ATX Rod Bearing Fun. (Not Really)

[Mrhappytuzi]

Well... I just got out of work to go start my car and let it warm up. I had my windows open since I was talking to a buddy of mine and then proceeded to pull around to the shop doors so I could punch out.. what ever. When i accelerated I happened to notice a rather...odd sound coming from the engine. I Stopped starting lightly revving the engine.. and sure enough I could hear the dreadful rod bearing rattle. I'm not entirely sure how long it has been knocking. I didn't notice anything out of the norm. during the last oil change 2,500 miles ago. There hasn't been any sort of Oil pressure light of death nor any sort of funky idle. So all in all I'm pretty surprised by this since this engine ran so strongly for having 155,984 miles on it.

So... I'm curious about how bad the crank is going to be chewed up.

Anyway I have a set of rod bearings in my garage so I guess I'll have fun with it tomorrow

 

[rubydist]

It depends if a rod bearing spun, or if its just got enough clearance so that you hear the rattle/knock. If the bearing spun, then the crank needs to be reground or replaced.

When you get the rod cap off, run the end of your fingernail along the crank journal. It should be perfectly smooth. If you can feel any kind of ridges at all, the crank is toast.

 

[jmpSHO]

I drove mine for about 3k miles with a rod knock and when I changed the rod bearings the crank was fine. I have put about 10k on the motor since changing them. I'm not saying to keep driving, I was just willing to take a chance since my motor has about 300k on it, if I spun a bearing I would have just replaced the motor.

 

[SHOtime2511]

It depends if a rod bearing spun, or if its just got enough clearance so that you hear the rattle/knock. If the bearing spun, then the crank needs to be reground or replaced.

When you get the rod cap off, run the end of your fingernail along the crank journal. It should be perfectly smooth. If you can feel any kind of ridges at all, the crank is toast.

what he said^
I wouldn't drive it anymore untill you change them.

 

[pitaSHO]

Yeah. Park it until you can check the bearings. If you did indeed spin a bearing then replacing them with new ones won't fix it. Replace or regrind the crank or replace the motor. If you regrind the crank you'll need oversized bearings. If you replace the crank with a stock one you can use the new bearings you bought.

Chris K.

 

[Mrhappytuzi]

Oh yeah I'm definetly not planning on driving it. Especially when its on jackstands with the y-pipe half taken off. Right now I just need to find my new set of rod bearings So i can have those ready to throw in. This should be interesting taking the oil pan off of the ATX

 

[boat]

RCM is a good place to get them. Yeah, they take a little bit, but if you email Mark at [email protected] and tell him its an emergency, he can get them to you as soon as possible.

It has the oil pump pickup tube gasket, oil pan gasket, rod bearings, plastigauge, and black RTV, in the kit. Should be about $65 before shipping.

 

[SHOMON]

Are you sure it is not the timing belt tensioner that let go? I to thought I had a rod knock turned out the timing belt was slapping the cover. Easiest way to check is pull the upper cover and see if the belt is loose. If not start the car and watch the belt to see if it flaps around. When I replaced the tensioner the one I took out could be compresed by hand. My car is a 95 ATX.

 

[Mrhappytuzi]

Replaced.. and actually.. they werent bad.. like .. as if they were already done some time ago, no metal shavings or anything oil was cleeeaan..... Although I did pop them valve covers off since they were in dire need of a gasket. Poked around a little bit up there and didnt notice anything out of the ordinary... other than the heads were super clean. There is still a bit of a noise somewhere.. did a valve adjustment and changed the plugs and wires.

I had actually bought the rod bearring kit from RCM a few years ago. Just never used them on my other car. If I remember right they were at my door within three days.

 

[whiteguy3]

I would second the timing belt tensioner slapping. I don't run a hydrolic (stock) tensioner on my 94 ATX anymore. I got rid of that ******* after 3 went within 2 years. Nearly impossible to find a new one anymore.

I just fabbed up my own using the stock housing. Works like a charm now for over 6k miles. Everytime I need to release tension on the timing belt it's a sinch. All I have to do is loosen one bolt on the tensioner to relieve pressure on the belt.

 

[Earthshaker]

I'll third the timing belt. I just diagnosed that on my buddy's 93 ATX....flopping big time and made a similar to a rod knock sound, but the difference was it would smooth out.

So, now to my question on this.....what outfit has a new tensioner as we need to buy one! I'll be searching right now, but anyone that has the quick answer, please chime in. Thanks!