!998 Dodge Neon

Cold knock is probably worn lifters. I had a Dodge Spirit that sounded like a diesel from the outside. Ran thousands of miles like that.

The other ping may be a timing advance lag at partial throttle.

Real mechanics here will help you more.

Floor it 'n go!!!!!!!!!!!!!!!!

Change the oil.

That's What I was also thinking about the timng.

In the "Old Days" one could give small twist on the distributor to cure this. Now with these computer controlled cars,,,, well,,,,,

But can the chip or brain be programed to just like the old days, to give the timing a slight twist?

Reprogramming is not the solution. The chip determines the exact timing and will advance and retard it as conditions demand.

However, the chip's performance is only as good as the sensors that supply the data to the chip (they are the chips eyes).

A common failure is the crankshaft position sensor.

This is why I recommended Autozone to read any fault codes that may be present. It's free and may help you pin down the problem with a minimum of diagnosis or part swapping.

OK, well no error codes at all. Was a few misfire ones from a couple years ago, but new plugs and wires cured that. so No check engine light and via the port no error codes.

Joe

I would start asking a technician at the dealer and maybe Autozone. At least you ca get a price for the crank shaft position sensor if that is what looks like the problem.

Also, you can have carbon build up on the inside of the cylinder heads causing pinging. There are off-the-shelf items that you can add to the gas to help with this problem.

Techron is one product that is good to add once or twice a year.

Mopar Combustion Chamber Cleaner is another one.

All available at Autozone or your car store. This is not a bad idea to start with as it does not cost a lot of money, easy to implement, and may avoid costly experimental repairs.

I'll have to try the Mopar stuff and see what happens.

One Mechanic that listened to it after checking the no codes also thought pre ignition, and suggested to try premimum on next fill up. so that is the next thing also. and maybe even add one of those octane boosters?

That will at least help confirm that it is pinging, but you still need to understand what has changed and why to fix it.

I cannot recommend an Octane booster, most are just expensive Cons....

I think that your engine/oil pump is worn, get someone to measure oild pressure when the engine is hot.....I think it will be low and probably bearings have already stated to suffer.

Th more worn the bearings get, the lower the oil pressure generally....usually the worn bearings knock till oil is pushed around the engine when cold and later when the oil gets thin from engine working temperature.

The specific torque for the knocking may be the maximum torque point of the engine, (thats where the problems usually start), sometimes the manual shows graphs of power and torque, check it out carefully.

Can't imagine that the max torque point of this engine is just barely above idle...

Me neither, think about the knock under load at higher revs.......not at start.

Plane old water is another one.

Trickle it slowly into the throttle body and keep the revs up. Lots of steam will happen but the combustion chamber coking will be reduced. (you could even consider installing a permanent water injection setup that will fix the ping and give you a bit more power and fuel economy)

98? is that OBD1 or OBD2? Your knock sensor might be deaf and not report a fault. Maybe.

If one uses this method for carbon build-up removal, it is VERY VERY important that the water be S-L-O-W-L-Y added to the intake, perhaps even use a spray bottle. Water does not compress (Yes, we do all know that) and therefore decreases the gas volume in the combustion chamber increasing the the compression, you could blow a head gasket, bend a (connecting) rod or break a piston.

It should produce some green - yellow smoke as the carbon breaks up.

My buddy and I setup a water drip system on his Fiat X1/9 and it not only boosted performance a bit, but it kept the engine clean as a wistle. Not hard to do and quite effective if you don't over do it.

I played with this in like the late 70's and early 80's.

I tapped into a vac line with a "T" needle valve, and a hose going to a jug of water.

Granted the amount of water did not vary with the throttle position, but it was something. A question is, how much water would be a good rate?

What I did all those years ago was open the valve every slowly while idleing, and as soon as the engine started to show lower performance Idle rough or slowing down, i closed it till it smoothed out and came back up to normal rpm.

But i do not remember how fast it would use that water.

Joe

The startup knock is probably a collapsed lifter or two for the valves.

An oil change might help, particularly a high detergent oil, but chances are the offending lifters need replacement. This is not a major engine service.

The other knock/ping is probably pre-detonation. That could be a faulty crankcase sensor.

Dodge also has a TSB (Technical Service Bulletin) #03-006-04 that might be an issue. This is the half-shaft for the drive shafts and you would need to be moving to hear it.

If it is an engine problem (and not the half-shaft) I then would start looking at causes for pre-detination as the root of your problem (i.e., bad HAL sensor, etc.). If your car has OBD II engine electronic diagnostic port, Autozone will read the fault codes for free. No appointment required. Just drive up and ask the attendant at the counter to read your codes. He will tell you if your car has the OBD II port.

