Need help i just had a crankshaft bearing go out was wondering how you can tell if crankshaft may need replacement or not. Havent looked at it yet but thats what i was told was the problem. Car has a light knocking sound. Also, these turbo cars have steel crankshafts dont they? Will I just have to look at it or should i be able to tell by the way the car acts or the sound of the knocking if the crankshaft will need to be replaced also? (This is a 83 Regal T-type)
main bearing
- Thread starter buick83-T
- Start date
Turbo-Rich
ALBATROSS
- Joined
- May 25, 2001
I thought I threw a rod once (this was in a Chev.).
The eng. started knocking like crazy & it wasn't running right.
Boy, I was MAD
Luckily I had a smart friend who convinced me to pull the valve covers FIRST.
Sure enough,
a rocker arm had slipped right of the pushrod
SSSHWEW! BIG relief!
Hope your troubles turn out to be something as simple!
The eng. started knocking like crazy & it wasn't running right.
Boy, I was MAD
Luckily I had a smart friend who convinced me to pull the valve covers FIRST.
Sure enough,
a rocker arm had slipped right of the pushrod
SSSHWEW! BIG relief!
Hope your troubles turn out to be something as simple!
- Joined
- May 28, 2001
crankz
83-T, the stock crank in a turbo engine is NOT steel, it is cast.
The correct way to determine the cause of the probem is to remove the engine, take the crank to a machine shop and have it checked and magnafluxed.
I don't know the condition of the engine, but if it's been beat on and abused, it may well have a bad main cap, the bore alignment could be off, the block could be cracked above the main bore. There are ALOT of possible causes, including it just plainly being worn out.
HTH,
83-T, the stock crank in a turbo engine is NOT steel, it is cast.
The correct way to determine the cause of the probem is to remove the engine, take the crank to a machine shop and have it checked and magnafluxed.
I don't know the condition of the engine, but if it's been beat on and abused, it may well have a bad main cap
HTH,
b4black
Well-Known Member
- Joined
- May 24, 2001
Like Turbo-Rich said, it might not be what you think.
I suggest you list the symptoms. When it makes noise, how loud, what RPM, hot or cold, etc. Too many things on these engines tick, clack, bang, and knock to be sure it one thing or another.
Wouldn't it be great if it's just the smog pump going out, or a header leak (they tick!) or other simple thing.
I suggest you list the symptoms. When it makes noise, how loud, what RPM, hot or cold, etc. Too many things on these engines tick, clack, bang, and knock to be sure it one thing or another.
Wouldn't it be great if it's just the smog pump going out, or a header leak (they tick!) or other simple thing.
Sound is in oil pan. A mechanic checked out the car and said it was the crankshaft bearing but he didnt look to see how bad it was on the crank. Does the whole engine have to come out to fix this? How long should it take before you get the deep grooves in the crank? Car was parked not long after I heard the noise so it hadnt gone far once I heard it.
THANKS
THANKS
F
Freddie's Buick
Guest
A bad rod bearing is not a big deal. Any mechanic can deal with that. I've done this job in 2 hours taking my darn sweet time. However, the condition of the bad bearing will indicate what caused the damage. If it is severe enough then the possibility that the crank was damaged is more than likely. *(If it is a turbo crank remember that these cranks are heavy duty. They can take a lot of severe punishment and still not need to be replaced. Unfortunatley, it cannot be machined). The crank would still have to be checked. This check falls upon the hands of a machinist. (A mechanic can do this if he knows about tolerances and has an understanding on how to read and use a micrometer).
Obvious checks would be a scored or scratched surface on the crank. If it is a turbo crank then it is not salvagable! Turbo cranks are roll filleted on the rod bearing surface and main bearing surface. Meaning that it cannot be turned, (cut).
If a new crank is needed then one would then need a 'crank kit'. Aproximate cost is ball park $300.00. (This does not include labor). It is doubtful that the replacement crank will be a turbo crank since they are very rare. The machinist would probably then use a standard 3.8 crank.
Obvious checks would be a scored or scratched surface on the crank. If it is a turbo crank then it is not salvagable! Turbo cranks are roll filleted on the rod bearing surface and main bearing surface. Meaning that it cannot be turned, (cut).
If a new crank is needed then one would then need a 'crank kit'. Aproximate cost is ball park $300.00. (This does not include labor). It is doubtful that the replacement crank will be a turbo crank since they are very rare. The machinist would probably then use a standard 3.8 crank.
- Joined
- May 28, 2001
Crankz
SORRY FREDDIE, a turbo crank CAN be turned and if done correctly and NOT cut below the fillet, it will work just as well as a new crank
Secondly, the regrinders can supply a reground turbo crank. Kendall Fredrick and I had this very same discussion yesterday. The kits he found have the turbo crank and all brgs for the before mentioned $300 area.
Back under my rock.
SORRY FREDDIE, a turbo crank CAN be turned and if done correctly and NOT cut below the fillet, it will work just as well as a new crank
Secondly, the regrinders can supply a reground turbo crank. Kendall Fredrick and I had this very same discussion yesterday. The kits he found have the turbo crank and all brgs for the before mentioned $300 area.
Back under my rock.
Sure are some confused people out here!
Seems there are some confused people out there. Mark Twain wrote "It's not the things a man doesn't know that cause trouble, it's the things he knows that just ain't so." Actually, I'm not sure that it was Mark Twain who said that, come to think of it.
Anyway, the crank is cast steel; it can be turned by any competent machine shop. For a carbed turbo car, IMO either a turbo crank or a good NA (non-rolled fillet) crank would be fine.
If it spun a bearing, the motor should come out. If it's a main bearing the main bores should be checked; the caps will probably need at least a line hone. If it spun a rod bearing, the rod will probably need to be resized. You can replace bearings and the crank, but without fixing the caps, your chances of it living aren't good.
Good luck!
Seems there are some confused people out there. Mark Twain wrote "It's not the things a man doesn't know that cause trouble, it's the things he knows that just ain't so."
Actually, I'm not sure that it was Mark Twain who said that, come to think of it. Anyway, the crank is cast steel; it can be turned by any competent machine shop. For a carbed turbo car, IMO either a turbo crank or a good NA (non-rolled fillet) crank would be fine.
If it spun a bearing, the motor should come out. If it's a main bearing the main bores should be checked; the caps will probably need at least a line hone. If it spun a rod bearing, the rod will probably need to be resized. You can replace bearings and the crank, but without fixing the caps, your chances of it living aren't good.
Good luck!
F
Freddie's Buick
Guest
Sorry guys, I take my cues from the Buick Service Manual....
Quote: ' If turbocharged V-6 crankpin journals are scored or ridged the crankshaft MUST BE REPLACED! Regrinding journals with rolled fillets would damage the fillets and reduce the durability of the crankshaft....
So far the 'Buick Service Manual' has not done me any wrong. Unless I personally know the grinder then I would still argue that Buick made it....and they would know more than your average street greaser. (Unless one specializes in Buick engines).
Perhaps you're right, Perhaps I might have a point. But let's not get buick83-T confused. The safe bet is always OEM....
Incidently, I also found out that the N/A crank's main journals are also roll-filleted. Only that the rod journals are not. (Pat Ganahl, V-6 performance Pg.76).
Quote: ' If turbocharged V-6 crankpin journals are scored or ridged the crankshaft MUST BE REPLACED! Regrinding journals with rolled fillets would damage the fillets and reduce the durability of the crankshaft....
So far the 'Buick Service Manual' has not done me any wrong. Unless I personally know the grinder then I would still argue that Buick made it....and they would know more than your average street greaser. (Unless one specializes in Buick engines).
Perhaps you're right, Perhaps I might have a point. But let's not get buick83-T confused. The safe bet is always OEM....
Incidently, I also found out that the N/A crank's main journals are also roll-filleted. Only that the rod journals are not. (Pat Ganahl, V-6 performance Pg.76).
Originally posted by Freddie's Buick
Sorry guys, I take my cues from the Buick Service Manual....
Quote: ' If turbocharged V-6 crankpin journals are scored or ridged the crankshaft MUST BE REPLACED! Regrinding journals with rolled fillets would damage the fillets and reduce the durability of the crankshaft....
So far the 'Buick Service Manual' has not done me any wrong. Unless I personally know the grinder then I would still argue that Buick made it....and they would know more than your average street greaser. (Unless one specializes in Buick engines).
Perhaps you're right, Perhaps I might have a point. But let's not get buick83-T confused. The safe bet is always OEM....
Incidently, I also found out that the N/A crank's main journals are also roll-filleted. Only that the rod journals are not. (Pat Ganahl, V-6 performance Pg.76).
Freddie, I apologize if I offended you; I was trying for humor there.
OK...I'm bored and I have no beer and I'm an insomniac. Turned turbo cranks have lived in plenty of 10 second cars; my GN currently has a .020/.010 crank in it. As long as the fillets aren't cut into, it's a non-issue, IMO. There are no more new stock cranks regardless.
I also have Ganahl's book even though it's severely dated like the Buick Service Manual.
I even have a NA crank or two in the garage....yes, they have rolled fillets on mains but not rods. If you think about that, you'll realize that if you couldn't turn a turbo crank because of the fillets, you wouldn't be able to turn a NA crank either. All right, I'm done...it's all fun as long as nobody loses a limb!
b4black
Well-Known Member
- Joined
- May 24, 2001
Re: Sure are some confused people out here!
I will second this opinion. A turbo crank is overkill in a 4.1 or Carb/Turbo just as a 8.5" rear would be.
In 1978, Buick enginneers were concerned with the NA crank, so they rolled the rod journals just to be safe. Remember, they just split the rod journals for even-firing only a year earlier. The Buick V6 crank has proven through time to be very durable. If a turbo crank can go 10's, then a NA crank can surely handle quite a bit as well.
GM (or AC/Delco?) sells reman 3.8 V6's which they specify for VIN's 3 and 8 (Carb/Turbos) as well as A (2-bbl). I highly doubt they have rolled rod journal cranks.
I will second this opinion. A turbo crank is overkill in a 4.1 or Carb/Turbo just as a 8.5" rear would be.
In 1978, Buick enginneers were concerned with the NA crank, so they rolled the rod journals just to be safe. Remember, they just split the rod journals for even-firing only a year earlier. The Buick V6 crank has proven through time to be very durable. If a turbo crank can go 10's, then a NA crank can surely handle quite a bit as well.
GM (or AC/Delco?) sells reman 3.8 V6's which they specify for VIN's 3 and 8 (Carb/Turbos) as well as A (2-bbl). I highly doubt they have rolled rod journal cranks.
F
Freddie's Buick
Guest
No offense taken....
Similar threads
