what is engine knocking mean

Asked by Jul 05, 2013 at 08:37 PM about the 2006 Nissan Altima 2.5 S

Question type: Maintenance & Repair

engine knocking when stopping and turning car off

4 Answers

When stopping...keeps running is a phenomenon called "dieseling" which means that the combustion chamber is running hot and the fuel supply isn't being shut-off when the key is turned off~ might be a stuck relay...see what the trouble codes tell us~

1 of 1 people found this helpful.

I kind of puzzled your complaint and instantly thought "detonation", which is real bad and usually occurs when you've got an out-of-position distributor OR the engine was put together wrong~....but thankfully is just dieseling~....whew.

25,615

Just to supplement what the Judge said....From Wikipedia : Knocking (also called knock, detonation, spark knock, pinging or pinking) in spark-ignition internal combustion engines occurs when combustion of the air/fuel mixture in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front. The fuel-air charge is meant to be ignited by the spark plug only, and at a precise time in the piston's stroke cycle. Knock occurs when the peak of the combustion process no longer occurs at the optimum moment for the four-stroke cycle. The shock wave creates the characteristic metallic "pinging" sound, and cylinder pressure increases dramatically. Effects of engine knocking range from inconsequential to completely destructive. Detonation can be prevented by any or all of the following techniques: the use of a fuel with high octane rating, which increases the combustion temperature of the fuel and reduces the proclivity to detonate; enriching the air-fuel ratio which alters the chemical reactions during combustion, reduces the combustion temperature and increases the margin above detonation; reducing peak cylinder pressure by decreasing the engine revolutions (e.g., shifting to a higher gear, there is also evidence that knock occurs more easily at high rpm than low regardless of other factors); decreasing the manifold pressure by reducing the throttle opening, boost pressure or reducing the load on the engine.

4 of 4 people found this helpful.
255

There's a recall by Nissan to fix this very problem. It has to do with the Engine Control Valve. Call your Nissan Dealer for details, and they will set you up.

4 of 4 people found this helpful.

Your Answer

Add photo

Related Questions

Altima

Looking for a Used Altima in your area?

CarGurus has 81,564 nationwide Altima listings starting at $1,200.

ZIP:

Search Nissan Altima Questions

Nissan Altima Experts

#1 Tom Demyan
Tom Demyan
Reputation 2,050
#2 Cassie Sapphire
Cassie Sapphire
Reputation 660
#3 putolile
putolile
Reputation 630
View All

Related Models For Sale

Used Nissan Maxima
306 Great Deals out of 25,213 listings starting at $999
Used Honda Accord
813 Great Deals out of 84,287 listings starting at $1,050
Used Toyota Camry
1,011 Great Deals out of 90,917 listings starting at $650
Used Honda Civic
656 Great Deals out of 88,603 listings starting at $995
Used Nissan Sentra
480 Great Deals out of 54,266 listings starting at $900
Used Toyota Corolla
785 Great Deals out of 73,830 listings starting at $1,995
Used Hyundai Sonata
779 Great Deals out of 51,051 listings starting at $1,400
Used Chevrolet Malibu
950 Great Deals out of 79,654 listings starting at $1,500
Used Ford Fusion
1,120 Great Deals out of 83,259 listings starting at $998
Used Kia Optima
462 Great Deals out of 29,998 listings starting at $1,995
Used Dodge Charger
407 Great Deals out of 28,172 listings starting at $1,988
Used Chevrolet Impala
521 Great Deals out of 31,725 listings starting at $1,450
Used Ford Mustang
472 Great Deals out of 45,735 listings starting at $1,999

Used Cars For Sale

2017 Nissan Altima 2.5 S For Sale
13,826 listings starting at $16,995
2016 Nissan Altima 2.5 S For Sale
49 Great Deals out of 3,752 listings starting at $10,900
2015 Nissan Altima 2.5 S For Sale
159 Great Deals out of 5,178 listings starting at $8,995
2014 Nissan Altima 2.5 S For Sale
172 Great Deals out of 3,362 listings starting at $4,200
2013 Nissan Altima 2.5 S For Sale
24 Great Deals out of 1,273 listings starting at $3,900

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.