well I checked all my valve clearences today...

[fiyota]

Well, I checked all my valve clearences today, and all seem to be right in spec according to the TSRM, all were right around the smaller side of the recommended spec. I checked them to diagnose what I thought was just valve that was out of adjustment.

Well, since they are all perfect, the motor has about 9,000 miles on it since it was fully rebuilt, and the head looked spotless inside. I am thinking it is something else more severe. The noise is a single loud, midium pitched tap, coming from, what sounds like the top of the engine, that is most noticeable once the engine has warmed up, and is only at idle. I watched the "Valve Train Noise" video on youtube, and mine sounds similar, but not quite as loud, and with WAY less background valvetrain noise.

I am thinking it could be a number of things... but don't know what to do next to find out exactly what it is. It could be something wrong with the valve train (bent/sticky valve, worn out spring, worn cam lobe, etc). It could be wrist pin slap or rodknock (that would make a double knock sound and be much louder wouldn't it?)... or it could just be an exhaust leak or my crank pulley.

Where would you start? :1zhelp:

woops, kinda ran on a little longer than I had planned, sorry! :sarcasm:

 

[Poodles]

exhaust leak, loose cam cap (possibly, but doubt it), injectors...

get an automotive stethescope...

 

[fiyota]

hmm... that's a good idea, I never thought of that... (the cam cap)

It's a little loud to be the injectors.... there is a very audible tap/knock and it sounds like it's being done by one thing, once per revolution... wich is why I thought it was a single shim that was out...

 

[Poodles]

dunno if it would be a good idea to run the engine with the cam covers off...

that's how we've found drivetrain issues in other cars, but I think the 7M pumps a ton of oil to the head...

 

[fiyota]

no, I wouldn't do that either. A mechanics stethascope should be able to pinpoint my issue.. I just hope I don't hear it knocking in my oil pan... it's hard to tell by just listening by the wheel well if it's coming from the head or the oil pan...

 

[americanjebus]

heh, yea dont run the engine w/ the valvecovers off, i remember a vid of a guy doing that on his dsm.

I have the same annoying ass tapping sound coming from the cam areas. I know its coming from the cams but i have never gotten it to go away. I took a large screwdriver and put one end to the valve cover and the other to my ear, the closer i got the louder i got. the injectors make allot of noise too.

is it much louder than this? you can hear it as it gets closer to the engine.
http://youtube.com/watch?v=IPal_MxOVFc

 

[fiyota]

hmm, sound quality isn't the best in that video, but it sounds about the same... mine is a little more refined sounding, but that could be because of the camera used...

 

[MmmBoost]

check all the clearances of the cam journals. they should be within .15 to .25 mm

you will probably find all of them way off like mine. i traced my tapping noises to this exact reason, cuz all my shims were within limits.

 

[fiyota]

hmm, I'll do that on my next days off work. Sounds like it could be the issue, since I'm pretty damn sure the noise is head related. Is there any way to check the cam journals with the cams still in place (without having to go through redoing the timing belt and retiming the motor)

 

[3p141592654]

No chance. You need to pull the buckets and shims off at the minimum to unload the cam from the spring pressure of the valves.