Is there a way to tell if it is a spun bearing or collapsed lifter without tearing the engine down?
03-04-2003, 01:04 PM
#1
Drifting
Thread Starter
Is there a way to tell if it is a spun bearing or collapsed lifter without tearing the engine down?
A buddy of mine thinks I have a collapsed lifter not a spun bearing. I really do not want to tear the engine down at this point yet. Is there an easy way to determine which I have???
Thanks
Bob
Thanks
Bob
03-04-2003, 02:46 PM
#2
Moderator
Re: Is there a way to tell if it is a spun bearing or collapsed lifter? (BeachinVette)
If you have a spun bearing it will get worse very quickly....louder, louder, LOUDER!! A collapsed/loose lifter or more likely a lifter stud pulling loose is easy to check. Use an automotive stethescope (or a length of heater hose if you're really cheap) and snoop around. You will locate the noise. :yesnod:
03-04-2003, 03:13 PM
#3
Safety Car
Re: Is there a way to tell if it is a spun bearing or collapsed lifter? (MasterDave)
If we're talking about a rod bearing, the easiest way to tell is to pull the spark plug wire on the suspect cylinder(s). Once the hole quits firing, the load is off the rod and the knock will go away. You can also tell by when the rod knocks while driving. If it knocks under load but not when you lift off the throttle, it could be a rod knock.
If it knocks when you lift off the throttle but not under load, it could be a wrist pin but it will be a double knock.
If it's a main, then you can usually tell by just letting off the throttle at speed. The closed throttle load will usually make a main bearing get to knocking.
A bearing knock can go on for quite a long time, depending on the nature of the problem, and it's not something you want to drive to failure. If the knock is just from excessive wear, it may be able to be repaired with a bearing replacement and a little polishing of the journals with the engine in the car. Repair costs for this diagnostic method can get to be quite high if left as is.
If it knocks when you lift off the throttle but not under load, it could be a wrist pin but it will be a double knock.
If it's a main, then you can usually tell by just letting off the throttle at speed. The closed throttle load will usually make a main bearing get to knocking.
A bearing knock can go on for quite a long time, depending on the nature of the problem, and it's not something you want to drive to failure. If the knock is just from excessive wear, it may be able to be repaired with a bearing replacement and a little polishing of the journals with the engine in the car. Repair costs for this diagnostic method can get to be quite high if left as is.
03-04-2003, 08:38 PM
#4
Team Owner
Re: Is there a way to tell if it is a spun bearing or collapsed lifter? (gerry72)
If we're talking about a rod bearing, the easiest way to tell is to pull the spark plug wire on the suspect cylinder(s). Once the hole quits firing, the load is off the rod and the knock will go away. You can also tell by when the rod knocks while driving. If it knocks under load but not when you lift off the throttle, it could be a rod knock.
If it knocks when you lift off the throttle but not under load, it could be a wrist pin but it will be a double knock.
If it's a main, then you can usually tell by just letting off the throttle at speed. The closed throttle load will usually make a main bearing get to knocking.
A bearing knock can go on for quite a long time, depending on the nature of the problem, and it's not something you want to drive to failure. If the knock is just from excessive wear, it may be able to be repaired with a bearing replacement and a little polishing of the journals with the engine in the car. Repair costs for this diagnostic method can get to be quite high if left as is.
If it knocks when you lift off the throttle but not under load, it could be a wrist pin but it will be a double knock.
If it's a main, then you can usually tell by just letting off the throttle at speed. The closed throttle load will usually make a main bearing get to knocking.
A bearing knock can go on for quite a long time, depending on the nature of the problem, and it's not something you want to drive to failure. If the knock is just from excessive wear, it may be able to be repaired with a bearing replacement and a little polishing of the journals with the engine in the car. Repair costs for this diagnostic method can get to be quite high if left as is.
John
