i heard knocking...

[a240sxpinoy]

ok so i do not want to blow my motor so i am very cautious.

i had the car on neutral and reved it from the engine bay, not sure how high but i heard loud knocking...

i tried it again but this time i slowly increased the rev and i didnt hear the knocking...

it seems like it only knocks when the rpm jumps up, what could this mean?

my afrs are pretty decent

idle 13.8-15s *(still fluctuates )under boost 11scruising 14.5-15s

help! i do not want to blow my motor!

[shimizu_17]

Maybe you got a bad batch of gas? Timing is not where it should be? Your a/f ratios seem ok to me.

[480sx]

How many miles on the car?

Have you done any work to the car recently?

Kinda sounds like the beginning stages of rod knock dude.

[a240sxpinoy]

How many miles on the car?

Have you done any work to the car recently?

Kinda sounds like the beginning stages of rod knock dude.

the motor has about 123,XXX miles. i turboed it at 122,000 miles.

no recent work on the car. just a new tune sent from emance. (i didnt contact him he contacted me and asked for my addy and a week later i got mail with a new tune inside it. switched out the chips and i can say it runs better from the first tune. afrs are what it is now. his first tune ran a little rich.)

my friend said it might be predetonation?car runs strong and no problems.

Maybe you got a bad batch of gas? Timing is not where it should be? Your a/f ratios seem ok to me.

im going to double check timing this weekend. it was at 20* going to double check. whats better if it is at 20*? bring it to down or higher? to see if detonation still occurs?

[WDRacing]

Detonation only happens when on boost, NOT when in neutral. The motor has to be under a load and in your case, under boost. If it detonates without being in boost, the tune isn't correct. But you have a wideband so...

Sounds like rod knock to me as well. I hope not, cause that's a rebuild.

My problem is that at one point you ran an Emance tune that was very rich, that means fuel got into the oil and probably ruined the bearings. If this is the case, you can thank Jason for destroying your motor.

WD

[480sx]

My problem is that at one point you ran an Emance tune that was very rich, that means fuel got into the oil and probably ruined the bearings.

+1

How rich were you running and how long did you run it like that?

[KA720]

are you sure the knocking sound is coming from the bottom end?I ask because it's not uncommon for a head gasket to blow between cylinders and for it to sound like a light knock, due to the cylinders swapping compression back and forth between each other. The old z24 engines in the 720 truck are well known for this, I've also seen the same thing happen to a KA, not saying it isn't rod knock, but it wouldn't hurt to do a compression test.

[a240sxpinoy]

Detonation only happens when on boost, NOT when in neutral. The motor has to be under a load and in your case, under boost. If it detonates without being in boost, the tune isn't correct. But you have a wideband so...

Sounds like rod knock to me as well. I hope not, cause that's a rebuild.

My problem is that at one point you ran an Emance tune that was very rich, that means fuel got into the oil and probably ruined the bearings. If this is the case, you can thank Jason for destroying your motor.

WD

well when i was reving it, i guess i reved it high enough for the bov to sound? does that mean i had some boost build up? when i was running rich it was more like 11-12s on idle. i didnt run it that long until i got better afrs. the noise was more like a popping sound?

How rich were you running and how long did you run it like that?

not long. i never drove it while i was running rich. i am pretty sure i only drove it when i had afrs of +13 never any time below that except the first time i took it around the block, but it leaned out after that first test drive. i always checked the oil and changed it if i had a hint of gas smell in the oil.

are you sure the knocking sound is coming from the bottom end?I ask because it's not uncommon for a head gasket to blow between cylinders and for it to sound like a light knock, due to the cylinders swapping compression back and forth between each other. The old z24 engines in the 720 truck are well known for this, I've also seen the same thing happen to a KA, not saying it isn't rod knock, but it wouldn't hurt to do a compression test.

im not really sure. all i know was that when i reved it from the engine bay, it was more like popping sounds at high rpm to make the stock bov recirculate, but how come when i rev it up at a steady increasing rate, i do not hear the noise? i am planning to do a compression test asap.

[a240sxpinoy]

i was lookin at some vids on youtube for rod knock and thats not how my car sounds..i guess i should have stated POPPIN noises around the same time the bov recirculates.

ill try to get a vid to make everything make sense...sorry for the confusion. but ya not knocking more like a popping noise

[esahuque]

i was lookin at some vids on youtube for rod knock and thats not how my car sounds..i guess i should have stated POPPIN noises around the same time the bov recirculates.

ill try to get a vid to make everything make sense...sorry for the confusion. but ya not knocking more like a popping noise

take a long screwdriver and put the tip in different places of the motor while putting your ear at the end of the screwdriver (especially your head) and pin point where the noise is coming from. then post back with results, i bet its your timing chain.

check all your pulley for play and belts ware. I knocking motor has a very distictive sound, you cant mistake it for enything else. Its very deep and make a clunking sound.

