mixtape

Hey guys,

Last week I heard the sound that no one ever wants to hear.

I have a pretty bad leak coming from somewhere in the back of my engine. I was able to get it on a lift but the Z28 is one cramped car lol. It looks like possibly the rear of the intake or maybe the rear seal is the culprit. Not 100% sure. The sad part is that I had the intake manifold done less than a year ago with a gasket and RTV sealant. However the trans is covered in oil. In addition to the leak, the car also burns oil too. I was told the issue could relate to the intake as well, and possibly not the actual o rings. I've just never been in this boat before and am unsure where to go from here. With the burning and leaking, I'm putting in about 1.5 quarts every seven days .

So last Thursday I noticed that my oil was about halfway on the dipstick so I added a quart of oil to top it off for the weekend. Three days later I did a little donut on the way home with a friend to find that my motor was tapping afterward. I know my low oil light works, but it didn't come on at all that day, and sure enough, later that night I had my friend check the level (was too on edge to check it myself) and he said it was empty. So I pretty much had my car revved up with no oil in it (a FML moment).

I added three quarts of 10w-30 that night and let the car sit for a week. I was told that the slightly thicker oil could help the tapping and lubrication a bit. I checked the oil and it was really dark, but pretty much full . I don't understand how 3 quarts filled it. Though a tapping/mild knock is definitely the product of running a car with little to no oil.

Since I suck at describing noises, I put together a video of the car. I have a few clips from before the tapping, the donut, and then a shot of the engine bay a week later.

Sorry for the long post, but I was hoping someone could help me with what I have to do now. What exactly needs to be rebuilt? I'm no expert, I've done bolt-ons and accessory replacements before, but never engine internals. I guess I'd be looking at a shop or expert for a job this big. Any idea how much a repair like this would cost to fix the engine leak, tapping, and burning? I looked up replacement motors, but they're going for quite a bit, and not the lowest of miles. I'm only working part time right now due to school, so my budget is maybe a hair over $1000. What's a ballpark estimate of what I need? Otherwise I guess it's gonna have to sit the whole summer while I save up.



I really appreciate it guys. Thank you!

speedracer2536

iTrader: (15)

Hello rod knock..

speedZ28

Rod knock

93M6Formula

Either way you're looking at a rebuild or a replacement motor, it's burning oil so that could be rings or valve guides and that knock is not good in any way so it's time to pull it. It looks like a diesel with that smoke rollin out the exhaust haha.

93 LT1 Vette

Yes it sounds like a rod knock and will be terminal. No amount of thick oil or mystery oil can help your cause. Run it for awhile and check for a glitter looking metal in the oil when you drain it. The only true fix is to pull the motor and tear it down to diagnose the problem fully. A good used short block will be the cheapest way to go. Sorry about the bad luck.

1995blacktattop

iTrader: (2)

FWIW the low oil light will not come on while you're losing oil. i had a similar situation where i was on my way to get an oil leak fixed and when i got there i had oil all over the back of the bumper and had approx 2 qts of oil in the motor. only after i shut down the car and restarted it to pull it into the garage at the shop did the low oil light actually come on.

gregrob

iTrader: (8)

I applaud you for your approach to this.

Unfortunately it does sound like light rod knock.

The important thing is dont keep driving it. The crank may be ok but if you keep driving it could damage it a lot.

Do you have any car friends who really know what they're doing? What kind of budget are you on?

The cheapest by far is a mild stock rebuild and doing it yourself. You could always do all the big labor such as removing the engine and then take it to a machine shop, they will usually assemble the engine after doing the work for a couple 100 bucks.

Make sure you choose a shop who is familiar with LT1s or at least one where you control the parts selection. These aren't old school small blocks in several respects. Any way I can help let me know

jaycenk

iTrader: (1)

I couldn't hear crap in the video other than what sounds like rockers tapping. I say it was fine at low Rpms but any sustained 3000+ Rps would suck the two and a half or 3 quarts left in the pan out and start taking air. Either way it sounds like it needs to come out and be gone through.

gregrob

iTrader: (8)

Another idea is for you to connect with some other NJ memebers on here who may be able to help you out. Ramair95ta is up there and a few others.

