Is This Knock?

[Daboss]

There is a link tht best describes the noise I am hearing from my car. I woul;d like to know if this is knock and also how is this possible? I just got forged pistons and I took it for a spirited drive for like 2 mins giving it a thrashing and i noticed a noise like this when I got back. Checked the oil level and it was extremely low. Could low oil level cause knock? Or is this noise something else? I just put in standard bore pistons there are not oversized or anything. So any help or suggestion will be greatly appreciated. Thanks!!!!!!!!! Just change everything man Fu#$ this is a disaster if anything is wrong. I just changed pistons, headgasket, oil pump, water pump,timing belt, main and con bearings, spark plugs. I mean it was suppose to be a complete service so how the hell could he have not put oil in it, sh*&. I mean the oil level was barely on the L mark and also something was burning, smoke was coming from in the engine bay not much, but it was and it was from the exhaust manifold/dump pipe/turbo area.

Edited August 15, 2008 by Daboss

[paulr33]

knocking (detonation) occurs when the engine is under load from too much timing typically

you don't get knocking (detonation) at idle so its not knocking

that sounds like bearing knocking - could be big end bearing?

dont know enough about engine mechnics but its not timing related knocking

[116.hks]

yeah mate by the sounds of it you could have a noisey lifter. i don't think it sounds like a bottom end knock. as paul stated knocking or pinging as it is mostly refered to, happens more when the vehicle is under load. hope this sheds a bit of light.

[Daboss]

Yea it does still a pain in the a$$ tho cause i just giot a complete rebuild including replacing the bearings. Thrashing it for about thirty seconds with little to no oil did this right? Man this is a royal pain!!!!!!!!!!1

[116.hks]

when you say " little to no oil " where did the oil go? you may have caused more damage then i initially thought. if you have starved the bottom end of oil, it's possible that you have caused bottom end damaged.

[KiwiRS4T]

when you say " little to no oil " where did the oil go? you may have caused more damage then i initially thought. if you have starved the bottom end of oil, it's possible that you have caused bottom end damaged.

When you say you have just done this work did you take it out of the workshop and give it hell? My advice would have been to avoid hard acceleration but to build up reasonable revs and then lift off alternately for a bit and not to give it stick for a few hundred Ks at least.

Was the work done by a professional? If so take it back immediately.

What was done to the bores - could the rings hit the lip around the top? If there was oil on the stick then you should be OK on that score. Sounds like you need to at least pull the head off and have a look before you do any more damage.

[R32 Driver]

fried rings?

injector pulse?

noisy lifter?

my supra sounded like that and it was just injector pulse, you sure it wasnt like that b4 u went for a fang?

tow it back to the workshop to be safe and see what they say mate

for a rebuild why didnt they start with fresh bores and oversize is 20 thou?

[666DAN]

My injectors are that loud as well

[Daboss]

Ok here is the results of my troubleshooting, I gave it an oil change, changed and regapped all the plugs. Now she runs ok I still her a slight miss at idle so i checked the timing with the tps unplugged and noticed it was fully advanced, so I put timing back to 15 and she ran great. I plugged the tps back in timing dropped to about 5 degrees and the miss came back with a slight knocking sound, took the tps off revs and timing advanced to 15 and the miss and knocking went away she ran great. Put the tps back on and well you can see the pattern. Now my question is what is causing the timing to retard and miss to come about when I plug the tps back in?

OHHH, and to answer your questions it was done by a workshop(don't know if I could call them "skyline professionals" as I am in the Bahamas but they know their stuff when it comes to machining cars) the blocked was bored to suit the new forgies.

I did give it a lil fang when I got it back wasn't a long period say for about thirty seconds a lil spirited drive and thats not all out just a quick boot in first and second probably got to 6000rpm didn't get to third. Before I fanged it about 300km were put on it no boost and no revving pass 3000.

It had about a gallon of oil in it when i changed so oil so tht one still is a mystery to me, when I look on the dipstick now I can't see a level but I know its full because I placed a gallon and half a quart of oil in there myself.

Thats not my car in the vid either was to work and it was the closest noise i could get to my car sound will try to get a vid together of my ar and the noise and palce it on here.

Thanks for all the great responses so far and I hope u can help my figure this out just this last prob and I am done, You Guys are great!!!!!!!!!!!!!!!!!1

[R32 Driver]

thats weird to run it in with 300kms 3k rpm and NO boost?!

cant be right?

just take it back to the workshop dude..... hope they can/will recrify it for you

gallon and a half = 5.5 litres?

isnt that waaaay to much for a rb25?

[Daboss]

thats weird to run it in with 300kms 3k rpm and NO boost?!

cant be right?

just take it back to the workshop dude..... hope they can/will recrify it for you

gallon and a half = 5.5 litres?

isnt that waaaay to much for a rb25?

No not a gallon and a half of oil. A gallon of oil and half a quart of oil. No I was just sayin tht to show it wasn't a str8 out the workshop flog. I just boosted it that one time after about 300kms of driving off boost.

[(B1) MR_fanny]

id like to know the cause of this too. i have had a similar sound that occured 3 times only earlier in the year on and off only on super hot days (bahamas..lol) and only after i did an advance driver course with heaps of spinning around. sounded like a deisel motor but would go away if i let it sit and cool for 20min or so. hasnt done it since. will have to see when it starts to heat up again.