FraggleRock

I'm trying to diagnose the noise in this video on my 93 Trans Am LT1:


A couple of weeks ago I started hearing a click/slap type noise for the first time in 20 years on the car. I thought it was a loose lifter on the drivers side, so I pull the driver's side valve cover and reset the lash on each one. Unlike when I did it 10 years ago this time I did it while the engine was running so its probably less precise than the spin the rod until it stops and snug method. The click/slap didn't see to go away and I thought maybe I'm just starting to get piston slap, but now three weeks later I just did some other work (new power steering pump, pulley, plugs, wires, and a coolant flush) and fire it up and I'm getting this noise. Valvetrain? Tensioner (haven't pulled the belt yet to check accessories)? Other ideas?

I'd really appreciate any input on this. Thanks!

BALLSS

the groan, bearing sounds more of an accessory. drop belt to see if noise goes away

and on valve lash if you found zero lash by tightening until PR stops spinning.....you past zero lash by miles

FraggleRock

Thanks for the reply, I'll check the belt. On the lash, I was perhaps too abbreviated in my description given I was on my mobile device. I set it per shbox dot coms description:

FraggleRock

I pulled the belt and the sound is still there. Anyone have any other suggestions? It seems like it's coming from the front half of the drivers side valve train, so maybe I'll have to pull the cover and recheck the lash but I would expect that to be more of a knocking sound than a chirp...

SS RRR

iTrader: (2)

What kind of setup do you have on the valvetrain? I am not going to say it could be bearing related yet... pull the valve covers and see if there's anything abnormal. If there isn't, you need to pull off the intake and check the rollers on the lifters as well as the lifter bodys and bores for any abnormal wear. I would not start it or drive it until you get this figured out. If you haven't already, drain your oil now and see if there is any sort of metal flake. If it is indeed the roller lifters, you can simply replaced them, but because the metal on the rollers is hardened it can cause severe damage to the piston skirts and cylinders.

FraggleRock

Everything is stock on the valvetrain--springs, rollers, lifters, and pushrods. Any guidance on what I might be looking for that is classified as abnormal? I had planned to pull the cover and watch them run looking for the noise as a possible rocker loose or perhaps too tight. I was going to just reset the lash on any that seemed problematic. That said, if I really shouldn't run it I can check for excessive play in the rocker to see if it rocks left to right, but I'm not sure what else to look for so any guidance is appreciated.

If that doesn't yield any results then I'll check the oil first and pray there isn't any flakes. I just barely changed the oil--do you think I need to pull the filter and/or cut it open too?

If neither of the above shed any light then I will secure a replacement intake manifold gasket and then pull the intake. It's only been off once about 10 years ago in 20+ years I've owned it.

Thanks!

BALLSS

when you pull valve cover some rockers will be slightly lose as the lifter would bleed down because the motor has been sitting. You would need to rotate engine by hand and do the lash procedure to confirm they are right

with that said if one rocker was stupid lose when you pull valve cover...than yeah focus on that

check your dip stick for any signs of metal flakes in the oil. If there is ANY sign...drain oil and cut open filter and if the metal shavings are in both...you need minimally new bearings

Before you start pulling anything apart, get a stethoscope and carefully probe around motor (each cyl, top of vc and on exhausr manifold at each cyl) to see if you can isolate sound. Put on front of water pump and opti cover. Either of those could be causing the noise

SS RRR

iTrader: (2)

That noise doesn't sound like a loose rocker. By abnormal I mean any marks/scratches on things that should be covered in oil. If you don't see anything like that on the top then I'd take the manifold off and take the lifters out and check the bodys to see if they are scratched. Check the rollers on the lifters to see if there are any unusual markings/pitting.
It'll be messy, but you can also take the valve covers off, start the car and make sure all rockers are getting oil. Fab up some cardboard to block the oil from getting all over the manifolds and engine bay if need be. I know I said to not start the car again, but just thought about if you don't see anything abnormal at first glance, then start it for a short period for oiling purposes.

