Increased Knock... Clacky Noise?

[R33-Kid]

hey guys

my car is a R33 GTS with a highflow, nismo 555cc, splitfire coils, z32, hks evc, apexi power fc and all the other usual bits

ive had my tune in the car for about 2 weeks know and everything has been running smooth with no excesive knock (knock levels were below 20). now the other day i started my car in the morning and noticed a bit of white smoke from the exhaust when i reved the engine slightly, not huge amounts just a bit. i then noticed a increase in the knock on my hand controller was going up to 40-50 whilst driven carefully, i thought i had a serious problem on my hands (not to say i still dont).

now i havnt noticed anymore white smoke from the exhuast at anytime. driving today carefully i noticed the noise that is causing the knock. when cruzing along in any gear usually between 2000 and 3000 revs i can here a clangy tapping noise. i noticed this was when the knock sensor was going of its head. this is when im just maintaing speed if i take my foot of the throttle it goes away, if i accelrate it goes away, even flat foot it goes away knock drops back to normal levels but comes straight back when cruzing.

me and my old man have ive been under the hood to see if anything was loose and hitting anything and couldn find anything, done the screw driver test listening cant seem to find the source (not noticable on injectors, head, block, turbo, rocker covers). we can get the noise to occur when we blimp the throttle but if we rise the revs slowly it doesnt occur.

any ideas or help would be greatly appreciated

just ask if i havnt explained anything clearly.

cheers coop

[dmac_25]

Hey mate who tuned it?

It sounds like it could have a bit to much timing in the map in that area where you are putting round take it back and get them to check it out usually happens there are a few issues like that

[The Dan]

The white smoke is called steam and is normal on cold starts

The knock you are describing sounds like a bigend. I hope it isn't but every symptom you describe says bigend bearing.

It can't be timing because at cruise you'd have to be running somewhere around 50-55deg BTDC for it to ping.

[R33-Kid]

ohh cok

anyway to tell other than the obvious?? could it still be a big end if the knocking sound is not consistant when it comes about whislt driving. if it is a big end could you just giv us a quick idea how its happening, explain the reason for the noise whislt cruzing.

is its becasue it has a load on it when accelrating or deaccelrating, where as cruzing or blimping the throttle its got no load on it and moving about or simply has just crapped it self.

yeh il talk to my tuner tommorro to see what they say and maybe let them have a listen.

[The Dan]

is its becasue it has a load on it when accelrating or deaccelrating, where as cruzing or blimping the throttle its got no load on it and moving about

Precisely.

Basically on decel it is under load and on accel it is under load. It will only make it around 2500-3000rpm at the beginning stages of a run bigend. If it's like 5 or 6 rapid knocks as it comes past 3k when you blip the throttle then I'd be putting money on bigend.

Alternatively, you can send me a 200ml sample of your oil and I can tell you for sure. I have oil tested for our race cars so it's no biggy. It's only $40 and comes with a full written report.

You need to run the engine until it reaches operating temp, then either drain oil into an EXTREMELY CLEAN container or suck it out through the dipstick tube using a 3 or 4mm clear tube and a mighty-vac.

It will 100% tell you if the engine is fubar or not

[R33-Kid]

thanks alot Daniel

yeah il giv it another listen tommoro but that makes sense to me must be it, now to rb30 or not if it is the case.

it doesn come as a huge shock as when i did my motor i painted my rocker covers and due to my poor painting abilities i failed and ended up gettin them powder coated. turns out that in the rb25 rocker covers it ni on impossible to get all of the crap out of them and it was to late when i changed them adn flushed a couple of hundereds of dollars of oil and oil filters through it. my tuner told me this at a later stage as he didn see the car when it came in for the tune and hes seen it happen before.

il drop some oil out tommorro and see if i can see the swirly crap on top as that should give a big hint away.

oh well guess another one of lifes lessons. and for all you other guys DONT POWDERCOAT YOUR RB25 ROCKER COVERS often laeds to motor death.

thanks again

coops

[The Dan]

I wouldn't jump straight on f**ked engine. Just understand that going from your description and based on the experiences I have had, that is my best guess. The only way to tell for sure is to pull it apart or have the oil tested. Obviously it's a lengthy task to pull the engine out to 'possibly

find out it was something else. I urge you to consider oil testing as simply looking at the oil that comes out will not always yield accurate results.

Even if you don't get the testing done through me, I'll happily give you their contact details so you can purchase your own test kit. It takes about 48 hours and the report is extremely informative. It will take out the guess work.

If you go ahead and drain the oil you may upset any chance of getting a clean sample so make sure you get a sample first, then you can at least fall back on that if you have to.

[R33-Kid]

yeah totally understand will get my tuner to have a listen and il defenitly look into the oil testing as you sed alot easeir than pulling the motor out. if i need the details il be in contact with you. fingers crossed it may be something stupid.

thanks daniel

[joeyjoejoejuniorshabadoo]

$40 i'd do it as a matter of course

[geraus]

hey man! i wouldnt mind doing this test thing? where do u live??? can i give u a call bro ? how would i put oil and send it?

[bozodos]

isn't there a company on the net based here in Australia that do those oil tests?

[The Dan]

Yeah there is a company here in Brisbane that does it. We send the oil in from our track cars after every event. You can buy the kits direct from them and it includes the return post container and clear tube. Return postage is paid in the original amount.

I'll post up a scanned report when I get to the workshop so you guys can see what they test for. They test metals down to parts per million and can even tell you if your air filter is dirty or the engine is running too rich.

[bozodos]

sounds like a pretty handy diagnostic tool then!

[tridentt150v]

Sounds more like a stuck lifter, if it was a big end the noise and knock level should get worse when you accelerate.

But also, if you still get white smoke [not cold start vapour], it could be a head gasket, just a little hole with a ticking/tapping noise - it will get worse.

Your knock levels are more likely a measure of the noise than any real leaning out.

[BLSTIC]

You forget, lifter noise doesn't change with noise.

I had a similar knock detector picking up engine noise experience... I had a Legacy GT with rooted rings and bearings. After ~2000km the oil would get horrible, and the engine would make enough noise to trigger the knock sensor, retarding the timing, heating the exhaust valves, causing knock, retarding the timing, heating more, etc. But the point was the knock sensor came back with a signal with worn big-ends.

[/pointless post]