Why so much knock with a stock car?

[xcelr8n]

Recent issue with my new car, car is practically bone stock, aside from a k&n filter, ported manifold and BCS removed (11-12psi).
My issue is anything over 4000rpms and WOT i get stupid amounts of real knock, 10-20 counts and it holds all the way til I let off, my timing is suffering a good deal, and the car isnt performing as it should.
I havent had a chance to perform an intake leak test with a compressor yet, just with a bike pump, I managed to hold like 6psi before my arms gave out from pumping!
Another thing that I find curious is that at 12psi and wot over 5000 rpms the logs show my injectors are pretty much MAXED.
Any thoughts or ideas?
Thanks.

 

[JiggahMan]

Here's an idea - post a log.

 

[xcelr8n]

I will when I get home from work, but really I dont see the point, Knock is non existent until I go WOT and rpms are over 4000rpms, O2 trim reads dead on 100% when I'm wot the entire time, and o2 voltage reads like .90-.92. What else do you need to see?

 

[ITSME4G63]

Fubared knocks sensor maybe? is knock always present or jsut sometimes?

 

[xcelr8n]

Knock only happens when I floor it and the boost pegs to its max setting, aside from that the Knock readings are normal, most of the time it reads 0, occassionally a little Phantom Knock within the first 3-5 mins of driving the car because of ticking lifters.

 

[sbiggi]

Check you base timing.

Should be at 5 degrees, I bet it is advanced more then that.

-Seth

 

[spyderturbo007]

I dont see the point, Knock is non existent until I go WOT and rpms are over 4000rpms, O2 trim reads dead on 100% when I'm wot the entire time, and o2 voltage reads like .90-.92. What else do you need to see?

Ok, for starters, there is always a reason to post a log.

During WOT operation, the ECU could care less about the O2 trim and O2 voltage. The stock narrowband O2 voltage is worthless, so the information you are giving us (O2 Trim, O2 voltage) is also worthless.

With a log, we can look at things like airflow, IPW, IDC and see what else is going on when the knock begins. I'm not saying not to check out base timing and do a leak test, but logs are always a good thing to post.

 

[JiggahMan]

Ok, for starters, there is always a reason to post a log.

During WOT operation, the ECU could care less about the O2 trim and O2 voltage. The stock narrowband O2 voltage is worthless, so the information you are giving us (O2 Trim, O2 voltage) is also worthless.

With a log, we can look at things like airflow, IPW, IDC and see what else is going on when the knock begins. I'm not saying not to check out base timing and do a leak test, but logs are always a good thing to post.

Another rep point to spyder!!!

 

[xcelr8n]

Man, whats going on with this place, Jiggah thanks for ALL your help really....
I'm not a damn newb I've read about a million logs before, I will figure this out on my own w.o this ONCE awesome forum.
Thanks anyways.

 

[andymoraitis]

If posting a log is difficult, then I have to ask if you've replaced the knock sensor or checked it for goo coming out of the back. If there's no goo coming out, make sure it's torqued down properly. If there is, replace it.

Keep us posted,

Andy

 

[xcelr8n]

Well looks like base timing was 11* fixed that now will log it again tomorrow, felt better driving home from my buddies house though, I think the problem may be resolved...
Also, to add I did a boost leak test as well, and the VC breather hose is pushing alot of air, while pressurized. (It's routed to the ground, not intake).
Is this a sign of a bad PCV valve, compression is about 155psi straight across if that matters.
Thanks

 

[xcelr8n]

Just to put this thread to bed, the PCV valve was pooched, put on a new OEM unit, and all is well again in DSMland for me.

 

[andymoraitis]

Glad to hear you found the issue although I'm sure the timing wasn't helping matters.

Andy

 

[xcelr8n]

Without a doubt the timing was the cause of the knock, but after we fixed it we performed a boost leak test to 20psi, and discovered the PCV valve was leaking like a sive, so that was replaced the next day.

 

[JiggahMan]

Without a doubt the timing was the cause of the knock, but after we fixed it we performed a boost leak test to 20psi, and discovered the PCV valve was leaking like a sive, so that was replaced the next day.

And what would've showed a timing issue instead of arguing about not putting one up?

 

[TwoLiterV8Eater]

Not a log, since loggers report timing advance from base, not actual timing.

 

[xcelr8n]

Not a log, since loggers report timing advance from base, not actual timing.

beat me to it, thanks!