FraggleRock

Thank you ****** and SS RRR for your replies. I've pulled the valve covers and the video below is what I see with regard to condition of the rocker arms on both sides.


Does the amount of play side to side in the rocker arms seem normal? Also, I checked the dipstick and didn't see any flakes but I haven't dropped the oil yet. I plan to do that tomorrow along with pulling the intake to check the condition of the lifters.

atlantadan

IMHO, you can't tell much by rocking the rocker arms with the engine off. Even with perfect lash, they'll rock a bit because the lifter is on the backside of the cam lobe and there's no oil pressure. What I see in that video is normal.

With the valve covers off, turn the car on like SS RRR said and look to see where the oil is going (or not going) and also its a great time to poke around with that mechanic's stethoscope. Don't give up hope, yet. I've had a water pump that started to squeal when it was going bad, and others have had optis that squealed. Both will obviously continue to make a racket with the belt off.

BALLSS

Fraggle

your rockers look "normal" in the video

the noise as you describe is resonating equally from using stethoscope on VC, oil pan.

Assume you put it on opti & wp also to see if noise appeared to come from either.

I would get the car up on jackstands so you can also probe the transmission dust cover area to se if the noise is possibly coming from TC or front of transmission.

I know its frustrating and pulling the intake is no fun but to either confirm or eliminate the lifters as being the problem it is something you will have to do if you can find the source otherwise. If one or more of the lifter rollers shows signs of galling or scratches or just does not "roll" right look down the bore of that lifter while someone turns the motor by hand and carefully look at the cam lobe surface for any signs of galling also

with the intake off check the oil pump drive gear on top (don't remove) where the small bolt holds it in place...confirm the plastic top of the drive gear is not cracked. Just look at it to se

FraggleRock

Thanks Atlantadan and ****** for your feedback. I have probed the opti and the water pump and they were quiet, so I just dove in and pulled the intake and started going through the lifters and rockers on cylinders 1, 3, 5, and 7. I used a chemical dip engine parts cleaner on each one for 30 minutes, blew the out, rinsed in water, blew them out again, and then soaked in 5w-30 oil while the next set was cleaning.

All of them looked good (wheels rotated freely, no bent pushrods (hardened on 93), etc until I got to the last lifter (#7 exhaust) on the drivers side. Then I saw the attached pics. Here's a video of it as well once youtube finishes processing it:


I know I need to inspect the cam lob once I can get some help rotating the motor while videoing. If the #7 exhaust lob is messed up what am I looking at minimum? New cam, new lifters, and rockers? I still haven't dropped the oil yet, but I'm guessing there may be metal from that lifter, right? What is the likelihood that bearings, etc are impacted?

I've got 170-175k on the original motor and tranny. Should I be considering a rebuild if I need a new cam? I always wanted to put something more aggressive in for more horsepower, but this may quickly escalate beyond my comfort zone and/or budget. Thanks!

atlantadan

Owie! Man, sorry about that, but at least you know what the problem is. Don't worry too much about inspecting the cam - I can virtually guarantee that its seen better days.

Were it my car, with that sort of mileage, I'd just do an R&R on the engine. Is it possible that the bearings are ok? Well, anything is possible, outside of the normal wear-and-tear that 175k would inflict upon them, but I wouldn't be able to trust any of the bearings without putting my eyes on them directly. If I am diving in deep enough to see the bearings, they're all coming out and being replaced. Since I'd have to yank the engine to replace the cam-bearings, I may as well have the block checked. Aaaaaand down the rabbit hole we go.

Comb through the classifieds here and on the other LTx forums. If memory serves, there are a few shortblocks out there for sale. Sorry about your luck

BALLSS

fraggle..

from the looks of the lifter...you wiped the corresponding cam lobe also. Happened to me and the metal did score bearings. You need to pull the motor and rebuild or replace.

I bought a 383 4 bolt main short block from Golen and and put the motor together myself with a new cam and the ported heads I had on the 350 motor. 25k miles later, all good.

