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9 votes

How can I be sure that a rod knock is actually a rod knocking?

When you start the engine and you hear the sound, does it sound better after the vehicle is warmed up? A rod knock will only sound worse (louder) as the engine heats up. It will not go away as the ...
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5 votes
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Diagnosing pinging issue in 2003 Nissan Sentra

Pinging is caused by one of several different reasons. It is usually a hot spot in the combustion chamber which is causing the issue. A hot spot is usually made of carbon buildup, the edges of which ...
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4 votes

How can I be sure that a rod knock is actually a rod knocking?

Sometimes it is hard to tell the difference between a rod knock, wrist pin or piston slap in the early stages even when using a mechanics stethoscope. A main knock is a deeper sound that is more ...
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3 votes
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2003 Dodge Ram 1500 3.7 engine knock

The 3.7 is notorious for having a rocker arm fall off and or lifters collapsing. This is usually accompanied by a check engine light being illuminated. Use a stethoscope or a long screw driver and ...
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  • 10.7k
3 votes

If a car has a rod knock what is no good the head or the block?

There's no way to tell for sure, but since a true "rod knock" has nothing to do with the block or the head, you could most likely reuse both of them. You'd probably want to do some work to them to ...
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3 votes
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Drove over a semi-large rock and now vehicle vibrates in Park - Goes away in Drive

It's possible but unlikely that the engine mounts are the problem, at least they wouldn't be the only problem that needs to be addressed. An engine mount is a flexible cushion that connects the engine ...
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  • 14.5k
3 votes
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Van makes knocking noise, even after it has been off for hours

It sounds like the shutting mechanism for the door is not quite getting the door closed, or maybe the switch which tells the door closer to do its thing is broke. As @NateEldredge says, get the ...
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3 votes
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How often does my engine check fuel octane?

The ECU(or at least the better ones) can indeed actively 'search' for the point of pinging as you said. The pinging sensor listens to the combustion, based on that the ECU determines how close it is ...
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3 votes
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Is it common for ECU's to maintain individual limit maps for each knock sensor?

Yes, it is quite common. I initially said that it isn't, but I was wrong. I had another look at my Subaru's mapping and saw that there are more ignition timing tables than I first thought. Here's a ...
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2 votes

Honda FIT GP1 HYBRID 2011 knock

I don't think you replaced the injectors. I think you replaced the spark plugs. Injectors are what spray gas into the combustion chamber, and those are usually replaced or cleaned on older cars. You ...
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2 votes

How often does my engine check fuel octane?

The only sensors used to determine fuel quality are the knock and mixture (Oxygen) sensors. The adjustments are continuous whenever the engine is running. The vehicles I have experience with, this ...
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  • 11.5k
2 votes

2001 Toyota Sienna LE P0330 Error

It is more than likely not the sensor. The problem lies in the circuit which goes to the sensor. Replacing the sensor is probably the last thing I'd do in this case. In this case, I believe it is ...
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2 votes

How can I tell if I would benefit from higher octane fuel?

Having a live scan running is by far the easiest way to tell if the ECU is pulling timing while the engine is running. Beyond that, you need to be aware of what the manufacturer's requirement for an ...
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2 votes

Why is my car making a knocking noise?

The 2001 Sebring with the 2.7 engine holds 5 quarts of oil. Sounds like you ran it out of oil. That would make the engine knock and do all kinds of bad things to the internal engine parts. If you ...
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  • 9,035
2 votes

02' GMC Envoy. Engine KNOCK, not rod knock

Another thing it could be is a failing exhaust gasket between the header and the head. These types of leaks will exhibit the knocking sound, but often quiet when things warm up and expand. Sometimes ...
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2 votes

Can exhaust problems cause a knocking sound in anyway?

Because you can move it by hand means it can probably move enough to hit something. So, replace the supports holding the exhaust for stronger ones or fit 2 loops instead of 1. Did that on a car once -...
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  • 34.4k
2 votes

Can exhaust problems cause a knocking sound in anyway?

If you can move the exhaust by hand, there are a few options: (Remember that your exhaust line is steel, which typically doesn't flex well.) You've lost a stud or a nut where the line meets the ...
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  • 3,134
1 vote

Knocking sound from under car when going slow, what are the likely causes?

Your issue is probably connected with driveline. I will assume that it is rwd/4wd car as you are suspecting driveshaft problems. To diagnose whether it is driveshaft related problem, drive slowly ...
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1 vote

Sudden pop when turning, what could be cause?

it's usually the ball joint on the opposite side of the direction you turn in. If they go bad, they can freeze and you can get a pop as it unseizes. It could also be a cv axle but you would have ...
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  • 616
1 vote

Drove over a semi-large rock and now vehicle vibrates in Park - Goes away in Drive

The problem was a bent crossmember touching the tranny. I was told I could continue to drive with it but would always have vibrations but it's under 300 to fix so I'm fixing it. Fingers crossed that ...
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1 vote

Engine knocKing noise...please help

When it comes to engine knocks, I like to verify the worst possible scenario 1st, and that is rod knock. From a professional view, if this is the cause of the knock, depending on the value of the ...
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  • 624
1 vote

If a car has a rod knock what is no good the head or the block?

Generally, a "rod knock" occurs when the clearance between the connecting rod journal and the crankshaft rod journal is out of specifications. This can happen for numerous reasons; most common reasons ...
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  • 111
1 vote

02' GMC Envoy. Engine KNOCK, not rod knock

any way to record and upload the sound it is making? Usually a knock does not happen when the engine is cold and at low / idle RPM. Have you kept up with changing your oil and did it run low last ...
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  • 2,859
1 vote

Oil change: level was so low it didn't show on the dip-stick?

Without oil the engine could be damaged, yes. Oil is essential to keeping your engine running and healthy. An engine knock can be a sign of problems so get it thoroughly checked out.
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  • 18.5k
1 vote

Knocking/clunking sound coming from back end on flat road

Visit a wheel alignment shop and ask them for an inspection. Usually, rubber bushings wear out causing metal to metal contact. Could be strut mount, trailing arm bushing, link bar, upper or lower ...
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  • 163
1 vote
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What will happen if the knock sensor fails?

Most knock sensors in use today are microphones. The most common sensor type is a piezoelectric crystal type. Failure is detected by: 1 Testing the circuit during a power on self test. 2) watching for ...
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  • 11.5k
1 vote

Why is my car making a knocking noise?

Kinda sounds like you lost the lower end of the engine. How much oil does the engine hold? If it holds 4qts and you had to add 4qts. It was most likely ran with out oil and took out the lower end(...
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  • 813
1 vote

Knocking in a 1970 Dauntless V6

If you still have knocking, it means that there is too much clearance somewhere. While you replaced the main crank and rod bearings - did you have the crankshaft ground and the new bearings matched ...
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  • 34.4k
1 vote
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What is this knocking noise in my 2002 Corolla?

Turns out there is a billion out on this problem. I don't wanna play links but it's there. Inside of the intake there is a baffle that comes loose and creates this noise.
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1 vote

Bad exhaust leak or valve interference after HG change?

It was indeed an exhaust leak. One of the exhaust gaskets wasn't on one of the studs so it didn't seal properly. I fixed it and the knocking is gone. But it didn't get rid of the smoke completely, ...
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