guadofreak

iTrader: (1)

I was helping a friend out on his car (99' SS S2 H&C) and there is a VERY peculiar(sp?) situation. First off i want to say we pulled all the pushrods and rockers checked all plugs connections etc to rule out anything like that. Car has NOT thrown a code yet either.

Well here it goes a few nights ago a race occured. As soon as it was almost over the oil pressure dropped and the car made some loud knocking noises. And could barely stay on for the trip home. Car sat in the garage for a cuople of days and then the ? above ? was done. After all that we started it up and it ran fine once the HUGE cam decided to find an idle. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> There was no knocking until we would give a few quick revs then we could hear the knock. IT was too fast to even attempt to locate the knock. The weird part was that the car staying on w/o shutting off.(unlike the previous time) <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

Moving on, we took it out for a spin gave a couple WOT runs and we could hear the knock during the WOT but only at that time.

We then reached optimal operating temparature and the oil pressure dropped to about ~5-10lbs but would stay around 40 while driving. meanwhile the knocking was becoming more and more prominant. <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

We drove back home and once we got closer it just began shutting off. The car would NOT stay on anymore. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> When we would turn it on we could hear a louder knocking but immediately it would die. However it sounded like it was coming from the intake manifold. It was a very hard plastic sound but then again it could just be whatever it is resonating through the intake manifold. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

Once again this car is an A4 w/ an ST3500 we could not keep the car on long enough to find and pinpoint a knock(once it was finally knocking loudly) and we are stumped. Nothing that we have come up with has made any sense. Please give any ideas you could even think of anything at this point will help! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Thanx~ Eddie <img border="0" alt="[guns]" title="" src="graemlins/gr_guns.gif" />

***edit*** There also seemed to be no huge noticeable loss in power....

<small>[ March 27, 2002, 12:43 AM: Message edited by: guadofreak ]</small>

TimZ28

A new shortblock should take care of it. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

AlonzoVersion 1.0

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by guadofreak:
<strong>I was helping a friend out on his car (99' SS S2 H&C) and there is a VERY peculiar(sp?) situation. First off i want to say we pulled all the pushrods and rockers checked all plugs connections etc to rule out anything like that. Car has NOT thrown a code yet either.

Well here it goes a few nights ago a race occured. As soon as it was almost over the oil pressure dropped and the car made some loud knocking noises. And could barely stay on for the trip home. Car sat in the garage for a cuople of days and then the ? above ? was done. After all that we started it up and it ran fine once the HUGE cam decided to find an idle. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> There was no knocking until we would give a few quick revs then we could hear the knock. IT was too fast to even attempt to locate the knock. The weird part was that the car staying on w/o shutting off.(unlike the previous time) <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

Moving on, we took it out for a spin gave a couple WOT runs and we could hear the knock during the WOT but only at that time.

We then reached optimal operating temparature and the oil pressure dropped to about ~5-10lbs but would stay around 40 while driving. meanwhile the knocking was becoming more and more prominant. <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

We drove back home and once we got closer it just began shutting off. The car would NOT stay on anymore. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> When we would turn it on we could hear a louder knocking but immediately it would die. However it sounded like it was coming from the intake manifold. It was a very hard plastic sound but then again it could just be whatever it is resonating through the intake manifold. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

Once again this car is an A4 w/ an ST3500 we could not keep the car on long enough to find and pinpoint a knock(once it was finally knocking loudly) and we are stumped. Nothing that we have come up with has made any sense. Please give any ideas you could even think of anything at this point will help! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Thanx~ Eddie <img border="0" alt="[guns]" title="" src="graemlins/gr_guns.gif" />

***edit*** There also seemed to be no huge noticeable loss in power....</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I pray to god it didnt happen but I think it sounds like your oil pump took a nap.Time for a new motor.

guadofreak

iTrader: (1)

I was thinking the oil pump crapped out but why would it still read 40+ psi on start up and stay there for about 10 minutes of driving. After that is drops(not to zero) but will still maintain pressure as long as the car is being driven(Still does not drop below 5-10psi. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> Wouldn't it show "0" oild pressure if it did die? the oil pump is an aftermarket ported oil pump not a stocker.

I am figuring prob time for a new shortblock but still want to know what is wrong! <img border="0" title="" alt="[Embarrassed]" src="gr_emb.gif" /> <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

Tekhombre

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TimZ28:
<strong>A new shortblock should take care of it. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yup.

guadofreak, once you loose oil pressure (specially at WOT) allot of damage can happen in a short period of time. I would say that the bearings are hammered.

Julio

BlownC5

iTrader: (81)

Sounds like rod knock to me, good luck to you.

