My car is officialy dead...
I've had this happen 4 times, did the work myself the first 2. I forgot who said it before but they were right, what you have is a rod knock. That means one of the rods have come loose from the piston and is banging around inside your block. Now, depending on the extent of the damage, it MIGHT be rebuildable. And going from what you said, you drove it way too much while it was knocking. You probably bent your crank, which is extremely expensive and hard to get to, and scored up your block which will need to be re honed. Not to mention a new rod, possibly new head, and new rod bearings. If you don't have alot of cash invested in this motor, your best bet would be to get a new one all together. You'll have to pay your mechanic for the time he will need to take the motor apart to see the damage, which is a waist of time and money. A used motor with decent amount of mileage should run you no more than 500, but I'm not 100% sure about those specific motors. Then your mechanic shouldn't charge more than 800 to swap them out. Rebuilding should cost around a grand. But if you pay him to rebuild this motor, come to find out it's so bad you cant rebuild it, or too expensive, you've just waisted your cash you paid him to take the motor apart. Like I said, get a used motor. Junkyards have them for pretty cheap, there are places on the internet to check, or just check some forums. Good luck man.
Theres a difference between rod knock and a launched rod. Rod knock happens from two things A.) The wrist pin (does this engine have floating, or pressed pins?) or B) On the cap. Its not swinging around all violently, otherwise it would be hanging outside the block. What rod knock is, is that either of those (A an B) have gone wayy out of tolerance (were talking engine tolerances, so these are in the thousandths) What probably ended up happening on your motor is the rod knock hot spotted a bearing, causing you to spin it (the bearing). This is why your motor is pretty much frozen and won't start, everything is seizing / binding up. You most likely did NOT bend your crank, but almost positive you scored it up. You might be able to get it undercut and re-finished, but its not worth it. Rod knock has NOTHING to do with your head. I just looked up a rebuild kit and its $900 min then add at least another $700 in machine work. I would suggest getting a used short block for minimal cost. Unless you want to start pouring money into this to 'build it' , this will be the cheapest for going back to stock and having a reliable car.
If your mechanic doesnt have too much experiance with the 7m engine and you want to save yourself from a headache, call up Jarco and have them rebuild you an engine. At least get them to put a MHG along with the ARP bolts and you can tell them to do more things if you want to. They have experiance with this engine and many people have used them without a problem. They are a little bit more expensive compared to other places that sell JDM engines but you get that piece of mind that you got yourself a engine that will be reliable.
As I quote south park. . . "Dumb Dumb Dumb Dumb Dumb Dumb Dummmmb"
Theres a difference between rod knock and a launched rod. Rod knock happens from two things A.) The wrist pin (does this engine have floating, or pressed pins?) or B) On the cap. Its not swinging around all violently, otherwise it would be hanging outside the block. What rod knock is, is that either of those (A an B) have gone wayy out of tolerance (were talking engine tolerances, so these are in the thousandths) What probably ended up happening on your motor is the rod knock hot spotted a bearing, causing you to spin it (the bearing). This is why your motor is pretty much frozen and won't start, everything is seizing / binding up. You most likely did NOT bend your crank, but almost positive you scored it up. You might be able to get it undercut and re-finished, but its not worth it. Rod knock has NOTHING to do with your head. I just looked up a rebuild kit and its $900 min then add at least another $700 in machine work. I would suggest getting a used short block for minimal cost. Unless you want to start pouring money into this to 'build it' , this will be the cheapest for going back to stock and having a reliable car.
Theres a difference between rod knock and a launched rod. Rod knock happens from two things A.) The wrist pin (does this engine have floating, or pressed pins?) or B) On the cap. Its not swinging around all violently, otherwise it would be hanging outside the block. What rod knock is, is that either of those (A an B) have gone wayy out of tolerance (were talking engine tolerances, so these are in the thousandths) What probably ended up happening on your motor is the rod knock hot spotted a bearing, causing you to spin it (the bearing). This is why your motor is pretty much frozen and won't start, everything is seizing / binding up. You most likely did NOT bend your crank, but almost positive you scored it up. You might be able to get it undercut and re-finished, but its not worth it. Rod knock has NOTHING to do with your head. I just looked up a rebuild kit and its $900 min then add at least another $700 in machine work. I would suggest getting a used short block for minimal cost. Unless you want to start pouring money into this to 'build it' , this will be the cheapest for going back to stock and having a reliable car.
I won't get into a pissing contest, especially with someone over the internet. But I'm going by what I was told by multiple mechanics. I guess they could all be wrong, though. I always just replaced the motor, I didn't deal too much with the engine internals. I think it's pretty much common sense though the rod knock means the rod is loose and hitting the cylinder walls. Which is why eventually it shot through the bottom of my motor. And the loose rod is connected to your crank, if anything that would have a extremely strong possibility to screw up your crank journals, and depending on what caused the rod knock, the crank may be bent - from high resistance due to low oil for instance. But like I said, depends on what led to the knock. This is all just my opinion. But again, to the OP, I strongly suggest getting another motor. Don't waste your cash on chancing a rebuild.
Last edited by Sandfrog; Jan 1, 2008 at 07:50 AM.
http://www.jarcoinc.com/
Call them up and tell them to do machine work and put in a metal headgasket with arp bolts. They will also build the bottom end up with parts you want if you pay extra so depending on how much power you want to make in the future, thats up to you. Jarco is little bit more expensive but they warrenty their work and if anything goes wrong their customer service is great. This way when you receive the engine you can drop it right in.
Call them up and tell them to do machine work and put in a metal headgasket with arp bolts. They will also build the bottom end up with parts you want if you pay extra so depending on how much power you want to make in the future, thats up to you. Jarco is little bit more expensive but they warrenty their work and if anything goes wrong their customer service is great. This way when you receive the engine you can drop it right in.
Im not bias towards the 7m engine but im not ignorant to say its a POS either. Even if you use a metal headgasket you can easily blow it right away if you only torque it down using factory specs. On the 7M people usually torque the headbolts down to 75+ lb ft and this is what it should have been from the factory. Another problem is the mkiii community. Now im not saying all but the majority are always are looking for a cheap way to fix things. Thats why most mkiii supras you see are nasty looking, falling apart, or not running right at all. Because of those people, the 7M gets a bad rep because these people tend to have plenty of problems with the engine while people that did things right from the beginning have no problems at all.
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