[whincup]

out 4wding today in my sierra, a strange noise has started from in the engine... only way to describe it is a rattling/grinding noise, and it sounds like its coming from the back of the top end, but it's hard to tell... i'll get a video of it when i get home so i can show what the sound is like, but does anyone have any ideas as to what to look for? the engine runs fine other than the noise, there was no lack of power (had to risk driving it for about 100m up a steep hill because nothing could tow me out of where i was) so its not a dead piston or anything like that, but the vibration is bad enough to feel through the whole car...

[alien]

put a screwdriver (long one) against the rocker cover above each piston and on the block and listen to the end of it... it might be a bit of a knock developing on one of the pistons.

that or your oil cap is loose and rattling (had that before).

[whincup]

http://www.youtube.com/watch?v=yyHmvj00LRk

thats the video... doesnt sound quite the same. before anyone asks, water level and oil level are fine, fans not hitting on anything, nothing that can be seen from the outside of the engine...

hoping its not some form of bearing failure, but thats what it sounds like...

[whincup]

alien wrote:

that or your oil cap is loose and rattling (had that before).

haha i wish thats all it was... its WAAAAY louder than that

[alien]

holy fucking crap thats loud!

[FullyZooked]

Oh fark, that doesnt sound good!

Back of the engine? I would be pulling off the rocker cover and checking all cam mount screws are intact. It is common for these to come loose and go "missing".

The sound is also not quite consistant with engine rpm which would also indicate something rolling around where it shouldnt be.

Oh and don't run it while its doing that crazy shit. BAD.

Keep us updated!

[whincup]

FullyZooked wrote:

Oh fark, that doesnt sound good!

Back of the engine? I would be pulling off the rocker cover and checking all cam mount screws are intact. It is common for these to come loose and go "missing".

The sound is also not quite consistant with engine rpm which would also indicate something rolling around where it shouldnt be.

Oh and don't run it while its doing that crazy shit. BAD.

Keep us updated!

well my first thought was of people saying some form of screw or nut always coming loose amongst the cam or valves or something... guess im pulling the tappet cover or whatever thats called tomorrow and taking a look.

[alien]

sounds like a broken piston to me...

[whincup]

i thought the same at first, but im pretty sure a broken piston id notice a massive lack of power, but it did drive up a hill after the noise started... had to when a mates 80 series couldnt pull it up.

[MrRocky]

alien wrote:

sounds like a broken piston to me...

fail - broken piston or skirt normally results in smoke hard to start cold, loss power ect...i think you will find one of the nuts on the top of the rocker gear has come loose/off. take the rocker cover off, find the nut/s and re-tighten

[joe5701]

are you sure its not coming from the gearbox/bellhousing?

[whincup]

joe5701 wrote:

are you sure its not coming from the gearbox/bellhousing?

its possible, i only did about 30kms since replacing the clutch... but im about 90% sure its from the tappet cover, gonna have a proper look tomorrow... what you thinking?

thanks to everyone so far thats helped

[joe5701]

did you have the flywheel off aswell?

[whincup]

i did. it was machined, spigot bearing replaced, and tightened as per the service manual. it did run fine for a while...

[joe5701]

whincup wrote:

i did. it was machined, spigot bearing replaced, and tightened as per the service manual. it did run fine for a while...

i thought this may be the problem

[christover1]

I'm very deaf, but gee thats even loud to me :O
the clatter and that high speed whizz sound near the end
suggests a spinning object coming loose.

As suggested, the screws that hold cam shafts do fall out,
but I suspect a fly wheel issue, or something around the
clutch region has disintegrated.
New things can fail.
And clutch pressure plates and bits have a right and wrong way around,
often tuff to notice.

[christover1]

PS sounds travel around the car, pin pointing can be difficult,
hence a stick to your ear, and touching around the noise area.

It is my only way to locate noises, by feel, sort of

[joe5701]

maybe even the starter has come loose and its touching the ring gear?

