Pinging with 87 octane

[bestatchess]

Originally Posted by alw

Whatever the noise is (purge valve, injectors, crappy gas), it's back.

I guess the dealer will finally take action and get off their rear when this damn thing finally blows up. 5 years and 60K, here I come.

I think I would run the tank way down and fill with premium. If the noise stops, that would be an indication of pinging as opposed to injectors or purge valve.

[dandy]

I have also noticed a slight pinging on my current tank of gas. This happened without pulling my trailer (no extra load) traveling uphill at around 55ish in 5th gear. It was the first time it knocked, and i concluded cheap gas @ last fill-up. Sometimes you can get bad gas. Try another station. There is no way I'd put in 93 octane @ 2.25 a gallon. good luck

[alw]

I have a long trip this weekend, ~400 miles....I plan on filling up with 89 or 91.

I'll post my results.

[Austin]

Originally Posted by dandy

There is no way I'd put in 93 octane @ 2.25 a gallon.

Hrmph... Our 87 AKI runs $2.40/gallon.

[alw]

Still making noise with 89...will try 91 or 93 next.

Posted my best gas mileage to date- 19 mpg running at 70 mph...little to no hills and no passing.

[SupraTitan]

Have the dealer confirm your timing is correct and that the spark plug gaps are within spec. While their at it they should also run a compression check to rule out excessive carbon buildup causing increased compression.

Pinging and detonation are not the same thing,. Pinging also known as pre ignition and occurs when the air fuel mixture is ignited before it should have been. Detonation is when two flame fronts collide and cause catastrophic increased cylinder pressure. Pinging is just more of a nuissance than a major problem. Heck the owners manual for my 4runner even said its normal to hear pinging while climbing a hill or with the engine under a load, although it never did. Detonation on the other hand leads to broken ring lands, blown head gaskets, holes in the pistons etc. However the knock sensors will pull timing before it gets to that point, generally speaking.

Your engine should not be pinging though, possibly your engine timing was not properly set from the factory.

[alw]

Took it back to the dealer.... Anyway, once again they claim they cannot find whats wrong.

Said they hooked up their computer and everything is within spec, and the timing is not adjustable. Told me if it gets worse to bring it back.

Let's see....Lemon Law in Texas is two repair attempts in the first 12,000 miles, then two more within 24,000 for problems that "reduce resale value of the automobile" Looks like I'm on my way. What I find odd is they keep listing on my receipt that they are "unable to verify customer concern". This is BS because anyone can hear this rattle/ping/tick that is happening.

I bet if this truck was out of warranty, they could find whats wrong really fast.

[DallasTitan]

When I bought mine, the dealer told me that if I started to experience pinging on 87 octane to go to the plus. He said that after attending a seminar on the new Titan that's what they were told to tell owners(this was Dec, 2003).
Thank goodness so far it's going great on 87!

[SupraTitan]

The ignorance of dealership technicians is almost unbelievable . They said that the timing is non-adjustable, My reply would have been ok, give me a new engine that doesn't ping on 87 octane then . I didn't notice it in the manual but most automakers cover thier butt by saying that pinging is ok and that it is normal. I don't claim to be an expert in metalurgy but i'd suspect engine harmonics would be more pronounced with an aluminum block so pinging would be more noticable to the driver. Obviously if you can hear pinging the harmonic dampner is not eliminating the high frequency that is using your rods and other engine components as tuning forks. This in time leads to metal fatigue and a grenaded engine, another reason to also steer clear of under drive pulleys that eliminate the harmonic dampner.

If I were you I'd first reset the computer by removing the negative battery terminal for a couple minutes. I would also use different brands of fuel. If none of that works I'd bring it to the dealer and at least have them inspect the sparkplug gap, since they have to remove the plugs they should also perform a compression check to confirm that the compression is not elevated due to carbon buildup causing your pinging.

[Big Platinum]

Actually it does have a part in the manual that says SOME pinging is OK, but excessive is not good and you should either tune the engine up(obviously does not apply to a new truck) or step up to the next highest grade of fuel. It also says you should use the lowest grade of fuel possible without pinging.

Sounds a little fishy to me for a truck that is supposed to run on 87 Octane!

[bestatchess]

Originally Posted by alw

Said they hooked up their computer and everything is within spec, and the timing is not adjustable.

It is an electronic ignition, with timing controlled by the ECM (the ECM sends a signal via an amplifying transister to the primary side of the coil, which induces the high voltage in the secondary), and yes the service manual gives timing specs at idle speed, with a flow chart of stuff to check if it is not in spec. It seems to be a "check and replace if failed" type of arrangement, without much provision for adjustment. So it is the ECM that is doing the "adjusting" of the timing pursuant to the firmware in the ECM and dependent on various control inputs to the ECM. I don't know if their CONSULT software permits them to tweak the timing or not.

Now I am not one to believe in magic, so if the dealer has other trucks on the lot that don't ping on 87 octane, I would tend to put your pinging down to some mechanical, electrical, or software problem with your truck.

[cardesigner]

I'm still on my first tank of gas from the dealer. They filled it up with 91 before I headed off for the streets.

I'm coming to the halfway point to this tank, 4 days later. I anticipate a fill-up over the weekend...should I go 87, or go 89? I'm happier knowing that the truck runs on 87, since So. Cal. gas prices are..well, we all know it sucks. But with some members experiencing the pings, I'm wondering if I should just go with 89.

91 is just not worth it, I think. The difference between 87 and 89 is a few bucks, so it's not so bad.

Any ideas?

[Steve04SE]

Question: Do the Titan's have a crank and cam sensor?
If so, is it possible one or both could be a little out of adjustment causing a timing issue?

Also, could pinging be caused due to one of the numerous fuel blends? After reading about the various reformulated gasolines across the country, perhaps the factory engine specs don't work as well with some of the blends.

[Austin]

Originally Posted by Steve04SE

Question: Do the Titan's have a crank and cam sensor?
If so, is it possible one or both could be a little out of adjustment causing a timing issue?

Yes, the 5.6L Endurance motor has both a crank and cam position sensor.

No, it's not possible for the sensor to be aligned or adjusted incorrectly.

It's possible for one of the cams to jump a tooth or two, although this is very unlikely.

[BillS]

I'm experiencing light pinging on 87 (R+M/2) in Canada. The sound is faint but persistent, happens on light acceleration, seems related to load, but doesn't happen on heavy acceleration. High temp and humidity seem to make it a bit more pronounced. I find it annoying and friends riding in the truck notice it. I've tried different brands of gas with no change. In Feb when temperatures were cooler there was no detectable pinging. On a hot and humid day a month ago after picking up the truck from dealer service the pinging started. I had taken it in for an oil change and the 4WD Lo light flashing issue. Apparently they carried out a "transfer position adjustment" prior to giving up and ordering the ATP switch, which has not come in yet. I wonder if there is a relationship between the ATP switch adjustment and the pinging and wonder why this started after the visit to the dealer. Also my gas mileage is quite poor. In US gallons my best is 13.5 mpg hwy averaging 70 mph, and worst is 10 driving moderately in the city. The last 2 tanks of gas I've been driving it hard and getting around 12 mpg. Three tanks ago I babied it in city driving and got 12.5. Something doesn't seem right.