Engine ' clack ' at around 2-3 rpm

[blackcurrant]

Well, i bought the $7 walmart gage and it read 50 psi cold and 25 eek! warm. I didn't trust it so i put on a gage i had and it settled right into 12-13 psi warm. Maybe the idle was still 100 rpm or so higher when the walmart gage was connected...

So, does this mean the bearings are ok? I found no copper crud in the oil filter and the oil pressures seem ok, right?

Still, this noise persists. I only started noticing it last week. I wonder if it was always there? My driving route has changed from hiway 80mph commutes to backroad 2 lane twisties. thumbs_u More stop and go and gear changes have made me more sensitive to it, perhaps?

Maybe it was there before but i didn't notice cause she was mostly running over 3k rpm in 5th gear and the radio was on...not to mention wind and road noise at those speeds helped to mask it as well.

I suppose it could be valve clatter...I pulled the oil cap like Scott suggested to listen to the front bank...it didn't get louder. The 60k was done right at 60k...she's got 98k now.

Besides, it still is only audible while driving. Never has or is at idle/startup. Never got a red oil light, BTW, just the noise.

I wonder if there's an exhaust leak making it sound different. it sounds fine at idle aside from the water pump rattle. wink And revving it up a little doesn't cause it unless it's being driven.

What about the throwout bearing? I've noticed it's starting to be noisy during shifting about a month ago. Could it have been the problem all along?

the 10w30 castrol himile helped, i think, but, i can still hear it. It's unmistakeable.

What do you think?

Mike

 

[blackcurrant]

bump...

 

[Off Road SHO]

Scott,
Yes I did all the bearings. I learned how to do the "rotate" thing back in '72 on an old Datsun Pickup with 375,000 miles on it. At that time I used a feeler guage to push the upper bearing half out. Since then I've found some nice flexible plastic strips that work fine and wont scratch the crank surface. Some other old farts say to not remove more than one main journal at a time due to possible crank sag, but I say that only applies to long term not short term.I'm getting ready to do the bottom end rebuild on my new 95 and I have a lift in my garage so I'll take some pictures.

Tom
BTW Scott, are you still doing service on SHO's in your spare time? I'd drive mine over from Phoenix if you still are.

 

[blackcurrant]

Well, i'm pretty certain the 'clack' is a valve on the driver side rear bank. I was under the hood looking for the right spot in the firewall for the oil pressure gage tubing to go and as it was warming up i could hear it. It's definately from the top of the engine. Boy, when sho valves ping, they PING. Sounds like a clack to me.

So, thus far i've put less than 5k miles on this car and it needs a valve adjustment, clutch, water pump and the brakes are starting to vibrate. It's surely getting noisy under that hood! From all the mechanical cacaphony going on in there you'd think i had me a diesel sho.

 

[Spin]

i've read every post on here, i'm still leaning toward the bearings... my sho was barely making any noise but i noticed it, since i didn't know much at the time i kept driving it and all. 2 weeks later i got off the freeway and now i could hear the noise while idling at the stop light. i turned left, the clack got louder, oil light came on in the car and stayed on, was at the next light took another left and i couldn't even get up like 3% incline, i was had the pedal floored and i still wasn't moving anymore than 10mph, it was the sadest thing i have ever experienced, the car stalled numerous times when i had to wait at a light to turn into a parking lot. so yea, now i need to get my engine rebuilt which is gonna cost a lot more than just getting the bearings replaced good lookin' out.

 

[blackcurrant]

Thank you Spin, I'll check them out.

It's been MUCH quieter since the castrol GTX hi-mile oil went in.

 

[dunndt]

i had the same sound before and i was stupid and drove it only for about a day and i ended up having to replace the engine in mine and that was verry expensive (i wasn't with the shoforum till after that)

 

[DavidT]

dunndt,
Can you describe how loud, how often, what rpm range, the sound that was made, etc...? Is a tick what you heard, or a knock? Or are they the same?

 

[PROPHET]

Couldnt this also be detonation?He did mention sounds like diesel .Or couldnt it be timing issue?

 

[Mike Kopstain]

blackcurrant:
Thank you Spin, I'll check them out.

It's been MUCH quieter since the castrol GTX hi-mile oil went in.

Please, please, please heed my warning on this. Oil will not fix your problem. What is done is done. The oil won't repair anything. Don't put off a repair because it is now quieter. A shim that is out of spec can definetely clak, and then it can be shot out of the lash cap, effectively destroying the cam. If you have a clak coming from the top end chances are you already have some cam damage on at least one lobe, probably more. It's up to you how hard this problem has to be to fix.

Keep the SHO on the road... Please.

 

[MGidish]

OK, here's my story. A little over a month ago i was racing and went into second instead of fourth. Needless to say i replaced my tranny. went to test drive it and a similar experience happened to me with the bearings. I lost significant power and the oil light would come on. at a stop light on the way back to the shop it froze on me taking off from the light. I have new rod and main bearing put in and drove it to listen for clattering hoping i didnt bend a rod. There is clacking, though not evident at idle. It does become apparent at about 2500 rpms. I'm am gonna have this guy come listen to it today and am curious, are rods still available for our cars? i suspect the rod in the front pass side to be bent since the bearing there was totally spun. Or do you guys think a new engine is in order. Those of you that have rebuilt the engine, what did it cost you?

