My Ping Theory

[TallPaul]

Wife's '92 3.0 Aerostar van has had a nasty ping for several years. Often would run midgrade fuel to eliminate ping. Van uses a quart every 1300 miles and my theory was that the oil was mixing with the fuel air and causing a lowering of octane. I did Italian tuneup and ping went away, but came back. Same with water decarbon treatment.

Then I thought maybe if I could reduce consumption the ping would go away, so I loaded it up with Redline Oil. Consumption seems to be reducing over the first 2700 miles with the Redline, but still had the ping. Last week I did the Italian tuneup and the ping pretty much went away.

My new theory is that the ping is caused by the oil consumption, not by lowering the octane, but by making deposits. If I can get consumption low enough or if Redline reduces deposits, maybe I will find out. Otherwise, every time the ping comes back, I'll just do another Italian tuneup. Seems to work.

 

[Winston]

I think your theory is correct. Deposites are a common source of ping.

Why do you think Redline will reduce oil consumption? I have never heard that one.

 

[porcupine73]

I think maybe because Redline's high ester content might help swell the seals?

I had a ping issue on a 91 Escort that only 93 octane would fix. I think it was probably carbon build up on the piston tops as I've heard that effectively increases the compression ratio thereby requiring higher octane fuel to run without pinging?

 

[Propflux01]

I would still go with the oil theory. It does not take much at all to make a car ping...

 

[cousincletus]

Try using colder spark plugs next time you give it a tuneup. Have heard of several tricks, including colder thermostat, 70/30 antifreeze/water mixture, but if 89 octane cures it I would just go with that.

 

[Tosh]

Is there any chance of you borrowing a boroscope to have a peek inside the combustion chambers?
Is the timing advance working right?
Must be quite a sight seeing the Aerostar go for an Italian tuneup.

 

[ShortBuSX]

TP Ive got a ping/spark knock problem Ive been chasing too. I originally suspected the PCV, I replaced it and its hose and the ping went away briefly. I added a catch can and new hoses, this also worked temporarily although Im working on making the can catch more. Anyways, I switched from M1 to Amsoil ATM for its low volatility...I believe this is helping some, but the pinging is still there but at a fraction of what it was before.

All of my efforts to decarbonize have worked briefly too, but I feel this is just cleaning the PCV route and thats what the relief is from...until the oil passes through the PCV again...and this is why the Italian tune up doesnt work very well for me.

Piston soaks only worked temporarily if any at all, those usually followed other attempts to decarbonize with Seafoam and the PCV/intake...but its always come back! And my pistons never looked terribly bad anyways.

I cleaned my EGR, car drove nicely...but still pinged.

BTW this car has done this since 16k miles to currently 50k.

Id almost be interested trying in an ester based oil as a compairison over the PAOs(M1 and Amsoil)to see if theres any differrence.

Also I tried the colder range plugs, didnt work either and has the potential to cause more carbon build up as the plug is no longer at its optimum cleaning temp. The colder thromstats supposed to bea real no-no...and would think the mix of coolant would be similar(if effective at all).

 

[Hirev]

quote:

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My new theory is that the ping is caused by the oil consumption, not by lowering the octane, but by making deposits.

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I agree 100% it the deposits that are the killer both carbon and metallic.

I own a KTM 380 2 stroke dirt bike that uses pre mix at 36:1 it has a measured cylinder pressure of 210 PSI. Yet I can run 91 pump gas on it with most oils I've tried except one.

Bet not many cars use oil at 36:1.

 

[GoldenRod]

"Italian tune-up"

 

[andyd]

quote:

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Originally posted by GoldenRod:
"Italian tune-up"

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driving car at higher than normal rpms to decarbonize the top cylinders. Can be done by high speed runs or using a lower gear if legality is an issue.

 

[TallPaul]

Why would Redline reduce consumption? I am thinking it will do some cleaning and in that process maybe free up the piston rings enough that they can give a slightly better seal. Or possibly the film strength of the Redline will give a better seal.

It's a major pain to change the plugs and so I am reluctant to try the colder plugs. No boroscope either. Shop checked timing was good. Don't know how to check the timing advance, but I guess there are many factors that could cause ping.

I did my Italian Tuneup at 70 to 80 mph in 4th gear (locked out OD) and it was running in the 3000 to 4000 rpm range or somewhere thereabouts.

 

[jeepzj]

quote:

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Originally posted by TallPaul:
Why would Redline reduce consumption? I am thinking it will do some cleaning and in that process maybe free up the piston rings enough that they can give a slightly better seal. Or possibly the film strength of the Redline will give a better seal.

It's a major pain to change the plugs and so I am reluctant to try the colder plugs. No boroscope either. Shop checked timing was good. Don't know how to check the timing advance, but I guess there are many factors that could cause ping.

I did my Italian Tuneup at 70 to 80 mph in 4th gear (locked out OD) and it was running in the 3000 to 4000 rpm range or somewhere thereabouts.

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Try this, it worked for me.
http://jeepsunlimited.com/forums/showthread.php?s=&threadid=180595&highlight=mopar+combustion

 

[mechtech]

If an Italian tune up stopped the ping, the problem is not with your spark plug heat range.

 

[TheTanSedan]

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=5;t=003374;p=2

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=5;t=000633

 

[simple_gifts]

TP, I found changing the cat on my 1989 F150 allowed me to drop back to 87 octane; this is an often overlooked possibility. 150,000 miles / 15 mpg = 10,000 gallons thru the engine.

 

[jamesn]

have you tried fp60? i have an integra with 128k imles that has had a ping under load since i got it. 93 octane almost did away with it. after about 700 miles of fp60 (and a healthy MPG increase) i am running 89 octane and have to really lug it to hear the ping. its worth a shot for 20 bucks or so for a quart.

 

[TallPaul]

Oh yeah, it had some Redline SI-1 Fuel System Treatment, then it had a year (about 7000 miles) of Neutra 131 at 1 oz per gallon gas, then it has had Fuel Power since last November (a couple thousand miles worth) at 1 oz per 5 gallons.

I may just give up on fuel system treatments altogether, but for the occasional (once per OCI dose) and probably Neutra in the motorhome when it is going to sit long periods without running to prevent gumming.

 

[GeaugaFletcher]

quote:

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Originally posted by cousincletus:
...70/30 antifreeze/water mixture...

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That really should read "70/30 water/antifreeze mixture".

 

[Matt_S]

quote:

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Originally posted by GeaugaFletcher:

quote:

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Originally posted by cousincletus:
...70/30 antifreeze/water mixture...

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That really should read "70/30 water/antifreeze mixture".

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In Michigan, you've gotta be kidding! You'll wind up with an antifreeze slushie in your engine block.

 

[Gary Allan]

In Michigan, if you go too far the other way, you can end up with an antifreeze slushie in your engine block. AF comes with 3-7% H2O in it. It would be hard to sell a truckload of frozen antifreeze in Frostbite Falls, ND (Rocky and Bullwinkle).