Need recommendations...engine pinging?

[Scooby]

Hey guys and gals. Got a question. Sorry for the length, but please read and give you expert opinions.

The car in question is a 2000 Ford Taurus with the 12 valve 3.0 Vulcan V6. It currently has 70k miles. Since about 20k miles the engine has been making a sound like marbles under the hood. This only occurs during mild to hard acceleration. It was my wife's car, but I am now driving it since it gets better mileage than my new Tacoma thats coming in.

The car has gotten either Mobil 1 or AMSOIL 5w30 since about 5500 miles. I used AUTO-RX at approx 55k. Car has been getting LC and FP for the last 4-5k miles. I feel better about running the LC/FP, but it has not helped the "marbles" at all. It has increased mileage somewhat. My wife said she has in the past run 91 octane and it seemed to help "a little". With gas prices as they are in my area ($1.75 regular, $1.95+ for 'high test'), I just cannot afford to get the 91.

My questions:

1- Do you guys thing that this marble sound is pinging?

2- Is there anything else I can do/add to stop this?

3- Is there any potential damage from this?

4- What should I do/What would you do?

We must keep this car for another 18 months until it is paid off. The car will have about 100-110k miles then and we are selling for a minivan. The car has already had three transmissions...and e can't afford another major repair bill. Especially with our recent (55 hour old daughter) addition to the family.

I am very "anal" about my maintenance, and this is driving me crazy. I have never owned a vehicle that had this, so I am dumd when it comes to this.

Thanks in advance!! This is an AWESOME forum!!

 

[TC]

The only marbles are in your head, Scooby! Lay off the Jack Daniels!

Just kidding... You mentioned "mild to hard acceleration," so it sounds like pinging to me. This is basically when sharp metal edges or carbon/other deposits pre-ignite the fuel charge before the spark plug has a chance to do so. The octane rating of a gasoline has little to do with its "power," but mainly addresses the fuel's ability to prevent pre-ignition. Many engines will routinely advance the spark timing, increasing engine power, based on whether sensors detect pinging. Advancing timing can increase pinging.

I'd suggest:
1. Looking in your owner's manual to see if there's any bits of wisdom on this, including specifically what it says about octane requirements, and any comments on pinging.
2. Switching gasoline brands to see if that helps.
3. Using a fuel system cleaner which claims to "remove combustion chamber deposits." This may (or may not) help remove some carbon deposits present.
4. Using a higher octane gas (you've already addressed this).
5. Try an octane booster additive.
6. Don't be afraid to rev a warmed (but not cold) engine, such as flooring it for a time when entering a highway. Doing so will not harm the engine, but may progressively blow out some deposits, especially when combined with the fore-mentioned cleaners. It's well known that some European engines begged to be revved, and can carbon-clog when owned by "granny."
7. Easing back on the throttle when pinging is heard. Modest-moderate pinging is not harmful, but constant, heavy pinging can essentially "hammer" the piston tops.

 

[Scooby]

Thanks for the quick reply. I should have mentioned that the manual calls for a "minimum" gas octane of 87.

I have tried the Techron additive, with no help. I do back off when it is heard, but usually happens when merging on interstate with an inclined ramp.

Thanks again.

 

[DavoNF]

Scooby,

If you engine has a MAF, give that a good clean, also check the EGR system. Both of these will cause a lean condition if malfunctioning.

When you do any jobs like this, undo the battery lead for 30 mins so the computer may re-learn the new conditions.

Dave.

 

[Amkeer]

Scooby,

Do:

-Change plugs.
-Replace air filter.
-Replace PCV.
-Another dose of Techron, Seafoam, etc...
-Highway run of 50-100 miles minimum.
-Maintenance dose of FP or Lucas in gas until pinging stops. Then dosage every other fillup.
-Only run 87.

Congrats on the new addition!

Daily Drives:
-2003 Toyota Tacoma PreRunner XtraCab, 2.7 Liter , Mobil 1 Synthetic SS 5w30.
ODO 8350 Miles.
-1995 Toyota 4-Runner 3.0 V6, Mobil 1 Synthetic SS 10w30.
ODO 84500 Miles.
http://community.webshots.com/user/amkeer

 

[Not the Autorx Frank]

This is a good candidate for Fuel Power. Bet it would help a lot...

 

[1maniac]

A can of BG44k Fuel System Cleaner would be a good bet also. However, this is a STRONG cleaner and I would reccomend changing the fuel filter and your oil & filter shortly afterward.

 

[Scooby]

If you missed it...I have been using Fuel Power (FP) for some time now.

Also...used BG44 at about 40k miles.