1993 MTX "Engine?" tapping sound

[1993MTXSHO]

Hey guys I have a 1993 MTX and a few weekes ago i noticed a slight tapping sound that went up as the engine rpms went up. My car has 97000 miels on it and i was in the parking lot of walmart when i noticed it. Now my clutch was going bad and really sstarting to act up locking me out of gear and such so i thought maybe the clutch ripped apart and one of the straps was smacking the casing. So i just went and bought a spec stage 2 clutch with 9lb alum. flywheel (love it grabs amazing). I have been drivign around for maybe 50 miles on the new clutch and the sound is still there and is seeming to get worse now, (louder) the 60k mile was done at 60k so the guy i bought the car from says but from the looks of her she was well taken care of. I put a screwdriver to the valve covers and listened to the engine when it was ideling and i herd no tap i only hear it when its in gear. Now i think i MIGHT hear it when its in neutral when i rev it havent gotten the chance to do the screwdriver test again though. Does anybody have any idea what this could be?

Nick

 

[Jaz2099]

Check your rod bearings maybe? Thinik that may be more of a clunking sound though. Do you know the general area it is coming from?

 

[SHOtimer]

I would be changing your rod bearings - ASAP. It is possible it could also be a timing chain tensioner - but you would hear/feel it against the valve cover.

Doug

 

[Jaz2099]

I would be changing your rod bearings - ASAP. It is possible it could also be a timing chain tensioner - but you would hear/feel it against the valve cover.

Doug

That is true.

ASAP BTW means if it is the rod bearings STOP DRIVING IT NOW. And you did say it is getting worse ---- thats not a good thing.

 

[F-22 Raptor SHO]

try to isolate the sound...do the screwdriver test to the following areas:

Valve cover front right ****
Valve cover rear right **** (this checks each tensioner.
Check each injector by putting screwdriver on each one thru the fuel rail
Check the left rear area of the motor for tapping on number 1 cylinder (timing belt tension).

check oil pressure and oil quality (via an oil change)

 

[1993MTXSHO]

try to isolate the sound...do the screwdriver test to the following areas:

Valve cover front right ****
Valve cover rear right **** (this checks each tensioner.
Check each injector by putting screwdriver on each one thru the fuel rail
Check the left rear area of the motor for tapping on number 1 cylinder (timing belt tension).

check oil pressure and oil quality (via an oil change)

thanks all, ill try that stuff as soon as i get a chance also the oil is onlay about 100 miles old and is changed every 3k miles and the oil pressure is the same as normal it reads a little over 25 psi when cruzing on the highway and like 15sih at idel it goes up around 50-75 when under a full load. Also what exactly are the rod bearings can i cahance them myself? im still fairly new to the shos i just got my first in august but have read alot on them since iv wanted one for 3 years and finally found the right one.

Nick

 

[F-22 Raptor SHO]

Your pressure sounds about right for good bearings. I would change them simply for peace of mind, but I dont think that is your tapping source. If it isnt the tensioners, you may indeed still have issues with the TOB. Its hard to tell over the internet ya know.

 

[Rockledge]

Also what exactly are the rod bearings can i cahance them myself?

You ought to crawl under the car as well with the screwdriver to see if you can isolate the noise at the lower part of the engine. Hopefully, you won't.

In any case, as was mentioned, when you get a chance you ought to consider changing the rod bearings as a matter of maintenance. Less than $75 in parts in return for a whole lot of peace of mind. Yes you can change the bearings yourself:

http://www.shophoenixproject.com/rodbearings/rodbearings.htm

http://kurtmetros.com/bearings.html

.

 

[1993MTXSHO]

Your pressure sounds about right for good bearings. I would change them simply for peace of mind, but I dont think that is your tapping source. If it isnt the tensioners, you may indeed still have issues with the TOB. Its hard to tell over the internet ya know.

I dont think its the tob becasue i jsut replaced it with a ceramic one from shonut and the sound was there before the clutch job. Could it still be the tob even if i just changed it? Im going to try to listen again to those places with the screwdriver and maybe do my error code checks again. before the clutch job i got an arror that said i had a bad pcm or no power to pin 1 would that have anything to do with it and i jsut remember ed it doesn happen all the time but before i changed the clutch i had a really rough idel one time and others it more rough then normal. I haven had a rough ideal after the clutch job though it seem OK but i think it used to idel smoother then it does now but its not bad now to the point where this is a cylinder misfiring or something. Could this sound be a valve tapping this early (20k miles early)?
It seems to only do it noticibly when in gear which is the part that is getting me. Unless its only heard when the engine is under a load.

 

[ManySHOs]

Is the car misfiring at all? Did you recently replace your plug wires and follow the incorrectly printed diagram in the Chiltons?

Where in NJ are you?

Ian

 

[1993MTXSHO]

Is the car misfiring at all? Did you recently replace your plug wires and follow the incorrectly printed diagram in the Chiltons?

Where in NJ are you?

