DerrenZ

Thanks to the help of many, I got my LS1 swap to point that it fired! Yay!

But there is a knock coming from the lower end. Supposedly a 30k mile dropout, and it appears to be, I expected no problems with the motor.

I had 2 guys more experienced than myself listen and both agree that my knocking sounds like a con rod bearing. They say that sometimes an LS1 can get such a problem from simply sitting for too long with load on a bearing.

Has anyone heard of bearings suffering as a result of sitting for months? The motor sat here for 6 months before I turned it over.

Best case scenario, a set of con rod bearings will fix it. So what is the easiest way to achieve this?

I don't believe I can get access without pulling either the motor or the k-member. I'm thinking about dropping the k-member, but I have never done it before.

How bad will it be dropping the k-member? If I use the crossbar gadget I saw Ghettocruiser use, will this allow me to drop the k-member and a-arm assemblies without removing the springs and leaving the engine just hanging there?

Sigh. I just wanted to drive it.

1ADan

iTrader: (4)

sorry to hear the bad news. if you can find a way to support the motor from above, you should be able to drop out the kmember as a complete unit. for safety sake, get a strap around the springs so they can't cause any damage if they pop out. also, remember that you've got a couple of brake lines down there you'll want to disconnect before dropping or you'll have more headaches later

DerrenZ

Thanks.

How much extra work is it to remove the springs before dropping the k-member? I have stock springs right now.

1ADan

iTrader: (4)

stock springs are a bear to remove safely, dropped ones are easier. you'll need to grab a piece of pipe and an inner style spring compressor. you could use this as an excuse to lower the car too, that's what I did

ghettocruiser

iTrader: (4)

Yikes... Thats a bummer.

The bar that I used works great, but you will have to remove the springs and a-arms. Unless you come up with a VERY VERY secure way to leave the springs in, I suggest just taking them out. Its really not THAT bad. I have my method posted in the same spot as the bar pictures probably. Stocks springs are a big harder to deal with. If I remember correctly, one side is a bit tougher. I think the driver's side...

That being said... If you have a nasty knock, HOPEFULLY all thats wrong is a bearing. Ive never heard of LS1s in particular having an issue from sitting. Mine sat for a long long time before I ran it, and I had no issues. If you suspect a bearing problem, you might want to just plan on pulling the motor. Makes it 10x easier to get at the parts, and if you drop the k-member, find crank journal damage, pulling the motor at that point will be kind of a pain. You'll have to get an engine hoist hooked up around the support bar etc etc.

But to answer your question..yes that bar that I used will work for you as long as you pull the front suspension. Its not as bad as it sounds, and you should get used to pulling it apart and putting it back together...it'll come in handy eventually... If you did the LS1 swap, its not beyond your ability thats for sure!

J.

Shift06

I did conrod bearings on my 305 while the engine was in the car, and the k member was still in place too. What a pain that was.

DerrenZ

Thanks guys.

That's a good point Ghetto about being in a bind if I need to pull the motor after all. Though I do need to do something about the front springs now that I have the LS1, I think I may just have to pull the motor out the top.

I saw your bar photo in two or three threads, not sure if any of them went into detail about how to drop the k-member...

Your thread:
https://www.thirdgen.org/forums/ltx-...-again-10.html

And threads by others:
https://www.thirdgen.org/forums/ltx-...d-oil-pan.html
https://www.thirdgen.org/forums/susp...r-without.html

Did you have another thread that went into more detail about pulling the k-member this way? Though like I said, the uncertainty of what I will find may dictate that I pull the motor out the top...

Pocket

iTrader: (24)

Thats a wash. LS1 bearings are no different than generic SBC, BBC or any other engine. Automatic transmissions have a shelf life, bearings dont

DerrenZ

Yeah, I don't know what to think. The seller is pretty reputable, and I have a copy of a salvage title (supposedly for this dropout) showing under 27k miles. And they claim they run each motor before it goes out.

So either it lost a bearing very early in it's life span, or it lost it just as soon as I fired it up.

GGRRrrrr....!!!!

