Replaced Knock Sensor still tons of Knock??

[LKWTSI]

Ok guys, I'm getting a little "P'd" at this knock situation. I posted my log and everyone thought I had too much boost, so I turned it down and still pulled a ton of knock. I replaced the Knock sensor, the old one was definitely shot, and the car feels like it's pulling harder than ever, but my log shows otherwise. I'm running 93 octane at 11psi boost and checked the gap on the plugs and it's got new wires and all the mods are pretty tame, nothing wild.

SO what could be causing my knock now

 

[juanpac0]

I'll have to try it out.

To answer the previous questions NO I don't at this time have any means of measuring "wideband". My concern was that I have a reading called WB O2 and it's reading about 18.94 every log and there's no literature with the software explaining what this reading is. So I guess I'm in the dark until I figure that out. BUT I know from other posts I'm not running anything other than my stock O2 sensor so, to run wideband do I need a different sensor or another one downstream or what??

The WBo2 is a separate o2 sensor. You want to place it as far down the downpipe but before the cat as possible. The reason for this is that higher temperatures kill wideband sensors faster, but if you put it in or past the cat you're not going to get accurate readings.

 

[allthrottle]

As far as I know, you'll need a wbo2 sensor and a wideband controller, such as the Innovate unit. I don't think the ecu or datalogger can read or translate a wideband signal on it's own. This wideband o2 sensor replaces the factory front o2. Most decent wideband controllers have a narrowband output to convert the wideband signal and give the ecu the narrowband o2 signal it's looking for.

 

[LKWTSI]

Thanks for the reply, first problem is thought, I have a Apexi N1 down pipe that is the extended version that eliminates the Cat' altogether. So would I have to have a bung welded in. I appreciate the input and I'll have to look into the wideband set ups. I suppose that's another thread.

 

[turbo90gsx]

Yeah, defiantly get some NGK BPR7ES spark plugs in there with NGK wires.

 

[Colt4G63 also]

Put your wideband downstream, it will last longer. You could use the narrowband output to replace your front sensor, but it's not reccomended.

 

[PIMking]

hmmm this explains my knock at low throttle problem. as soon as I get off the throttle and back on its gone. Its always at 2500 rpms too.

 

[-red97rum-]

I too am experiencing the bastard ass PK issues. I'm going to attempt to re-torque my knock sensor and see if it helps - I know it is too tight right now. Also ordering some revised lifters as I do get quite a bit of tick on initial start up.

It is just as described in an earlier post. For example: Take off normally in 1st gear and at about 1500-2000rpm (not everytime btw) I get a huge spike in knock. I let off the gas *just slightly* and get back on it with absolutely no knock. It does this in 2nd gear sometimes too. If I don't let off and keep my foot in it the car falls flat on its face from the pulled timing. Is this what you are experiencing? I'm about to introduce Mr ECU to Mr SLEDGE HAMMER with a vengence!!

Are you using MMCD for logging LKW? It is my understanding that the WB02 option you see can be changed and used for different inputs. I believe (don't quote me on this) it takes the value from the EGR. I'll look around and see if I can find out for sure. I know I've seen a thread on dsmtalk about using the same input to log boost levels via changing the pref in MMCD. I've been meaning to try to hook my wide band up to log it but I've been lazy.

 

[-red97rum-]

Ok I was right, here you go.

http://www.dsmtuners.com/forums/tuning-engine-management/211140-datalogger-mmcd-wideband-input.html

I'm going to try and set this up this weekend, having the actual AFR on my logs would help out so much.

 

[LKWTSI]

Thanks for the input, I am in the middle of doing a fuel pump install new walboro 255 and rewire kit. Hoping to push some extra fuel for the top end issues. Also installed new BRE7es plugs and haven't ran on them yet. Did a seafoam clean in the tank and through the intake and a couple of days ago I did a hard pull from 1st to 2nd. Didn't mash the gas to WOT and hold it I fed the power into WOT and wadda ya know the knock is almost non existent. Lucky I have to commit to the fuel pump and rewire now as I'm just about to pull the pump out after PB blasting it all week. I'd love to see if I can get the same results before the pump swap, but not going to happen. So if the knock issue is better after I'll presume it was the pump and not the seafoam.