Ian

im in patternburg its 10 minutes from clinton. I havent replaced the plug wires but im assuming they were done at the 60k but from what i remember they are motocraft which would lead me to believe they were not replaced i have an extra set of red wires o forget what brand i believe they are hipo wires that came with the car when i bought it im currently in college and can only get home on the weekends. Hey man if your willing to come and help me out maybe just listen to it i have a 1994 sho atx taht im parting out if you need some small odds and ends id be willing to give you some stuff bucause i just dropped 1500 buckson my clutch setup and labor and umm im sure you know how it is being in college... haha thats a lot of money

 

[ManySHOs]

im in patternburg its 10 minutes from clinton. I havent replaced the plug wires but im assuming they were done at the 60k but from what i remember they are motocraft which would lead me to believe they were not replaced i have an extra set of red wires o forget what brand i believe they are hipo wires that came with the car when i bought it im currently in college and can only get home on the weekends. Hey man if your willing to come and help me out maybe just listen to it i have a 1994 sho atx taht im parting out if you need some small odds and ends id be willing to give you some stuff bucause i just dropped 1500 buckson my clutch setup and labor and umm im sure you know how it is being in college... haha thats a lot of money

I forgot; I just talked to you on the phone this weekend.

I dunno, I'll probably be up in Bellmeade one of these weekends to visit SHO92 and hang out. Maybe we can swing on by and take a look see. I have your cell; I'll let you know!

Where are you going to college? Rutgers? Ramapo?

Ian

 

[ManySHOs]

Wait, did you buy Heikki's SHO!?! I just saw your sig pic. I didn't even realize he had it for sale. That's one mean car dude. I knew the previous owner and I know Heikki fairly well. If you have any questions about the car, I can try to remember stuff.

Those red wires are Magnecores that you're talking about.

Ian

 

[SHO92]

I wonder if the diff pin could be on the way out, since it only makes the noise while in gear... I've never heard of it making noise as it goes though.

TOB could definitely be making the noise, it's pretty common for the TOB to rattle on the quill sleeve. If you put the clutch in, does the noise go away?

 

[1993MTXSHO]

Wait, did you buy Heikki's SHO!?! I just saw your sig pic. I didn't even realize he had it for sale. That's one mean car dude. I knew the previous owner and I know Heikki fairly well. If you have any questions about the car, I can try to remember stuff.

Those red wires are Magnecores that you're talking about.

Ian

Yeah man i just relized about an hour ago probably the same time you did when i was posting more parts that were sold on my listing that you were the one buyign the engine and YES! i bought his sho, this is so wierd, so yeah if your willing to come buy and help me with his/my car ill give you some money off on the engine. Small world huh. Heck if you guys are friend not that hed wanna but he can come by too hed know his car best. Im attending bloomsburg university its about 2 hours from my house
mayeb an hour 30 if im driving the sho but it gunan b 2 hours becasue ever since i started hearing that sound iv been going easy on her. well let me kow by phone or e-mail w/e because im comign home this weekend to take more parts off and i really have to get those parts off such as the instrument cluster computer intake and stuff which ovously the car wont run them so i want you to hear it run before you take it if you do. im just in amazement right now about this whoel thing.

 

[1993MTXSHO]

I wonder if the diff pin could be on the way out, since it only makes the noise while in gear... I've never heard of it making noise as it goes though.

TOB could definitely be making the noise, it's pretty common for the TOB to rattle on the quill sleeve. If you put the clutch in, does the noise go away?

well form what i remember its really only when its in gear at like 3 or 4k rpm i havent brought it higher becasue i dont wanna break anything. I dont drive it that much bueacuse im in school so the only time i drive it is to walmart and home for weekends sometimes. As far as the diff i guess its time for a quaife.

 

[gbizzle27]

If this noise is only happening between 3k and 4k its probaby the rod bearings. Mine did the same thing as soon as the secondary's open it goes away. Stop driving it immediatly and get yourself some rod bearings. Sorry my friend.

 

[1993MTXSHO]

If this noise is only happening between 3k and 4k its probaby the rod bearings. Mine did the same thing as soon as the secondary's open it goes away. Stop driving it immediatly and get yourself some rod bearings. Sorry my friend.

ok heres my questions how long can it goes without replacement and if i let it go what can happen? I was planning on doign a complete rebuild in december boring to 3.3 supercharger or twin turbos lightweight pistons etc. So can i leave these bearings in and stretch it if i dont drive it a lot or will they seize or something.

 

[Jaz2099]

Do a search for spun rod bearing. http://www.shoforum.com/search.php?searchid=419406

 

[Jaz2099]

ok heres my questions how long can it goes without replacement and if i let it go what can happen? I was planning on doign a complete rebuild in december boring to 3.3 supercharger or twin turbos lightweight pistons etc. So can i leave these bearings in and stretch it if i dont drive it a lot or will they seize or something.

To give ya an idea ----- Rod bearings determine the clearance between the bearing and the crank journal. That excessive clearance could be your oil pressure droppage. With excessively worn rod bearings, everytime the crank spins ---- the rod will knock against the crank. (not a good thing --- IT WON'T LAST LONG IF THIS IS PROBLEM)