<small>[ November 18, 2002, 04:04 PM: Message edited by: MGidish ]</small>

 

[shojuan]

sdpatt:
Thomas, when you say the mains, do you only replace the lower bearing surface? Have you been able to replace the upper surface without removing the crankshaft? That is a much bigger effort.

Scott,

You've got enough miles on your SHO I think you could justify replacing you rod and maybe even your main bearings for insurance purposes. Regardless of how great the need, it would be interesting to see how much wear is present on 265K mile bearings in a well maintained SHO that gets "moderate" exercise. There is no escaping the fact that bearings are wear items, although wear can be minimized it can never be eliminated.

Lol, you're probably thinking the same thing. IMHO, better to replace bearings before they absolutely need it rather than after

Rick

 

[93MTXSHO]

Mikeys_Taurus:
A shim that is out of spec can definetely clak, and then it can be shot out of the lash cap, effectively destroying the cam. If you have a clak coming from the top end chances are you already have some cam damage on at least one lobe, probably more. It's up to you how hard this problem has to be to fix.

Keep the SHO on the road... Please.

How often does a shim get shot out of the lash cap??? My SHO either has 117K or 197K on this engine and the previous owner was a dick and I'm positive he had no clue what a valve adjustment was. I've already ordered the tools and shims and have the VC gaskets. Please, please tell me that I'm not risking a shot shim and destroyed cams. I had the valve covers off before because I replaced the outer gaskets and siliconed the plug well seals, to no avail. The cams looked like they were in really good condition as did all the shims. No holes or indentations, but after reading this post I'm really really worried about screwing this motor. I surely can't afford $5000 for a rebuilt Jasper motor, or a new car. Some much needed preventative maintenance sounds much more desirable to me.

<small>[ November 18, 2002, 07:49 PM: Message edited by: 93MTXSHO ]</small>

 

[Off Road SHO]

OK, here's my story. A little over a month ago i was racing and went into second instead of fourth. Needless to say i replaced my tranny. went to test drive it and a similar experience happened to me with the bearings. I lost significant power and the oil light would come on. at a stop light on the way back to the shop it froze on me taking off from the light. I have new rod and main bearing put in and drove it to listen for clattering hoping i didnt bend a rod. There is clacking, though not evident at idle. It does become apparent at about 2500 rpms. I'm am gonna have this guy come listen to it today and am curious, are rods still available for our cars? i suspect the rod in the front pass side to be bent since the bearing there was totally spun. Or do you guys think a new engine is in order. Those of you that have rebuilt the engine, what did it cost you?

MGidish,
If you spun a bearing, you can't just put in new ones and be on your way, unfortunately. The spinning process destroys the crankshaft journal, it causes grooves in the journal that take all your oil and doesn't leave any for the job of separating bearing from crank. Kind of like the "rain Tire" groove channels the water away from under the tire.

It would be much cheaper and a lot less hassle to go and buy a used engine from a wrecking yard. If you try and rebuild your motor it will cost much more. I like tinkering and I have an almost complete shop including a car lift and I won't rebuild one again, just too expensive. I just picked up 2 of the 3.2 liter for 650.00 each so they can be found. You also get a lot of spare parts when you buy another motor. Also it would be next to impossible to bend one of our rods from a spun bearing unless the engine locked up from heat build-up. Good luck

Tom

 

[Spin]

MGidish - i'm more than likely gonna bring my SHO up to the SHO Shop in Huntington Beach and it's going to cost ~ 2,000 - 2,500 prolly to get it rebuilt, that is. Also Tom had a great suggestion, I'd say try that out too. I think i am gonna check out what Tom said before I spend that money to get my engine rebuilt

 

[Denny]

What did Tom suggest?
And, I never siezed up my motor, it just lost power and started rattling...could new bearings be good enough, or are the journals fudged up too?

 

[shojuan]

I think he was referring to the ThomasDooley Tom and not Tom G. from ShoShop. If it were me, I would at least inspect the bearings and crank to see what, if any, damage was done and if so, how extensive. If there's just some minor scoring on the crank, you might want to try just replacing the bearings, then hook an oil pressure gauge up to see if you're making good pressure. If so and the car runs good you may as well milk some more miles out of it.

Rick

 

[RogueSHO]

i posted about something VERY simillar in my car a couple days ago and no one mentioned rod bearings.... the difference though, is i lose power when i hear it.

 

[Off Road SHO]

Denny,
A good rule of thumb ( I wonder how that saying got started? ) to go by is this. When you take out your old bearings and have the lournals of the crank exposed, try and scratch the journal with a fingernail from side to side. If your fingernail catches on a groove, it's beyond help. It will need to be turned down in size and fitted with oversize (thicker) bearings. This is expensive. If your fingernail doesn't catch on any grooves, you can use a piece of crocus cloth and light oil to "polish" up the crank journals. Keep in mind that doing this on a crank that is in the engine make it VERY difficult to get all of the grit out the oil passages and you will get it in them. They used to sell small plugs made out of a tough neoprene with a handle that you could grip with needle nose pliers. You insert them in the oil passages before you do the crocus cloth and when you flush out the crank area with mineral spirits, nothing gets in the oil passages. Just don't forget to remove them!! Salvage yard engines are still the best way to go. Good luck.

Tom

 

[dunndt]

when i got the nois it was i believe at around 2500 rpm it was almost a grinding sound but when it got to around 4000 rpm i went away it was not verry loud but it was audible inside the car i parked it went out in the morning and it would not start.

<small>[ November 19, 2002, 09:02 AM: Message edited by: dunndt ]</small>