Fazz73jr

iTrader: (3)

Nice job on the video editing! Unfortunately sounds like the beginnings of rod knock to me as well. As said above as bad as that was burning oil it was time already. The black smoke was probably from the o2 sensors gunked up with oil causing the computer to richen it up. I'm surprised it didn't foul any plugs like that. This is what mine sounded like when I brought it home. I bought it from a friend that had the same oil issues as you, but he ran a mustang on the highway when it started to knock. He drove it home about 5 miles ...
http://www.youtube.com/watch?v=MQwemaw2dxc

Look at it as an opertunity to upgrade! Maybe to a cc503 or le top end kit!

quik95lt1

iTrader: (7)

very nice job on documenting the issue bud.........but unfortunatly it doesn't look/sound good..........like gregrob said above the key thing now is to not drive or start the car......

just to give you a quick idea of what happened with the no oil........when the main/rod bearings go dry you get metal on metal contact.....the bearings usually ride on a film of oil roughly the thickness of a piece of computer paper.......when you get metal to metal contact some of the bearing material is removed thus opening up the space for oil and making the clearance too large..........because of the added clearance the oil cannot stay pressurized between the bearing and the rod/crank and what you are hearing is actual physical contact of the rod hammering the crank journal at the top and bottom of every stroke........

key thing at this point is to not run it anymore........chances are the crankshaft is still in good shape and the rods probably are as well.......resurfacing the crank journals and resizing the rods and replacing bearings will probably effectively solve the issue.......

as for the smoking it could be a few things rings/valve seals/ or a leaking intake gasket........easiest way is to do a compression test.........inject compressed air into the cylinder........if you hear air comming out of the intake manifold its either a bad intake valve seat or a bad valve seal........if you hear air comming out the exhaust its something to do wit the exhaust valve......if you hear air comming out of the crank case its probably rings or possibly a very poorly reinstalled intake manifold gasket.........


again great job documenting but looks like its time to get your hands dirty........if you put the car back together stock you should be able to do it fairly cheap.......but be prepared to do some work yourself.......

good luck


like greg also said see if any of the NJ guys are around to help............if you were closer to RI i'd be able to but usually the only trips i take to NJ are in the summer to ATCO and Englishtown

1996firebirdformula

iTrader: (3)

How many miles are on the Car/Motor??

Have replaced rear-main seal or valve stem seals?

Just find nice used LT1 for $500 would be cheapest way try calling salvage yards and check craigslist unless want it rebuilt.

wrd1972

iTrader: (12)

Likely bearings shot.

fex77k

iTrader: (2)

The is a great way to share a problem, I like it.

However listen to gregrob, DON'T DRIVE IT.

If you think it is bad now, try driving it. I had a old SBC with quite an oil leak and I did the same thing as you except I let my brother drive it 3 miles down the road to school, I thought it was just the hydraulic lifters didn't have enough oil or something. He got most of the way there and a connecting rod snapped and seized the engine. Like quik95lt1 said, you have wiped bearing material away and opened up the clearances, now it is only a matter of time before the metal on metal contact overheats and breaks/seizes something. Usually you throw the #1 or #2 rod (they are the first ones to get starved of oil as they are the last to get it) out the side of the block and pretty much ruin the crank and block.

If you stop now, the most you are going to be out is probably a set of gaskets/seals, some rings, a honing of the bores, a polish of the crankshaft, and a set of bearings. You'll have basically a brand new engine if rebuilt right. Ohh yea probably replace the oil pump if you have been sucking bearing material.

Good luck man.

mixtape

Wow, thank you guys. You went above and beyond with the explanations! I really appreciate it. Though it looks like I have a long trail of work ahead of me. The car is sitting at my mother's house now and hasn't been started since the video (afraid of causing further damage). It looks like that was the best move at the moment.