Pinging is caused by the spark timing not firing at the exact correct time.

Just noticed that you have a 998 Neon and not the 1998 Neon - and the Spanish version at that!

In that case, what are you feeding the horses? That knocking and pinging may be a case of flatulence due bad diet. Do notice a smell when it happens?

Autozone doesnt have anything for horse flatulence ?

EquestrianZone.

Anywhere Online someone can go and read this bulletin?

You can just do a search on the web.

You should also call your dealer (have your VIN number handy). They can look up in their data base and tell you if your particular car is impacted and if that service has been done or not.

there's an anti-knock sensor that's screwed into the side of the the block that sends a signal to the computer to retard the timing.

Very good. These can be checked for function by using a timing light and an assistant. Have one person hold a steady engine speed that is anything above idle. (Some systems block the knock sensor function if the engine is not showing any movement on the throttle position sensor.) While watching the timing marks, have an assistant tap on the knock sensor while still connected to the engine. This should force wide swings of the timing marks if it is functioning.

Joe,

Can you have someone start the engine cold while you watch under the hood? What you describe in both cases, cold start and warm part-throttle load describes a rod knock.

If you can isolate the noise to a top-end tap, then it probably is as others have mentioned, a lifter or lifters going bad (collapsed). This can be from wear/tear but also from gum and deposits in the engine. Penn-soil and Quaker-cake are the worst oils for leaving deposits in the head and top-end of an engine.

If it's top-end tap, you can do a few old mechanic's tricks. It sounds scary, but it's all about controlling the conditions: you will need to prepare for an oil change. Before you start the engine to warm it up to drain the oil, overfill the crankcase by adding either ATF or diesel fuel to the oil - a couple of quarts of whichever you prefer; I like using ATF. Let the engine *idle* with this mix for a few minutes. Do NOT load the engine even by dropping it into gear (automatic trans). Anything that can come loose will do so. Immediately change the oil. If you've got the time, change it again later that day or very soon after to make sure nothing stayed in there. If it still taps, it's going to need mechanical attention. It's old-school, but it works - I have done it a number of times to buy a little more life out of an old hydraulic cam engine.

If it's knocking from the bottom end, rod(s) (usually) or main bearings, there may not be much you can do. At least some of the first run of Neon engines did not have rod bolts - it was a 'throw-away' engine, and is not rebuild friendly. I have a feeling though, that the turbo-Neon crowd has some ways to improve those engines as well as overhaul them (I've seen a number of people pop them by getting greedy with the boost). There are forums on the web for enthusiasts who surely will be familiar with the problem.

If it turns out just to be spark knock, then a fresh set of plugs and a new knock sensor are, as mentioned before, the place to start. If those items don't fix it, you have some carbon build up in the chambers that is either creating a hot spot, or there is enough soot in there to actually raise the compression ratio. A compression test will give you the answer. If it's soot, there are a few remedies, but you need to remember your downstream sensors (o2's) and your catalytic converter. Again, the old-school way was to give the engine a few small doses of cold water into the intake, while running (NOT enough to hydro-lock the engine!!!). As you dose it, you will have to hold the engine at a fast idle, and keep it in a sort of controlled stumble condition. You will litterally steam-clean the combustion chambers. Or, if you can find some sensor-safe Sea-Foam or similar product, it will be safer than the water method. On old cars, you'll get a black puddle by the tail pipe. On your Neon, the honeycomb of the catalyst will catch a bunch of that stuff, and it will have to burn off over time. Usually though, carbon deposits give a consistent problem at all operating conditions, but will be worse as the throttle is opened...

Good luck!!!

My mother asked me to check a Dodge Dart she was driving because it made a squealing noise. I checked the oil and found only metallic dust on the dipstick. I started the car and heard the army of hammers working inside the engine block. I poured 4 quarts of 70W aircraft oil in the motor, and the knocking almost went away. She was able to drive that car another 18 months. It was a bit slow to start in cold weather.

Most likely your engine is going "lean" due to one of the following:

1. A vacuum leak such as a failed EGR valve.

2. Your FI throttle body low speed bypass circuit is sticking and needs cleaning.

3. The throttle position sensor is worn out or loose or out of adjustment and is feeding the wrong signal back to the ECM.

4. All of the above conditions will not generate a fault but will cause the engine to knock at low speeds.

5. Once the engine is above design "low speed RPM" threshold, the bypass, EGR, and Throttle positioner issue doesn't affect the perfromance due to the pulse width of the fuel injectors bieng wide and the engine will be running rich in order to produce the power hence "no knock" just a black exhaust pipe.

If you have good mechanical/electrical skills an OEM or after market repair manual will guide you through the steps to troubleshoot your problem. Otherwise spend the money and take the car to a reputable repair facility and they will "fix" it.

