I am at 100k km (60k miles) and the dealer has recommended the fuel system service. It is about $125. I have noticed a decline in my mileage and the engine pings unless I use premium. Has anybody tried this service? What were the results?

 

Phil,

Have you been using a top grade of gas (i.e. not a budget no-name gas) since buying the car? If the answer is no, you probably need to clean the injectors with a fuel additive designed for this. If you buy name brand gas (BP, Shell, Exxon, etc.) you will not need to do this as the detergents are already in the fuel and are keeping your system clean.

Do you drive your car easy (no abrupt starts, no heavy acceleration, no high speed runs)? If yes, you might just need to disconnect the battery for 10 minutes or so and let the ECU "re-set" to factory spec. Modern cars will learn how the driver of the vehicle operates the car and will adjust (increase) the timing advance of the engine for the best performance.

If that is the case, your ECU has increased the timing to the point that "pinging" is occurring during acceleration or while under a load (climbing hills). Forcing a reinstall of the factory timing specs can reverse this.

The other possible cause for the problem is a carbon buildup in the combustion chamber of the car. In that case you (or the dealer/your mechanic) can use something like "Seafoam" to clean the intake system and combustion chambers as this will eliminate two possible problems 1) The carbon buildup is getting hot spots that are pre-igniting your intake charge and 2) the effective compression ratio has been increased due to the carbon buildup.

You might also have a spark plug that is breaking down under load and not giving a complete spark to a cylinder but normally that will throw a code for a “misfire” that will show up on the MIL

Make sure that the dealer understands your problem and will stand behind the fix if you let them do this service. Make sure that they know about the “pinging” issue and the reduced mileage. Also ask them EXACTLY what they are doing for this service. I have a sneaky idea that they will hook it up to their diagnostic reader, check for codes and run a cleaner thru the fuel system. If that is all they are doing, buy a $10.00 bottle of injector cleaner, pour it in the tank and save yourself $115.00.

 

I emphatically second the advice from David (Georgiahybrid), and I would add the following:

I always keep my cars into high mileage, and over the years I have done both the fuel system cleaner routine and the carbon cleaner routine many times -- 100% success in getting the desired result.

I have had the easiest time and best results with Seafoam for the carbon cleaner and Techron for the fuel system cleaner.

Techron is a Chevron product, and Chevron gasoline was the first gas to demonstrate good results keeping fuel injector systems clean. The lore is that Chevron supplies the Techron to most of the other brands, but they put a healthier dose into their own gas than the others can afford to.

I was an Exxon employee when my got my first fuel injected car in the early 80's, and I used to use Exxon gasoline exclusively because I got it at a discount. When I started getting fuel injector clogging, after about a year and a half of a steady Exxon diet, a friend recommended the Techron routine. It worked like a champ, I switched to Chevron exclusively and thereafter did not need another added Techron routine for another 20 years. Yes, I still have the car !

The carboning up and the fuel system clogging are, of course, separate problems with distinctly different symptoms. Carbon deposits in the cylinders are the leading cause of pinging; so I'm not sure why the dealer is recommending a fuel system service, unless they mean to include the de-carboning routine also.

Nevertheless, were I in this situation, I would probably do both the Seafoam and Techron routines. A few years ago my oldest car failed emissions testing very badly. I did both routines, and it passed with ease.

Both of these routines are easy and cheap, and they often help a lot, probably always help some, can't do any harm, and are useful as preventive measures. Curing the problem cheaply and easily gives a great feeling of empowerment, and if you DIY, in addition to the expense saved, you will probably find that you can get these particular chores done by yourself for less time and trouble than just driving to the dealer and back would take, to say nothing of avoiding the hassle of dealing with know-nothing service reps.

PS: I have done the Seafoam first and then the Techron, reasoning that the Techron would clean out any remnants of the Seafoam. Also, the Seafoam job is finished right away, but the completion of the Techron job requires driving through 10 gallons of treated gas, and possibly a repeat. And, thinking of the order of things, I suppose that I would try David's suggestion to reset timing by battery disconnect first of all. (I did not know about this and was glad to get the info. Thanks, David !) That won't cost anything and it will be the easiest thing to try. I'd be interested to hear if anyone advises the reverse order.
Good luck, and give us a report.

Also: Do not be surprised or dismayed if the Techron makes the car run worse before it runs better.

 

John,

I did not mention that I burn Chevron gas. Two reasons, number one is that it has the best cleaning properties (IMO) of any gas that I have tried and two, it's the ONLY non-ethanol gas in my area.....

 

I have some concern (maybe unwarranted?) that spraying a decarbonizing agent into the air intake system before the mass air flow (MAF) sensor may actually cause damage to this sensor. If so, any decarbonizing should be done with great care. On a related note, surely if there's carbon build-up in the cylinders, something could be wrong with the engine's fuel-air mixture control system (which includes the MAF as well as the oxygen sensors), and this should be investigated. Are there any stored error codes?

Stan

 

Stan,

Carbon buildup can occur from an incorrect air/fuel ratio but most often occurs when a car is used for short trips at low rpm's. The ECU will enrich the fuel mixture while the engine is cold. If the trips are short enough, the engine will not get up to a high enough temp to burn off the carbon deposits that will occur.

Depending on the shop, some of them will introduce "seafoam" through a vacuum line opening "after" the MAF sensor. Don't get me wrong; it is better for a shop to do this if you are not familiar with the process. The injector cleaner on the other hand can be done by anyone.

 

My gas mileage had drop to 39 mpg after a year and half of driving in Atlanta. I bought the fuel system service (throttle body cleaning) when I had my last oil change and now the gas mileage is back to 42+ mpg.

Gasoline! I always buy the cheapest no matter what the brand. I will never buy premium because of the cost.

 

100% gas works best year round if you can find it. Try to stick with a top tier brand of gasoline. A top tier gas from this list can keep your injectors, valves and pistons clean for better gas mileage.

That's strange, I don't see Sunoco listed for America. I figure it would be one of the better gasolines. I found the Fina, Diamond Shamrock and Exxon's don't keep your engine as clean s the Chevron, phillips 66 and other brands listed.

click the links at the bottom for more details on this study.

http://toptiergas.com/retailers.html

 

It's my understanding that Texaco is the same as Chevron. Chevron uses Techron as their addative. Texaco has maybe the same addative but under a different name.

Phillips 66 same as Conoco and Union 76. All three use a similar additive to make it on top tier gas list.

 

Thanks for all the replies.
I have been using good gas most of the time. For the last few months Shell V Power premium. Sometimes Chevron premium. When pinging first started last summer 07 the car only had 20K km. This year it started pinging as soon as the weather warmed up. Now if I use regular even from good stations I get pinging under load even in cooler weather.
From what I can tell, based on the responses it could be 2 things. Carbon, or the computer set up has changed and needs resetting.
Since disconnecting the battery is free I will try that first. I was pretty sure the fuel system cleaning includes decarbonizing but will postpone it until I see the results of a reset.
I drive about 2-3 hrs a day so it's not short trips. Part of my commute is at 80km/h the rest at 110km/h. I don't push it hard but it purrs along for a good section. I have also done several long trips at normal freeway speeds. The computer theory makes good sense.
I am concerned about doing the Seafoam correctly but the Techron is no problem.
I will post the results.