My sister has a 1986 cutlass ciera oldsmobile 4 cyl. It started pinging rather loudly yesterday . It only does it on excelleration. She has been using cheap gas that is 10% ethanol. Today we filled the tank with 93 ocatane EXXon and put in a bottle of Champion fuel system cleaner. Will this help? If so how long might it take? Also what about the EGR valve could that be the problem?

Wow, big problem... valves... oil change... where do you live, Alaska !

Yes, using higher octane gas should definitely help eliminate engine knock. However, you may only need to change the spark plugs (ACDelco only), using the exact plug no. that came with the car. This link may help:

https://www.askmehelpdesk.com/cars-t...tml#post617111

Since the pinging still exists, have the mechanic retard the timing, by loosening the distributor and rotating it slightly (1/4 inch) to the right. This may completely get rid of the pinging.

If the problem still exists, going to a "colder" spark plug may solve the problem, which was my experience:

https://www.askmehelpdesk.com/cars-t...tml#post324106

When was the last time you had a complete tune-up? Plugs, wires, distributor cap, rotor, fuel filter, oil, & oil filter.
With that small of an engine you should be getting really good mileage. That engine is made to run on 87 octane so running it on higher octane is a waste of money. "Bad gas" doesn't mean lower octane. It means there may have been water in the tank when they pumped in the new gas. Or, it may mean the business owner is crooked and added water to it deliberately. (against the law)
Start with the simple things first. Sometimes even a clogged fuel filter ($3-4) can cause problems. The fuel filter should be changed once a year, along with the tune-up. Changing the oil will prolong the life of your engine dramatically. Some people change their oil twice a year, but it depends on how much and what kind of driving you do.
The EGR valve is part of the exhaust system & if defective (clogged) would make your car run rough and get poor gas mileage.
Since your car is older I wouldn't doubt it's fairly dirty, and wouldn't hurt to get a new one. Keep the old one and clean it up. It can be used again!
You can get a big discount through PartsAmerica.com. They line you up with their partner in your area. I have saved hundreds of dollars this way.

"Pinging?" As in pre-ignition?
It could be the EGR valve system. That can be tested by your mechanic. Both the EGR valve and the passages need to be functional and clean.
A different octane won't help. Higher octane fuels burn slightly slower (providing slightly more power) but also burn longer, which can lead to even more pinging.
Don't waste money on cleaners that go into the tank. That stuff will help reduce deposits in the fuel system but it can't clean the system. If it was strong enough to do any good, it would be to harsh for fuel system components.

Have the "ping" diagnosed and let us know what your mechanic discovers.

If you suspect "bad gas" get some fuel additive that will specifically say it will "dry condensation" in the fuel system. Ithink it might be called "Gas Dry" or something like that. You should also keep at least half a tank in the car at all times. Condensation (water) can build up inside an empty tank.

Pull the head off??

$$$$$$$

I just got the car back . It was a blown head gasket. Blown between two cylinders. He showed me the old one. It runs great now. I trust my mechanic. He's an old classmate of mine. Money well spent! Thanks Captain Rich and Shady Lady for your help.

Interested to know how much that cost you Nancylee, especially for an 86 olds.

Also I meant to thank Txgreasemonkey for taking time to help me.

Sorry you feel the need to ignore my question. I don't usually like having the last word and your displeasure was duly noted from the start but chose not to make a comment at that time, Nancylee. I guess my diagnoses was almost correct, valves, I think was my first thought and you did have to replace a head gasket which is normally a very expensive job on even a more recent model then you have.

I am glad however that you did receive satisfaction from our site and hope you will return with some easier questions of your choice for some of our more misinformed long time members.

Good day to you and hope you don't have any more problems with your olds.

Ms tickle

Sorry Tickle. No hard feelings. Thanks for taking time to help me.

Oh in answer to your question. It was 250.00 labor. But I had to have oil change and antifreeze.

Cool.
Another car fixed.
I think it's time for a group hug.
GROUP HUG, I SAID! :cool: