Grinding noise at 2k rpm

[Ian]

Hi

I have a light grinding noise at exactly 2k rpm, not above and not bellow.

Car is 900 km off a service and oil is quite old, prehaps has something to do with it?

What is it? Does anyone know?

Thanks
Ian

[Nate]

need more info ... pop the bonnet and see if you can locate the source of the noise... it could be any number of things

[chicaboo]

This grinding noise didn't mysteriously start after you pranged the car last week did it?

[Ian]

No.

I pranged it ~3 weeks ago now.

It started after I got into a race with a hektik chromies turbo vl bro and took him for a trip out to samford.

[project.r.racing]

yes - more info need, stick your head under the bonnet.

stop racing peps until you get your engine completely fixed. if you don't wanna take it to a mechanic, then stop killing it on the street.

[boostedbatman]

You may need a length of conduit to locate the source of the problem by holding one end to your good ear and poking around the engine bay with the other

Aniother question does it make the noise at 2000rpm whilst stationary

And yep stop flogging a sick car or you will have a dead car
Fix it, drive it, break it, fix it
Not break it, drive it, break it, drive it, fix it

[Ian]

The car was not sick, what gave you the impression it was?

As for the source of the noise: I have poked my head around the engine bay and I havent the foggiest where in the engine bay its comming from exactly. It does it while stationary and while under load. I will try changing the oil, oil filter and flushing the coolant tonight / tommrow and see if it helps (for a coolant flush, I drain, garden hose in top of radiator and top hose off, right?)

[Rupewrecht]

Metal on metal? or

Clutch bearing perhaps, and it's throwing things out of balance and you get to hear about it at the particular rpm? Could even be a bearing in your gearbox.

As pete mentioned, get a piece of hose and hold one end to the bellhousing and the other to your ear, and rev the car. keep moving it around the engine and gearbox until if sounds different/louder.

[Ian]

Yeah.

Cars on jackstands atm while I wait for my new rubber.

Not keen to rev it up and down while its on stands really... itll have to wait.

[ROB-80E]

Why not?? I do it all the time! lol Jack 'er up, wack the stands under, start 'er up and put it in 2nd gear and let the clutch out. The only thing you're missing in this diagnosis is a bit more load...but it's better than just free reving it (unless the problem is still audible in neutral).

[Ian]

Yeah it is.

Ive been told that it may be a problem with the oil at that particular RPM.. The oils very old, 900 km off a service and quite dirty, also as it gets colder it might be a problem with the vicosity of the oil. A thicker oil would probobly go better...

[boostedbatman]

If you have oil (enough of it) and it is dirty then changing to thicker oil will not fix grinding.
If you were extremely low then I would tend to agree.
If theres enough oil regardless of how dirty it is you will still have enough lubrication
Grinding will be due to imbalances in the movement of parts or misalignment
You really need to work out if its engine or gearbox to start with
You then need to take some of the diagnosis advice yo have been given and implement it
Then you can come back here and let people know where you're at , so they can further assist you

As I have said to you before if you dont help yourself HOW can you expect others to help you
Apart from that unless you do the afore mentioned ides you will be NO closer to finding the problem then you werte when you originally posted the dilemma
NOW GET TO IT and we will see you back here later

[Laser the Amazer]

Originally Posted by ROB-80E

Why not?? I do it all the time! lol Jack 'er up, wack the stands under, start 'er up and put it in 2nd gear and let the clutch out. The only thing you're missing in this diagnosis is a bit more load...but it's better than just free reving it (unless the problem is still audible in neutral).

many a time have I seen us do this on the hoist at work

very helpful for trying to find a noise under load.

Rob

[Ian]

Pete, I dont want to sound harsh or put you off, I appreciate the help, but im sick of you talking to me as if you were my father. Your not.

I have been doing whats been said here, for the most part. The oil was lowish, so I got some new stuff today, have it draining atm overnight and while I waited I moved the battery to the boot as it should of been done a long time ago. (Yes, it was done correctly with gold terminals, 2 gauge cable, a proper boot box and vents.)

Running the car on jackstands under load is not cool. At least, not with my jackstands. It starts wobbeling badly from side to side, there the type with large platforms and ramps on either side, and it slides between the ramps. Im not too keen to try it again.

As far as I can tell, no metal shavings came out of the engine in the oil. The noise is constant throughout the gears and when free-reving, so I would suspect engine rather then gearbox related woes.

Oil was down to one quater when last checked before I drained, so im thinking it might just have something to do with that. We will see when I put the clean oil (penrite HPR 15) in tommrow.

Also, how big is the oil capacity? will 5 liters be enough? AFAIK its 4 L.

I couldnt find an appropriate length of tube so I used a large screwdriver instead, touched it to my ear and went around touching the flat end on various bits while someone elese held it at revs, and I couldnt locate the problem. We will see what happens when I put new oil and fresh coolant in there tommrow, and when I get my wheels back tommrow/tuesday with fresh rubber.

Sorry if this post is misjointed, kinda just blurbed it out.

Could it be something non-engine related? A loose pannel or something? Too many possibilities...

[project.r.racing]

No its sounds like you are now on the right track - keep up the good work.

Pete is the older wiser voice oh AGT in Queensland - he is like a father figure. jkz

[Ian]

Updates:

replaced old oil back in engine, plus a Liter of new stuff, ran engine oil flush for 10 mins, $hited myself when I saw smoke comming out of engine bay, sliped on spilt oil in dash for ignition key, wound up tits up and v. sorry I ever got involved in modding cars, got up, turned off engine to discover that it was only spilt oil burning. I really didnt need that brain of mine anyway...

Drained/draining old oil + cleaner now, removed and replaced oil filter (3 trips down to supercheap to exchange one crappy tool for another until I found the solution), replaced plugs. Inspected pistons while the plugs were out, one and two were fine, dry as a bone, 3 and 4 had some form of liquid on the surface, probobly fule. When runing engine with cleaner in it, engine was runing quite rich according to my gauge, and after the 10 mins there was a liquid deposit at the end of my exhaust pipe. Oh deary me.

Thats where im at now. Im leaving it sit for the time being getting all the old oil out before I put new stuff in.

I feel like theres something im forgetting, but I cant for the life of me remember what. I will prob update this later. Pistons 3 and 4 could be dodgy ignition, plugs or leads or coil or dizzy / dizzy plug. Or I could be a mile off the mark.

Any words of advice would be appreciated.

//edit:
Ah yes. Spark plugs. No signs of anything bad, they were a nice black with no buildups and a tiny bit of white around the edges. If you desire pictures, please let me know.

[MitchEG]

Liquid in the exhaust is normal, its water...shouldnt spark plugs be a nice brown colour?

[chicaboo]

Which one are you Ian? http://www.dansmc.com/Spark_Plugs/Sp...s_catalog.html

[Ian]

not exactly like that, it was half black half white-ish around the edges, but if theyd been left in there theyd get there eventually. Thoes plugs are only 4100km old.

[chicaboo]

The most important thing is: Did you check the plugs before you did the engine clean and oil change?