First, a little background. Skip down to the bottom if you have no patience for long posts.

My daughter'* boyfriend bought a 1996 Sunfire with rod knock so loud that it sounded like a hammer hitting a skillet. He knows nothing about cars, has practically no parental support, and had to have a car to get to work. He just recently turned 19 and is basically on his own. He works at a Whataburger.

The car died back in August due to a bad crankcase position sensor, and because he is a really good kid who we all love, I decided to step up and fix his car for him if he bought the parts.

After getting it running, I learned what rod knock sounds like first hand. Really bad. We discussed just junking the car and getting him a new one, but when you look at cars in the $1000 price range, most if not all of them are not running or have major engine/transmission issues, so we agreed that pulling the engine and rebuilding it was the way to go. I've rebuilt a few engines over the years, so I had no doubts about my skill level.

So over a two or three month time frame, working on it when I could while my daughter taxied him around (he bought all the gas). I pulled the engine, took the components to a machine shop, reassembled, and reinstalled it. I greased all the components well during the reassembly and primed the oil pump.

It cranked right up on the first try. I was so relieved to be done. During the first few test drives, I accelerated to about 50 mph, then coasted down to 30, repeating this a dozen or so times. During the test drive, I noticed that the low oil pressure warning light came on after the engine was hot and idling in drive. A little bit on the gas pedal made it go out. Each time I stopped, I held one foot on the brake and gave it a little gas to extinguish the light. Although the oil pump and pressured sender were both new, I read somewhere that the low oil pressure light was a problem with this engine.

Anyway, when I got back from my first test drive, I noticed a disconcertingly loud tapping. With my mechanic'* stethoscope, I determined it was coming from the bottom end. Next day, it went away, and I hoped it would stay away, but I had this sick feeling in my stomach that was confirmed when he drove up in the car yesterday. Rod knock! When he started it a few hours later, it was knocking as loudly as before.

The machine shop I used made a mistake on each of the other two engines they worked on for me. One was a sticking valve causing bent push rods, and the other was failure to reinstall a rubber plug causing massive oil leak. I went back to him this time because the devil you know is better than the devil you don't know, plus, he has an outstanding reputation as the go-to guy for engine work on a local fishing/boating forum.

Here'* what I suspect: The connecting rod from the previous spun bearing was pretty damaged. I was surprised that he didn't get me a new one with the parts kit he ordered for me. He said it was okay, and because the bearing is fixed in the connecting rod and slides around the crank, I didn't object. I suspect that the exact same connecting rod bearing spun and it was because the connecting rod was buggered up.

The original crank was beyond repair, so he got me a new crank kit. Same with the camshaft. All bearings were standard size.

I haven't dropped the oil pan yet to inspect everything. I plan on doing that this Sunday.

I can't believe I'm going to have to take that engine apart again. :(

Did the machine shop grind down the journals and install undersize bearings, or just change the bearings. Rod bearings are only a temporary fix for rod knock since the underlying issue is the crank journal is not round anymore.

Brand new crank kit.

There are tons of these engines in bone yards.......a low mileage one, would have been the way to go.....done quickly......

Going back to someone, who screwed up twice? That'* a head scratcher....

Most likely the rod should have been recondition were they knock out the rod bolts then clip the caps making it smaller inside but now its egg shaped.
So they hone it out round again after that.
The bearing will spin or fail if there is no bearing crush so most likely the rod was out of speck on the cap side so the bearing stared to fail as soon as it was started.

I talked to him today about it, specifically, what they did to the connecting rod in question. He said they honed it and it was within specs. I don't think they did what you mentioned because the inside surfaces weren't fresh, shiny metal like a bored out cylinder. At this point, I'm just speculating. He told me to drain the oil and look for metal, then we'd go from there. If there'* a significant amount of metal, I'll drop the oil pan and access the damage.

The bad thing is that Sunday is the soonest I can have the car to check it out, and he'* got to drive it to work.

Thanks.

So what do you want to bet its the same rod that failed before.
Every time the cylinder fires its hammering that rod like a sledge hammer making the opening bigger or egg shaped.
Just honing it wont cut it who knows maybe a dingle ball hone was used by them.
There is a special machine you use to clip the caps then you torque it to specifications in a rod holding vise. Then you hone it back round checking the opening for proper size.
If its out much at all there is little or no bearing crush so the bearing is hammered as soon as you start it so I will put my money on its the same exact rod that failed before.
Or they could have mixed up the bottom of the rod caps they have to go back on the same rod they cant be interchanged,
Take a picture of there rod hone machine and there rod cap clipper I bet they don't even have one.

I'm betting it'* the same rod, too. I just feel sick about it.

Before I went back to him for the third time, I got recommendations on machine shops on a local fishing/boating forum. A dozen people would testify about how great his shop is. A half dozen people would tell me to stay away from the other major player in our town. My marine repair shop even recommended him. So, I gave him the benefit of the doubt.

Question is, is he going to step up to the plate, if it'* the same connecting rod problem? Otherwise you may have to go to small claims court....

I hope your mechanic helps you sort things out, seems like he should cover a lot of the work that needs to be done again, because if he did it right the first time there would be no problems.


If you lived in VA I'd sell you my 96' Park Ave, its motor is in great shape, and the transmission still shifts nicely, only has 139k on it, and I have owned it since 27k, before that my Moms Husbands parents owned it..
I'm tying to get 1,200.00 for it, but for a good cause I'd consider 1,000.00
It needs a little work though, the seats need to come out, carpet needs cleaning, and a water leak needs to be found and fixed.
As well as any grounds under the carpet will need to be cleaned up, as the interior lights quit working.
It could easily be fixed up enough to be a reliable car to get somebody back and forth to work..
I'll try to post some pics and info on my car in our for sale section here sometime.