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RoastBeefCurtain Commando
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6,015 Posts
Discussion Starter #1
Well I took my car to the track yesterday to see how she would fair.
I knew the clutch is pretty shot and slips alot, but I went anyway.
I got on the dyno there for free so said screw it. dyno in 3rd to minimize the slipping.
The car did [email protected] Not too bad considering how bad the clutch is. I know its got more in it though.
So Im feeling good and go for a run a little later.
I launched and bogged cuz it was my 1st run in RWD, 1st picked up hard, 2nd picked up harder, then in 3rd it seemed to slip a shit load and to 4th.
So I said screw it, its time to do the clutch.

Now for the interesting part.
I am on my way out of the track and I hear this knocking/tapping. Im like WTF?
So I opened the hood and cant hear anything? I get in and drive more and determine that it really starts at like 3k or so. So I have a friend hold the RPMS ther and I get under the hood and the knocking is coming from the back of the engine bay.
First thing I thought is SHIT I got rod knock. I checked the oil and the oil is at a perfect level.
I said shit there isnt anything I can do now, so I drove it home. I noticed the noise isnt at Idle at all and doesnt seem to be thruout the whole power band. Most of the time its there, but some of the time its not. So I am hoping to rule rod knock out of it.
The other thing that scares me is my oil pressure is still pretty damn low. It is FULL of oil. So it is not that at all.

I was thinking maybe because of it being in the back of the engine, it might be a spring or somethng that worked loose from the clutch after that run I made?

Anyone care to tell me what else to check. I am doing the clutch prob in the next week or so. But I gotta figure out this noise and low oil pressure issues.
The car still runs hard too.

Anyway thanks ahead of time for whoever reads thru this book and decides to help.

Thanks
 

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JZA70 448 rwhp everyday
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2,994 Posts
get a mechanics stethascope. Those things are worth their weight in gold.

~scott
 

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RoastBeefCurtain Commando
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6,015 Posts
Discussion Starter #3
Im reading thru old posts now where people are saying they got rod knock even with perfect oil levels in the motor.
Man if this is rod knock Im gonna rip the motor out and light a few sticks of dynamite under it and go 1or 2jz and say fuck the problems for life.
I hope its not that though. I dont know why it would do this?

What are some other causes of low oil pressure but still fine oil levels? Bad oil pump maybe?
I guess at this point if I have such low pressure I guess its probably a given isnt it?

I am gonna see if I can borrow a stethoscope this week maybe
 

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RoastBeefCurtain Commando
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6,015 Posts
Discussion Starter #5
Well seriously though. I dont wanna build the motor and have the same probs.

Anyway, any other suggestions to narrow this down. Words of encouragement?
 

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Premium Member
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5,301 Posts
Why don't you tell us what the oil pressure is and let everyone else that has had experience with this tell you if it's low or not? What you may consider low for pressure may be just fine.

Throwout and pilot bearings can make some weird noises when they go out and depending on how bad the clutch is/was, it could be many different things. Get the stethescope and hopefully that will help out some or at least get you in the right direction.

1jz or 2jz isn't the answer. THey have their fair share of problems just like the 7m. A different motor isn't the solution for a lack of knowledge of what is wrong with your current setup.
 

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Not ur jizz, not ur bizz
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6,571 Posts
itr206 said:
Well seriously though. I dont wanna build the motor and have the same probs.

Anyway, any other suggestions to narrow this down. Words of encouragement?
yeah, good luck...:lol:

the noise...it happens with engine rpm?

sometimes people mistaken valve clatter for rod knock or shitty pilot bearings for rod knock...
 

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RoastBeefCurtain Commando
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6,015 Posts
Discussion Starter #8
The oil pressure at idle is just a C hair above the 1st line. Under load a little under the second line. At about 3k RPMS where it should go up considerably. Just kinda stays just below the second line or right at it. I think that like 30psi?

Anyway, the clutch still engages and dissengages fine. It slips quite a bit, but still drives and boosts fine.

The noise doesnt really go with RPM too much . LIke I cant hear it at idle at all. Sometimes I can hear it from 2.5-3k. Sometimes it seems to not be heard at all.
If it was the TO bearing, wouldnt it only do it engaging and dissengaging the clutch?