 

[snakeyes711]

I've got this problem now too. Even with a Brand new Mits. sensor, I've got 93 v-power fuel with some 104 oct. booster added in its PK like crazy... I'm at a loss. I'm going to inspect the plugs later(ngk7's), and maybe check the wires. I've got logs from a month ago with pulls with zero knock. I'm beginning to think it was my front mount install thats doing it.

 

[LKWTSI]

Never thought about that before. Are yours original or poly'? Might have to look into the possibilities.

 

[jeffo]

I've got this problem now too. Even with a Brand new Mits. sensor, I've got 93 v-power fuel with some 104 oct. booster added in its PK like crazy.

The first thing you should always check is to make sure your base timing is at 5*, as set by a timing light, as per the VFAQ. I find way too many guys with their timing at 7-10* BTDC, which just doesn't work well with the aggressive 1G maps.
keydiver

 

[snakeyes711]

Never thought about that before. Are yours original or poly'? Might have to look into the possibilities.

Whats that? whats poly?

Yes base is set at 5*. Logger shows good. I checked my timing marks too thats good. I think It may be time for new wires. After I rearranged them last night, and put a bit more tightness on the knock sensor its gone down a lot. BTW I got bpr6's in not 7's. thought they were 7's. They appeared to be in good condition when I pulled them also. Its very nerve racking. Today on the way home from work I figured..."maybe If I smash into the concrete highway divider It'll stop knockeing"!!

 

[jeffo]

Yes base is set at 5*. Logger shows good. I checked my timing marks too thats good.

You CAN'T check the base timing with a logger. The logger always ASSUMES you have the base timing at 5*. It doesn't know if you have moved the CAS. You MUST ground the connector under the hood and check it with a timing light.
keydiver

 

[LKWTSI]

Poly', sorry, is short for polyurethane. These are usually what people replace the crappy old rubber bushings in engine mounts and suspension mounts with. It's basically a hard plastic that doesn't move and can cause a lot of vibration, which most don't care about in a race car, but can be a pain in your daily driver. That's why I asked about yours. If they are poly' it might have explained your concern on your engine mount causing the "knock".

 

[snakeyes711]

You CAN'T check the base timing with a logger. The logger always ASSUMES you have the base timing at 5*. It doesn't know if you have moved the CAS. You MUST ground the connector under the hood and check it with a timing light.
keydiver

Yes of course, thanks I have a timing light.

 

[snakeyes711]

Poly', sorry, is short for polyurethane. These are usually what people replace the crappy old rubber bushings in engine mounts and suspension mounts with. It's basically a hard plastic that doesn't move and can cause a lot of vibration, which most don't care about in a race car, but can be a pain in your daily driver. That's why I asked about yours. If they are poly' it might have explained your concern on your engine mount causing the "knock".

Roger that, sorry for not being clear. I meant my front mount intercooler install. I'm going to change wires this weekend see if that helps. It runs better after I moved them around, and tried to keep them from touching the engine where I could. The little rubber separating block had shifted. I believe that snap from an ignition wire is enough for the engine to think its knock. I noticed that the #4 wire doesn't click on the plug like it used too also.



I also need to replace the flex pipe thats on the car. Its just the old 6 dollar fix from auto zone with some clamps. It makes that area of the exhaust sound like a barrel of marbles down there when you give it gas. It seems like the knock is worse when the engine is warm.

 

[snakeyes711]

I searched but didn't find any more threads with problems like this, with a new knock sensor. Any body? I tried a bunch of different search words.

 

[snakeyes711]

My knock is gone!

