OK........deleted this since this is the past lol......

working on the 3.5 but running into problems..and need a new block...

thanks for all of your help guys...

 

given cold weather and the low gas tank youve had i'd say you probably got some water condensation in the lines and/or tank, id fill it up all the way with premium and use some gas line antifreeze after a tank you should be ok

 

But would the water condensation in my fuel system cause the knocking noise? Maybe I shouldn't siphon out the gas then and just fill up the whole tank? Thanks for the input

 

Wow....that was a very detailed interesting story.I think maybe water in the gas somehow.Lets here what the others have to say.

 

Yea...I should of posted this earlier here instead of the nycmax....but damn...this sucks lol.

 

sell and buy the civic like i told ya... I researched this alot and gettin mixed things... Espeically with the knockin sound at 4k

 

LOL no civic! gf has a rsx type s....close enough but better that I drive a lot anyway lol...I think it was caused by looking at the damn 2003 350z track......

 

Since you said that this just happen as you put in sunco ultra that should be 89 right,If so that could be the reason why your car is acting up. I would think that there is water In fuel lines. I was also going to say that it was the MAF because It won't let you past 3000-4000 RPMS. So tryed a new MAF same result. The knocking part do have a sound clip of it so we can help out a little more?

 

I never fulled up any car with low octane gas. Ultra is 93. I will be doing the sound clip when I get to the shop later tonight. I will siphon some of the gas out and then drive it to a BP station. Full it up and swap mafs and hopefully see some results..

 

Ok so when I first start up the car...rev it to 4k then to 5k...no problems. As the car warms up for about 2-3 mins, rev to 4k again...makes this noise. Here's the vid clip



I drove the car around a few times and just losing power when I step on the gas....
I went to the BP gas station and filled up the tank..close to $50 and headed back to the shop. When I give it gas slowly, the car will move...and when I just step on it...just loses power and makes this hissing noise like something is wrapped on my air filter....

Is this a sign of a clutch slipping? I'm just throwing out ideas....I never drove a car with a clutch slipping before but I forgot to check the clutch master cylinder...I'll check more tomorrow...but if it does slip..it should just rev and car wont go correct???.it was just very late working on the car and I didn't want the cops to bug me again so I will look into it further tomorrow..

 

I think It's your cam heads or the valves that are tapping to fast. You did the 00VI swap that's nice.
If your losing power with the acceleration I would try the MAF than do the TB and ICAV cleaning than go from there. Make sure all the vacuum hoses are clamped up if you here hissing noises.

 

Yea...Tavarish said it might be something with the valves......I did this 00vi swap about 2 years ago. Its def not the MAF...I used 2 different ones day and one that was on my brother's maxima. The TB i just cleaned today and I'm using the 5th gen IACV. All the vacuum hoses are clamped.

 

I will say this Take a good look at the swap than find out If there Is any leak with the LIM or the UIM whatever your using these are also to cause some loss of accaleration and power.

 

Yea I had the vacuum leak before and I fixed it awhile ago....but that tapping noise....it's killing me...lol..

 

WTF? seriously i doubt all these worst case scenarios thrown out here are the problem, Bad gas causes the knocking noiseand will cause that "hiss" sound while trying to accelerate like i said go get you some gas line antifreeze and fill up on some premium so you can run the last of your bad gas out,if 2 tankfulls dont take care of the problem then i'd worry about valves and Mafs

 

You have an internal engine failure. Could be up in the heads, could be lower bearings. Either way, that motor is toast and needs to be torn down to find the cause. Possible rebuild or find another motor and swap it.

That ain't no bad gas, water or MAF issue. Seriously people......

 

yea....very random...it has under 111k miles on the motor....

I was hearing the noise either from the head or timing cover area.

I guess I have to step up on my 3.5 swap asap now...

 

Like already mentioned, this is an engine mechanical issue and needs to be inspected to know exactly what's going on. The timing cover needs to come off at the very least.

