Well I'm pretty sure I've got a rod knock based on some research. I'm going to put new rod bearings in. I don't think anything else is damaged because it just started. Has anyone done this? Can I do it without removing the cradle? I seen it can be done on the grand Prix gtp with some pretty basic tool without removing the engine. Does anyone have any recommendations?
Have not tried it in a 3800 but the question needs to be asked and answered... why do your now have a rod knock... loss of oil pressure, but why... replacing the bearings with out this fixed is a waste of time.
things you must do or you will be wasting your time 1 Check the rod journal for out of round if it is out of spec then the rod knock will be back 2 have the connecting rod bearing end check for out of round again if out of spec you will need it re-sized or you will be pulling the pan again for rod knock
Most often a bad rod bearing is caused by a worn out of round crankshaft journal.. Unless you first inspect the journal and mic it up a new bearing will not last long.. Also have you scanned for KR's? Knock can cause a bearing to fail
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Were the lower intake gaskets replaced on this engine recently?
Regardless, I wouldn't just replace the rod bearings. It is quite possible the main and cam bearings could be trashed too, depending on what caused the rod bearings to fail. It would be best to pull the engine and do a full rebuild at this point (making sure all bearing journals and bores are checked for spec).
[This message has been edited by Darth Fiero (edited 01-06-2017).]
Yes a complete engine gasket kit was installed before I installed the motor. I !right have 1000 miles on it. So which rebuild kit do you recommend?
How did you clean the old gasket material off of the cylinder heads where the intake manifold mated up to them? Did you use a die-grinder mounted surfacing disc?
There is no full engine rebuild kit I've ever used on one of these engines. Since I lack a dial bore gauge, pin press, boring and honing machines, etc., I've just disassembled the engine and taken all the parts into the machine shop and let them do the rebuild - short of putting the heads back on the block (which I do here in my shop). I let the machine shop buy the bearings and rings through their sources, and I purchase the head gaskets and other gaskets needed directly from GM parts.
[This message has been edited by Darth Fiero (edited 01-07-2017).]
I actually wasn't the one that replaced the gaskets. Now I'm curious why you ask? He said he flushed all the oil ports and whatever. Appearently one of the oil ports had quit a bit of crude in it.
I actually wasn't the one that replaced the gaskets. Now I'm curious why you ask? He said he flushed all the oil ports and whatever. Appearently one of the oil ports had quit a bit of crude in it.
GM has a TSB out about how using die-grinder mounted surfacing discs can lead to engine bearing failure. That can happen because of the small particulate matter that can get thrown into the lifter valley during cleaning that ends up embedding in the bearings. And it is very common for a rod knock to develop shortly after lower intake gaskets have been changed if a surfacing disc was used to clean the heads while they were still installed on the engine.
If the engine was never completely disassembled, I don't know how your builder was able to flush oil ports and make sure any foreign matter didn't get trapped in there or embedded in the bearings. Seems impossible to me that you could ensure nothing got trapped in the bearings with the crankshaft still installed despite how much "flushing" was done.
That being said, if the engine had plastic lower intake gaskets from the factory and those were leaking anti-freeze into the oil at any point, the anti-freeze could have compromised the bearings on its own. And that could have been the cause of your bearing failure / rod knock.
In any case, based on the fact you have a rod knock AND the fact you have transmission problems - I think your best bet would be to pull both the engine and transmission and replace them with another good powertrain or get yours rebuilt properly.
ONLY installing New Bearings is a monumental waste of time and money ! " TIC TIC TIC", the sound of the bomb you are creating. Do it Right, or get a new short block.