If Im driving or cruising at like 4k i might hear it, then as soon as I push in the clutch it seems to go away.
Also noticed that if I am in another gear it will go into reverse fine. (Obviously standing still). If I am in the neutral position and slowly put it into reverse it will grind and scratch going in.
These are things that are making me hope it is clutch related. I know springs have the tendancy to break off in the discs.
But I get scared and cant be too sure


Wasnt saying that I would just swap it and that be that. But If I determine it is something major like rod knock I prob wont put the effort into fixing it and building it to possibly have the same thing happen later.
 

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Not ur jizz, not ur bizz
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6,571 Posts
its monday....every auto part store is open with hundreds of steths available.

the best part is that its only 3 bucks! or so...

give us an update when you get one and check it out.
 

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RoastBeefCurtain Commando
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6,015 Posts
Discussion Starter #10
oh they are that cheap?
Ill go get one today then and check it out tonight.

Does rod knock usually happen at idel too right? Or is it usually not amplified enuff at idle?
 

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boost freak
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10,042 Posts
bad rod knock can be heard @ idle.....early rod knock is hard to pick up. try revving it, that should load up the bearing enough for it to make some noise....
 

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RoastBeefCurtain Commando
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6,015 Posts
Discussion Starter #12
Ill have to have the wifey rev on it while Im under there.
Damn I hope its not knock. This will put this car in hibernation for atleast a year. Wedding coming up and house work in the progress and cant afford a rebuild at this point in time
 

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(╯°□°)╯︵ ┻━┻
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1,761 Posts
coming from the back of the engine bay leads me to assume it's the throw out bearing, but I'm probably wrong. my TO knocks occasionally, but only when the clutch pedal is to the floor and I'm idleing do you hear it knock softly.
 

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Registered
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328 Posts
If it goes away when the clutch is pressed I would say there's your problem, something in the clutch/transmission assembly. Thanks,
Matt
 

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Premium Member
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5,301 Posts
itr206 said:
Ill have to have the wifey rev on it while Im under there.
Damn I hope its not knock. This will put this car in hibernation for atleast a year. Wedding coming up and house work in the progress and cant afford a rebuild at this point in time
Your oil pressure sounds just about right actually. It won't go above that 2nd line hardly ever, if at all. Just under the first line at idle is fine. Mine usually idled around half way between zero and that line. You should be ok there.

You do know you can rev the car from under the hood yourself right? You don't need anyone in the car to rev it for you if you don't want.
 

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RoastBeefCurtain Commando
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6,015 Posts
Discussion Starter #16
my pressure was a little above 40 before and right after i changed my oil the other week. I usually knew it was lower on oil or the oil was thinning out when the pressure was going down. Thats what scared me. I checked it and fine level and put a little 20w50 in there to thicken it up

I know I can throttle it in the bay. But I was assuming I would need to get under the car and hold the stetho to the bottom of the block to check for knock. I guess I can prob do it from the side.
Now if its in the last cyl before it gets to the tranny. Will it be noticable difference between the tranny and that last cyl if they are kinda close in the same area?
 

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RoastBeefCurtain Commando
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6,015 Posts
Discussion Starter #17
I checked it tonight with a steth and its hard to tell.
Its deff not coming from the head. I got that much from it.

Its hard to tell if its coming from the bottom end or the tranny because they are soo close together.
Would it be better to check it from underneath like on the oil pan?
Im at a loss here
 

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RoastBeefCurtain Commando
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6,015 Posts
Discussion Starter #18
I just got under it quick to see. It seems to kinda make more noise from the tranny. But it could be my imagination. I dunno.

Any other ways to check? 1st thing Ill prob do is drop the tranny though
 

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wastegate hose is pulled
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4,586 Posts
Kill cylinders one at a time and rev it. If the noise goes away, It is something in the bottom end of that cylinder. I doubt rodknock, since you have normal oil pressure.
 

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I don't want an MK4!
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1,727 Posts
Always the best to dyno and hit the strip, when your clutch is slipping.

And yes, oil pressure does go above the second line.

Mine is around 52-54 (best i can estimate) doing 75 on the freeway.

Mine is very rarely ever under 40 except at warm idle under no load.

Good luck. Is your clutch slipping significantly more than it was prior to the track outing?
 
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