what is engine knocking mean

kingb1000
0

Asked by kingb1000 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

judge_roy
Not Active

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 out of 1 people think this is helpful.
judge_roy
Not Active

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.

Racer_X
16,515

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.

2 out of 2 people think this is helpful.
Robert Walsh
215

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.

3 out of 3 people think this is helpful.

Your Answer

Add photo

Related Questions

Altima
Looking for a Used Altima in your area?
CarGurus has 85,761 nationwide Altima listings starting at $1,495.
ZIP:

Search Nissan Altima Questions

Nissan Altima Experts

#1 Tom Demyan
Tom Demyan
Reputation 950
#2 tenspeed
tenspeed
Reputation 450
#3 Cassie Sapphire
Cassie Sapphire
Reputation 320
View All

Related Models For Sale

Used Nissan Maxima"
456 Great Deals out of 13,914 listings starting at $1,800
Used Honda Accord"
1,187 Great Deals out of 62,361 listings starting at $950
Used Toyota Camry"
1,570 Great Deals out of 79,943 listings starting at $1,200
Used Honda Civic"
988 Great Deals out of 63,924 listings starting at $825
Used Nissan Sentra"
615 Great Deals out of 36,206 listings starting at $800
Used Toyota Corolla"
1,261 Great Deals out of 52,501 listings starting at $1,499
Used Hyundai Sonata"
944 Great Deals out of 64,612 listings starting at $1,999
Used Chevrolet Malibu"
1,071 Great Deals out of 57,887 listings starting at $799
Used Ford Fusion"
1,166 Great Deals out of 64,552 listings starting at $2,483
Used Kia Optima"
622 Great Deals out of 34,068 listings starting at $1,087
Used Dodge Charger"
424 Great Deals out of 24,866 listings starting at $3,980
Used Nissan Murano"
358 Great Deals out of 17,071 listings starting at $2,495
Used Chevrolet Impala"
1,237 Great Deals out of 56,621 listings starting at $1,500
Used Mazda MAZDA6"
224 Great Deals out of 15,053 listings starting at $2,400

Used Cars For Sale

2015 Nissan Altima 2.5 S For Sale
50 Great Deals out of 26,710 listings starting at $14,980
2014 Nissan Altima 2.5 S For Sale
122 Great Deals out of 2,907 listings starting at $12,999
2013 Nissan Altima 2.5 S For Sale
144 Great Deals out of 2,956 listings starting at $10,500
2012 Nissan Altima 2.5 S For Sale
117 Great Deals out of 2,955 listings starting at $7,980
2011 Nissan Altima 2.5 S For Sale
26 Great Deals out of 803 listings starting at $7,995