You can certainly rebuild your motor. Likely be able to polish the crank, re-bearing everything, resize stock rods and get .030 larger pistons and you have a fresh 355 motor

SS RRR

iTrader: (2)

Here is the big problem with your discovery. The roller bearing is hardened steal. When material flakes off the bearing it dropes down onto the piston skirts and I guarantee you have some that look like this:

Your cylinder walls are also most likely scratched up as well. Now, there have been those who have just installed a new cam and lifters and drove it, but in doing so you will still run into problems with blow by and oil consumption. In order to properly fix this you will have to get the block checked out to see if it can be honed, or if it has to be bored out. You may even be able to use the original pistons by getting the skirts coated, or locate some other stock sized pistons to throw into it if a hone can be done without taking away too much of the cylinder wall, or you may be able to locate a short block. A few options, but no matter what you do it will cost you money sooner or later.

cookseyb

You will need the block vatted as well, the brinelling of the roller sent thousands of tiny hardened metal flaked throughout the oil system. All new plugs and casting holes removed and don't forget the ball bearing in the oil gallery to the rear main. Quite a mess. Sorry

BALLSS

some machine shops don't know about that oil galley ball and either hot tank the block with it in...or forget to put it back in once block has been freshened & cleaned

If Op is tearing the block down himself and sending off to machine shop, he needs to remove that ball with a long drift tool. Taps right out. Otherwise confirm with whoever will be rebuilding the engine they are aware of that step.

FraggleRock

Thanks everyone for your continued advice on this issue. I'm been in quite a slump since the discovery. I took the lifter in to a local shop and they agreed that a full rebuild is in order. They quoted $2349 for a long block rebuild plus the cost of whatever cam I want and any other upgrades on top of the stock rebuild. I was thinking something from Comp Cams that will play nice with the bottom end and just a bit more power. That price assumes me pulling the motor myself and dropping it off to them. If I want them to pull it, they want $2762 in parts (motor rebuild, water pump, plugs, thermostat, coolant, break in oil, and filter) and an additional $2,728 in labor for a total of $5,918. He also made the comment that if they do the pull and replace the price always goes up duo to incidentals by about $1000 average.

They also stated that they can't tune it, so if I get a different cam, etc I have to take care of that myself. I haven't shopped around to other shops here in Utah, but that labor seemed high to me to the point that I would pull it myself (never done it before). It seems the 93s are a pain to tune as well with a lot of people saying to upgrade to a 94/95 chip and up goes the price again.

That said, as soon as I freshen the motor I can't help but wonder about the original trans with 175k on it. Not sure what a rebuild runs on those lately. I could probably get by without it for a while but if I'm pulling it out anyway

And then there's the stock 7.5" rear end, which has been whining pretty loudly for a while now. Possible pinion bearing. I pulled open the carrier several years back and changed out the axle bearings but didn't have the tool to properly set the pinion depth so I never changed out the pinion bearing and the whine persists.

So, I'm guessing I'm probably looking at least $5-6k if I redo the full powertrain or $3k-$3.5k just for the motor work, with me doing all the engine and tranny swap labor, plus buying/renting a hoist and the cost of trying to get the thing tuned somewhere around here.

I'm really conflicted now as I've loved this firebird (my 3rd) for the past two decades. My now 18 year old son has laid claim on the car since he was was about 8 years old and I was planning to give it to him when he gets back from an overseas mission in 18 months. That said, it has been a daily driver and I need transportation. I need to decide whether to invest in it or just cut my losses and direct that money towards a down payment on something else. I could then either park it and let it sit for a while in case I decide to fix it or try and sell it to someone who is happy to do the work of rebuilding the motor, needs a parts car, or more than a roller. I would hate to part it out as it really is probably in better shape than most given it's age.

Anyone care to offer an opinion or an estimate on what it might be worth as is?

Here are the details:
-93 Trans Am A4 3.23 with 175k, clean title, never wrecked
-2nd owner, purchased used from dealer with 36k on it back in '98
-17" WS6/SS rims and tires
-New Magnaflow cat back exhaust and Corsa style quad tips (pics attached)
-Spare set of wheels (original 16")

Newly replaced last month--all new: Upper & Lower ball joints, Tie rods, Power Steering Pump, New billet Power Steering Pulley, Thermostat, Front Brakes & Rotors (LS1 spindles), NGK plugs, wires.