[NateDogg]

Check for exhaust hitting somewhere.

[a240sxpinoy]

ok i am starting to think its my timin chain hitting against something when i jump the rpm. i previously took the timing guides out when the motor was first swapped in the summer.

also i remembered my friend who helped swap the motor in, told me that the chain tensioner might be a little worned out?

[480sx]

Could be, you can visually inspect the upper timing chain tensioner pretty simply by taking off the valve cover and the upper timing chain cover. Check for signs of wear on the tensioner piston.

[a240sxpinoy]

ya ill inspect it visually, but i dont have time until maybe december...cause of school and since its my daily.

i believe as long as i dont drive the car hard to hit that point where it makes the noise i should be ok right?? like i know it only makes noise when the rpms get high and when i jump the rpm to that point.

ever since hearing the sound i have not passed 3500 on the rpms and have been just cruising at afrs 14-15

btw when i do inspect the chain tensioner, what can i change internally that will be exposed already that is worth changin to aftermarket parts?

i know the cams would be exposed...

[480sx]

Theres no way to know if your going to be OK, heck we dont even know what the noise is for sure yet. It might help if you made a video with sound of it happening but thats up to you.

Theres not much else you can change while your looking at the tensioner.

[a240sxpinoy]

ok so i havent taken a video yet but i was searching you tube for tensioner noise and found this. my car sounds better. its fine no noise at low rpms but when the rpms get higher it sounds similar but once again i have to rev higher to hear that similar noise...

i will try to get actual video of my car asap. i need to borrow a video camera.

http://www.youtube.com/watch?v=R-Ll_0-22hk

[480sx]

If it sounds like that its most likely rod knock. Its soo easy to destroy a motor if your running rich, even at idle.

[240sxvaj]

If it sounds like that its most likely rod knock. Its soo easy to destroy a motor if your running rich, even at idle.

i agree

i would start saveing up to rebuild the KA

[a240sxpinoy]

really rod knock?? how come its at a higher rpm when i start hearing the noise

the car on idle has no noise when revving around 3-4 thousand rpm no noise engine sounds smooth only when you jump the rpm.

[240sxvaj]

really rod knock?? how come its at a higher rpm when i start hearing the noise

the car on idle has no noise when revving around 3-4 thousand rpm no noise engine sounds smooth only when you jump the rpm.

try post up a vid of your engine.

my engine had timing chain rattle and i was scared as heck too til i did some research and it was only my timing chain which was normal so i kinda relaxed

if it is your timing chain then remove your timing guides and the rattle will go away.

if your rides sounds like the one in the vid then its bad.

[480sx]

really rod knock?? how come its at a higher rpm when i start hearing the noise

the car on idle has no noise when revving around 3-4 thousand rpm no noise engine sounds smooth only when you jump the rpm.

What your describing really just sounds like rod knock man. When a car first starts to rod knock, you can ease onto the throttle and go up in RPMs without it making any sounds. However when you try to give it any amount of throttle you will hear it knock then it will smooth out.

[WDRacing]

Rod knock...

[a240sxpinoy]

ok so i havent been able to check out whats wrong, but i did stop driving the car to prevent anything else from happening.

i was talking to one of my close friends and described what the noise was and first thing he said was valve lash? he said his boosted civic started to make the same noise as i desribed, only in high rpms. he said something about adjusting it or gapping it? after doing that to his civic the noise went away.

could that be another possibility? i have taken a vid of the sound but yet had the time to upload it bc of school and midterms. everything sounds fine until 4500.

[480sx]

If it was your valve lash it would happen all the time regardless of how much throttle was applied. Since your telling us that its only happening if you give it throttle and not when you rev it slowly, that rules out a valve issue.

[a240sxpinoy]

ohh it does it when you rev slowly also...when i was taking a vid it did it both times, when i jumped the rpm to 4500 and when i revd it slowly to 4500, both times it made the noise at 4500. sorry for the confusion. i really need to post the vid up. just dont know how to convert it and all. lol

[240sxdrifter93]

im prett sure its valve lash to my car makes a rattle noise to and has the same rpm effect but i thinks it time for a ka rrebuild for the both of us