This is a little saga which may prove enlightening to the members about the detective work sometimes needed to properly diagnose a "KNOCK" condition and also to show a case study in HOW I approach a car that is exhibiting KNOCK counts

First a little definition

Actual Knock or predetonation is a condition where combustion in the cylinder occurs in an uneven and uncontrolled manner. This knocking condition is tuning related and can be adjusted by tuning parameters or by using better fuel,

Engine NOISE is a mechanical sound that can emit from a mechanical condition such as a loose bolt or exhaust banging against the sub frame for example

The Evo ECU reacts to signals that are measured by the KNOCK SENSOR

The KNOCK SENSOR emits frequencies which the ecu interprets according to the mapping and the ECU is programmed to react in a pre-determined manner in relation to the knock signal observed

The car I am discussing here is a

2004 EVO 8 with

Injen Intake
HKS Cams
SMC Alcohol Kit
Walbro fuel pump
MBC
3" full Exhaust
ACT clutch

The car was previously reflash tuned by another local flash "tuner" who also recently installed the cams and clutch

The car was brought to me to retune it after it had previously made a claimed 370 whp on a local Dyno jet dyno but had faired very poorly at the local race track in fact going slower than it had gone before withOUT the cams previously

The customer suspected something was not "right"

Upon observing the tuning map I was shocked to find that the ignition timing was IMHO overly aggressive beyond anything I would expect to see in a car running pump gas and alcohol

The timing maps was a block of 10 ramping up to 27 degrees at red line

The first pull on the dyno with a evo scan data log showed the MOST knock counts I have ever seen in any evo with a reading over 19 from spool up to red line

The car was only making 295 whp @ 27 psi (now on a Dyno Dynamics Dyno which reads lower but this power is very low for the level of mods on the car)

At this point I suspected ONLY a bad tune so I decided to load in one of my base maps and start from scratch

Sadly, the car was still knocking but less and the power was still way down

Now it was time to diagnose so we lowered the boost DOWN to 20 psi and the power remained the SAME - same as at 27 psi - which was bizarre

Here are the diagnostic steps undertaken to attempt to remedy the condition of knock at low boost and a conservative tune

1 - Added some race gas - NO EFFECT

2 - Tested Alcohol kit pressure

3 - Changed alcohol

4 - Changed spark plugs

5 - Removed cross ties which were hitting exhaust

6 - Removed front cover and checked the cam timing and balance shaft timing

Note - it was noted that the head gasket was leaking or seeping coolant around the edges

Now we replaced all the fuel in the tank and put the car back on the dyno only to discover that the knock was unchanged and the car continued to make the same power at 20 psi and 27 psi (dyno sheet to follow)

Next we removed the valve cover to try and observe if the cam rockers were all in position and Jimmy of The Shop soon observed that the cam install was not done properly and the end cam cap was located backwards

Sadly, the cam journal and cap were wiped and apparently the KNOCK sound was the cam bouncing about in the end of the head. If the customer had continued to drive the car in that condition any longer it is very likely that the result would have been a failed motor. It is a good thing he brought it in to be checked and that I was so determined to find the cause of the knock I was seeing, this kind of result takes time and a patient customer who is not in a rush.

MORAL to the story - when cars are modified close attention must be placed on any work that has been done and any problems that may occur due to faulty workmanship

ALSO - knock counts DO NOT always mean detonation

This is a common theme that owners of Evos pulling timing blame the tuner when the car could have a mechanical issue - as in this case - and not a bad tune (which clearly this car had BOTH mechanical issues AND a bad tune)

I am not naming any names or bashing anyone - please do not talk any trash here - this post is made in the hope that two days of wasted time may help others who have this kind of condition

Al

 

This is VERY good to know


Good job AL

 

The cam bearing cap on the cam gear end was backwards?

 

What Al is refering to is one of the camshaft retaining caps that hold cam onto head was installed backwards(very hard to do,but possible) as it is designed to be installed one way so that this type of thing does not happen.I recall a few years back that some member on here was "line boring" the cam journals as it was found that when cams had been installed and care was not taken when removing cam caps that they would become "out of round" and cause some "noise",after line boring the cam journals the "noise" was all but gone.Al,do you remember who that was that was line boring these heads?I think it was someone from the city,not positive though.

 

The end cap on the intake cam - driver's end was placed on backwards with the arrow pointing in the wrong direction

Mistakes can and will be made on occassion

The main thrust of what I am trying to highlight with this thread is that often the TUNE is blamed when a car is not running properly

In some cases mechanical issues can be the fault

One customer of mine made several threads on these forums about random "KNOCK PROBLEMS" - some haters were quick to blame MY tuning and in the end his car still knocked the same way with the stock tune and it was determined that a faulty knock sesnor or down pipe contact we his problem and the Knock went away 100%

Sure, I guess I take some satisfaction out of correcting the careless errors of a local so called "tuner" who tries to tune evos - but that is only a side point

Main point is keep an open mind when trying to determine the cause of a car problem

All too often on these forums arm chair "experts" pontifciate without any data or facts

There is no substitute for hard work, experience and common sense

 

Wait Al whats the issue with having blocks of your ignition timing map all the same, is that not optimal?

Scorke

 

Your statement is ignorant for several reasons

1- this thread is about CAM caps and mechanical problems which cause knock count readings from engine sounds

2 - I did not tune this car it was another tuner's tune in there (I imagine I will tune it when its fixed)

3 - There is no truth that MY ign timing is always a so called "block" I use different set ups for different configurations of mods and this issue has already been discussed elsewhere - ad nausieum.

Please if you have nothing positive to contribute to an otherwise inteigent conversation take your thoughts to another forum.

Al

 

Wow, good work tracking that one down Al. And definitely thanks for taking the time to write it up.

+1 on not always knee jerk blame the tuner. It seems like thats the default reaction of the unexperienced.

 

haha, ok. If it was the cam gear side cap that would have been ridiculous

 

Good find Al, that's why you're paid the BIG bucks.

 

Actually this story has a happy ending as the original "tuner" shop acknowleged the error and has taken back the car to repair the damage at no charge to the customer which was a class move.

Mistakes happen - how shops resolve any problems which arise is what seperates the good ones

With that said - this mistake should never occur as the arrow is on the cap to prevent this

 

was there any noticable sound coming from under the vavlecover when this was accuring?

 

A 12” 3/8 extension between your ear and the engine block would have “heard” the problem.

 

I have had a problem with lots of valvetrain noise in my head after i installed some cams about 3 weeks ago. I have taken my valvecover off twice now to recheck the rockers and the cam bearing caps and they are all fine, i also check to make sure that there was not any uneven wear. I have a feeling that this sound is driving my knock sensor off the wall. Anyone have any ideas on what it could be.

 

Did you bleed the lash adjusters?