Who needs ?throttle system service? and ?fuel injection service?

gasoline
nissan
sentra

#1

Recently I took my car for a regular checkup (basically oil and liquids levels, etc.) and the dealer came up with a “to do list”. Among the “issues”: new battery (Ok, since the car still had the original for almost 7 years. Not sure, though) and ?throttle system service? and ?fuel injection service? for which (these last two) they charged me almost $300. Was the dealer right? I doubt it. Reason number 1: I never had problems with ignition or performance. Reason number 2: those two procedures are not even mentioned in the official Service Manual (3410 pages!). Please, help me here. Thanks. My car is the great Nissan Sentra Spec V, 2004.


#2

If you were to search this site for complaints of “dies at idle” “Won’t start unless the accelerator is pressed” “can’t take foot off the gas when stopped” “RPMs drop very low when the AC cycles on,” etc, etc,etc, you would find the cause of all those problems is usually sludged up throttles and Idle Air Control valves. The throttle service that is being recommended prevents such problems. Many shops include that cleaning in a tune-up but who gets a tune-up any more? And,$300 is a little pricey for throttle and fuel injection service(?). Was there possibly more included on the list?


#3

I would only do those items if your engine has some kind of problem. The vast majority of times those services are unneeded, and will never be needed.


#4

On some vehicles it is very clear that cleaning of the throttle body is needed, the clue is increased pressure required on the gas pedal to get things going but immeditaly after the throttle ‘cracks’ open all is well again. It makes for a real jerky start off and can be dangerougs for some drivers in some situations.

At times the fuel system cleaning service is needed and has value but I would not be very happy if a 300.00 service was performed without discussion with me before hand had occured. In fact I would resist paying the bill to the very end. Who do these Service Writers think they are doing this without approval from the customer?


#5

Considering the shop labor rates and if this induction service consisted or removing the throttle body and/or intake manifold the price could be fair.

It could mean the difference between a throttle plate sticking wide open or engine damage due to an inoperative EGR system.


#6

The short answer: People who have an extra $300 to spend.
These rarely are anything short of throwing some injector cleaner in a car, and replacing the air clearner… maybe usign a Throtle body cleaner as well. I’d ask them what work they do for these check-outs.

  1. DO NOT GET THE BATTERY AT THE DEALER… I saw a dealer rate of $160 to change a battery… Battery = ~100… Labor = 15 min… Autozone will do it for free.