[christover1]

joe5701 wrote:

maybe even the starter has come loose and its touching the ring gear?

A distinct possibility too, spinning starter with no load could make a whizzing noise

[whincup]

christover1 wrote:

joe5701 wrote:

maybe even the starter has come loose and its touching the ring gear?

A distinct possibility too, spinning starter with no load could make a whizzing noise

nah looked at that too, pretty sure its not...

[Lockie666]

it's from the head, you can hear it.

[foolsp33d]

I had a similar situation when something decided to get friendly with one of the pistons in a reco motor about 10 months ago, and it didnt sound ANYWARE near as bad as that, admittedly it was blowing smoke, For your sake.. I hope its a simple fix!

start stripping it down buddy!




http://www.youtube.com/watch?v=z5lb6BoT ... rofilepage

be sure to keep us updated!

[whincup]

ok so ive pulled the tappet cover off, all the head bolts are intact, the nuts on top of the tappets are there, and whatever those screws are on top are there... and i cant see anything loose amongst the valves. is there anything else that i should be looking for?

[steak_knife]

Just for giggle's, start if with foot on the clutch, if the noise is less, pull ya g/box out again & tighten the flyingwheel.

[foolsp33d]

If the ignition lead is off and the engine turned over, can you hear the 'ratttle/grinding' noise? are you 100% sure its from the engine? what condition is the oil in? Maybe a VRS kit and dig deeper into the heart...?

[steak_knife]

& look for damage to the block!!!!!!!!!!

[whincup]

steak_knife wrote:

Just for giggle's, start if with foot on the clutch, if the noise is less, pull ya g/box out again & tighten the flyingwheel.

clutch in or out its the same...

foolsp33d wrote:

If the ignition lead is off and the engine turned over, can you hear the 'ratttle/grinding' noise? are you 100% sure its from the engine? what condition is the oil in? Maybe a VRS kit and dig deeper into the heart...?

oil is about 30k's and half an hour old, so still the color it was in the bottle. you can hear it with the starter turning, just nowhere near as much.

having had a proper listen (yesterday i was on a track, very pissed off having put a day and half into putting the car back together), much worse today, it does have a grinding noise to it, but it sounds more like something is hitting something else. whatever it is, it started instantly while driving. there was no buildup to it, no noises beforehand...

[whincup]

foolsp33d wrote:

I had a similar situation when something decided to get friendly with one of the pistons in a reco motor about 10 months ago, and it didnt sound ANYWARE near as bad as that, admittedly it was blowing smoke, For your sake.. I hope its a simple fix!

start stripping it down buddy!
http://www.youtube.com/watch?v=z5lb6BoT ... rofilepage

mine doesnt sound as fast as that, but much louder... thinking before i strip it down, i might try undoing the timing belt and turning the crank and cam independently, see if i can narrow down the noise...

[steak_knife]

Pull the starter out & look for damage to it.

That grind/whirr sound's like the ring gear hitting something.

[skyman]

What is the whirr sound to the end of the video?

Ya know, I had bad bearing on the cam tensioner pulley, and it sounded awful, much like what yours is sound like. It started instantly as we pulled off the tarmac, and onto the trail. it was so bad that we assumed it was engine damage and I let the guys take the trail while my wife came to tow me home.

it turned out the tensions bearing wasn't bad per-say, the bolt holding it to the block was loose and had almost completely undone itself.

The combination of the wobbling, and the belt smacking the cover sounds like someone had set loose a marble in the engine or under the valve cover.


To me yours does sound like a stuck starter, it does not sound like bad big end on internal bearing.

Put a long screwdriver on the water pump housing, and the other end to you ear, and see what it sounds like, do the same to the cam belt tensioner bolt. You can also use a small piece of pipe, or even a mechanics stethoscope.

Hope that gives you some ideas of where to look.

Again, what was that whirr type sound at the end?