Code P1326 knock sensor, is there a way to test the knock sensor?

TOTALMC

MEMBER
2015 HYUNDAI SONATA
2.4L
4 CYL
2WD
150,000 MILES

Customers car listed above. Customer stated, Check Engine Light was flashing and took the car to AutoZone to have checked. Then had me replace knock sensor.

I erased a p1326, and the same pending, but it said there was a p1326 permanently stored, which I could not erase.

Upon starting the engine (with the new sensor), I thought I could hear a knock - especially between 2,000 and 3,000 RPMs. The customer then decided to tell me that the sound was there the whole time (after repeated conversations of how the knock sensor works, which I don't know why he wouldn't give me that info then).

The Check Engine Light is back on after a 15-minute drive. Customer says knock kind of went away.

So, if this were a rod knock, wouldn't it have been always there, not just intermittent?

I have the old knock sensor; is there a way I can check it to see if it was operating correctly?

Thanks for any and all ideas.

5 Replies

JACOBANDNICKOLAS

MECHANIC
109,867 POSTS

Hi,

Yes, it can be tested. What you need to check is resistance/Ohms. Set your multimeter to ohms. Place the + connector pin to where the wiring harness connector would go and the other connector pin to the housing (metal) of the sensor. If the sensor is good, it will read between 93 and 110 ohms.

Let me know if this helps or if you have questions.

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Sunday, June 19th, 2022 AT 10:16 PM

TOTALMC

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Okay, thanks for the sensor info.

If it checks out that the sensor is good, does that mean I do have a rod knocking on an engine with only 130,000?

Customer has been driving vehicle and says sound " kind of went away ". I'm under the assumption that if it were a rod knocking, it would be clearly evident, and never goes away.

Thanks again for any info.

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Monday, June 20th, 2022 AT 8:08 AM

JACOBANDNICKOLAS

MECHANIC
109,867 POSTS

Hi,

It is possible, but as you said, a rod wouldn't change. I would need to hear it. Also, can you tell where the sound comes from? For example, is it the loudest above or below the engine? Does it seem to be more pronounced at the front or rear of the engine?

Take a look through this link. You may find it helpful.

https://www.2carpros.com/articles/engine-noises

Keep in mind, the knock sensor's job is to fine-tune ignition timing. At 130,000, I wouldn't think the timing chain has stretched, but it is possible.

Let me know.

Joe

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Monday, June 20th, 2022 AT 9:59 PM

TOTALMC

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106 POSTS

Well, the customer drove the car another day or two, then it shut off and he had it towed home.

I thought his battery was no good because it dropped to 6 volts while cranking. After two tests and recharges, and then a replacement battery - all of which still dropped to 6 volts while cranking, I decided to remove the spark plugs and passenger wheel and put a bar on the crankshaft pulley.

Stuck, stuck, stuck, it wouldn't budge. So, I guess the engine seized, right?

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Saturday, June 25th, 2022 AT 1:09 PM

JACOBANDNICKOLAS

MECHANIC
109,867 POSTS

Hi,

If you are unable to turn the engine at the crankshaft pulley, it is likely seized. I have a feeling the knock you heard was a rod bearing.

Hyundai extended the powertrain warranty for rod bearing issues. It was 10 years or 120K miles. See pics 1 and 2 below.

These things are starting to show up just out of the warranty extension. I just replied to another person with a 2013. He has a hole in the side of the block from the connecting rod coming apart. He is out of warranty by 5K.

Even though this one is further out, I would contact Hyundai and see if they will help. Even if they don't replace the engine, they may pay for part of it.

It's worth a try.

Let me know how this works out for you.

Take care,

Joe

See pics below.

Images (Click to make bigger)