1jz bottom end knocking

[BigSupe]

I started my car up earlier whilst it was on a set of axle stands and the bottom end started to knock noticably. I jacked it up and removed the stands re-started it and the knocking stopped.

Why did this happen? The stands aren't very tall and the oil is full on the dipstick and there was oil pressure as the light was extinguished

Could this be the start of the end for it?

 

[Jostar]

MMMmmmmm maybe... I had similar sound coming from my bottom end in winter then summer came around boom rodknock..

 

[BigSupe]

Great news! What oil are you using? Is 10w40 ok
I changed my 7m cos it got rod knock and was under the impression the 1jz was bullet proof

What would be the best route now as I have a gt3076r and about 420bhp, should I just carry on using the engine or is there something I can do to prevent it getting worse

 

[tsuper92]

was it sitting for a while before you started it?maybe you should have cranked it with the efi fuse pulled,help get some oil flowing.

 

[s383mmber1]

under the impression the 1jz was bullet proof

No motor is bullet proof....

Your sure it was comming from the bottom end?

 

[BigSupe]

It was sat for a few weeks so I pulled the fuse and cranked until the pressure light was extinguished, it was definately coming from the sump pan weirdly though with a small bit of throttle it went only knocking at idle, after about 15secs I shut it down and lowered it off the stands and it was fine

Took it for a 20mile drive with no problems, what's the next step to take?

 

[suprahero]

I'd say ten hail mary's and sacrifice a virgin just to be on the safe side.


Other than that, I don't really know. If it's not knocking, I'd just make sure I kept some good 5w 30 Redline in it and also make sure you have a quart extra in there. I make sure I'm at least a half quart to a full quart over my full mark.

 

[Gritz]

I'd say ten hail mary's and sacrifice a virgin just to be on the safe side.


Other than that, I don't really know. If it's not knocking, I'd just make sure I kept some good 5w 30 Redline in it and also make sure you have a quart extra in there. I make sure I'm at least a half quart to a full quart over my full mark.

general rule of thumbs say that running a quart over the full amount puts extra pressure on the rear main seal, causing it to fail over time...but what do i know, i come from a family of 8v lovers!!

 

[BigSupe]

Is it worth changing the shells at this point or just use it until it goes bang?

Obviously the oil is between the shell and crank journal for lubrication does it also take up some of the tolerance, I'm trying to get my head round why it was knocking. If there was no oil for some reason would that cause it to knock instantly?

 

[CyFi6]

Is it worth changing the shells at this point or just use it until it goes bang?

Obviously the oil is between the shell and crank journal for lubrication does it also take up some of the tolerance, I'm trying to get my head round why it was knocking. If there was no oil for some reason would that cause it to knock instantly?

Yes. If you listen very carefully when you first start engines up you can hear it knock for a couple seconds until it gains oil pressure

 

[bobiseverywhere]

not that it matters to much now but that stock light in the dash for the oil is only a oil level light so if the oil level is low it will light up.

Much better to See what the actual oil pressure is.

Was there an aftermarket clutch on there? Skimmed through the thread and did not see anything about that. Don't think it's a real major problem but could be contributing to the knock at fist.

You sure it was a knock though?

 

[juhanis]

No motor is bullet proof....

Your sure it was comming from the bottom end?

i learned this lesson last week... good thing my car is running again.

 

[IJ.]

general rule of thumbs say that running a quart over the full amount puts extra pressure on the rear main seal, causing it to fail over time...but what do i know, i come from a family of 8v lovers!!

Seriously do you even have the faintest clue what you're talking about?

This is the tech section if you don't know don't post...:nono:

How the hell does 1qt extra put "pressure" on anything?
(hint the rear main ISN'T pressurised in these engings meaning the only pressure it will ever see is crankcase pressure)

 

[BigSupe]

I have a 6puck clutch, pressure plate and flywheel from driftmotion. It was definately a deep constant knocking

The engine must have been getting oil as when cranking the speed got slower when the pressure light extinguished, suggesting to me that the pump was picking up thick cold oil

Just trying to save money/time if it's better to remedy this now, or is it a case don't fix what ain't broke?

 

[suprahero]

What IJ said, and we don't have 8v's in our car.

 

[tlo86]

Great news! What oil are you using? Is 10w40 ok
I changed my 7m cos it got rod knock and was under the impression the 1jz was bullet proof

What would be the best route now as I have a gt3076r and about 420bhp, should I just carry on using the engine or is there something I can do to prevent it getting worse

why are you using 10w40?

i used 5w30 pennzoil platinum. 0w30 castrol syntech. and 5w30 amsoil

bullet proof? not if you are a moron i have seen 2jz's blow headgaskets and get rodknock without performance mods it was purely the owners fault

 

[CyFi6]

Seriously do you even have the faintest clue what you're talking about?

This is the tech section if you don't know don't post...:nono:

How the hell does 1qt extra put "pressure" on anything?
(hint the rear main ISN'T pressurised in these engings meaning the only pressure it will ever see is crankcase pressure)

I think he is trying to imply that oil would be high enough that the main seal would literally be holding the oil level rather than just stopping splash oil from leaving

 

[grimreaper]

i learned this lesson last week... good thing my car is running again.

solution?

I have a 6puck clutch, pressure plate and flywheel from driftmotion. It was definately a deep constant knocking

The engine must have been getting oil as when cranking the speed got slower when the pressure light extinguished, suggesting to me that the pump was picking up thick cold oil

Just trying to save money/time if it's better to remedy this now, or is it a case don't fix what ain't broke?

what pressure plate? You have a clutch start switch override?

cold start knock is my guess. let the car sit for a few days and see if it does it again on start up.

 

[T701jz]

I have a 6puck clutch, pressure plate and flywheel from driftmotion. It was definately a deep constant knocking

The engine must have been getting oil as when cranking the speed got slower when the pressure light extinguished, suggesting to me that the pump was picking up thick cold oil

Just trying to save money/time if it's better to remedy this now, or is it a case don't fix what ain't broke?

I would bypass your pedal switch if you are running a higher pressure plate. The thrust washer might be wearing out (crank walk). 20 yr old bearings...10w40's are just fine.

 

[BigSupe]

We dont have to depress the clutch to start our engines over here, I have been told that all 1jz engines are noisy on initial start up

A guy on the mkiii supra website has said his had the same noise for 6 years

I notice thats theres quite a big thread on SF but I don't think anybody has found out what/why it happens

I will be keeping my fingers crossed and leaving for a week then starting it up again and see what happens