Chrisssssssss
Member
- Joined
- Jul 27, 2008
Hey all,
So... I have been trying to chase some knock. I will tell ya what is happening. I will post my scanmaster readings tomorrow when I have a chance to actually write them down. I will be as thorough as possible so that I can get as much info as possible and maybe if I can figure it out it will help others maybe with the same problem sometime. I have tried to search and see what is said about my issue and spent a lot of time reading. Here's what the issue is and what I have done... Sorry for the long post, but I wanted to be as clear as possible so it may help pinpoint the issue and what I have done to resolve it. Any and all suggestions welcome.
I have been having some knock issues - when I get into boost on the upswing mainly - like as in when it first ramps up as boost is climbing. For example if you floor it and as it goes from about 1psi to 14 psi (I have a pillar mounted autometer boost gauge) - I can hear the engine ping or I hear some sort of knocking noise that I can't quite figure out where it is coming from. It then will set off the knock sensor and then give me as many as 10 degrees of knock... Usually somewhere in the 2-3 degrees mark. This usually comes as it ramps up, but as it settles down at 14ish psi I settle at about 0.9 degrees of knock. I have a chip burned for 91 octane that matches the injectors (37.5 # i think) It is a thrasher chip but I am using 94 octane all the time. I live in Canada and can get real Chevron 94.
I have notices these scanmaster readings. When my highest knock is recalled with the button, I am usually sitting at ~.832mv at 2.9 degrees of knock. This is a common recall number.
When I am in wide open throttle, I am usually always around .830-.840mv still showing some knock.
My IAC's are usually low single digits like 2-3 in park
My cc's don't go up at all when in park, nor really much at all... sometimes they will go when I am off and on the throttle. It is very sporadic if they count up. What causes this?
So... Here's what has been done to try and do a spring cleaning and see what kind of improvements they make. All specs and OEM replacement parts as per spring cleaning checklist.
-Changed oil (no improvement)
-changed spark plugs - (helped with smoothing idle, but still no improvement to knock)
-changed wires (no improvement)
-replaced the fuel filter (no improvement)
-increased fuel pressure (a bit of improvement) but I went through a full tank of gas in like 100 miles - so I backed it back down. I am gonna get a fuel pressure gauge and see exactly what is is set at and set it right. I haven't got one yet. That is next.
So - here's what I am gonna try next:
-check all vac lines and replace most of them - I heard spraying carb cleaner around them may help find leaks?
-my turbo screws keep loosening out of the turbo housing out to the downpipe. I replaced them and used new ones but they keep loosening. I used copper gasket stuff as the gasket, but the screws keep loosening. Is it safe to use some sort of thread locker on the cast turbo bolts? thoughts?
If you have read this far. Thanks for staying tuned...
So... I have been trying to chase some knock. I will tell ya what is happening. I will post my scanmaster readings tomorrow when I have a chance to actually write them down. I will be as thorough as possible so that I can get as much info as possible and maybe if I can figure it out it will help others maybe with the same problem sometime. I have tried to search and see what is said about my issue and spent a lot of time reading. Here's what the issue is and what I have done... Sorry for the long post, but I wanted to be as clear as possible so it may help pinpoint the issue and what I have done to resolve it. Any and all suggestions welcome.
I have been having some knock issues - when I get into boost on the upswing mainly - like as in when it first ramps up as boost is climbing. For example if you floor it and as it goes from about 1psi to 14 psi (I have a pillar mounted autometer boost gauge) - I can hear the engine ping or I hear some sort of knocking noise that I can't quite figure out where it is coming from. It then will set off the knock sensor and then give me as many as 10 degrees of knock... Usually somewhere in the 2-3 degrees mark. This usually comes as it ramps up, but as it settles down at 14ish psi I settle at about 0.9 degrees of knock. I have a chip burned for 91 octane that matches the injectors (37.5 # i think) It is a thrasher chip but I am using 94 octane all the time. I live in Canada and can get real Chevron 94.
I have notices these scanmaster readings. When my highest knock is recalled with the button, I am usually sitting at ~.832mv at 2.9 degrees of knock. This is a common recall number.
When I am in wide open throttle, I am usually always around .830-.840mv still showing some knock.
My IAC's are usually low single digits like 2-3 in park
My cc's don't go up at all when in park, nor really much at all... sometimes they will go when I am off and on the throttle. It is very sporadic if they count up. What causes this?
So... Here's what has been done to try and do a spring cleaning and see what kind of improvements they make. All specs and OEM replacement parts as per spring cleaning checklist.
-Changed oil (no improvement)
-changed spark plugs - (helped with smoothing idle, but still no improvement to knock)
-changed wires (no improvement)
-replaced the fuel filter (no improvement)
-increased fuel pressure (a bit of improvement) but I went through a full tank of gas in like 100 miles - so I backed it back down. I am gonna get a fuel pressure gauge and see exactly what is is set at and set it right. I haven't got one yet. That is next.
So - here's what I am gonna try next:
-check all vac lines and replace most of them - I heard spraying carb cleaner around them may help find leaks?
-my turbo screws keep loosening out of the turbo housing out to the downpipe. I replaced them and used new ones but they keep loosening. I used copper gasket stuff as the gasket, but the screws keep loosening. Is it safe to use some sort of thread locker on the cast turbo bolts? thoughts?
If you have read this far. Thanks for staying tuned...