 

i wouldnt tear **** down till i know the gas isnt the culprit, if it turns out to be something else its probably a spun rod bearing, check your oil make sure you dont have any particles in it, then tear down your engine

 

thanks for your input guys...I hear the noise around the timing cover/heads when the engine is warmed up and revving to 4k rpm...when the engine is cold...it doesnt make that tapping noise.

I'll open up the valve cover and check a few things out but not going to spend too much time on it till I pull the motor out...

It seems like I have to rush on my 3.5 project but haven't had the time due to work and interviewing....well later today, I will hone the block, clean the pistons/rods and wait for the piston rings to come sometime next week....I wanted to see if nissan sells the piston rings separately, not a complete set with the oil rings like how I got the 07 altima oil rings. Its just to compare a few sets of vq35 piston rings to see IF they are the same or different specs

 

Please explain how bad gas will cause an RPM-specific tapping noise....

 

ok so now the oil seems like to have metal shavings.....the oil had some grey particles which are very fine.....

 

oh boy thats definite mechanical engine failure, not worth stripping it down and fixing i think, get a lower mileage motor or do the 3.5 you were mentioning

 

yea...the 3.5 block that i have has a vertical scratch that i noticed after taking the rods/pistons out..on 2 of the cylinders...the scratch was glazed over so not sure if that was me or what....just honed it today and i guess one of them is deep..i can feel it with my finger..

 

man this sucks, do you drive it hard frequently?

 

spun rod bearing, it seems to be very common on vq's ive stripped down, does anybody know of any oil flow/control issues in the block? next time i strip it down i might port some of the passages


Nismology:
I wasnt adressing the RPM specific issue i was adressing the hesitatation issue- which could be a gas/water issue. But no gas/water wont affect a RPM specific knock.

 

not good man........ Ill call ya in a bit to let u know bout the door

 

i barely drive the car lately since I work in nyc and i take the train. only drive the car on my days off to run errands or a drive to central nj, nyc or even AC at times....and i dont drive hard all the time. I knew something was going to happen because I can feel the car hesitatating on idle for awhile....vibrations, nothing wrong with the idle though.

 

The reason this problem probally accured Is because there two things here that 1. The oil leaked out certain amount and when you drive hard or not because was not there to protect the crucial parts like the rods that grinding with no oil.2. There could of been late or no oil changes to casue your engine to crash.P.S are you the orignal owner of this car or your the orignal owner of the car.

 

I'm the 2nd owner. I used regular castrol oil for the first oil change and switched to mobil 1. Usual oil change 3-4k miles...I did however changed the oil after 7000 miles one time...About 2-3 months ago I switched synthetic oils....so I'm not using mobil 1 anymore.

I do remember I have a slow leak on the rear main seal.....maybe not enough oil....I forgot to check before I took that long trip..

 

deleted the whole story...didnt want to see it anymore lol..whats done is done...now...3.5 project!

 

I THINK I FOUND THE PROBLEM....


My dad gave it a try at the shop today.....he called me and to come and check the car out with him..


He told me to check the cat out first before rushing on the engine swap.....I checked the cat about 2hours ago and it was shot. He thinks the other cause was the bad gas that might have started the problem.

Rev the engine to 4k+, no knocking noises and left the car running for about 15mins and no nosies...

To explain the grey spots in the oil...I'm still not sure..it can be the gases that were going back up on the engine due to a bad cat. Not metal shavings that it looked like when i whipped the dipstick on a white towel. So I changed the oil.


I changed the cant around November 2007 that I bought from Warpspeed...I had to gut out the cat since it was useless at the moment.

Once I get the door saturday I will be driving the car around and see whats up....

 

the only things really that cause a clogged cat are rich A/F mixture,or Coolant seeping into the exaust.
maybe you should check your spark plugs.

 

I'm pretty sure I was running lean on both banks before and the codes were gone after awhile. This is my 2nd cat that I bought......bad luck with cats from the EU and now.
I'll check on the plugs again...these were the same plugs I took off last year from running rich due to a bad EU board but had these plugs on the car for about 3-4 months..