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

65,695

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.
65,695

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.

67,375

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

47,755

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.
67,375

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

67,375

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

Add photo

Related Questions

Rendezvous

Looking for a Used Rendezvous in your area?

CarGurus has 1,095 nationwide Rendezvous listings starting at $1,995.

ZIP:

Search Buick Rendezvous Questions

Buick Rendezvous Experts

#1 jimmypd65
jimmypd65
Reputation 700
#2 Bilhar
Bilhar
Reputation 570
#3 Clamblin85
Clamblin85
Reputation 560
View All

Related Models For Sale

Used Ford Escape
1,421 Great Deals out of 90,829 listings starting at $900
Used Ford Explorer
926 Great Deals out of 70,243 listings starting at $997
Used Hyundai Santa Fe
295 Great Deals out of 19,274 listings starting at $800
Used Nissan Murano
325 Great Deals out of 25,849 listings starting at $1,200
Used Chevrolet Impala
589 Great Deals out of 34,066 listings starting at $899
Used Jeep Liberty
261 Great Deals out of 7,307 listings starting at $991
Used Jeep Grand Cherokee
1,014 Great Deals out of 72,235 listings starting at $700
Used Buick Rainier
7 Great Deals out of 287 listings starting at $2,500
Used Honda Accord
941 Great Deals out of 77,703 listings starting at $899
Used Chrysler Pacifica
49 Great Deals out of 27,731 listings starting at $1,900
Used Honda Pilot
391 Great Deals out of 22,287 listings starting at $1,500

Used Cars For Sale

2007 Buick Rendezvous For Sale
7 Great Deals out of 133 listings starting at $3,900
2006 Buick Rendezvous For Sale
10 Great Deals out of 259 listings starting at $1,995
2005 Buick Rendezvous For Sale
219 listings starting at $2,100
2004 Buick Rendezvous For Sale
211 listings starting at $2,500
2003 Buick Rendezvous For Sale
141 listings starting at $1,995

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.