I'm sorry to hear that Fazz73jr. That sounds pretty rough . Besides from the initial few seconds at start, mine really didn't sound all too bad at idle. Until I brought it up past 2k RPM, it sounded relatively healthy . Plus they may not be fouled yet, but I can't wait to see what the plugs look like, yikes.

I found a guy somewhat locally who's selling a '95 LT1 for $400. It's complete with all accessories, and he claims it ran "great." Unfortunately it came out of an Impala or Caprice, so the heads probably aren't aluminum. Is that a huge problem? I've read that they flow pretty much the same. The second down side is that the engine was used in a cop car :\. So while the miles are low, it probably idled for 8 hours a day.

Though for the price, it's hard to say no. Plus with the money I save, I can look into a cc503 or Crane 227 cam, Crane Dual Coil Kit 10308-1, and maybe Comp Magnum 1.6 Roller Tip Rockers. With the engine out of the car, it would be much easier to get this all done . Is this the best route for me?

Besides from green hoses, what else does the police package give the LT1?

quik95lt1

iTrader: (7)

absolutly nothing lol.........its the same motor...........as for the iron heads there really is not much of a power difference..........from what i hear the heads flow the same as well..........only difference is i think the compression is down on the iron head motor vs. the alum head motor.............if you are concerned about that though im sure theres a set of aluminum LT heads kicking around on here for $150 or so........they're cheap to come by now......

good luck!!!

mixtape

Update:

So the Caprice cop car motor deal fell through. Thankfully though I found a '94 Impala SS LT1 engine for just a few bucks more and just a few more miles away. I was shocked to see only 45,000 miles on this motor! It comes complete with ecm and wire harness, but I'm guessing I'd just use the '94 Camaro's harness and computer, right?

So it seems like iron heads are the only difference from the motor currently in my car, nice . It shouldn't be a (too) painful swap. but the thought hit me the other day, what type of distributor system is on the Impala? Does it also use the Opti Spark? If so, since both motors are '94, is the Impala using the non vented opti? I upgraded my original Camaro's engine to an MSD opti and MSD ignition coil due to the stock non vented one failing. Since the Impala uses different heads, maybe it uses a vented Opti. If so, I may just keep the Impala one on it instead of swapping the MSD.

Any suggestions? Thank you guys!
At this rate it looks like she won't miss much of the spring sitting!

indyboom

iTrader: (11)

NOOB MOMENTS.. love em

quik95lt1

iTrader: (7)

swapppaaa daaa optttiiiiii........put ur good msd on the impala motor and pop it in........all lt's ran opti's........all non vented ones sucked lol......switch it over and ur good to go

mixtape

haha yeah the Opti Spark was the first thing to fail and go out on my Camaro. I did my research and upgraded to MSD right away. Though from what I hear, the revised Opti (vented) was introduced on the 1995 Y and F-Bodies, but also on the 1994 B-Bodies. So technically the timing cover of the '94 Impala may be similar to a '95 Camaro. Talk about confusing lol. I remember when buying my MSD unit there were two models.

GM LT-1 5.7L 93-94 Distributor (Part number: 8381)
GM LT-1 5.7L Distributor 95-97 (Part number: 83811)

For the stock engine, I bought the 94 kit (MSD 8381). However, if B bodies introducted the revised version a year before the F Bodies, does that mean I'd need a MSD 83811 style Opti instead of the 8381 I have?

a.k.a =

Also, I'm not sure how accurate it is, but I got this info from ImpalaForums.com:

The 93-95 F-bodies were rated at 275 horsepower and 325 lb/ft, while the 94-96 B and D-body versions were rated at 260 horsepower and 330 lb/ft.

The primary difference between the LT1 in the Impala and the LT1 that was in the Corvette and Camaro was that the Impala engine was fitted with cast-iron cylinder heads instead of aluminum ones, and a camshaft that was designed more for low-end torque than high-end horsepower.

Another difference was that the Impala LT1 had 2 bolt main bearing caps while the Corvette LT1 had 4 bolt main bearing caps.

Well we all have to start somewhere