Good luck!

If you think you have two different sounds, I would suggest that you test for each of the conditions.

If you think you hear a knocking sound when cold, the worst thing that is repairable chemically would be a bearing knock. Adding a viscosity booster such as STP oil treatment, or any other thick honey like additive will thicken the oil, and if the oil clearance is too much when cold, the thicker oil will quiet it right down. If it does not, have your oil pressure checked with a quality pressure gauge and compare results to the specs.

If the other noise is pre-ignition pinging, an increase in octane will reduce it, or stop it. If octane, from high test gasoline, or an aftermarket octane booster helps, you will need to know what the cause of the pre-ignition is. Is the temperature of the coolant too high? Is the knock sensor bad? Cam sensor, crank sensor carbon build up? All are possible causes. Is the car a city dweller that never gets any highway engine speeds? If so a carbon removing treatment MAY help. I have used plain water as a carbon removing treatment for almost 40 years. But I have also bent a connecting rod, and spun a rod bearing doing this. Watch your engine speed, and the amount of water going into the air inlet. Any and every repair will be more expensive in time and money if you rush the water treatment. I have used the ported vacuum port on throttle bodies and carburetors combined with the thinnest hose available with consistently good SAFE results. I would suggest at least a quart of clean tap water for a fair test to see if the water is removing sufficient amounts of carbon to remove the pre-ignition.

Go slow and one change at a time. Do not damage the engine trying to remove pre-ignition that could be cured with three dollar a week gasoline upgrade. Good luck.

UP-DATE:

OK the premimum gas went in, and at first run it does seem to have lessened the amount of knocking/pinging. So it has helped. not gone, but helped, will see if it improves more as time goes on.

Now two questions, I havent done the carbon removers yet. Still a good idea?

And this knocking and pinging, if it doesn't go away, what does it do to the engine? Will it eventually damage anything?

Joe

In time it will erode the top of your piston away. As the piston gets weaker, it will eventually burn a hole in a piston. Good luck.

Total and utter rubbish......

I agree completely.

Maybe cheap Chinese or Russian petrol might possibly damage some engines (although I have never ever heard of that either), but normal DIN products and a motor in a normal or better condition never........

The car will (if you are lucky and its adjusted correctly) might do a mile or two more per gallon.....that will be the only difference....

It won't be any faster, except maybe on a test bed......maybe a percent or two more BHP, again, if you are really lucky....don't expect that.

The only way I have seen pistons burnt through is when the wrong plugs (temperature and/or length) are used and or when a plug is physically damaged and the spark transfers to the piston crown.....there are probably other reasons like missing oil cooling spray on some engines for example, water cooling missing for some reason, etc etc, but fuel never....

Even converted petrol engines to gas (CNG and the like) which run far hotter than with petrol, for example, pulling heavy loads using gas is often not allowed, now they can burn a piston through if driven badly/wrongly.....and that does not happen that often either as far as I am aware....

So,

This level of pinging has gone down at least so far probably 75%. It was really bad, it sounded like a diesel. It is a LOT less now. so Better. I'm still going to try to find some of the Mopar cleaner and run a can of that.

Granted this premimum gas aint cheap he he he but it's better than pinging so bad.

so the pinging is NOT? going to hurt it? it just sounds nasty and probably is hurting power right?

Joe

Pinging is always bad. The action of the premium grade in reducing it quite dramatically implies that the engine timing is off, maybe due to a bad sensor or some adjustment.

Pinging is actually there before you can hear it, if you can hear it that's bad, you must get it fixed as the sound is of the petrol exploding (instead of burning) and suddenly loading up the piston, in some cases causing the bearings to make metal to metal contact.

As pinging is an indication of a too early spark, another effect is that the engine may run warmer than it should. You may not see this directly on the temperature gauge as nowadays the markings are sht* anyway....

You must get it fixed properly as soon as possible, the longer you take, the more you may be damaging your engine.....I am also sure that an average mechanic could fix this.

Close, but not exactly right.

Pre-detonation or pinging causes a pressure spike that can be very severe and of very short duration. That pressure spike can actually disrupt the boundary layer of gas that surrounds and protects the piston crown. Pre-detonation, in severe cases, can create short spikes of combustion temperatures in excess of 1,800°.

1800° will normally melt a piston, but the reason it does not is there is normally a boundary layer of gases over the piston crown. Aluminum is also very good at wicking heat away from the hot spots and the shape is designed to do just that.

