35 Coupe, 6 speed manual, getting knocks when eccelerating in low rpm's. Boght fuel injector cleaner, 3 tanks later, 1st 2 tanks with fuel injector cleaner then 1 with the same plus octaine additive. And I'm still getting knocks. We used to blow those out manually, which is what I have tried with no success. Any ideas. I've been htiing about 5k in first to third. Shoudl I keep it up or have a mechanic look at it, many some stuborn carbon?

 

seafoam?

 

If it's knocking and your not throwing a CEL, try a different gas brand. You ARE running 93 octane, correct?

I would also try SeaFoam if the gas doesn't help. There is a vacuum port on the plenum that will work great for that.

One last thing, check your oil, if it's really low, you can get funny noises.

 

Put seafoam in your PCV System (Brake Booster Hose), Gas system (Gas Tank) and Oil System (Oil Filler Cap). The seafoam in the PCV system will burn off after 10 min or so. The seafoam in the gas system will clean your lines and injectors and burn off once you burn all your gas. And the seafoam in your oil system will clean your lubrication system and send all the deposits to your filter. I would recommend driving the car for 250-300 miles then change your oil with fresh new oil. Might also try using Lucas Heavy Duty Synthetic Oil Stabilizer in your next oil change. Hope some of this helps!

 

If you use seafoam though a vacuum source be careful not to add it too quickly, liquid does not compress. Make sure you use a vacuum source that will evenly distribute it to all cylinders also.

 

Is this car new to you? Many of them knock at low and mid RPM while accelerating - especially the 6MT's. It would be good to know if this is a new occurance.

 

What injector cleaner you using? 90% of them are junk

 

You have bad grounds. Stock has 1 ground to start and run the whole car that goes from block to body right below the overflow tank for the radiator. This cable will turn green when corroded (2 years or less) then your screwed. The fix, buy a new one (38 bucks) and solder it B 4 install. Next install grounding kit and solder the crimps, pre tinned 8GA car amp cable is best it won't corrode, wire it 2 all points under hood that go2 body panels and lots of points on block, i have 9 points on block and 11 points on body including (injector ground M66 behind glove inside car) dont forget coil ground at front of block 2 points 06 G35X. I will post pic soon and it works!!!!!!!!!!!!
Your getting carbon from bad spark 2 plugs.

 

You have bad grounds. Stock has 1 ground to start and run the whole car that goes from block to body right below the overflow tank for the radiator. This cable will turn green when corroded (2 years or less) then your screwed. The fix, buy a new one (38 bucks) and solder it B 4 install. Next install grounding kit and solder the crimps, pre tinned 8GA car amp cable is best it won't corrode, wire it 2 all points under hood that go2 body panels and lots of points on block, i have 9 points on block and 11 points on body including (injector ground M66 behind glove inside car) dont forget coil ground at front of block 2 points 06 G35X. I will post pic soon and it works!!!!!!!!!!!!
Your getting carbon from bad spark 2 plugs.

 

Or you could have a bad knock sensor....

 

No, the knock sensor only retards timing not fuel/air, this carbon problem did not happen overhight it took a loe of months matbe years. Still the spark problem and can be fixed. to Also means your cats are clogged (restriction) after the wiring fix the water injection will clean out your whole system, I have done this, pics soon first is factory pop 4" charger looks like this after removing that a good start to improving responce.

 

There are a bunch of people that run wiring kits on these cars - a few vendors sell them too. Most people are 5AT that run them for the benefit of transmission. You don't need 100 new connections though. I have never heard anybody say that a grounding kit relieved spark knock before though.

 

My bad 4 trying 2 help, no one said anything about knock just carbon. Are U more focused on bashing me or FIX THE PROBLEM?

 

His problem is spark knock - he is assuming that carbon buildup is the culprit for his knock.

I wasn't telling him not to do a grounding kit - just informing him that I have never heard of someone who eliminated spark knock from doing a grounding kit. I have a grounding kit on my car.

 

well in that case appoligies did not get the whole story, the cure 4 the carbon is more spark and water injection had the same thing w/o the knock.