My oil trap is crude and redundant but it's what has evolved in order to stop oil from getting back in. Stopping it eliminates knock and a brown bumper. Due to the characteristic of oil just using a trap wont work, the oil will eventually be on every surface and get sucked in. It consists of two Walmart air driers in series opposing each other. The first uses oil absorbent to to pull it away from the outlet. The second uses the same stuff, just backward to get oil that does make it through. Air is oil free before entering combustion. The MAF pipe side just uses a fuel filter which is all thats needed there, but a fuel filter will do nothing on the PVC side.

I had plans to use a fractioning column and glassware but I found out those items are on the DEA watch list

 

I will have to try this out. Could you post some pics or a diagram for me please? I am running meth and the car has knock problems. I think the leaking PVC could be the problem. I have removed the PVC and done the blow test and it holds, but I know I cant blow 25psi.

 

My fuel filter is inline on the MAF side of the system, of course. Just in case there was a confusion on my particular setup. A true oil catch can might be a good investment in my future.

 

if you increase the octane and the knock goes away then clearly it wasn't phantom. Personally I think way too many people write off knock as being phantom and call it a day...people need to put more trust in the knock sensor, it's quite good.

 

I personally never consider phantom knock a possibility unless I HEAVILY lower the boost, check the mechanicals and UP the octane and the problem persists. I have only found phantom knock twice on a few friends evos and it ended up being the DP hitting the transfer case fin on one and a cracked valve spring on the other (that was a PAIN to find!).

 

something changed in gasoline formulation... I started getting knock from 5K to redline also. I've reduced boost and timing but still get some at ~7krpm. I took my plugs out af found this.



Looks like some sort of ash residue that is easily scraped off. Never seen this stuff on my plugs before.

Other side of plugs...

 

First off, how old are these plugs?
What kind are they?
What were they gapped to?
Did you replace them with new ones before messing with your tune????
What are your mods and boost level?

They seem to have the normal wear on the ceramic but it looks like ash deposits elsewhere.

Look at this webpage HERE and see which one best represents your plugs (since we can't see as well as you can). I would throw in some NGK BPR7ES plugs gapped to .025-.026" and see how they perform. They are the most widely used and trusted plug in the EVO community.

 

These are OE plugs gapped at .023 they have about 4k on them. 4 weeks ago I inspected them and checked gap . I drive about 50 miles a week, mostly stop and go traffic.

Nothing was changed on my tune , suddenly with a new tank of gas I start getting 5-6 counts knock, changed brands it went away. I've been monitoring it for 3 weeks... yesterday I filled up and it started doing it again.

Today I pulled the plugs and found this...

Mods=cams, tbe, EVO9tme and 22-20psi...3rd set of OE plugs my car only has 18k miles

 

Most guys will suggest changing the plugs every 3K miles or so. By the looks of your plugs, I personally would change them. Aren't the OE plugs like crazy expensive?? The NGK's are like 12 bucks for a set. Generally, a batch of bad gas will cause a good amount of knock and knock will eventually kill the plugs. So even if the true culprit was a bad tank of gas, I'd change the plugs. Advance Autoparts usually carry the NGK's in stock if you decide to try them.

 

wow, looks like something from a scary movie.

I've seen color changes with fuel formulations but not ash like stuff.

It looks like it was left on the downstream side of the plugs/ / washed blown off with the incoming charge.

Are you not getting the engine hot enough, that with some sort of fuel problem...

what is your timing, could the fuel be burning out the exhaust, way to late?

 

Engine gets plenty hot and fueling is fine...they have done something to the gasoline here, 93 is not 93 anymore.

This is my last datalog, most knock is gone except for the >7krpm. I've richened AFR .2-.3. from 6k on.

 

Most gas companies ran up to 10%MBTE in their gas, now they've replaced it with up to 10% Ethanol. MTBE was a better additive IMO. Check for the sticker on the gas pump.

 

I agree MTBE was much better...BTW Houston gets reformulated gasoline, whenever they switched us to the ethanol blend it started to suck.

I just ordered a 6pack of Torco

 

How did you finally find out it was the idler pulley?

 

Well #1 it is/was really loud and it was obviously coming from the passenger side of the vehicle. Then I got out my stethoscope that I use for wheel bearings and such and started listening. Turned the car off checked the idler pulley (which at this point I suspected) discovered the pulley had loosened up some, tightened it down and while it was better it wasnt fixed. Checked the drivebelt and it was all chewed up.

The other reason I knew it wasnt something like plugs, PCV, etc. is I had a perfect tune for 25psi to redline on pumpgas earlier in the year (with the Green). After I did cams and this problem showed up I had to take more and more timing out where I hadnt before. I threw in 100 octane and it wouldnt go away and it was never consistent for the amount of boost nor rpm when it would occur. I have yet another set of new plugs on order that I am not going to regap this time and make sure that isnt magnifying the problem.

Here is a sample of one of the logs that shows I was knock free (more or less). It is not a full log and when I started to hit 27psi I felt out of my comfort zone for being on pumpgas even if it wasnt knocking at that point: