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New to the site and need some advice. Just recently bought an a4 hard top 94 TA.The good= body is in great shape, interior is next to perfect.The ugly= I've got a knock. Car cranks and runs fine oil pressure is good but it knocks. I drained the oil when i bought it didnt see any debris or any on the drain plug..didnt pull the filter just put in new oil only shop i have access to is my dads body shop so i was on a time restraint the noise level of the knock droped with new oil. Could it be a push rod or is it a spun bearing ive been told if it was a push rod it would skip and run bad but ive also been told it wouldnt.Do I need to commit and pull the oil pan and look i just dont want to take a bay of my dads shop and pull it for nothing! Thanks a bunch!
 

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You could just have a noisy lifter.
If the pushrod were bent or broken it could go from just a rocker arm ticking to a dead cylinder.
Spun bearings from my experience usually result in a loss of oil pressure, that was the case on my Z28 and a friends TA. The oil pan is a b**** and a half to remove. The factory oil pressure gauge is not very reliable, so don't always trust it.

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I get a kick out of all the guys who tell someone to install a LS engine.......when they don't even have a LS engine themselves :roflmao: .....

KW
 

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If i was to do it over all again id do an ls. So much more parts and tuners available than for the lt but i still love my lt1
 

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Discussion Starter #6
You could just have a noisy lifter.
If the pushrod were bent or broken it could go from just a rocker arm ticking to a dead cylinder.
Spun bearings from my experience usually result in a loss of oil pressure, that was the case on my Z28 and a friends TA. The oil pan is a b**** and a half to remove. The factory oil pressure gauge is not very reliable, so don't always trust it.

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Thats what i figured when i crawled under and took the dust shield off it looked like it was gonna suck...Gonna pull the filter and cut it open see what i see.......And the ls1 thing..lol...I know i picked the ugly sister when it comes to those two but in my opinion you cant beat the sound of an lt1 with full ehaust!
 

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Before checking the valve train, just for giggles, remove the serpentine drive belt and see if noise goes away. Only takes a few minutes to eliminate those suspects.

If after checking valve train and you find nothing wrong there, make sure your air pump isn't making noise. That's an easy check because it only runs a couple of minutes when car is first started.

If all else doesn't find the noise, then it's time to remove the oil pan and check the bearings. Do the rod bearings first as they are the ones that usually fail. Then main bearings if no bad rod bearings.

If you do find bad bearings, and you'll know it when you see them, It's new crank shaft time. When a bearing gets so bad it knocks, or spins and knocks, the crank shaft has been damaged beyond what grinding can fix.

A machine shop could weld up and regrind the offending crank pin, but that is not an economical way to go.
 

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Discussion Starter #9
Had to charge battery overnight and move it this morning.Still knocking go figure.lol.Noise is louder at start up and a bit quiter after running a minute.I know its comeing from the passenger side just kinda hard to pinpoint exactley where.I do hear some chater through the exhaust if that helps any.I know ive got a build ahead especialy with a stock 4l60e under it and 155,000 on the odometer just trying to get an idea of where or what this major problem is
 

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Thanks coco. From all the videos ive been looking at this morning it sounds like a spun bearing just odd about the oil pressure being so good.Sucks to here that more than likely the crank is ruined i know rebuilds are common but i just wanted to keep the motor as close to originial as i could.One more question how badly am i gonna be sodomized on price on this ballpark geuss and i wanna do the disassembly and reassembly myself are there videos or manuals to help walk me through because I have no idea what I'm doing!
 

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4th gen section has 94 factory service manual for download. Look for thread titled "GM service manuals".

In 4th gen sticky threads you'll find the 4th gen parts books, which will help with parts numbers and exploded views.

This one isn't free but should help you. There's a lt1 rebuilding book that you can find at jegs, ebay, etc. Believe it's about $25 + shipping.

Also, if you have specific questions, members can help you there.

My 95 with a bad rod bearing, maintains normal oil pressure until engine starts getting warm. Then it drops gradually to the check gauges light comes on.
 

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You can probably find an original GM lt1 crank on craigslist, either good to go, or needing turn down, but not wiped out like your crank would be with spun bearing.
 

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Discussion Starter #13
If you dont mind me picking your brain a bit more what are your opinions/experinces with reman engines. Found one online for 2600...2100 with core charge.I dont intend on sending my motor to them 500 bucks isnt worth loseing the original motor.I'm thinking of going that route and rebuilding the stock one over time (married with a kid so that means when i have the money).Thanks for all the help sad as it is to say this is one of my dream cars wanted one since 1993 twenty years later ive got enough since to own one!
 

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Quality of a reman engine depends on who's doing the job. There are big reman companies who hire street people to do their work, with the expected results. Other companies have probably sent the jobs overseas for cheap labor.

If going with a reman engine, I would pick a small company with a good reputation. Or have my machine shop do the work of assembling the engine.

However, I prefer to do the work, except for machining, myself. Then if something fails, I only have me to blame.
 
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