Powerfc, Again.. Constantly Low Knock While Driving

[Fredde]

So i solved the idle issue, dont really know if this is a problem but have to ask to be sure..

Had a testdrive and the commander showed small knock readings all the time, 10-13 constantly without any load.

Dropps to zero if the gas is released and break with the engine.

Tried to back the ignition 3 degrees, also tried to add more fuel but the knock doesnt change, could there be something else causing the sensors to go mad?

Did try to put some load to the engine too and got a max reading at 24, but the main concerne is the constant knock..

/Fredrik

[R31Nismoid]

As long as the knock doesnt go about 20-25, dont worry about it.

10-13 is normal dude. There is always going to be some noise.

Thats just part and parcel of the motor innards moving around, a motor isnt 100% silent and thats the 10-20 knock that the sensor is picking up, just engine noise

[180or200]

thats just background noise anything up to 30 I wouldn't worry about, warning light should flash at 60, mine see's 80 if squeeze 1 to many psi into it

[The Mafia]

I try and keep mine below 20. I've heard loud pings 40.

[Fredde]

Thanks, then i dont have to get worried until i can get the car properly tuned..

Never heard about the constant knock readings before..

Better be safe than sorry

Edited May 20, 2007 by Fredde

[ahh 33 s2]

im in the same situation atm with my car.. but after reading this and a few other threads im not as worried as i first was... i had a 79 the other day was a little concerned

[R31Nismoid]

79 is a concern definately

20-25 is not.

[Devils_Advocate21]

what sort of conditions did you recieve the high knock at for 79? thats the question also u need to ask.. but yeah i see about 8 - 10 normally, and mine ive noticed mainly drivetrain related or going over bumps does it too damn knock sensor

[Muffa180]

i have a 32 gtr which knocks to 30 under minimal loads such as cruising and at no throttle when eng braking. Under wide open throttle it doesnt go over 30 but if i add timing the car will ping quite noticably for a split second but the knock level doesnt go over 30. My conclusion is a dodgy knock sensor. Ive had 3 power fcs in 3 previous cars and never have seen this before. Oh and the eng is quiet at all times except ticking injectors. That might help

Thanx michael..

[The Mafia]

maybe grab some other knock sensors?

[NYTSKY]

I use to get 50-70-80 over 6500rpm

[mle808]

I use to get 50-70-80 over 6500rpm

used to?

how did u fix it?

[Muffa180]

you might need to use the map tracer and freeze the tracer when your knock waring light comes on. Then you need to go into settings and reduce the timing in the area you froze the tracer. Start by taking out 1 degree at a time. Im sure if you did a search in the FAQ section there would be a step by step instuction of how to do it.

Thanx Michael....

[buggor34]

will a knock reading of around 70-80 only at high rpm for a small amount of time do much damage to the engine?

[STATUS]

will a knock reading of around 70-80 only at high rpm for a small amount of time do much damage to the engine?

yes it may.

[Adz2332]

yes it may.

hmmm i get high knock noises sometimes... i took it into boostworks and they tuned it and said there was nothing wrong wid it etc. but since then i still get high knock readings every now and then. so i just presume thats the way the car is.. and its been going on bout 5 months now i guess

[R31Nismoid]

Its not how the car is.

It should not be hitting 70-80 knock regardless.

[fEkuaR]

I deffinately wouldnt be happy with 10 - 15 knock without load. The engine doesnt make that much noise. When im cruising my knock sits on 1-2 and ever now and then will tap 3-4 and go straight back to 1. In other words its a long way off 10 - 13 constant.

[Muffa180]

hmmm i get high knock noises sometimes... i took it into boostworks and they tuned it and said there was nothing wrong wid it etc. but since then i still get high knock readings every now and then. so i just presume thats the way the car is.. and its been going on bout 5 months now i guess

They probably said it was ok because it was ok on the dyno. They cant match exact load on the rollers as your car will have on the street. Especially if you use a bleed valve and you are already doing 4500 rpm plus (which is when most peoples turbo is making boost) and you floor it the boost will spike higher than what the vehicle was tuned at. Some tuners dont allow for this when they are tuning but in their defence some turbos and boost controllers dont work that well either.

You can correct it each time you drive by going in to settings scoll down to ign/inj press next, there will be a 0 highlighted next to the 0 says adj i think, arrow down twice and it should say -2 then press back until your on your monitor screen. This will take out 2 degrees of timing through the whole map. Once you turn the car off the ecu will go back to normal settings so this will need to be done every time you start the car. This will work until you have the timing removed from the area that is the problem.

Thanx Michael...

[widebody32]

The only way to really tell is to use either a knock meter like snap on or some of the Jap ones like TOMEI. Each engine is going to register different knock readings dependent on numerous factors EG: Forged piston or standard, bearing clearances etc.

I had one car that had twin screamers and one was slightly touching the engine and would register obscene readings.

I have also heard that some of the older fc's had some issues with knock readings so if unsure get it double checked as $100 of labor is well worth it compared to a engine rebuild