'96 Intrepid ES engine ping

[TboneMan]

Here's a gasoline question for the gang. The gas cap lid and owner's manual for my wife's car, a 1996 Dodge Intrepid ES with the 3. 5l engine, recommends that 89 octane (plus grade) be used.



In general that is what she has done for the past 134,000 miles. With the price of gas being what it is (HIGH) she put in a tank of regular unleaded. Now the engine pings on accelleration (it doesn't ping when she uses 89 octane).



This is a high milage engine, that we need to last until the Liberty Diesel comes out next year. Is it worth putting in the higher octane? Will the pinging cause damage that could shorten the life of the vehical?

 

[B.G. Smith]

Ping

Pinging as you know is caused by preignition of the fuel/air mixture before the spark plug fires. Preignition can be more prevalent with carbon build up in cylinders however if the recommendations for the engine are 89+ then the lower octane is most likely the culprit. Slightly retarding the timing might help but I'm not sure that can be done with the cumputer controls, also will cause loss of power. The pistons are aluminum or an alloy therof. The preignition could eventually burn the top of a piston out. Best bet is probably to bite the bullet and buy the 89 octane. bg

 

[Motorhead]

Even 10 cents a gallon more isn't worth losing an engine over. You have a medium to high mileage engine. Pinging is very detramental for a gas engine. It will eat up pistons and can cause head gasket erosion problems also. In short, A good running "Used car" is worth alot more than a non running used car. Spend the money now and count your nickles later at the pump with the Diesel Liberty.

 

[Philip]

My wife drives a 99 model Intrepid. When it was new running on 89 it would ping when you were heavy on the throttle. The dealer couldn't find out why. We switched to 92 oct fuel to stop it.



Like the other people said. Running the cheaper gas to save money will not add up to the cost of a engine replacement if a piston goes into the oil pan.

 

[TboneMan]

Thanks for the advice. It was along the line of what I was thinking, but I need some reassurance.