Knocking from engine

Bludge · Post by **Bludge** » Sat Nov 01, 2014 10:18 pm

I foolishly managed to run my engine dry of oil on the drag strip not long ago and hit vtec a couple of times and it kinda lurched back like i had hit the speed limiter.

Filled it up and it still drives ok and doesnt seem to lack any power, but i noticed a nasty knocking at (i think) the top end up the engine. it knocks in time with the engine (ie speeds up when you rev).

Can anyone advise what this might be?

Im not sure i have explained very well, will try and get a video tomorrow.

Post by **Thebusofwoe** » Sat Nov 01, 2014 10:28 pm

V tec wouldn't work without oil pressure, so what ur saying is it lurched out of v tec?? If it sounds like hard knocking in time with the rpm, and you ran it real low of oil, then I would bet it has spun a bearing possibly. How much oil did it take to get it up to max?

Post by **4thgenphil** » Sat Nov 01, 2014 10:32 pm

Bad times, I'll be surprised if its the top end I'm afraid. If you came to me and told me that in a garage id be tempted to drop the sump and have a look at the bearings and go from there. But that's just me..

Post by **Thebusofwoe** » Sat Nov 01, 2014 11:35 pm

I would agree /\ /\

Bludge · Post by **Bludge** » Sun Nov 02, 2014 9:57 am

Thebusofwoe wrote:V tec wouldn't work without oil pressure, so what ur saying is it lurched out of v tec?? If it sounds like hard knocking in time with the rpm, and you ran it real low of oil, then I would bet it has spun a bearing possibly. How much oil did it take to get it up to max?

yeah it lurched out of VTEC. i think it took about 3 litres maybe a bit more to get to max.

ok, i have no idea what spinning a bearing is. the engine internals is a bit beyond me. how bad would that be and what would be the fix. i have another engine lined up if need be.

Post by **4thgenphil** » Sun Nov 02, 2014 10:39 am

Bludge wrote:
Thebusofwoe wrote:V tec wouldn't work without oil pressure, so what ur saying is it lurched out of v tec?? If it sounds like hard knocking in time with the rpm, and you ran it real low of oil, then I would bet it has spun a bearing possibly. How much oil did it take to get it up to max?
yeah it lurched out of VTEC. i think it took about 3 litres maybe a bit more to get to max.

ok, i have no idea what spinning a bearing is. the engine internals is a bit beyond me. how bad would that be and what would be the fix. i have another engine lined up if need be.

I'd go new engine personally bud, probably cheaper than new bearings and oil pump and thats before you even look at changing the crank and a rod or 2. What motor is in there?

Post by **Thebusofwoe** » Sun Nov 02, 2014 10:59 am

Id agree again. . . . . Get the replacement motor in mate. Spinning a bearing is where it momentarily runs out of oil supply to a bearing, the bearing shells then come into contact with the spinning surface (e.g. The crank journal) and then it grabs the bearing shells, and spins them inside there housing (e.g. Big end of con rod). So the bearing shells would no longer be 'locked' in place but be spinning and grinding away at the crank and con rod.

Best to get the Moto in mate.

Bludge · Post by **Bludge** » Sun Nov 02, 2014 1:03 pm

Right, i had another listen and without actually getting under the car it really does sound like the noise is coming from under the rocker cover.

You can hear it quite well on the video.

Are there any other symptoms of spinning a bearing? im holding out hope it might be something easier to fix! im not very confident about doing an engine swap!

[youtube]R10e-Xzh5pk[/youtube]

Post by **Thebusofwoe** » Sun Nov 02, 2014 2:58 pm

Yes but don't forget, these are all alloy engines and transmit noise/sounds very easily. I think then that you would want to remove the rocker cover and check for any abnormalities regarding valve height ect. Defo knocks in time with rpm??

mercutio · Post by **mercutio** » Sun Nov 02, 2014 3:17 pm

doesn't sound well but could possibly be a valve?