what happens with a bad knock sensor?

[wbzautocustomiz]

What will a bad knock sensor cause? please advise?

 

[Chuck Leeper]

Head gaskets go "poof"...
Crank falls out of the bottom of the block...
At minimum, the ends of your spark plugs "disappear"...

 

[SNOWBIRD]

I snapped a crankshaft passing a tractor trailor (25 psi boost ,100 mph) and all of a sudden i heard a shotgun blast and pieces of engine bouncing on the ashphlt to the under side of my car....scared me and the truck driver to.LOL

 

[wbzautocustomiz]

just checking for trouble shoot

ok that aint good but let me be more specific, car no knock on sm and I am only getting 10-11lbs boost, I am checking have a bad "gremlin" car breaks up at high rpm, have troubleshot all I could; all the crank,cam,tps,map,maf,hoses tight, etc Just seeing if a knock sensor has a malfuntion could it contribute to a bad ruuning car at wot?

 

[87chrisss]

found anything out if the esc module is good or bad?? my car run's fine its @ 20# of boost with alky, but no knock or retard on Scanmaster im wondering if my module is damaged or if Scanmaster isn't rdg it correctly?? no mal codes on Scanmaster either i just bought a casper's knock gauge from a member.. to see if i maybe i can get some type of reading with that?? but i also made sure my tuning parameter's are inline with Basic Scanmaster tune tip's .. are there any way's to test the esc module??? would it give a mal code on the SM? and should my car give some type of retard degree or + (advance) degrees on SM??? anyone got any suggestions??

 

[Grumpy]

take a long extension an tap on the block. Have someone watch the knock . very easy to see if it's working.

 

[87chrisss]

i haven't installed the knock gauge..i have'nt received it in the mail but.....is the stock esc module working?? if it were defective would a mal code be present on the ScanMaster? when i do receive the gauge i just splice the yellow/black stripe wire connected to the ecm and connect to knock gauge and my 12vpositive/neg..but if my esc isn't working what's the point of installing the gauge

 

[87chrisss]

ok i read it would have a mal code 43 so no mal code on my scanmaster so im guessing everything is ok what im wondering is why never retard's any timing never? is that correct? always on 0 that's why i started to think maybe something's wrong with the knock sensor or something?? even in WOT no retard should that be normal

 

[87_we4]

Yesterday was the first day ever I showed knock. 1.2... That was at 18psi on 93 octane. No knock is a good thing

 

[BlackBandit]

If you suspect your knock sensor isn't working follow grumpy's advice. The only thing I would add is to check and make sure someone didn't put tape or something on the threads of the sensor and verifiy it's torqued properly as I believe the torque can affect it's readings. (I'm not %100 on that last part)

 

[Daniel Jost]

To see if its working, tap the block and with a multimeter you will see the signal wire voltage from the esc module go from a constant ~8.5+v to zero or close to it for a split second.

87chriss alky and 20 psi shouldn't detonate. Also I can add my autometer sport comp shows I have 22 psi and my megasquirt ecm shows 14.5 and im 100 percent sure my MAP is correct. I bought the guage band new so I makes me wonder about other autometer products...

,Dan

 

[BlackBandit]

..... my megasquirt ecm shows 14.5 and im 100 percent sure my MAP is correct. I bought the guage band new so I makes me wonder about other autometer products...

,Dan

you're not running a 2 bar map are you?

 

[Daniel Jost]

Haha, no as soon as I posted it I realized I should have specified im running a 4 bar map because I would have asked the same thing... they come standard with a 2.5 barmap and its readings were the same so im positive it is correctly calibrated. Also 22 psi on 91 would detonate bad!

,Dan

 

[87chrisss]

well im running a VDO boost gauge but 1/2 the time dam turbo spools up so fast i cant look at the gauge i gotta look straight or i'll end up eating a tree. so once im wot ive glanced once or twice it was around 20# or maybe 21# VDO gauge light isnt very bright at night are VDO's 100% accurate on Boost rdg's?