Why does knock sensor keep vehicle from starting

70

Asked by Jul 31, 2015 at 07:43 PM about the 2003 Buick Rendezvous

Question type: Maintenance & Repair

10 Answers

68,995

When the knock sensor senses a tap,it shuts motor down to keep damage from engine.

1 of 1 people found this helpful.
70

Only when it's been drvning around and is warm when it cools it starts rte up

3 of 3 people found this helpful.
70

The sensor gets hot and retards the timing hense the no start out of time

1 of 1 people found this helpful.
68,995

Yes, Joe in a way it does, show when timing is off all so,it is about like a cam or crank sensor,it is a pulse signal,which goe,s to the ECM,and control firing and fuel in turn shutting it down if there is a issue with any of these.

71,025

The knock sensor is like a microphone. It listens to the engine and if it hears spark/knock or pinging it sends a signal to the computer. The computer then begins retarding the ignition timing until the pinging stops and the knock sensor stops sending the signal. If you use cheap gas and the engine pings as a result the computer compensates for it as I've explained. Now if the engine develops a valve tap or other noise the knock sensor can pick that up too. When this happens, as did on my '93 Caprice, the ignition timing will be severely retarded and effect engine performance. But it will not cause a no start condition. You'll get loss of power, running hot, boiling over when the engine is shut off, and possibly popping back through the throttle body. But, again, it'll still start. I'd suggest checking for a no spark condition when your Buick refuses to start. Sounds like the ignition control module is getting hot and breaking down. HTH. -Jim

52,735

Knock sensor will not prevent it from starting.

1 of 1 people found this helpful.
70

What about the 02circuit no activity detected bank 1 sensor 1

1 of 1 people found this helpful.
71,025

No, it will just keep the engine in open loop operation. But it'll still start and run. HTH -Jim

70

What about the ignition relay

71,025

Let's start with the basics. Spray some starting fluid down the throttle body and see if it'll run a few seconds on the starting fluid. If it does, you have spark (ignition) but no fuel. If it won't run off the starting fluid you don't have spark or compression. Check for spark first by removing one spark plug wire and sticking large screwdriver in the end of the spark plug wire that plugs onto the spark plug. Be sure that the screwdriver has a plastic or wooden handle so you don't get a powerful shock! Hold the metal part of the screwdriver close to something metal that's not painted while a helper cranks the engine. The exhaust manifold works well for this test. As the engine is cranking you should see and hear a strong spark jump from the screwdriver to the exhaust manifold. It will sound like SNAP-SNAP- SNAP. If you have spark and it wouldn't run on the starting fluid time for a compression test. If all cylinders test low or zero it's jumped timing and won't run until the timing chain and sprockets are replaced and the valve timing is properly set. HTH. -Jim

1 of 1 people found this helpful.

Your Answer

Rendezvous

Looking for a Used Rendezvous in your area?

CarGurus has 1,023 nationwide Rendezvous listings starting at $999.

ZIP:

Buick Rendezvous Experts

  • #1
    jimmypd65
    Reputation
    720
  • #2
    Bilhar
    Reputation
    630
  • #3
    Clamblin85
    Reputation
    600
View All

Related Models For Sale

Used Ford Escape
1,049 Great Deals out of 95,775 listings starting at $1,200
Used Nissan Murano
363 Great Deals out of 25,462 listings starting at $1,895
Used Honda CR-V
770 Great Deals out of 57,949 listings starting at $1,850
Used Saturn VUE
29 Great Deals out of 2,020 listings starting at $990
Used Cadillac SRX
422 Great Deals out of 9,748 listings starting at $1,995
Used Toyota RAV4
730 Great Deals out of 47,059 listings starting at $1,195
Used Kia Sorento
484 Great Deals out of 29,508 listings starting at $2,000
Used Ford Explorer
935 Great Deals out of 69,577 listings starting at $1,495
Used Jeep Grand Cherokee
869 Great Deals out of 70,549 listings starting at $700
Used Honda Pilot
516 Great Deals out of 36,594 listings starting at $500
Used Honda Accord
1,016 Great Deals out of 60,156 listings starting at $1,099

Used Cars For Sale

2007 Buick Rendezvous For Sale
4 Great Deals out of 168 listings starting at $1,995
2006 Buick Rendezvous For Sale
6 Great Deals out of 234 listings starting at $2,496
2005 Buick Rendezvous For Sale
188 listings starting at $999
2004 Buick Rendezvous For Sale
174 listings starting at $3,000

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.