Raughammer

Knocking sound and low oil pressure once it's heated up?

Your bearings have gone to bearing heaven. <img border="0" alt="[angel]" title="" src="graemlins/gr_angel.gif" />

Sorry man. <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

The knocking will get progressively worse and may damage your block or rods if you keep driving it.

Good luck with the rebuild.

Jax White TA

WOT runs on a knocking motor with low oil pressure???? I guess he likes the idea of a new motor. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

VINCE

iTrader: (1)

This really sucks.. Reading the above sounds similar to my co-workers car. He purchased Tims shortblock..

Nine Ball

iTrader: (38)

Definitely sounds like a spun rod bearing to me. The oil pressure is higher on startup because it isn't heated yet. The viscosity of the oil comes down some when heated, and the pressure drops normally.

Quit driving that motor like that or you will need a new crank and/or rod.

Tony

guadofreak

iTrader: (1)

Don't be sad guys! IT only means it's time to go bigger!! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> Too bad it isn;t my car getting more cubes(YET <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" /> )

Thanx for all the help

VINCE

iTrader: (1)

Eddie I opt for Joey to just get another 346ci shortblock so us little guys can keep up.. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Country Boy

iTrader: (24)

Given that info, Its the bottom end. I feel bad for Joey. Like the others said, if you were driving it with very low oil pressure, then the bearings are probably shot <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> It could be a rod or a main. I dont know what they sound like in an aluminum motor. I really know what it sounds like in an iron block motor.

The good thing, it is rebuildable. Why waste more money on bigger cubes. I havent seen anything impressive except for the big dog 4**+ motors.

z28pwr

Instead of increasing the cubes he could get it forged and slap on a healthy dose of N20

<img border="0" alt="[Chevrolet]" title="" src="graemlins/camaro.gif" />

<small>[ March 27, 2002, 05:23 PM: Message edited by: z28pwr ]</small>

Joe99SS

Just to clarify a few things... The pressure has not dropped below 20psi at any time... The car has not been driven with the exception of the test drive after reassembling the top end last night and at that time there were no knocking sounds. Once it did start knocking we returned home... The initial oil change after the problem showed no signs of anything in the oil, no streaks no speckles and nothing on the drain plug. I will drain some oil tonight and verify when I get home from work to double check. Also, even after the car warms up there is no audible knocking at idle.

At this point it is time to start tearing it down to find the problem. I think the pump is OK since the pressure is there upon startup, and never drops below 20psi.

NHRAFORMULA00

iTrader: (2)

Sounds to me like a spun cam bearing.

JPR

It's most likely the short block, but I wanted to explore one thing real quick, make sure your torque converter bolts are tight, the reason why the engine could be turning off after a reasonably long drive is that the knock counts are through the roof. even if there are no signs of flakey metal in the oil dosen't nesessarily mean that a rod or cap end bearing has spun, it just needs more time to wear out to visually see it in the oil. But one thing does have me puzzled is the fact that you mentioned that there was no dramatic loss of oil pressure. (just passed 40 psi on the gague is normal for 4th gear highway driving) A-Tap it and it will tell you what cyl is making all the racket, pull that side head and rotate the motor over to just pass TDC on that suspect cyl, with your hand try to push the piston down and see whichever one moves, it will make a slight hollow thunk sound and that one would be the culpret, repeat the passed TDC "test" to all 4 clys unless you find it right away.
Good Luck!

[Edit]

Sorry, I just read this.

"I was thinking the oil pump crapped out but why would it still read 40+ psi on start up and stay there for about 10 minutes of driving. After that is drops(not to zero) but will still maintain pressure as long as the car is being driven(Still does not drop below 5-10psi. Wouldn't it show "0" oild pressure if it did die? the oil pump is an aftermarket ported oil pump not a stocker.
I am figuring prob time for a new shortblock but still want to know what is wrong!"

Yup, your short block is done.

<small>[ March 27, 2002, 11:25 PM: Message edited by: JPR ]</small>

MastaAce98

iTrader: (1)

I belive John hit it on the nail... The drop on the oil preassure is because the motor heats up and the bearing clearance increase, along with what Tony said the oil also gets hot. the cause is probaly a bearing, as for the Knocking it could be any of the bearings.

Brent

<small>[ March 27, 2002, 11:46 PM: Message edited by: MastaAce98 ]</small>

Dean98TA

Seen those symptoms first hand myself.

No doubt about it... rod bearings gone.

At least in pulling it, rebuilding it, and re-installing it on my own, I now feel quite capable of tackling any type of repair job on my car! It was quite an educational experience.

Well worth the $5000 tuition cost. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

CHRISPY

How is your oil level?
thanks,
Chris