Heres what I did. I got a set of 3G lifters yesterday, and threw them in. I also got rid of that Autozone flex pipe(which IS directly under the knock sensor BTW) And got a new braided one. It used to sound like marbles in there. I also shimmed my wastegate rod so it didn't vibrate around anymore. I got rid of the two small bolts that were hanging out on top of the valve cover area.

I also found a few items that were loose, and vibrating around. I also mounted down the boost controller I had, which was tucked away out of site but couls still vibrate against the frame. All that today going to work (20 minute ride) the most knock count I read was 11!And that was in first gear leaving my complex. The rest of the ride was at ZERO! The only (REAL) knock I recorded was at 6,000 RPM or higher on full boost 16-17psi which was 17! BOSS!! Thats on 93 Oct. fuel.

 

[LKWTSI]

My knock is gone!

Heres what I did. I got a set of 3G lifters yesterday, and threw them in. I also got rid of that Autozone flex pipe(which IS directly under the knock sensor BTW) And got a new braided one. It used to sound like marbles in there. I also shimmed my wastegate rod so it didn't vibrate around anymore. I got rid of the two small bolts that were hanging out on top of the valve cover area.

I also found a few items that were loose, and vibrating around. I also mounted down the boost controller I had, which was tucked away out of site but couls still vibrate against the frame. All that today going to work (20 minute ride) the most knock count I read was 11!And that was in first gear leaving my complex. The rest of the ride was at ZERO! The only (REAL) knock I recorded was at 6,000 RPM or higher on full boost 16-17psi which was 17! BOSS!! Thats on 93 Oct. fuel.

I'm still looking into mine. It seems to be better, but still getting up towards 20 counts at 4000rpm+, seems like I might need to go and replace the lifters, but I'm thinking about pulling the engine in the Fall and doing a complete rebuild. Alot of my bottom gaskets are weeping and can't take it on the track like that. Also, I'd like to get a new head as the thing has too many problems, with stripped out threads ( I had to use longer bolts to get good thread bite). I'll probably get new cam's at the same time, so I'll get new lifters obviously, so I'm just going to be patient and deal with it until then.


Also, I like the idea of shimming the wastegate actuator. What did you use?

 

[LKWTSI]

knock is GONE

Just got done doing the walboro 255hp and rewire.Took it out and have done 3 good hard pulls and all 3 are clean. Just a blip of about 5 counts, then goes away, in about 6300rpm just before gear change.

I have my MBC turned all the way off, so I'm running stock boost levels right now, so the test of success will be turning up the boost a little and see if I can keep the knock out of the picture.

Thanks for all the advice guys and will keep it posted if the knock changes as I add more boost.

 

[snakeyes711]

knock is GONE

Just got done doing the walboro 255hp and rewire.Took it out and have done 3 good hard pulls and all 3 are clean. Just a blip of about 5 counts, then goes away, in about 6300rpm just before gear change.

I have my MBC turned all the way off, so I'm running stock boost levels right now, so the test of success will be turning up the boost a little and see if I can keep the knock out of the picture.

Thanks for all the advice guys and will keep it posted if the knock changes as I add more boost.

Alright!

 

[LKWTSI]

Alright!

Thanks, I'm happy about it.

 

[snakeyes711]

I understand completely, you don't even want to drive your car when its acting like that. Then you get it fixed your anxious to go drive

 

[LKWTSI]

This is my first DSM and I was warned by a few, that I'd have the thing in the shop more than on the road. Last year, that pretty much was exactly how it was. This year after a new turbo and exhaust and the car has been solid. Even with putting on all the extra mods and upping the chances of something going wrong the car has been behaving really well. I'm enjoying driving it and eager to get it on the autoX or track and see how it really behaves. I'm going to take it to an AWD dyno in Concord, probably around Dec' or Jan' and see what I'm getting HP wise. Then I'm thinking about pulling the engine and doing the belts and new gaskets and probably upgrade the cams' and fuel rail and injectors. Then take it back to the dyno and see how much I gained.

So for the moment it's nice to have the reliability and still have a little fun with it.

Thanks for your input.