Bellisima_Z

Installed the motordyne mrev2 on my Z today and after the car warmed up I started to hear a slight engine knock at idle. The noise can be heard at about 0:40 and gets worse as the video progresses. Has anyone else experienced this? Any idea what could be causing this, or if it's normal?

Thanks for your help!

Koolsilver

Does the noise change with higher revs? Also make sure its not just our noisy transmission push in the clutch and see how it sounds.

RacingBlack350Z

doesn't sound like a clutch sound to me, you sure you got all the inch/pound torques right when putting everything back together. Just pointing out the obvious haha hopefully someone else has some better input

Bellisima_Z

Yeah I def did...torqued 40, 80, and 100 on all bolts except the 6 bolts on the upper manifold. My spacer is AAM Competition, and it didn't have the internal spacers that motordyne provides, so I just tightened those 6 bolts a little more than finger tight because I was afraid to crack the upper Intake manifold. I did call AAM to verify and that is what they suggested to do...? I've checked and double checked to make sure everything was reattached, and that no hoses were crimped, and as far as I can tell there are no noticeable hissing sounds that would indicate a vacuum leak. Oiled the aramid gasket according to MD instructions and am pretty confident that the install was done correctly. When I first started the car I didn't notice the sound. I then took it for a drive and laid into it a bit too test it out. The knocking seemed to start right after that. It only seems to do it at idle, unless the engine sound is drowning it out while driving, making it undetectable. The car also seems to be running fairly hot too, but I'm not sure if that normal.

Firebase99

Did you install it using the thermo (optional) piece? Its been sooooo long, i forgot exactly but i remember there was a optional piece to install depending on climate, etc.

Ser_Z

iTrader: (8)

My guess is Air leak somewhere.

Get a can of "starting fluid". Give littel short blasts around the bolts, gaskets and any other hose that is connected to it. If you hear the idle go up at all, you found your leak.

If not then...Make sure nothing is pinched in between...If that doesn't work try to un-install and re install.(You know the fun way! )

Good luck.

travlee

iTrader: (8)

doh, finally ran into a snag. I cant help ya on this one since they don't make em for the HR motors. hope you figure it out soon

Bellisima_Z

Its just the spacer, mrev2, and regular aramid gasket... didnt do any of the other optional parts.

JERZ350

iTrader: (2)

I agree it sounds like an air leak or check your MAF sensor? Also check around the throttle body for any leaks or specifically one of the hoses that attaches to the back of the manifold near the firewall.

It just sounds like the car is struggling to "breathe" normally. I don't think its a knock.

Also some cars can sound mildly like crap when a mod like this is first installed. That compiled with a possible leak I think could very well cause this sound.

RacingBlack350Z

could this have happened if he accidentally touched the butterfly inside the throttle body when he removed the plenum?

JERZ350

iTrader: (2)

It's possible it can be out of wack now. Should take some amount of care with handling the throttle body. Can try cleaning the MAF, cleaning the throttle body and checking the hoses for leaks.

Did you use red gasket sealant when re-installing?

Bellisima_Z

I did clean the intake manifold while it was apart but was very careful not to touch the butterfly.

Syner

she

she's a she, not a he.

Bellisima_Z

The MAF sensor was replaced about 3 weeks ago with a new one so I should be good there.
Thoroughly cleaned Intake manifold prior to putting it back together.
And have checked all hoses.

Bellisima_Z

Preach it Syner!

Syner

it's not unheard of to get sh*tty sensors out of the box. it's just quick test with a multimeter to confirm...

Syner

...at every opportunity i get...

Bellisima_Z

Ok I'll try that... Should I be worried about driving the car to a shop? Could it cause any damage to the engine to drive it that way?

Ser_Z

iTrader: (8)

Take it apart and re-do the process right this time(Take your time!)...asking us will only help so much until you figure out you have to re-do the install to figure out what's wrong lol. (Air Leak any bets?)

Bellisima_Z

No I didn't... But I don't recall the instructions indicating to do that. Should I have?