engine rattle(pinging) and oil question

[aztec12]

An engine that rattles or pings under acceleration,its that coused by a thin engine oil or just wear from high mileage.
I have read somewhere that that could be from a dirty fuel filter or winter gasoline any comments?

 

[BrianR]

I have no idea if oil can cause that. I do know that not using the proper octane gas can cause it.

 

[Gunatics_Adler]

Usually its gas or the ignition timing is off. Depends on the car.

 

[Gary Allan]

It depends. If the oil is entering the combustion chamber past the rings and hanging out for a while, it's not going to burn up right away. It's going to light off your fuel charge prematurely. That would be one instance where the worn engine thing can come into play. The same thing can happen with a perfectly good engine if you're over full and the crank whips it up enough and you put the engine under vacuum from high rpm.


You would normally be seeing some other symptom if this were the case. If not in outright drivability ..in the form of fouled plugs ..smoke of some kind ..etc.

 

[Steve S]

EGR valve, Knock sensor ,,,,,what kind of car?

 

[ProfPS]

I had a '92 Ford Tempo that had a similar problem that was solved by replacing the thermostat.

 

[sparkplug]

Try running higher octane gasoline or clean out the top half of the motor with some seafoam.

 

[HyperJinx]

detonation(pinging) usually is a result of a problem with engine timing.

 

[Rand]

crusty engine.. timing problem.. sensor problem

 

[joel95ex]

Originally Posted By: Steve S
EGR valve, Knock sensor ,,,,,what kind of car?


EGR valve may be functioning ok (opening/closing) but the passageways may be clogged.....mine were completely blocked and I was getting the rattle/pings no matter what I did (octane boosters/cleaners) when i cleaned out the EGR ports/runners I was able to use 87 without any pinging.....I am sure this is an EGR problem

 

[joel95ex]

by cleaning i mean I had to mechanically clean them by taking apart a plate on the intake manifold which was under the fuel rail....so i used the opportunity to replace o-rings too. what kinda vehicle? do a search for EGR port cleaning, clogged egr ...etc for your car. there's probably a write-up on another forum----found mine on a honda forum

 

[Shannow]

There's a couple of different types, and oil can cause problems in both.

First type is pre-ignition, where something, usually a hot spot causes the gasses to ignite before the spark starts. Oil leakage can lead to ash deposits that can be the ignition source here.

The other type is classic "detonation", which is technically "end gas auto-ignition". The gasses away from the spark plug are heated and compressed by the combustion behind them (the pressure and heat of compression travels at the speed of sound, while the flame travels at less than 100fps).

The gasses get hot enough and bang, there are two competing and colliding flame fronts.

Oil in the end gas region makes it more likely to happen, as do ash deposits where the oil has been.

As per other posts, lack of EGR can do it too, but EGR is usually a part throttle thing rather than reasonable acceleration.

 

[mechtech2]

Oil viscosity or even if dirty will not cause spark knock.

If the car ran normally before, there may be carbon deposits in the combustion chamber that raise the compression.
A faulty EGR system can cause part throttle knock/ping.
Ignition timing is of course very important, but with modern computer controlled engines, this is rarely adjustable.
An engine that runs hot will spark knock, as will overheated inlet air.

 

[aztec12]

Well its a 1998 f150 with the 4.6 engine 127k on the original motor.The truck pulls strong at any speed but it pings mostly when its in overdrive 55mph and higher.Long ago i tried seafoam in the gasoline,i did chevron thecron,rogane,89 and 91 gasoline but nothing helps.Like i said the truck pulls strong and it runs smooth.The only thing its the pinging,but i guess i have learn to live with it,its has had it for years and nothing bad has happened ,but i guess its not bad to ask right?

 

[JT1]

Have you even looked at the spark plugs?

 

[OVERKILL]

Pull the MAF sensor and clean it with a Q-tip and MAF cleaner. I bet it is crusted up.

 

[aztec12]

plugs went in at 90k.Plugs have around 37k miles on them.this engine uses platinum plugs good for 100k

 

[aztec12]

I'll give that a try tks

 

[HyperJinx]

detonation, spark knock, pinging or whatever you want to call is easily correctable. Just take it for a check-up and let them scan it. I am no expert but I have never in my life seen a situation of detonation that was caused by oil or anything related to oil. Octane level in gas? Purhaps but its probably a mechanical issue like engine timing.