Pinpointed Engine Noise Better--Different Question Now

[JRA2000TL]

I probably should have posted this in my original thread, but I was out playing with the SHO today and when I started it up, the engine noise was very apparent this time and easier to pinpoint. The noise is coming from the top of the intake-lower left hand side near the lower left hand mounting bolt, which is just above/around the front left hand cylinder. I've included a link to the my photobucket with arrows showing where it is. If you put a screwdriver on the lower left mounting bolt, you can hear it the loudest.

Now...I was told it was a cam chain or timing chain tensioner originally, but with it at this location, would it be something related to a valve? It's louder at cold startup and quiets more when the car is warm. If it were rod bearings, wouldn't it be loud full time? Someone said something about shims/valves can make a noise. The vids are still on YouTube of the noise.

Someone does want to buy the car but if the deal falls through I did consider keeping it. Either way, I'd like to know for his sake and/or my own.

You'll have to click to enlarge the pic for a better view. Sorry to beat the dead horse on this issue and I appreciate all the help, especially since it's probably being sold.

http://s108.photobucket.com/albums/n10/jasarisi/SHO%20Engine%20Noise/:deadhorse:

 

[JRA2000TL]

After doing some reading, I see that there is something I can unplug to see if the noise goes away. Anyone have a picture of where this is? I believe it's a vacuum line. I do know now that the absolute loudest place I heard the noise is where those yellow arrows are pointing--if the screwdriver is on that lower left-hand top intake bolt and/or the long silver rail under it, you can hear it very well.

 

[JRA2000TL]

Ok guys....I haven't gotten any responses yet but I need some help. I decided to run the codes even though though there's no CEL. I forgot the Gen I's have 2 digits (I had a 93 so was going by 3 digits). I may go do it again but figuring what I have written down shows the following codes:

Edit: I re-did the test and came up with the following KOEO

code 11, repated code 11 (system ok)

then a very long pause 18 then maybe a 38 then it flashed 3 times again...maybe these have to do w/ the tapping, they are timing codes i believe

Cyl Balance test...got all kinds of weird crap I can't interpret--here's the sequence (dash = pause) 1-2-7-7-7-4-2-1-7-7-7-4

What's the deal? Did the screwdriver stethoscope test--definitely coming from the front upper cam shaft all the way from the left to the right. Knocking/clacking noise is not present anywhere else, including the rear bank.

Oh yeah, fixed my cruise! Throttle linkage came loose. I love a free fix

Put headlight restore on the headlights...look better but still should be replaced. For someone that wants to sell this car, I can't keep away from it.

 

[Speedy_91_SHO]

Spark plug boot not fully seated and arcing on the head? Also, the long silver rail would be the fuel rail. Those can make some noise if clogged, but that doesnt sound clogged. Maybe one of the plugs isnt all of the way plugged into its injector.

 

[FastAndFurious]

It could be your butterflied as you mentioned. I guess you don't know where it's located. You can check it by unplugging the vacuum hose that goes to the black plastic cylinder shape thing on back of the intake. If the noise goes away after you unplug it, you are good to take it to the tracks!

 

[thecrew2999]

the black thing in the back controls the butterflies and it makes a ticking sound and can make you wonder but i guess its a yamaha defect.. my 92 does that now.

you might have a air leak near the spot you pointed out, try the tried and true method of unlite propane torch and also could be a injector since they sit very close to where you pointed.

post a update soon as you can ill try and check for this often

 

[JRA2000TL]

Thanks guys for the help. I may check that plug later on this afternoon. If it still makes the noise, I think it's the chain tensioner as many on here told me that's what it was after listening to the videos I posted.

I started it up cold and after a few seconds the clacking got really loud; that's when I ran and got the screwdriver and started listening all over. I feel a little better now that it's not rod bearings since I can put it in other spots on top of the motor and I don't hear the noise at all through the screwdriver. I kept thinking it was all over in different spots, then I decided to go left to right with it along where the upper camshaft would be and it made noise all the way across there but nowhere else, so that is probably it.

 

[Speedy_91_SHO]

What seems odd to me about it being the cam chain tensioner is that the tensioner is on the other side (tb side) of the motor.

 

[JRA2000TL]

Yeah I know. I thought it was odd myself. I don't know why it would be louder on the left side than the right, but it is. Either way, the tapping is concentrated along that upper camshaft along the front all the way across. If I put the screwdriver anywhere at the back center or along the back side of the engine, there is no noise---runs smooth. If it were a rod knock, I think it would make the same noise all the time and you'd hear it no matter where you put the screwdriver.

 

[K-Dawg]

I still think you have a rod bearing problem. If not that, then maybe you have an ejected shim or something, but I doubt it. I'd pull that front valve cover to see if anything seems out of whack, but I have a feeling you aren't going to find anything wrong.

 

[Eric VerValin]

I remember replacing a 'suspect' tensioner when I had a ticking bearing... lol

IF YOU HAVE GOOD JACKSTANDS.... jack it up, turn it on, and put your screwdriver against the bottom of the oil pan.. tell us how loud it is then.. you'd be suprised how sound / vibration travels.

I seriously thought mine was a front tensioner too but mine was #5 that was eaten, directly below my 'loud spot'... yours sounds like one on the passenger side if its louder over there...

the sad part of the story is.... your crank is probally already smoked if its been ticking / running as long as it has... ask me how I know...

 

[JRA2000TL]

What a pain. This car supposedly has only 68k on it. I'm going to be ****** if it turns out to need bearings. I hope the engine isn't damaged. I need to get my $2100 back out of this thing, but if the engine is ruined I can hang it up. Might as well set fire to it then or push it off a cliff. Either way, it's being sold--gone. I can't own one of these cars for a week w/o everything tearing up on them. They're so old now, they just aren't worth the upkeep. I'm going to see if this one guy still wants it and if not, I'm bumping my ad on the trader section. I don't have the patience for these cars. If it is the rod bearings then highest bidder will get a solid Southern SHO body with decent interior, rod shifter, 96 brakes, and slicers...and they can have fun putting a motor in it.

Maybe it's a cheap, easy fix---maybe not. I don't care anymore. I just want it gone.