How To Extend Life of An Engine with Rod Knock? Explained

Inside the engine, there are a few rods. When one or more of the engine rods knock against the crank, it makes a ‘knocking’ sound. This usually occurs when the crank is changing direction during its rotation.

When the barrier is compromised, it produces the knocking sound. But can you drive with this knock? How can you extend the life of your engine with this rod knock?

In this article, I will be discussing exactly how you can do that. To learn more about rod knock troubleshoot, read the entire article.

How Long Will an Engine Last with a Rod Knock?

Usually, these rod knocks start suddenly and may continue for up to six months. That means, it can go for as long as 200 miles approximately.

How To Fix a Rod Knock?

As we discussed, the bearing gets damaged due to prolonged use. But it may also get damaged due to any other unusual crank journal damage. Additionally, dirty oil, losing pressure of oil may also cause bearing damage.

So it is obvious that the bearing needs a change to fix the issue. The only way to do that is by dismantling the engine and doing a complete rebuild. Because you need to replace the bearings by pulling out the rods first.

But you need to take care of the crank as well. Because the knocking rods may cause physical damage to the surface of the crank journal. The common damages made by the rod are due to the grinding of the crank journal.

In the place where the rod bearing rides. This polishes off the journal and reduces its diameter.

Turning of the crank journal plays a role here. This damage occurs more with each turning. And there is a limit to the number of turns. Exceeding the limit will render the crank journal useless.

So when polishing the crank journal, it is necessary to make the right turns too. Using thicker bearings is the key to avoiding frequent rod knocks. It will happen eventually but after longer intervals. Make sure the bearing corresponds to the crank turn fixed. 

There are a few more things that cause a rod knock. It can be a faulty air compressor.

Damaged rotor bearings around the pistons and broken flywheels may be the reason too. Breakage of the timing belt tensioner may also be another reason.

Finally, water pump malfunction and lack of lubrication may cause rod knocks.

Before rebuilding the engine, you may want to check the above-mentioned parts and make necessary changes/adjustments.

How to Extend Engine Life with Rod Knock?

Sometimes, the knocking problems don’t demand engine rebuild as a solution. The engine can be made to survive a little longer depending on the severity of the problem.

Carefully change the crank connector rods. You should do this if your engine starts to make a knocking sound. You may also want to change these when the car engine is old. And while we’re talking about rods, check and replace the piston rods if needed.

Additionally, use high-quality lubricating oil. This will prevent any further dirt buildup and reduce the effects of damaged rods and cranks. In addition to lubricating oil, keep the coolant level in mind too. Why? Because coolant is used to run air conditioners and air conditioners keep the temperature cool. This avoids overheating of the engine.

The most important replacement after the connector rods is the crank itself. Abad bearing damages the piston and crankshaft as well. This should be inspected during the initial; search for problems.

Another thing to do is replace the spark plugs. Because it is connected to the connector rods and pistons. Moreover, try to reduce the weight of the engine. An overloaded engine cannot respond properly.

Is It Safe to Drive with a Rod Knock?

It is possible to drive with a rod knock. I won’t say it is 100% safe. You can put on some heavyweight gear oil in the crankcase. The car can be driven for anywhere around 7 months.

But if the damage is too severe, driving might not be a good idea. If it’s not too loud and you can only hear it in the idle, it’s much safer. But if it’s too loud, then driving for a prolonged time is not impossible.

If one of the cylinders is making the knocking sound, diminish the pressure on it by pulling the plug on it. This might lessen the knocking sound. Another thing to follow is to drive slow and keep the revs on the lower side. You might also have to drive slowly.

False Alarm? – Problems Imitating a Rod Knock Sound

Some other problems make a knocking-type of sound. This can resemble the knocking from rod knocking.

Some of these are: loose timing belt tensioner, damaged AC compressor, damaged flywheel or flex-plate, valves sticking or ticking, worn-out water pump bearing or alternator rotor bearing, and exhaust leak.

Misconceptions Regarding Rod Knock

There are some common misconceptions when it comes to rod knock. Sometimes the misconceptions are regarding fixing the rod knock. Sometimes they are regarding some symptom of the rod knock.

Thicker Oil Does Not Stop Rod Knock

Some people think putting a thicker weight oil reduces the rod knock. But this fixes engine knocking. And not a rod knock.

An engine knocking is when the engine fails to perform the peak combustion process in optimum time.

It is not as same as rod knocking. Therefore, a solution for a different problem cannot solve the problem at hand.

Does Not Cause Low Compression

The rod knocking does not cause low compression on an engine.

Low compression might lead to engine knocking. But engine knocking is different than a rod knock.

Final Words

Engine knocking is a very common problem. But the solution is pretty straightforward too. It is possible to increase the life of an engine with an engine knock.

Additionally, maintaining a few things, you can even have a safe drive with an engine rod knock. I hope this article will give you a boost of help towards that direction.

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