koolking

I am at wits end. Car is a stock 5.0 auto (except for h-pipes and cold air intake). I can not stop the spark knock had the car 1 1/2 years). Seems to be worse under light acceleration. Engine runs decent. I have replaced both O2 sensors, distributor cap and rotor, and had the timing adjusted to 10 degrees (yes, the plug was unplugged from distributor). Nothing I seem to do matter. I can;t notice any improvement with premium fuel either.

I have eafomed the car twice. Still no difference. Any suggestions would be greatly appreciated!!!

Gator

Make sure your balancer has not slipped, confirm #1 piston is at TDC when balancer timing mark is at 10* or whatever your setting it to. You may be running more timing than indicated if this has happened.

Pull your KOER and KOEO codes, make sure something isnt wrong there.

Correct spark plugs and heat range?

sn95_331_GT_ yellow

sure youre getting enough fuel? stock pump change the filter recently?...

my original pump didnt even like my stock motor...

sn95_331_GT_ yellow

damn double post...

AdderMk2

run a can of seafoam through the car, and replace your EGR.

very common problem in SN-95 5.0's

especially GT's

mjr46

have you cleaned the maf???

koolking

You are correct. A slipped balancer could cause the problem. I had it checked but did not check it myself. I will try that tomorrow and let you know how it goes.

Plugs are Autolite Copper core 25DP2. Is this correct?

Thanks!!

koolking

koolking

I have not checked the fuel pressure. I do have access to a fuel pressure guage. Do you know off hand about what the pressure should be at the rail?

It seems to perform well under wide open throttle conditions (well, as well as the really high stock gear will let it.) Of course, it may still be spark knocking at WOT but I am not hearing it because of the exhaust and other engine sounds.

Thanks a bunch!!

koolking

I tried seafoam on 2 different occasions. I did not put it in the oil, just poured it into the brake booster vacuum hose. Smoked like crazy then cleared up after about 10 minutes.Think I should have put some in the fuel tank??

My neighbor mentioned the EGR valve. I hate to admit it but I am not entirely sure how they even function. Would you replace the position sensor also??

Appreciate your help! I love this car and really want to fix it.

koolking

No I have not tried to clean it. I know where it is. Any advice on the best way to clean it?

Thanks!!

Koolking