Noise After Rebuild...

[meet07]

Engine specs: RB25det

-Wiseco pistons bored .040 over

-eagle rods

-acl oversized bearings

-Machined crank with collar

-cosworth head gasket

-mild port work on the exhaust side(humps removed)

-5 angle valve job

Make a long story short....I have had this motor gone through twice. Shortyafter the 1st rebuild the thrust got eat up and I was forced to tear it backdown and get her re machined and put back together. The 1st time I rebuilt theengine I had a ticking noise that was coming from the head(cylinder 5-6) or atleast it sounded like it came from the head. I removed the lifters,cleaned,bleed and put them back in. The noise never went away but since there wasglitter in the oil I didnt mess with it any more since I had bigger issues.Well I rebuilt the motor the 2nd time and Im still hearing the noise. The noiseis heard when cold, but it gets louder when the engine is warm and gets louderwith the revs. I removed the lifters for a 2nd time,cleaned and bleed and theproblem still exist.....

I am trying to pin point the problem so I can drive my car again. A few said toreplace the lifters with new but the motor only has about 80,000km on it...

Here is a video:

few engine shots:

please help...

Thanks

[NYTSKY]

Sounds like a spun bearing to me.

[75coupe]

could it just be injector noise?

I know I have injector noise because when I release the throttle on decel when driving the noise stops.

[NYTSKY]

Thats not injectors mate. Injectors are a slight tick, that sounds like a knock.

[Bsa]

Sounds like rod knock to me. Where all the oil galleries cleaned properly? Where the bungs for oil controll put back on the crank?

[abr33]

I recon its a lifter. unusually loud though. listen to the engine speed versus the knock, its a valve problem.

[meet07]

Sounds like rod knock to me. Where all the oil galleries cleaned properly? Where the bungs for oil controll put back on the crank?

Im assuming that all the galleries where cleaned properly. I mean all the work was done at the best local machine shop in town..

I mean usually lifter noise is heard when cold and then it somewhat lightens up when the engine is warm but In my case the noise is louder when the engine is warm. Not sure if it has something to do with the metal getting hotter and explanding or something. Or if it has something to do with the oil viscosity....The engine was purchased like 4-5 years ago with 62,000 miles on it. When the ring lands went on me the 1st time it had maybe 80,000 on it.

[meet07]

Thats not injectors mate. Injectors are a slight tick, that sounds like a knock.

I sure hope its not a spun bearing...Oil pressure was gained with the starter, no spark or fuel and took maybe 1 minute. Afterwards she was started right up...

Yeah I know its not injectors as well. I listen to everything with a stephescope and the sound is definetly from the head. At one time I was wondering if it was something like piston slap but the noise in person isnt that deep... Rod knock sounds like this:

Edited February 23, 2012 by meet07

[hy_rpm]

Try this test to narrow it down disable 1 cylinder at a time and if the noise get less then you've narrow it down to that cylinder. But in the bottom end if the noise doesnt reduce for all cylinders it's in the head the valve train

[DVS JEZ]

Did they do the assembly or u?

Never assume machine shops clean things. Most time u will and should clean everything before assembly.

Do the test as above to isolate the noisy cylinder,

Last time were all the earings marked or only a few?

[abr33]

Try this test to narrow it down disable 1 cylinder at a time and if the noise get less then you've narrow it down to that cylinder. But in the bottom end if the noise doesnt reduce for all cylinders it's in the head the valve train

This will be the best way to do it, maybe remove plug to disable and use stethescope (spelling) as the air coming form cylinder will be loud. disable the injector for the cylinder being tested to reduce your risk of explosive mixes coming out of plug hole

[Dajae]

Is it a really loud knock? Especially coming from the rear, i would imagine a spun bearing. Sufficient oil at all times? Do you have a stock sump, or extended?

The builders may have dodgied the oil by not putting enough in..

Forged engines are great, but from what i've read, are more prone to damage from lack of oil compared to stock parts..

[75coupe]

Thats not injectors mate. Injectors are a slight tick, that sounds like a knock.

Ok I should of actually checked out the YouTube link

[SargeRX8]

If your rod is knocking, that could mean that the piston won't be moving perfectly up and down the cylinder bore. Maybe get a worm camera and feed it through the spark plug hole and have a look around the bores see if they still look fine. Ive heard rod knock, its not a nice sound. This doesn't sound as brutal as rod knock, but at the same time abit harsh for lifter noise.

[meet07]

hy_rpm: I went outside and tryed what you told me and the noise is definetly coming from cylinder 6. Possible cylinder 5 but the noise could just be carrying over from cylinder 6. I removed each spark plug with the motor at 2000rpms since the noise isnt that noticable at idle..

DVS JEZ:The 1st time I rebuilt the motor myself but this last go around I let the machine shop do all the work. I made copys of the FSM and let them work from it plus they had there own manuals as well that pretty much has every motor made to man in it. When I dropped the block and head off I made sure to mark all the pistons. The rings and bore where left alone since the motor didnt have no more than 50 miles on it from the 1st build. Only cylinder #2 was tampered with since there was detonation found on that piston and the cylinder walls where damaged. I would hate to say that the machine shop didnt clean the block good enough but lets just say that it was cleaned...then that would make it 2 times that its had a bath.

Dajae: The noise doesnt sound anything like a knock, more so like a tick,tapping noise....I have great oil pressure. 100psi when cold and 25-30psi when warm. A crank collar has been fitted and the oil pump is a new oem replacement. The engine block was in a big clear thick bag of some sort wrapped tightly in tape and the head was placed on a peice of cardboard taped up as well. I installed the head, and installed all the add ons. I put the oil in the motor and made sure that oil pressure was reached before starting....

what does a siezed lifter look and sound like. Im thinking if its the bottom end then I would hear some sort of knock and see something from the tail pipe but im not get neither one. If I put the *stephescope* right beside the spark plug on cylinder 6 I can hear the tapping noise but once again it could be the lifters echoing, fuel being ignited on the compression stroke ,yada yada yada....

What I dont get is the the fact that the noise started after my 1st rebuild. I would hate to tear this motor down for the 3rd time. If I do I might as well part it out and take my lost......

[meet07]

Sounds similar to this I think and the mate said that he used an engine flush and cleared the noise right up. Of caorse I cant use that and I already went beyond that and bleed the lifters but here is the link:

[Adriano]

Besides the knock, you need to space the Cas away from the cam, or it will break the keyway, and stuff the cas

Edited February 24, 2012 by Adriano

[75coupe]

^^^ well spotted Adriano

[mico]

Besides the knock, you need to space the Cas away from the cam, or it will break the keyway, and stuff the cas

ha nice ! could even be linked with the knock ?! those bolts eat in deep to the cam gears without spacers.

[STATUS]

is it running oil restrictors in the block? ive seen the same thing when the builder run restrictors in both galleries.