GVR4-Almost unrealisticly high knock

[gijoe985]

So, I bought a Gvr4 with a blown motor, I replaced the long block, now I'm trying to track down a knock problem. After a test run today, I think it could be a boost leak, but last check I did was ok. I did just replace the lower injector seals since there was a small leak there.

Anyway, the engine is fairly stock. Upgrades include- Port and polished head, balanced pistons and rods, 3rd gen lifters, MLS headgasket, balance shaft elimination, and an ebay 16g turbo. The turbo was on it when I got it. I did a few things to the engine internals when I replaced it, but nothing radical. It still is running stock boost and vacuum lines. One thing that is of questions is the injectors. The vehicle has 220k on it and I am using the intake/injector setup that came with it.


So, as for my situation. I have a very high knock count. According to MMCD, I get pegged at 43 knock count if I free rev in neutral or pretty much any time I have my foot on the throttle. I drove it home from my work/shop, which was an 80 mile drive, and it had the 43 knock count the entire way. The engine sounds just fine. I may hear a little lifter tick, but not bad. So, I did a few pulls today and logged them (I have not figured out how to download my logs on my new computer). I noticed that in my entire 2nd gear pull my O2 sensor stayed above .92v the entire pull and then dropped down to .01v when I decelerated. So, I would assume I am rich under boost and lean when not, which sounds like a boost leak to me. The knock sensor was at 30+ knock the entire time and it cranked my timing back to -3 degrees.

Honestly, if I didn't know any better, and didn't know how much power the car should have, I don't think I'd ever notice a problem. She doesn't overheat, she starts and drives fine, it is just the lack of power and knowing what MMCD is showing.

Best next step?

 

[eDeclpse92]

Did you replace the knock sensor? And if so, is it tightened and in the correct position? I had the same problem and my knock sensor was not where it was supposed to be and that caused a bunch of phantom knock. The knock sensor should be in the middle of the block (in between runners 2 and 3). I would also check the wiring and also check timing again.

 

[gijoe985]

Forgot to mention that. So much has been going on lately, I figured I'd leave some stuff out.

Yes, I did get a new Mitsubishi sensor. It is in the correct location. I tightened it as I read on the forums. I basically did hand tight and then snugged it with my cut off 24mm wrench. As close to 17lbs (or whatnot) as I could guess.

After that didn't fix anything, I even tried the suggestion of using one of those metal washers with the rubber ring in it and that did not seem to fix anything.

By wiring I assume you mean my spark plug wiring. I doubt I'd be running this well if that were messed up, but I will check timing again. It's been a while since I checked that.

I also just had ECMtuning rebuild my ECU for what it is worth. They socketed it, but it has the stock chip in it.

 

[gijoe985]

A fabulous Christmas present would be if anyone had any other suggestions...

 

[AK Maniak]

This is a long shot but... I was getting ridiculously high amounts of knock and it turned out to be my spark plug cover. I was being lazy and didn't want to look for 5 bolts to mount it so I just called it good with 2. Ended up vibrating at certain RPMS and tripping the knock sensor. Second I put all the bolts in and secured it, it went away.

So there might be something literally knocking, or rattling externally on or around the motor that is causing the knock. Like I said it's a long shot but who knows. Good luck and merry christmas

 

[horizontalkev]

Its possible you have rich knock. Maybe lean it out some? I would maybe get a wideband immediately to get a better reading before messing with the afr though. Maybe your o2 sensor isn't running properly. Also, stock injectors? Your injectors might need to be replaced. If stock, and have never been replaced 220k miles is a long time sooo yeah get an accurate reading of your afr and go from there.

 

[RadDsm]

43 is the max counts it will display IIRC, I'd check the knock sensor for goo. It's either bad, or you have a lot of PK.

 

[jed344]

Sounds like sensor, bad connection somewhere between senor and ecu or even something loose in the engine bay could maybe cause it. My car has something in the bay that from time to time will cause a slight knock reading for a second when just cruising.