7 mgte tapping noise

faisel12

New Member
Nov 23, 2011
8
0
0
modesto
hi i got a 7mgte that make a wierd tapping sound that sound like the piston hitting the valves or the top of the head i need help i bought this car cause the guy said he rebuilt it and he broke a bolt in were the cam bearing bolts down to i ended up getting the bolt out but now that i got it running theres a noise
 

supraguy@aol

Well-Known Member
Dec 30, 2005
4,238
42
48
Atlanta
Use either a mechanics stethescope, or a long screwdriver, to press against the valve covers, and zero in on where exactly this noise is coming from. If it indeed sounds like it is coming from under a valve cover, remove that cover, and check the valvetrain itself out closely.
Post your findings.
 

faisel12

New Member
Nov 23, 2011
8
0
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modesto
yea i did use a stethoscope and i kno were its coming from the number 2 piston is either hitting the top or wen the guy did the rebuild he didnt tighten one of the rod bearings up or forgot to put a bearing in
 

IwantMKIII

WVU MAEngineering
Jun 12, 2007
2,477
0
0
Perkasie, PA
7m is a non-interference engine (thankfully). Odds are what you are hearing is valve tap. Post a quick vid to at least get the sound of it and most likely someone will confirm any possible knock or more commonly just valve tap. If there is no bearing left for one reason or another...youd know it undoubtedly.
 

radiod

Supramania Contributor
Dec 13, 2007
1,342
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Abbotsford, BC
If it sounds like a loud sewing machine, it's usually valve tap. If it sounds like someone's tapping the side of the block with a ball peen hammer, it's usually rod knock. You should be able to tell pretty definitively if it's top end or bottom end by having the scope on the valve cover vs. the block (I stuck my hand under the intake manifold and the probe on the the block on each cylinder when diagnosing my own stuff). Notice that these are USUALLY cases...not definite. People have had sounds similar that ended up being loose crank pulley bolt, loose cam shaft bolts, loose flywheel bolts, and many others.

If you do post a video, over everything else try and get good audio. Doesn't matter if the picture is junk, but without good audio it's impossible to give you even an educated guess. Diagnosing ticks, rattles, and knocks can be hard enough with the car sitting beside you, let alone from a video off youtube. If you can't get good audio your best bet is to just stop by a mechanic you trust and ask their opinion, maybe bring the stethescope and just show them the area you listened too as well.
 

Dan_Gyoba

Turbo Swapper
Aug 9, 2007
1,836
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Alberta
www.gyoba.com
I can't see any way of removing the pan from a 7M while it's still bolted into the engine bay.

My engine started making a similar sound at the end of this season, I'm kinda bummed about it. ~2k RPM, and it starts.

Pulling the valve cover is easy, and probably the best place to start. Rule out the simple things first. I'll also be pulling the inspection covers from my bellhousing to check the flywheel (Just did the clutch somewhat recently, too) I already took a good hard look at the crank pulley, since I've had issues with that before, too. My stethescope is missing (One more thing that my wife didn't think that I needed when we moved, I guess) so I've got to replace that.

Don't be so quick to jump to the conclusion of rod knock. There are plenty of other things that it could be. If the piston is hitting the head, then the head is junk, and probably much of the block rotating assembly as well. Personally, I'll look for repairable problems first.
 

Quin

Trans killer
Dec 5, 2006
1,989
0
36
33
Columbus, IN
You can use a hoist to hold the engine up and drop the subframe and get the pan off that way. Just an FYI, definitely quicker/faster to pull the motor though.

The good news is what you're hearing is quite possibly completely normal. Most 7M valvetrains are almost as loud as a diesel truck lol
 

enjoyer

New Member
Mar 28, 2009
164
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0
Lithuania, Klaipeda
Similar issue here. I'll try to get a vid. It's only heard on idle and on cold engine. Till 2k rpm. If i give it gas, the sound goes away, till it drops back to idle.
 

enjoyer

New Member
Mar 28, 2009
164
0
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Lithuania, Klaipeda
Here's a vid. You can hear the ratling. It is heard only on a cold engine and at idle. If you give it some gas, it goes away untill it drops to idle again. After a few minutes, as the engine starts to warm up, the noise is gone.

[video=youtube;S2Mfv1CEw2k]http://www.youtube.com/watch?v=S2Mfv1CEw2k[/video]
 

faisel12

New Member
Nov 23, 2011
8
0
0
modesto
so i actually got under the car today and found out that the pan towards the front is bent so it makes noise due to the crank hitting the pan cause theres no clearance
 

faisel12

New Member
Nov 23, 2011
8
0
0
modesto
so i guess im gonna either pull the motor out still or find some other way to do it and thanks to all the people that tried to help i really appreciate it
 

IwantMKIII

WVU MAEngineering
Jun 12, 2007
2,477
0
0
Perkasie, PA
Sounds like mine. Its been doing it for years. So far, so good. Post some pics for reference if you really find the problem.
 

faisel12

New Member
Nov 23, 2011
8
0
0
modesto
IwantMKIII;1781285 said:
Sounds like mine. Its been doing it for years. So far, so good. Post some pics for reference if you really find the problem.

yea i definetly will if it is the problem