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How can you stop an engine from knocking?

8/10/2017 3:17 PM  | Author: Henry

How can you stop an engine from knocking?

There are two types of 'knocking'. Hopefully, your problem is the first type I've listed below...!

1.Knocking (or 'pinging, pinking or pre-ignition) is usually cause by incorrect ignition timing or by using fuel with an octane rating that is too low. So, either used fuel with a higher octane rating or get the ignition timing looked at. (Many modern cars have knock sensors that automatically retard the ignition to prevent pre-ignition. It could be that the system has failed, so get the codes read).

2. Knocking can also be a heavy, mechanical noise, cause by the clearance of a bearing (or bearings) being too large. Such as big end knock (crank to piston rod bearings) main bearing knock, or a lighter more metallic knock from the piston rod to piston crank pin (or wrist pin). These problems are usually caused by wear due to sheer age, lack of (or improper) lubrication, excessive revs... etc.

If you're getting the latter, there isn't much you can do apart from getting the engine extensively overhauled or rebuilt.

If a higher grade of fuel doesn't stop the problem, you need to take it to a shop for further investigation.

If the engine were heavily coked-up with carbon deposits, this can also lead to pre-ignition, but it tends to be very rare in modern engines using modern fuels. (In days gone by, an engine would need a 'decoke' as often as every 30,000 miles! You hardly ever hear of this needing to be done nowadays).

If you mean due to the gasoline, There are all kinds of additives, most of them deadly poisonous, that can prevent knocking.

If you mean knocking in a particular engine, there always is something wrong, like the timing is way off, or there are deposits in the cylinders, or the knock sensor is bad.

the simplest cure to knocking, if it is the detonation type of knocking, is simply select a lower gear and let your poor engine spin at a decent speed.

the longer you let the flammable mixture in the cylinder a chance to spontaneously combust, the higher the chances that it will. running an engine slowly with large loads is a sure way to cause detonation. as honda found out way back in the 60’s, they could get away with 70 octane fuels, by using engines that revved at 16,000 rpm. answer to pinging, knocking or detonation…stop lugging along in top gear and change down a few gears!

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