can broken engine mounts set of the knock sensor?

[admir87]

hello everyone

lately ive been getting a rather odd hesitation/sluggish feel when i take off hard off the lights... it feels as if somethings holding it back for a few seconds until it reaches around 2500-3000rpm then it all of a sudden takes off

i checked leads, spark plugs, fuel filter, cleaned throttle and plenum, air filter, but still nothin has helped

then i noticed the other day my engine mount has broken on the left side causing the engine to move alot on take off

could this be setting of the knock sensor and causing the hesitation??

what else could be causing this?
its very annoying as the car feels alot down on power, then gets a surge of power of a sudden after 2500-3000rpm

btw the car is a vs calais series 2 v6

[BONSVR]

knock sensors go off when they sense the engine is detonating.

[hako]

You can simulate it by hitting the block or head with a hammer (this is not a joke). Do a search on it as testing the sensors involves doing this ........I'd check first exactly where to hit with the hammer. I'd imagine that the knock from the engine mounts would only affect the car for a split second as the ECU reacts instantly.

[greenfoam]

Even the loose rocker setup from a solid cam can make the go off so for sure a busted mount can

[BONSVR]

well then i'd say yes, because if the engine moves, i'm sure it would simulate a knock

[aceventura]

I'd be surprised if it did. I would imagine that the vibrational frequency caused by a broken engine mount is much lower than that caused by pinging. If a broken engine mount could cause the problem, then wouldn't bumps in the road etc...etc set them off?

As Hako said, you use a hammer to test them - this is going to be high frequency vibration in the block.

[admir87]

will try and check the hammer way if same sorta thing happens

on the other note,
what could be causing hesitation up till 2500-3000rpm, then all of a sudden it takes off??

its like as if something is holding the car back

just thought the broken engine mount might have something to do with it

[VrWagz1]

could be just a dodgy lead or plug.

[delcowizzid]

if its broken and the engine is banging the exhaust against the body or hitting the k frame can set them off easy as

[chrisdoesitbetter]

i thought the knock sensor olny went off when the engine was pinging? but i can understand if the engine mount is that loose that the engine can move and trick the sensor... try the old hammer trick

if youv checked fuel and ignition then try checking the trans...

[admir87]

i thought the knock sensor olny went off when the engine was pinging? but i can understand if the engine mount is that loose that the engine can move and trick the sensor... try the old hammer trick

if youv checked fuel and ignition then try checking the trans...

ive checked fuel wise, and checked coils leads and plugs

what could be with the trans? i know its not slipping...

[admir87]

bump.......

[admir87]

bump......

[immortality]

many things can effect the ecotec. dodgy TPS. leaking or blocked injectors and tired/stuffed O2 sensors.

have you tried cleaning the MAF?

the only things i haven't changed on my ecotec is the CAS and cam angle sensor, everything else is new and she goes like a rocket now.

does your car use coolant?

[admir87]

any other ideas? could anything be wrong with the gearbox, i know its not slipping, but could it be anything else

[immortality]

the best way to diagnose is with a ALDL cable and efilive or scannerpro type diagnostic software.

this way you can see exactly which sensor is playing up. otherwise you have to go through a process of elimination with usually means replacing parts untill you find the culprit.

personally i'd start with the O2 sensors if the car has more then 150,000km's on it and the original O2 sensors are still fitted. having said that, there is a common factory fault with the O2 wiring (4wire O2, VS models only) and you really need to check it with diagnostic software to ensure proper fuction otherwise your new O2 sensors could be stuffed in a couple weeks

[admir87]

the best way to diagnose is with a ALDL cable and efilive or scannerpro type diagnostic software.

this way you can see exactly which sensor is playing up. otherwise you have to go through a process of elimination with usually means replacing parts untill you find the culprit.

personally i'd start with the O2 sensors if the car has more then 150,000km's on it and the original O2 sensors are still fitted. having said that, there is a common factory fault with the O2 wiring (4wire O2, VS models only) and you really need to check it with diagnostic software to ensure proper fuction otherwise your new O2 sensors could be stuffed in a couple weeks

how do i go about getting one of those aldl cables and the software, best and cheapest way??

[immortality]

software is free t odownload for trial. you can make your own cable if your electronically inclined or you can buy one. you see em on ebay sometimes or try delcowizzid.