But your description Pocket makes sense. If there is no magic about LS1 bearings, what would sitting for a few months have to do with anything.

He thought maybe if it sat with a load on a certain part of the bearing for months that it might stick and "scoop" some of the coating off the first time you turn the engine. Maybe that is a little imaginative.

So what is the most likely cause of a knocking sound in the lower end on a motor with under 27k?

Pocket

iTrader: (24)

If water got in there it can cause rust to build up and lock a bearing to the metal surface

Front impact that knocked the balancer usually kills the thrust bearing which is never a good thing

DerrenZ

Well I have the salvage title that shows it was a total loss with nose damage. Once I get it out of the car I'll ask how to inspect for damage to the thrust bearing.

But on the plus side, the wiring harness rocks!

Thanks Pocket

DerrenZ

So I pulled the motor back out this weekend. It's propped up just enough to let me get the pan off. I'm hoping this will not lead to a major overhaul as the motor supposedly has fewer than 27k miles on it.




I'm looking for some guidance and advice:

1. What should I do or look for first, before I start pulling off caps?
2. What is a good way to keep my caps and bearings organized as I pull them off?
3. Will a bad rod bearing be self-evident even before I start pulling off the caps?
4. Is it recommended that I replace the oil pump while I have the pan off?
5. What is the right way to diagnose the health of each bearing and journal?

Pocket

iTrader: (24)

1) Id separate the trans and get it on an engine stand so you can flip it over and take your time with it. Everything else can stay attached

2) Take a punch or sharpie and label each cap and rod. You MUST keep them together and lined up because they are cracked caps and will only match one rod in one direction

3) Spun bearings almost always turn the cap dark blue from the heat much like a weld

4) Recommended when replacing the engine, but its not a bad idea now since its had metal shavings through it

5) Visually and run your fingernail across the crank journals. If you can catch a fingernail on any ridge, scratch or nick, it needs to be turned

Few charts, main one to look for is 2nd to last here
http://www.gregsengine.com/engine-be...ure-chart.html

Another
http://www.bobistheoilguy.com/bearin...aranalysis.htm

Least amount of downtime would be to get a good used crank from a 5.3, 5.7 or 6.0 and some spare rods (same engine). This means pulling one or both heads though

NBrehm

iTrader: (4)

What year LS1 is it? Depending on the year there may be a few things you should upgrade while it is apart. If you do end up needing a crank or rods I have a few laying around and can hook you up with a good deal, just shoot me a PM. But def check for any blueing on any of the bearing surfaces and the crank. If it is a pre-01 give the rod bolts a good look over also as they are notorious for failing. How did you prime the engine before first start up?

DerrenZ

It is supposed to be a from a 2002 Firebird. The salvage title provided shows 26,600 some miles. I didn't prime the engine before start-up, just put on a new filter and filled it with oil.

DerrenZ

In trying to verify that this motor matches the salvage title, I can only find this for identification:



It's only 6 digits. I thought it should be 9 or more. And the 6 digits do not match the VIN of the salvage title.

However, for every rule there are exceptions and I don't want to unfairly judge the seller. They have a good reputation.

NBrehm

iTrader: (4)

there is a casting number on the back of the block below one of the heads (I think D/S but can't remember) if it is 12561168 it is def an 01-02 because it is an LS6 block, if it is 12561178 it could be any 03 and older LS1 block. Did it have an LS6 intake on it? Another giveaway for older engines is if you loosen a rod bolt you can remove it completely, I believe in late 00 is when they upgraded the bolts. There should also be a casting date on it someplace, kinda looks like a clock face

rusty vango

excuse my ignorance, but whats the big draw with this LS stuff anyway??

DerrenZ

12559378 and it has the LS6 manifold near as I can tell (no provision for EGR). It appears to be 2002, but I can't seem to find any number on the block that corresponds to the VIN.

This is contrary to the vast majority of what I have read that somewhere I would find a matching VIN number on the block. I know the VIN is also stored in the original PCM (which I have but haven't accessed).

So I'm not too surprised if I can't find a VIN type number, but then what does that 6 digit code represent?


rusty vango:
http://www.hotrod.com/techarticles/e...iew/index.html

DerrenZ

Thanks to the internet and the VIN, I found the following pics. Apparently this is my donor car:







I found these on an original auction page for that VIN. Everything checks out so far.

I must have just had some bad luck on start up.

chevyowner02

iTrader: (3)

The best bang for the buck going.

NBrehm

iTrader: (4)

The laser etched number where you are looking is the VIN, it should match the last 6 digits of the car it came from, what is the VIN from the car?

NBrehm

iTrader: (4)

Did you prime the motor before you tried to start it?

DerrenZ

The last 6 of the VIN on the salvage title are 160639. So, as I said, they don't match. However, the 6 digits appear to be stamped, and I thought a laser etch would not be as deep or as visible.

And I replied above that I only changed the filter and filled it with oil, but I didn't otherwise prime it. Somehow I didn't think it would need any kind of special priming... Was that an error?

1quickirocz

I honestly wouldnt have primed it either. I dont see the need to as its not a "dry" engine. I think this thing had an unknown issue to begin with that maybe the seller didnt know about. I would contact them first before you take anything appart. If there Rep is good then they will do anything to keep it good.

DerrenZ

Thanks Quick, that's probably good advice.

I'm getting a new engine stand tomorrow, I'll take some stuff apart and see how it looks.

Is it acceptable to use the balancer bolt to rotate the crank on an LS1?

1quickirocz

Yes and if you havnt already pull the plugs out. it will make it much easier to turn over. If anything just pull the pan off. i wouldnt take any caps off until you contact the seller. if its knocking that loud there should be some type of evidence in the pan most of the time.

88 350 tpi formula

iTrader: (9)

biggest issue and the thing I hear the most "its not a new engine you dont need to prime them" people forget when an engine sits very little oil stays on the bearings and in the oil gallerys. drain it, new filter and even a cranking prime is doing damage new engines have new bearings for one, second they have Assembly lube


now look at ls1s and how long that oil pick up tube is look at a gen 1 big difference plus a gen one you can spin it with a drill

DerrenZ

How do I tell 1st design con rod bolts from 2nd design? I've searched LS1tech and google images, but most people discussing the subject already know the difference.

And can anyone state with authority whether or not the number stamped on the side of the block could be something other than the VIN reference? It does appear to be metal stamped, not laser etched.

EDIT: Never mind, I got up good and close for the first time and this could be the "Laser etched" number I was looking for.

So... Is this conclusive evidence that the block labelled 183169 could not have been originally installed in a vehicle with VIN 2G2FV22G522160639??

DerrenZ

I pulled a rod cap and bearing from number 6:





I think it looks fine. Comments?

DerrenZ

And a view of the journal:



and the bottom end in general:



I guess I'll pull the others tomorrow. I haven't found anything in the pan except oil.

five7kid

iTrader: (14)

First thing I would check is the torque converter bolts.

Pocket

iTrader: (24)

T56

ghettocruiser

iTrader: (4)

Heheh...

FWIW I didnt prime my engine either. I cranked it a few times with the fuel pump relay out, coils unplugged, and spark plugs out and saw oil pressure after just a second or two. And my motor sat for a while. Connected all that stuff back up and it fired on what seemed like half a crank and had instant oil pressure.

I find it hard to believe that a bearing ate itself immediately upon start up like that...but Ive seen stranger things happen.

Hopefully its something you can fix up and get her back together easily!

Keep us posted! I wanna see more rod bearings!

J.

NBrehm

iTrader: (4)

Easiest way to prime an LS1 (which is not the best way but there aren't many options) i slike stated above. Pull the plugs and the Fuel pump really and crank the engine. With the plugs out you will get enough RPM to get oil to the top of the engine. As for the bolts it is really easy to tell, if you loosen the bolt and it comes out of the cap it is the older style. If the bolts stay in the cap when you pull the cap off it is the newer style.

DerrenZ

Ah, ok. I have the newer style.

