Helpp!!! sr knock

[jacobs13]

Ok so when I got my swap running it sounded fine just ran like crap because of timing. My turbo is also blown. When I hit about 4k it will develope a knock with a little whistle. It will only do it under load, when I free rev its fine. Could it be my timing or the turbo? It is a built sr with hks intake cams 254 and greddy exhaust 264 with bc valvetrain and forged and sleeved bottom end. Does anyone know a culprit detonation? Timing? Any help is appreciated.

[Sileighty_85]

Is it tuned?

[jacobs13]

No, im running stock injectors, maf, turbo, and ecu. I know I need a tune to compesate for the cams and the compression so im getting a safc. Could that be the knock? Also when I took the vaccumm line of the wastgate and vented it to the air the knock didnt start till higher rpms

[daryl337]

Well, you want to remember that detonation occurs only a couple of ways.


high intake temps/lean conditions... or ignition timing.

If you swear up and down that you got your timing correct, then I would probably get an A/F reading immediately to help determine if it is a fuel map related issue.

[jacobs13]

My timing is far from being right, I have an lc1 wideband but I do not have an a/f guage. I'm pretty sure sure its running lean because I can smell it and I'm getting really bad gas mileage. Another thing is is when I first started it from swapping there was some 87 octane in the tank and the knock did knock start untill there was 91 octane in there

[daryl337]

Have you checked spark plugs for signs? Coloration of the plug can explain alot.

You need to be very specific about what you are hearing though. Is this a "ping" knock, or a "metal is hitting metal" knock?

Your quote Also when I took the vaccumm line of the wastgate and vented it to the air the knock didnt start till higher rpms indicates that the sound may be the turbocharger itself, and not an engine detonation related issue.

Hindering the wastegate actuator is going to only increase boost and gain levels, which should cause you to knock earlier if it is a detonation issue.

[jacobs13]

Im starting to lean towards the turbo because the 4 bolts holding the exhaust housing down backed out and was leaking oil bad and I could move the compressor housing with the exhaust staying still. I tightened the bolts but it still leaks bad and the noise did really start untill those bolts backed out

[jacobs13]

Alright so today I decided to actaully spool up a little and I heard a pop and bam got to drive it home in limp mode barely running, but I heard no engine noises when I kept it at idle which was hard to do. Sound like a turbo blow?