Its a long story but I wound up getting the car along with the motor and tranny not hooked or running\driving a year after I left it with a guy that could "do all of that stuff." I have to do the install myself. He did manage to replace all the gaskets and paint the engine. I bought the motor from NORAD for a ridiculous amount of money. I didn't know it at the time. It came with a short warranty but as I mention the car sat over at a shop for a year do the warranty is no good. Wheniread the last two posts I had a couple of thoughts. First I could just replace the bearing and drive it until it stops. Second I could find another engine and tranny for less than what it would cost to rebuild them. Third I could spend a bunch of money ey on a performance rebuild on both but I don't have a shop suitable to do it and I don't know of anyone that I can trust to do it right in a timely manner at a fair price. Just can't trust people. That's one thing I've learn when messing with this car.
what is NORAD ? IF IT WAS A used engine with a warranty, you Pay for the" Warranty", the engine Isn't Any Better, chances are THEY never heard it "run" either. just means if it's bad they will replace it with another one that they don't know anything about. and YOU eat the removal / install Costs. "Used" is always a "crap shoot" if you do not Personally Hear it "run". Even then, it may run good today and die tomorrow ! too bad you're not in the area. I rebuild Both engines and transmission. I've torn down 380SC w over 200k miles and they look like new. It depends on Who owned it and How they took care of it. the Best you can do (If you cannot do it yourself) is get a Re Manufactured, from a reputable builder (don't know if GM has crate 3800s) WITH A 50K-100K WARRANTY !
If your in ocala I'm only five hours away. I meant morad but the stpstpid autocorrect changed it. What would you charge me for a rebuild since I don't have the faculties?
I've had good luck with engines from Morad Parts. But I do seem to recall them saying they will void the warranty they offer if you replace gaskets on the engine - because of the known problems it can create if done improperly (which I commented on earlier).
You can certainly buy another used engine and trans but doing that could land you right back into the same position you are in now. Unless you can source a known-good powertrain.
Simply slapping new bearings into an engine that is currently knocking is probably going to result in those new bearings failing in short order, putting you right back into the same situation you are in now.
If you had plans to install performance upgrades (well beyond stock) for this engine/trans combo, I would recommend you just do a performance rebuild now and save yourself the time, money, and trouble of putting another used stock powertrain into the car. That is if the current engine's parts aren't too damaged (ie: needing the crank replaced and such); which you aren't going to know until it is disassembled and inspected. Of course this means you're going to need to find a good engine builder which can be a challenge.
[This message has been edited by Darth Fiero (edited 01-09-2017).]
Did you use a micrometer on it if not you really need to as if it is more than 1/2 of a thousands of a inch out of round you will have problems again and i would hate to see someone do all the work for nothing
I did not mic it. My thought is the engine has over 100k on it and the wear didn't happen over night. Or did it? Anyhow if I put new bearings in maybe I'll extend the useful life if the motor a little bit longer before I go and replace or rebuild. Its only costing me $150 and about 4 or 5 hours. Maybe run some Lucas with the oil.
I did not mic it. My thought is the engine has over 100k on it and the wear didn't happen over night. Or did it? Anyhow if I put new bearings in maybe I'll extend the useful life if the motor a little bit longer before I go and replace or rebuild. Its only costing me $150 and about 4 or 5 hours. Maybe run some Lucas with the oil.
The problem is if you could hear a knock, the big end of that connecting rod may not be within spec anymore. And if you didn't measure it, you will have no idea if it is. I would not rely on plastigage readings either.
That being said, what caused the bearing to fail in the first place? If the cause of the bearing failure was debris in the oil (such as what could happen if someone used a surfacing disc to clean gasket surfaces), it is highly likely ALL the other bearings are contaminated. And it would only be a matter of time before the other bearings fail - if not replaced. If the big end of that rod is out-of-spec, then installing new bearings isn't going to fix it either. Those new bearings will get trashed in short order too.
You can go ahead and slap a new bearing in there, but it is highly likely you will just be wasting your time and money by doing that because whatever caused the original bearing to fail hasn't been repaired. Bearings simply don't go bad on their own. And whatever caused that bearing to fail could have damaged the other bearings in the engine that you aren't replacing.
Good luck!
[This message has been edited by Darth Fiero (edited 01-10-2017).]
