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-   -   Oh fukn help me. It's the end. What is this sound my engine is making? (https://www.miataturbo.net/general-miata-chat-9/oh-fukn-help-me-its-end-what-sound-my-engine-making-45645/)

Faeflora 03-31-2010 09:28 PM

Oh fukn help me. It's the end. What is this sound my engine is making?
 
So my new motor is in and it idles.

But, it sounds like this:



or for shitty photobucket video go here

http://i14.photobucket.com/albums/a3.../th_car002.jpg

I've never heard a built motor before IRL so I don't know if it's supposed to sound like a fucking diesel. Opinions?

Here's the relevant parts list or at least the parts that could affect the sound:

Belfab rods
FM 9:1 wisecos
FM head
stock bearings
wiseco/fm supplied rings
stock cams
gt3071
tial wg
tial bov

aggh what the fucking hell.

WonTon 03-31-2010 09:33 PM

sounds like really really band valve tick! and i think a engine knocking is a lil more horrible than what i heard in your video! i would suspect lifter clearance! maybe you have to much clearance between your cams and lifters!

TurboTim 03-31-2010 09:45 PM

Or too much clearance between forged pistons and block? Does it get better when it warms up? What's the valve lash set to?

southernmx5 03-31-2010 09:46 PM

My engine was ticking loud like that after I took the lifters apart to clean them. Do you have solid lifters? Go for a short drive to get sufficient oil to hydraulic ones.

Faeflora 03-31-2010 09:47 PM

No, it's pretty much the same warmed up or cold. I think that was warm.

I don't know what the valve lash is. I will find out. As for cylinder clearances, I forget but will find out too. I am pretty sure it is whatever was reccommended by FM/wiseco.

more guru advices please!

WonTon 03-31-2010 09:47 PM

are you getting oil pressure?

the oil pump is irealivant to the noise but could cause noise like that if there is no oil getting supplied! kinda like when your car sit for a while and when you first turn it on and you get lifter tick till they get oil to them!

Faeflora 03-31-2010 09:52 PM


Originally Posted by WonTon (Post 548372)
are you getting oil pressure?

the oil pump is irealivant to the noise but could cause noise like that if there is no oil getting supplied! kinda like when your car sit for a while and when you first turn it on and you get lifter tick till they get oil to them!

There is oil pressure.

This doesn't sound like rod knock to you all?

neogenesis2004 03-31-2010 10:10 PM

No, rod knock is louder and more terrifying IME.

WonTon 03-31-2010 10:12 PM


Originally Posted by faeflora (Post 548380)
There is oil pressure.

This doesn't sound like rod knock to you all?

rod knock to me sounds like sombody with a sledge hammer banging the side of your engine!

plus the ticking in you video seems to fast at idle to be rod knock!

curly 03-31-2010 10:13 PM

Here's some advice: STOP REVING IT LIKE AN IDIOT AND TURN IT OFF!!1!

Seriously, stop running it what so ever. I don't care if it's your daily driver, you will not turn the engine on until you diagnosis, locate, and eliminate the sound, understand?

Did you build the engine? Did you check piston height before putting the head on? What's your timing look like? Solid lifters I'm guessing? Double check oil level, it'll require a lot more starting with a brand new engine, just like it's an extra 1/2 qt or so if you change your filter vs. leaving the old one on.

inferno94 03-31-2010 10:22 PM

Hard to tell from the vid but collapsed piston skirt from heat/abuse? Causes pistons to slap the wall, I had this happen on a previous car from sustained boosting.

I was thrown off by the revving, don't run the engine till fixed. True knock is loud (like knocking on a desk), this doesn't sound that loud.

Faeflora 03-31-2010 10:23 PM


Originally Posted by curly (Post 548402)
Here's some advice: STOP REVING IT LIKE AN IDIOT AND TURN IT OFF!!1!

Seriously, stop running it what so ever. I don't care if it's your daily driver, you will not turn the engine on until you diagnosis, locate, and eliminate the sound, understand?

Did you build the engine? Did you check piston height before putting the head on? What's your timing look like? Solid lifters I'm guessing? Double check oil level, it'll require a lot more starting with a brand new engine, just like it's an extra 1/2 qt or so if you change your filter vs. leaving the old one on.

AYE AYE CAPITAN!

I am going to get it towed tomorrow back to the shop that built the motor to ask them to figure out what the problem is.

Quesiton though: how do i diagnose and eliminate the sound without turning the engine on? Was that a koan you posed to me?

The block and the head are stock height, neither were decked. I have no clue what my timing looks like. The noise has my brain befucked and i can't think shit. Oil level is ok.

Faeflora 03-31-2010 10:24 PM


Originally Posted by inferno94 (Post 548409)
Hard to tell from the vid but collapsed piston skirt from heat/abuse? Causes pistons to slap the wall, I had this happen on a previous car from sustained boosting.

Sounds too slow for valve train but I was thrown by the revving. True knock is loud (like knocking on a desk), this doesn't sound that loud.

Piston skirt?

this is a fresh motor, no boost experienced yet at all. This is it's first startup :(

this is not how i want to break the motor in :(

Faeflora 03-31-2010 10:27 PM

-added youtube embed for non photobucket bullshi

WonTon 03-31-2010 10:27 PM

trailer the car to the guy how built the motor! turn it on in front of him and say WTF! :vash:

southernmx5 03-31-2010 10:30 PM

If those are stock hydraulic lifters you should go drive it or set the lash for solids. Reving at idle won't pump the lifters back up for zero lash.

Rod and bearing problems will sound much worse.

JayL 03-31-2010 10:34 PM

Is oil getting to the head?

WonTon 03-31-2010 10:35 PM


Originally Posted by JayL (Post 548422)
Is oil getting to the head?

thats what i was thinking!

inferno94 03-31-2010 10:39 PM


Originally Posted by faeflora (Post 548413)
Piston skirt?

this is a fresh motor, no boost experienced yet at all. This is it's first startup :(

this is not how i want to break the motor in :(

The part on both the intake and exh sides that stick down past the wrist pin. s they are the thinnest part of the piston, they can be warped. In my experience (running cast pistons at 15psi for ~1min) they can warp in towards the rod ever so slightly causing piston slap. This can score cylinder walls thus don't run the motor.

If it's the first start, talk to the builder. I've never had an engine make sounds like that after a build.

curly 03-31-2010 10:40 PM

Oh touche, did the shop know of that little trick Mazda built into the head gaskets? If you flip it upside down it'll look perfectly normal aside from blocking the oil to the head.

I will allow you 15 seconds of run time to turn it on, take off the oil cap, check for oil, and shut it off. No more.


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