Recently replaced within the last 12-24 months--all new: Rear brakes and rotors, Radiator (2/2015) and coolant/metal cooler lines, 1LE Elbow, Fuel Pump (with access door), Water Pump plus seal on timing cover.

Other notable repairs:
-Throttle body overhaul with new coolant plate and IAC (3/2014)
-New Delphi optispark (3/2014)
-Heads overhauled at machine shop (2010), new head and intake gaskets, MSD Opti, replaced all major hoses, etc. Note: head gasket never blew, I had a loose exhaust manifold bolt--found it after I pulled the heads. Freshened everything up anyways ;-)

If you're still with me this far, thanks for reading and helping me think this through a bit.

atlantadan

How much do you like the car? From your post, it seems like you have had it a while and that its something you want to keep around. If so, take the plunge. If not, dump it or part it out.

Nearly $3k to pull / install an engine? Man, I am in the wrong line of work. If you've never done it before, how mechanically adept are you? Even if you've never gone that far in before, if you are an adept wrench swinger and you've got a book/FSM, its far from an impossible job. Just make sure you've got all the special tools you need before you get started. (Fuel line clip tools come to mind...)

If you have the budget, and if you trust the local guy, that price isn't bad for a rebuild. You can just bolt down your existing heads since you had them gone through not too long ago. You can get a custom cam from Lloyd Elliot for $300 or so and be in great shape. I don't know about tuning a 94, but can't you get a mail order tune? If so, they're usually about $150-300

If money is tight, I've personally run the Mabbco LT1 shortblock in a wagon I had years ago. It was $800, (that's a link to the engine) no core. (I put in a new oil pump and other bits, and paid extra for King bearings). Bolted on a set of aluminum heads I bought off of a forum member, threw in a cam and a tune and drove the **** out of it. The only thing I did was double check all the torque specs on the rod caps, and mains. (They were all correct) That was years ago, and the car is still on the road in New York. Now, your mileage may vary, but my experience with that company was a-ok. I sold off the old engine for $250, so my out-of-pocket on the engine was only $550

(For what it is worth, I drove the car into the garage on Friday evening, and drove it out Sunday morning. It can be done if you're devoted to the cause!)

Your transmission is tired, there's no doubt. At that mileage, putting an engine in that's got loads more power will make it go bang in short order. There's a few transmissions on here for sale so look around a bit. Or you could find a local trans shop and have them go at it. Once the engine is out, the trans is right there and easily removed and transported. The local shop quoted me about $1k for a full trans rebuild using high-quality high-performance parts (if I delivered it to them).

So using the Mabbco block, your heads, and getting the trans rebuilt has you right at about $2750 once you throw in the incidentals like lifters, oil pump, gaskets, etc. That's the engine and trans.

The pinion bearing? You can continue to drive it until it disintegrates or take it to a shop. I drove that same Mabbco-powered wagon for over a year with a diff whine before I fixed it. The local shop charged me $250 to replace the pinion bearing and set it up.

Hoists can be found on Craigslist all day long for $150-$200, or you can do what I did and just go to Harbor Freight and buy one for $150 with the 20% off coupons that you can usually find floating around in the parking lot.

In the end, its all about your attachment to the car. It has served you well for a LOT of miles so if you're up for the work, do it. If not, sell it. A non-running car like yours would catch $1k-$1500 I'd wager.

SS RRR

iTrader: (2)

The problem with quotes like that is they have no idea if the block is even good enough to bore at this point. They are giving you flat rates and you can only plan for it to go up from there. Wish there was some way you could just park it and have you and your son work on it as a project to get it back on the road. Your price would drastically go down if you could just hand them the short block, have the rebuild it and then you assemble it/install back into the car. It's a huge undertaking, but can be enjoyable with the right people. Very sorry.