I noticed this noise early this week.. Its gotten much worse today... Its making a loud dull metallic noise, and i cant figure out what the problem is...

Its barely audible at idle... at 2000 its much more apparent.. Its definately noticeable through the rest of the rpm range as well, but it becomes louder if i ride the gas a little bit to rev it up... Its a very rythmic noise - it goes with the engine speed...

Im getting good vacuum off the intake. I completely retarded the timing with no results.. Also, when i had 2 of my valve cover bolts loose, i noticed a little bit of warm air being forced out the top... Im guessing i have an exhaust valve that needs adjustment, but i want to be sure i didnt spin a bearing or anything...

The noise is definately NOT a high pitched pinging... its a very dull mechanical sounding knock...

Any ideas?

-mike

 

sounds like a bearing to me. try having someone hold the gas at the rpm where u hear the noise, then unplug a spark plug wire and see if the noise stops. do this on each spark plug wire. if it is u can suspect a bad rod bearing. Same thing happened to me twice. As recently as a month ago, same problem, drove it to work, then boom.

 

Yeah.. i tried running it with each of the four wires off... still the same thing... also, its distinct across the entire rpm range.. nothing specific...

Im gonna adjust the valves tomorrow morning so the engine gets a chance to cool... other than that, any other ideas? its way too loud to be injectors or something like that.. Its running fine otherwise... actually it felt quicker than usual before it started...


-mike

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by inFamousOneSix &raquo;</TD></TR><TR><TD CLASS="quote">sounds like a bearing to me. try having someone hold the gas at the rpm where u hear the noise, then unplug a spark plug wire and see if the noise stops. do this on each spark plug wire. if it is u can suspect a bad rod bearing. Same thing happened to me twice. As recently as a month ago, same problem, drove it to work, then boom. </TD></TR></TABLE>

would unplugging a spark plug wire even do anything? its my understanding that ALL of the pistons are attached to the crank via a connecting rod, irregardless if there is spark or not. So your method of testings wouldn't tell if it was a rod bearing or not. It may be a rod bearing however because the rods are still moving even if the cylinder isn't firing.

mike

 

lost motion assemblys?

 

Ill check the lost motion assemblies tomorrow as well.. i dont have much experience with these... Is there an easy way to tell if theyre shot? if theyre bad, can i just soak them in oil, or should they be replaced? im guessing honda is the only place to get them...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MikeMAN &raquo;</TD></TR><TR><TD CLASS="quote">

would unplugging a spark plug wire even do anything? its my understanding that ALL of the pistons are attached to the crank via a connecting rod, irregardless if there is spark or not. So your method of testings wouldn't tell if it was a rod bearing or not. It may be a rod bearing however because the rods are still moving even if the cylinder isn't firing.


mike</TD></TR></TABLE>

An acura mechanic of mine told me to do this back when this happened to my first b16a, i believed the same thing as you as far as why it would make a difference since all the rods would be moving anyway with or without spark. Sure enough when i tried it, the #3 cylinder stopped making the noise as soon as i pulled the plug wire. Later after i disassembled the motor, i saw that the number 3 bearing was shot. Not sure why the wire thing worked at the time, but i figure it has to do with the rod coming down hard as combustion forces it, instead of riding along with the crank without spark. Perhaps the bearing noise is not as audible when just riding up n down.

here, i found a link referencing the shorting of plug wires to diagnose engine noise:
http://remanufactured-engines.com/page4.htm

Modified by inFamousOneSix at 4:40 AM 5/2/2003


Modified by inFamousOneSix at 4:41 AM 5/2/2003

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mikeman191 &raquo;</TD></TR><TR><TD CLASS="quote">Ill check the lost motion assemblies tomorrow as well.. i dont have much experience with these... Is there an easy way to tell if theyre shot? if theyre bad, can i just soak them in oil, or should they be replaced? im guessing honda is the only place to get them...</TD></TR></TABLE>

to check the lma's u can stick your finger under your vtec cam lobe and push down on them. If you can't get your fingers down there u might have to remove the cam holder plates or cams and flip the rocker arms up. just push down on them and they should come back up smoothly. The lma is basically a spring inside a canister, it should have perfect motion but sometimes they stick and take a split second to come back up. You can get new lma's for around 30 bucks apiece for b16a or gsr ones. and they are 32 bucks a piece for the itr's. the itr lma's are a bit stiffer and i'd recommend going with those if u want to swap them out. I got mine on ebay brand new for 135 bucks or so which is a steal. I think i saw another set on there recently.

 

Checked and adjusted all the valves to spec this morning.. nothing out of the ordinary... Im gonna try to get a sound clip of this... but its really friggin loud now... Its on both in vtec and out of it, so does that rule the LMAs out?

i can definately hear it over the motor... it seriously sounds like a jackhammer.. And its only when im on the gas... i hope its a rod bearing... the new turbo block is going in in a few weeks.. but i need that head...

-mike

 

btw: nice screenname

mike

 

Well its official... the car wont run on this motor ever again ... Barely made it down the freeway... i guess it was a rod bearing after all... good think the head isnt screwed up... its getting boosted in 2 weeks, and i need that PR3 head...

mikeman - where in minnesconsin are you from?

-mike

 

i am up at school in Eau claire, WI but i live about 30min south of milwaukee. I was born and raised in Lake Crystal, MN tho (20min south of Mankato)

mike