Any comments on how to ensure the 75 degree torque requirement? I'm not sure I can eyeball it quite that precisely.

NBrehm

iTrader: (4)

well 90 is a 1/4 turn so just go a little less. If you are that concerned get a marker, draw a line on the socket and put it at the 12 o'clock pos on the bolt and a line about a 1/4 turn away on the rod cap. Turn wrench until lines meet.

DerrenZ

I guess my question is: Should I get that concerned? The way the torque setting changed from 1st to 2nd design bolt makes it seem that a few degrees either way must make a difference.

And I guess what I want to hear is: Everyone eyeballs it and no one has ever had a problem.

Mkos1980

iTrader: (8)

Heck my engine was sitting for 4 years. Fired right up. Had OP within 2 seconds.

DerrenZ

I pulled caps off from #8 up thru #2. They all look like the one posted earlier. The worst one is this one (#4 I believe):







The bearing surface looks like all the others except for a couple tiny marks, most likely from foreign material. There is no metal in the oil pan, and no other marks to speak of on the other bearings.

NBrehm

iTrader: (4)

When you had the knock did you still have good oil pressure? (above 40PSI)

DerrenZ

Well, I have only the stock 3rd gen gauge that reads 60 at top and 30 in the middle. We listened to it at idle and the gauge reads below the 30, maybe around 20? (I can't go out and re-check it right now for obvious reasons.)

five7kid

iTrader: (14)

Oops.

FWIW, mine was pulled in '07 and first started in '10. Was supposed to have 56k miles on it. I didn't do anything special to "prime" or preserve it. Oil pressure is fine, no noises (even after being abused at the track).

Also FWIW, rod bearings were one of the few things that are the same as Gen I/II SBC's. Roller lifters being the other.

DerrenZ

So I haven't dislodged the upper half of any of these bearings. I just pulled the caps working from the back forward expecting to find something awful. Passenger back is where the knock seemed to be.

So do these bearings look alright?

If the bottom half looks good, how likely am I to find some problem on the upper half?

88 350 tpi formula

iTrader: (9)

are you sure it wasn't piston slap? bolt in a cylinder or even exhaust rattle? I like to remove the belts and kill cylinders first.

DerrenZ

No, I'm not sure of anything. I have heard it said that LS1's make some unusual noises, but I personally have never listened to one. That's why I went where I did. This shop dyno's these things regularly, and they have custom installed them many times. They ought to know their stuff.

I was really expecting them to tell me it was my shoddy home exhaust install, or maybe something in the valvetrain that could be adjusted.

But when you hear possible bearing problem of course you stop driving it.

What are these other potential noises? Bolt in a cylinder?

Removing belts and killing cylinders certainly sounds like it would have been prudent, but what do you determine by killing cylinders?

Is this piston slap I hear about an indication of a problem? Is it detrimental when it occurs?

Will you elaborate for me tpi?

Thanks!

NBrehm

iTrader: (4)

Piston slap is fairly quiet and doesn't really compare to a rod knock. Plus piston slap tends to go away off idle, if you are hearing the noise at higher RPM it most likely isn't piston slap. When you told me the engine ingested water I think you are on the right track and need to check everything anyway.

Pocket

iTrader: (24)

Those bearings are in great shape, none are spun

Doesnt look like your problem is bottom end related

DerrenZ

Thanks Brehm. But as far as ingesting water, that's not my case. That's possibly someone else's thread?

Just don't want to confuse anyone nice enough to take a few minutes and comment on my problems.

Oh, I see above Pocket offered water as one possible scenario that might demonstrate certain outcomes, but it's not my particular case.

DerrenZ

Thanks Pocket.

Yeah, I don't have an LS1 ear to know good noises from bad. But I would think anyone who works on LS1's much at all would be familiar with this piston slap, since I hear it mentioned every time LS1 noises are discussed.

But maybe not...

I think the insides look good and clean. I posted a pic above with the worst bearing discrepancy I could find.

Do you think it's possible that I might find something wrong on the upper half of the bearing when the bottom half looks so clean?