7M-GE knock or tap coming from intake cam side

[chris89]

I was having this problem where i'de hear tapping or knocking sounding that got louder and louder above 2k and it sounded like it was coming from the intake cam valve side of the head in the front (1st or 2nd cylinder)... so i had an extra ge head so i had it completely rebuilt etc... bought a head set and had the entire head redone... and completely polished the inside of the intake manifold including all runners and the ypipe/ throttle body. So it is all done now but the sounds still exists but much quieter, anyway a rod bearing noise could sound like it's coming from the head? I'll have to make a video to further diagnose the problem...

 

[Stretch]

Were the valves shimmed to within spec when the head was rebuilt? That could be one thing causing the ticking. Also, I noted you said it was on the intake side, and therefore it could easily be just the fuel injectors, and they have been known to emit a rather loud ticking when operational.
eric

 

[supraman420]

Rod knock.... it's a shame. I've got it and it sounds like its comming from the head. Take a stethiscope to it and you'll know where it comming from.... the block. Sorry, I really hope it's not the case for you, but sounds very similar to my case.
My 7mgte will be here friday. If I were you I'd buy a 7mgte, throw your rebuilt head on it and swap in the engine. But I hated the N/A.... do as you please. Good luck I hope it works out for you.

 

[3p141592654]

Pull the plug wires one by one and see if the noise goes away. If it does its almost certain you have rod knock.

 

[chris89]

Ok, did the plug wire thing and the noise stopped on the 4th plug wire...

 

[Stretch]

Uh oooh...:aigo:

 

[IJ.]

Mama take this badge from me
I can't use it anymore
It's getting dark too dark to see
Feels like I'm knockin' on Chris's Motor ....

<edit> care of 5150's lyrics !

 

[p5150]

Knock knock knocking on chris' motor!

Hey, yay yay yay.

 

[p5150]

Your motor is fucked buddy. I would look for a good replacement and use that head you purchased on your "new" motor

 

[chris89]

I'm gonna drop the pan sometime and take a look at the rod bearing caps and what not. Cheaper than buying a new block etc... If I have to i'll probably go gte.

 

[Shytheed Dumas]

Your motor is fucked buddy. I would look for a good replacement and use that head you purchased on your "new" motor

Okay, you guys having me sweating now. The guy I bought my 90 7M-GTE from last month said there was some rod knock on #6. He replaced the rod bearing and it has been very quiet since then. Are you telling me that I'm going to see this again, or am I good to go on the new bearing?????:1zhelp:

btw, I am in the middle of a bhg project right now and started a thread earlier today wondering why I have a fair amount of buildup throughout my intake - any relationship here?

 

[supra90turbo]

Knock knock knocking on chris' motor!

Hey, yay yay yay.

:yelrotflm

 

[chris89]

Okay, you guys having me sweating now. The guy I bought my 90 7M-GTE from last month said there was some rod knock on #6. He replaced the rod bearing and it has been very quiet since then. Are you telling me that I'm going to see this again, or am I good to go on the new bearing?????:1zhelp:

btw, I am in the middle of a bhg project right now and started a thread earlier today wondering why I have a fair amount of buildup throughout my intake - any relationship here?

It's gonna build up with carbon and oilly junk because of all the emmision control junk on these motors. PCV, EGR, etc etc.. I managed to clean my whole entire intake manifold, now it's actually shinny inside... Carb Cleaner works like magic. I bought a 1" or so wire brush wheel and a 4 inch extension and put it on my electric drill, Just went to work and used like 5 or more cans of carb cleaner.

I've got a question though about rod bearings... I don't know much about rod bearings. I was wondering What i should do to check... do i have to pull the head off to replace the rod bearings? can i just drop the pan and replace all 6 of em'? What do i need to do to drop the oil pan? lol too many Questions...

 

[p5150]

you cant just change a knocking rod bearing.

Rod bolts are torque to yield = you should replace them when you remove the nuts.

Rod ends must be resized after rod bolt replacement.

Crankshafts are usually damaged by rodknock.

Long story short = you need a rebuild or a good JDM engine. Changing the bearing is a band aid fix - you need stitches

 

[miggles]

My machinist showed me the underside of the rod that had the knock on it and you can see some slight marks where it was hitting.I was lucky i didnt have to grind this crank.
Time for a rebuild on the motor as if you replace 1 bearing (like the previous owner) you will have to replace another and so on.