was the case.) Are you still under warrenty? If not, dump these jokers and find a real mechanic!

You can build up some deposits modern car or not, but I’m not sure I understand what they want to do. Do they want to clean your fuel injectors by running a can of concentrate through the system? It doesn’t hurt to do this with cars periodically, but you can pick up a bottle of Injector/fuel system cleaner at a parts store for $10 or less and skip the dealer.

There is a process where a cleaning solution is run through the fuel injectors to remove deposits on the injector tips and on the intake valves. If you are having driveablity problems or you have failed emissions testing that point toward uneven fuel distribution, the cleaning would be adviseable. IMHO, modern quality gasoline formulations do a pretty good job of keeping the injectors clean so prophylactic inject cleaning is unnecessary.

This sounds like the Motovac system my mechanic uses on my cars. Besides using the machine to clean the fuel system and intake valves, he also manually cleans the intake; throttle body, MAP sensor, IAC, etc. He charges around $110 for the service. I have it done every 40 - 50k as preventive maintenance on my vehicles which is probably overkill. I’ll have it done on my 2006 Sienna when it hits 50k.

If you decide to have the service done, ask the dealer exactly what the service entails. It could be anything from putting a bottle of fuel cleaner in the tank to the service described above.

Ed B.

It is NOT regular maintenance. If the dealer says so, have him provide documentations from Toyota. He can’t because Toyota does not consider it standard maintenance unless they have issued an official TSB.

Dealers are no better (or worse) than independent mechanics for almost anything you might need done on your car.  They will almost always charge more per hour and often more for parts and supplies.  They also tend to look at repairs a little different than the independent. 

A dealer may well recommend work that strictly may not be needed, but could be connected to the problem or maybe replace a part when a little repair would fix it ALMOST as good a new.  

There is no need to bring your car to the dealer for any service other than service that is going to be paid for by a recall or original warrantee.  During the warranty period be sure to have all required (as listed in the owner's manual) maintenance done and to document all maintenance work.

I suggest that most people would be better off finding a good independent (Not working for a chain) mechanic. 

Note: Never ever use a quick oil change place. They are fast cheap and very very bad.

“Never ever use a quick oil change place. They are fast cheap and very very bad.”

Actually, they are not even cheap anymore, which just leaves their other qualities–fast and very, very bad. Not a bargain by any stretch of the imagination, IMHO.