knock knock. Video's here!

[93rev2sev]

So this 90 has been knocking for the past 5K+ miles so I thought I'd have a go at diagnosing it.

Here's step one.
http://www.youtube.com/watch?v=o_oprcnLytg
[youtube]o_oprcnLytg[/youtube]

 

[Kens1992mtxSHO]

Awesome makeshift tool you've got there. That was a good idea.

 

[Eric VerValin]

Agreed! I was waiting on the plug wires to bite him... lol

 

[Tecchie]

That sounds like your cam tensioner, I think I am having the same issue on mine when it's cold, and after she's hot, she's quiet as can be...

It was WAY loud until I changed the oil....after that not so loud anymore, I think I need to replace my tensioner.... I am not sure though.

 

[93rev2sev]

REAR HEAD
Valve lash and compression:

Exhaust Lash: E1: .013 and .012... |-E2: .014 and .014...|-E3: .013 and .013


Compression |178PSI |.................. |140PSI |..................|180PSI |


Intake Lash: I1: .009 and .010.... |-I2: .011 and .011....|-I3: .010 and .010

Looks like that rear head needs help.

 

[93rev2sev]

video of another comp test
http://www.youtube.com/watch?v=NUHHBd67tic
[youtube]NUHHBd67tic[/youtube]

 

[Tecchie]

REAR HEAD
Valve lash and compression:

Exhaust Lash: E1: .013 and .012... |-E2: .014 and .014...|-E3: .013 and .013


Compression |178PSI |.................. |140PSI |..................|180PSI |


Intake Lash: I1: .009 and .010.... |-I2: .011 and .011....|-I3: .010 and .010

Looks like that rear head needs help.

What does all that mean? I know they are clearances, but.... wtf? Please clarify, and for the PSI, etc..

 

[93rev2sev]

for tecchie (copied from www.shophoenixproject.com)

The exhaust side should be between .010 and .014 inches.
The intake side should be between .006 and .010 inches.

Cylinder 2 is slightly out of spec. There is too much gap between the cam lobe and the shim. A slightly larger shim is needed here. Since it's only out of spec by a smidge, I will assume this is not the source of the knock.


The number 2 cylinder is only getting 140PSI when I do a cranking compression test. The other 2 on that head make it up to about 180. 180 is fine. 140 is not.

When I oiled the cylinder and retested, it shot up to about 175. This indicates the problem is the rings or cylinder walls. This engine had a head gasket problem in it's history, so I'm guessing water got into that cylinder and rust has pitted the cylinder wall. :cry: just like racerX:http://www.shoforum.com/showthread.php?t=97618
It has new rod bearings, so it's not those...

 

[rubydist]

My experience is that if its sticky rings, it won't be that loud, and it will be different cold than hot.

I know you said it has new rod bearings, but it sounds a lot like a rod knock to me.... Of course, its not likely to have lasted 5k miles w/ bad rod bearings.

 

[93rev2sev]

it had the knock before I swapped the rod bearings...last winter. And they didn't look bad at all.

James...St.LouisSHO drove it for at least 5000 miles before that.

I got it all back together and running again so I'm at square one. I spose it'll be fine for a while; until I get the body back into shape and finish the 3.2.

I'm still open to theories. Assume it's not the rod bearings.

 

[JRA2000TL]

That sounds similar to mine. I drove it 2k like that without a problem.

 

[Bizzy]

How were the cam tensioners anyway? Any slack in those?

 

[93rev2sev]

How were the cam tensioners anyway? Any slack in those?

I didn't check the front head as the noise was definately coming from the rear. It's hard to check the rear tensioner. I tried to have a look at the chain, but didn't take the guard off.

When I saw the 140PSI on #2, I kinda packed it in.

 

[Bizzy]

Well, it may be 2 separate issues, so you might eventually want to check that out. I don't remember if I have any of those here or not, seems to me that I did at one point in time though.

 

[JRA2000TL]

Yours is coming from the rear? Mine sounds similar, drowns out at about 2k RPMs, quiets down to where you can't hear it (or barely can) after the car is warmed up. Mine is coming from smack dab on top of Cyl#4. If I put the stethoscope on that runner or bolt right above it, it's the loudest there. It's not loud on the **** where my tensioner is; makes me wonder if it is a bad wrist pin.

 

[Racer X]

If the noise is coming from the front moreso than the rear, I'm inclined to think crank cancer.

Any red dust behind the timing cover?

*edit*
Video here: http://www.supermotors.net/registry/media/306297

 

[SHOracer14]

No likey that bad compression... Are you planning on swapping the S/C stuff to this car??

 

[93rev2sev]

Jim,

*trying desperately to type the same way Teddy KGB speaks*

Dunj yu vorry, eye vill have zee tree pont du.

 

[93rev2sev]

As far as crank cancer, I'll have the front torn apart tonight. Plan on seeing more videos...cause I just downloaded Microsoft movie maker and now I gotta use it.

 

[JRA2000TL]

Let us know what you find on yours. I wasn't planning on messing with mine since it's for sale. I'd rather save my $ for my next car than put into this one. If I am stuck with it, I might as well fix it though since I bought some parts for it. If it's something major like the engine is screwed, I'll drive it until the engine goes; then just sell the body cheap.