Im replacing all of the bearings while im in there. Dont figure itll last very long but im not going to be out much. All of the bearings have at least some wear. That no 1 was nearly worn completely through. What could have been so abrasive?
Okay my cranks is actually worn. Im considering tearing the engine down to the block amd replacing the crank with a new one or good used one. Ill replace all the bearings, rings, gaskets, bolts, and stuff that has to be replaced. Have the cylinders honed, new valve seals, resurface the valve seats, amd may replace with performance upgrades.
Just talked to intense racing. Theyre going to put a block with the crank, rods, and pistons preassembled for me. I havent decided what ill do with the cam and head work as far as going stock or performance. Im shooting for 300-350hp.
make sure they are selling you a Supercharged" Short block", the Supercharged has "Forged" Components (Rods/Pistons), the NA does Not. if the Heads are OFF, might as well clean up the Ports ! just out of Cuiosity, what are they charging you for a Fresh shortblock ? I'm sure a lot of people here are Interested.
Thats $750 for labor, $250 for the block, then the bearings, rings, and shipping that I know of. You know an experienced builder who will give a me a better price for the same thing?
[This message has been edited by Ryanap333 (edited 01-12-2017).]
Is this with a New / "Reground" CRANK, freshly Bored Block, New Pistons (forged), Resized Forged Rods, New Cam / Roller Lifters, timing chain , pump. all Balanced, OR just new rings in a Honed block with new bearings ??? $750 for a "used" Block ?? Check around. I have Always done my own engines/ trans building. maybe that IS the going rate now in that area LOL
Series two and that is using my old rods and pistons if they are good. Anyway i found a remanufactured engine with heads, cam, timing etcetera delivered for $2500 with a three year 100000mile warranty.
Im replacing all of the bearings while im in there. Dont figure itll last very long but im not going to be out much. All of the bearings have at least some wear. That no 1 was nearly worn completely through. What could have been so abrasive?
make sure they are selling you a Supercharged" Short block", the Supercharged has "Forged" Components (Rods/Pistons), the NA does Not. if the Heads are OFF, might as well clean up the Ports ! just out of Cuiosity, what are they charging you for a Fresh shortblock ? I'm sure a lot of people here are Interested.
NOTHING in the 3800 Series 2 SC engine's rotating assembly is "forged". The pistons, crank, and rods are all cast. The Supercharged pistons, piston pins, and connecting rods are thicker (and stronger) than the N/A parts. The crank is the same, but is balanced differently between the two to account for the piston/pin/rod weight differences.
Well milzy motorsports has both a 0-20k mile engine and tranny for $3000 not including shipping. Should i just spend the $2500 and get a zero mile remanufactured engine with a great warranty? I think so and then deal with the tranny when I get there.
$2000 and he's not even BORING the block ?!" that's just a re-ring job,
NOTHING in the 3800 Series 2 SC engine's rotating assembly is "forged". The pistons, crank, and rods are all cast. The Supercharged pistons, piston pins, and connecting rods are thicker (and stronger) than the N/A parts. The crank is the same, but is balanced differently between the two to account for the piston/pin/rod weight differences." when I went to buy a new Crank, the Part # was the same for both SC and NA. Seems I've read a few posts Here ( cannot be taken as Gospel) that only the rods and pistions were forged, not just thicker , SC Rods are Shorter. again, this is what I've read on pennock's not a Tech manual.
best bet is a warrantied engine as long as they "Stand behind" the warranty
when I went to buy a new Crank, the Part # was the same for both SC and NA. Seems I've read a few posts Here ( cannot be taken as Gospel) that only the rods and pistions were forged, not just thicker , SC Rods are Shorter. again, this is what I've read on pennock's not a Tech manual.
The SC pistons are NOT forged. SC rods may be shorter than N/A rods, but they are also much thicker and stronger than N/A rods. SC rods are still cast just like the N/A rods.
Crank may have the same part number, but I assure you it is balanced differently between SC and N/A.
