Jacobs_RX7

iTrader: (3)

Hey guys, started hearing this strange noise, seems to be getting louder.

Seems louder when cold.

There is no accessories spinning in video (belt removed). Seems to be coming from front cover.

Deleted OMP but the gear is just loose in the cover with a block off plate.

Has dual oil coolers, with 10 AN hose. Custom setup.

Relief valve maybe? Cavitation?

Oil pressure is perfect, never low. Oil temp stays at about 170 measured at oil filter housing. Car runs perfect, still makes great power, starts instantly even cold etc.

I had the oil pan off when I got the engine, super clean inside and oil pump chain looked great.

Video:

Andre The Giant

iTrader: (21)

Engine new to you? Rebuilt? How long have you been running it?

96fd3s

hmmm does sound a little odd.
maybe an exhaust leak somewhere?

Andre The Giant

iTrader: (21)

Do you have automotive stethoscope?

WJM ROTARIES

Does noise get quieter when engine at normal operating temp if so sounds like oil pressure relief valve cavitating

Jacobs_RX7

iTrader: (3)

The engine is a 97 JDM, supposedly 27k miles, which I believe. Really good compression, really clean inside. Been running it hard for about 1000 miles.

I do have a stethoscope, it seems to be coming from the front cover area. It's not an exhaust leak.

I always warm it up slowly so this is the firs time I've run it up in RPM's at all while cold. Semed louder to me (cold)

A stationary gear won't make a noise like this, right, it would just blow up? lol

sir revalot

Are you talking about the whining, whurring noise?

Sounds to me like a torrington bearing has dropped..

Was or have you had the front pulley off?

Jacobs_RX7

iTrader: (3)

I did have the front pulley off, was there a procedure I missed?

I just took it off to cut off the a/c and p/s pulley on a lathe, then put it back on. Still has the lock plate, torqued it back on...

Edit: Oh my, if I did crush the bearing when it dropped that would really suck, and make me feel like an idiot. What kind of damage could it have caused otherwise?

and thank you guys!

My heart just dropped when I read this: http://www.turborx7.com/pulley.htm

I'm super meticulous about all my work, been repairing cars for a long time professionally, but just goes to show what you don't know can hurt you...

K-Tune

iTrader: (26)

Which part of the pulley did you remove? Did you loosen the 19mm bolt in the center? You may be able to verify end play with the engine in the car...by prying from behind the front hub pulley or remove the flywheel inspection cover and pry there... you should feel the center rotating assembly shift just a tiny bit in either direction. If it doesn't budge or moves enough to create a very audible thud then I would be worried.

I have never "heard" a crushed thrust bearing, it almost sounds like it could be a turbo charger rubbing the compressor cover.


If it did happen...then you should not run the engine any more and drain the oil to look for debris...if you see anything other than oil then I would remove the engine. The damaged parts will have to be replaced and any bearing surfaces will have to be checked, as well as a full flush of anything the oil touched.

Jacobs_RX7

iTrader: (3)

You know what, I don't think I did take off the 19mm center bolt. I just removed the 4 small ones. I'll check the endfloat tomorrow and see.

Pretty sure it's not compressor/turbine noise as it's directly related to engine rpm, not turbo spinning...

Jacobs_RX7

iTrader: (3)

Went down with a prybar, no dial indicator yet as I'll have to pull my intercooler setup; but there is endfloat. Seems perfect.

Really glad I didn't learn about thrust washer drop the hard way... But engine still sounds bad.

The plot thickens.

sir revalot

Mmm I did it in my Fc.. Sounds like a cavitating power steering pump. I managed to get the timing cover off and replace the torringtons and thrust plate and washers without too much damage being caused.. Don't forget to change the oil..

K-Tune

iTrader: (26)

If you didn't loosen that 19mm center front bolt then there should be no worries about crushed thrust bearings.

It could also be chewed up stationary gears... but the oil would show debris.

Have you tried using a rubber hose or long screwdriver as a stethoscope/listening device to try to locate a better proximity of the sound?

A free floating OMP drive/gear should not cause any noise unless it's damaged in some way.

Jacobs_RX7

iTrader: (3)

I can cut the oil filter open and see, I just changed the oil and it gets changed every ~500 miles (track/fun car only)... Synthetic.

Yeah, I used the long screwdriver trick and it's loudest at the front cover.

DaleClark

iTrader: (55)

You sure it's coming from the front of the engine? I've heard a similar noise from the rear port that the air pipe to the cat hooks up to. With no air pump it will make some odd noises.

Dale

Jacobs_RX7

iTrader: (3)

Yeah, I don't know why my phone mic picks up that ticking noise like that, the exhaust is all TIG stainless, really quiet in person. It has a Random Tech cat, welded in to a one piece cat-back after an HKS downpipe, no air tube...

When the camera is close to the front cover you can hear the noise best, I just moved it around to show where it was most prominent.

Thanks for the input guys, I'm going to try to do some more heavy diagnostic work soon, will report back here.

Jacobs_RX7

iTrader: (3)

I bypassed the oil coolers, noise remains unchanged. Shimmed the thermal pellet, out of desperation, noise remained the same. Now it appears to be doing the noise the same when hot (oil temp 200).

You can hear the noise best (long screwdriver trick) when touching the oil cooler output on the front cover. Almost can't hear it when listening to the oil filter pedestal.

It's a classic buzzing noise...

Endfloat is .08mm, perfect.

Oil psi is ~80 at 3000 rpm with engine and oil fully warm. Using the accurate stock sending unit :-/

I'm about to take the engine out, stumped!

andre sinclair

iTrader: (36)

Sounds like what happen to me sometime ago. I used a long bolt to secure the slave cylinder on my second gen; the bolt pertruded too long and was touching the gear teeth of the fly wheel.

Could be different on a 3 gen thou.