When the engine pre-detonates, the resulting shock wave can disrupt that boundary layer of gas over the piston crown and it can cause melting of the piston crown due to excessive heat (in theory). Left to its ultimate end it could melt through the piston crown, but it is much more likely to distort the piston due to thermal expansion and cause contact with the cylinder walls long before that would ever happen. It sort of follows a thermal runaway scenario where the engine starts to heat up from pre-detonation, The excess heat causes more pre-detonation and the cycle runs out of control (much like some CR4 arguments on climate change :) ).

Additionally, when there are carbon deposits on the piston crown it will compound the problem. Carbon does not allow fast heat transfer and it will act as a pre-ignition source for the pre-tetonation. This will cause melting at the crown and in severe cases collapse the dome of the piston.

Pre-detonation melting will lead to the piston seizing. When the piston scrapes the cylinder walls it can also damage the rings as aluminum is scrubbed off. This results in a more hot gasses blowing by the rings and yields more heat and more melting.

Pre-detonation may be the root cause and it may even cause piston crown melting, but it also causes a cascade engine failure effect that can lead to catastrophic engine failure from the excessive engine heat. A post mortem of the engine usually shows melting on the piston walls, which many people directly attribute to the initial pre-detonation, but it is not exactly the case. However, in the example pictured above, the crown melting is a direct result of pre-detonation.

A far better explanation than mine, many thanks.

It shows again that incorrect ignition can be an engine killer, not premium gas!!!

Premium gas is a waste for most modern cars, but a necessity for a few.

Absolutely correct.

Has already been said a few times here, also correctly!

So was my reply correct or not? Your answers seem to disagree with me, and then agree with AH.

I demand an answer. I have a right to know. The truth must be known!

Too high an octane will not harm an engine (assuming that all fuels discussed are available as standard in any filling station). It is just a waste of money basically as the gains usually do not reflect the price difference.

BUT a TOO LOW an Octane can harm an engine not made for it, not adjusted to use it, or with an ECU that cannot automatically adjust enough to use it. Most modern engines usually have such a "knock" sensor that tells the ECU that the ignition must be retarded when low Octane is used. Whether or not the range of timing will be enough to use the lower octane fuel correctly is a question that only the car manufacturer can answer.

The dangers associated with too low an Octane are often overheating and possible damage to pistons, gaskets, plugs, cylinder heads, valves and even bearings in the piston and bottom end of the motor. This list is probably not even complete... Knocking is really bad for an engine....

Very low Octane fuels typically need an engine with a lower compression ratio as well, so a high performance engine, especially one without a turbo, may not be able to burn the fuel without knocking, because of usually having a very high compression ratio.....again, ask the OEM for this information.

Foe example, the (very!!!) old European tractors generally had around 6:1 compression, burnt petrol at around 80 Octane for starting and stopping, but could run on paraffin when warm....using a carburetor!

Engines with Turbos, sometimes use a relatively "normal/low" compression ratio, so that they may actually be able to burn lower Octane fuel provided that the ignition adjustment can be set correctly, or that the knock sensor can adjust it to a valid value. Again, only the car OEM can accurately answer this question.

Different vehicle OEMs have different ideas and different setups, it is not possible to cover all differences in a proper and valid manner, so I have just covered in a manner of say "Pinking 101"

I found quite a good description here:-

Engine_knocking

Please therefore accept that the above is only a very simple overview to allow almost anyone here to understand the basic reasons behind "knocking", "pinging" or "pinking" as it is called in the UK.

I can assure you that this information on its own is not enough to allow you for example to program an ECU correctly to make an engine burn any octane petrol correctly. Such work is very knowledge/experience intensive.

I trust Bob c that this small offering is fully acceptable to you at last.

Well................. I was actually hoping for a sacrificial virgin, but this will have to do.

There were some engines here that just always seemed to ping, but with no harm. The Chrysler slant six comes to mind. Seems like they all would ping a little, and it never bothered them. But the big GM V-8s were different. If they started to ping, there was something wrong that needed to be corrected.

Just thinking ahead here. Still gonna have the sensors checked out, And run the Mopar carbon cleaner stuff. and see what happens.

Will also try the regular gas to see if it gets worse again, if it does will try the higher octane premimum again to see if it again lessense the pinging.

Now while several here said the octane boosters are more or less useless. How high of n octane can one go?

Been reading how people boost the octane by adding Toluene to the gas.

Yes? No?

Joe

Octane boosters, and higher octane gasoline are good for testing, but there is another reason your car is pinging(if that is what you hear). I do not think I could recommend the long term use of either of these. They will eat you up money wise. For a short time while evaluating is one thing, but if there is some reason for the pre ignition, it is only going to get worse if not corrected. You could connect the windshield washer reservoir hose to the throttle body, and go for a ride. With the car at 35 or faster, just turn on the washers, and let the water clean out the carbon as you drive. It would probably be worth it to remove the wires from the wiper motor while doing this. Good luck.