I have a 1997 pontiac sunfire GT (2.4l). Is it possible to change the rod bearings on the 2.4L through the oil pan? I ask because on christmas day santa delivered me a rod knock .

Are you sure its the rod bearings and not the main bearings? Secondly you must remove the connecting rod and piston ( piston is connected to the rod). Anyways I dont see how it would be possible. Looks like its time for a rebuild.




- 2004 Cavalier - 124k, owned since new

yes it can be done in the car, remove the spark plugs and then you should be able to push the pistons up and down with your hands, if not just take the cap off then rotate the crank untill it seperates, then just slide the new ones in then put the cap back on.It has been done i did it in my bros 99 gt.

I don't know how much experience you have with this..and if I treat you like you know nothing I am sorry...but I will assume you know very little for this explanation. Here's the quick and dirty.

Rod bearings wont fix a knock...it will for a short time but it will come back in a few thousand miles.

It knocks because your crank journal is not round anymore.
All be it you cannot see it with your naked eye. It may only be out by a few thou of an inch. This "out of round" condition is what is fixed by a machine shop on a rebuilt crank. The journals are ground down and they supply you with undersized bearings.

Just be sure its a bearing prob and not a wrist pin.
All you have to do...if you choose to do the rebuild anyway... is drop the oil pan and take the rod caps off than slide out the bearing, wipe it off and look at it. It should be a silver color, if it is a brass color than it is bad..this means your crank journal is touching the bearing and not riding on a film of oil like it should.
If it is a wrist pin issue than you have no other choice but a rebuild. Or drive it until it drives a rod out through the cylinder wall.

All you will do by replacing a rod bearing (or main bearing) is prolong the inevitable...as rob said...a rebuild. best thing to do...if you cant afford a rebuild right now...is just use a little heaver oil or use Lucas additive (I mean the engine is f***ed anyway so it really wont matter) to quiet it down a bit and drive around until you can afford it.

Just pull the pan and make sure it is a bearing prob before you drive just in case it is a wrist pin.

I have faith that new rod bearings will do it. The reason it started knocking is that a week ago my clutch MC mounting tabs snapped when I went to shift and it left me stuck in 2nd gear. I run the engine at a sustained 6K RPM for 7 miles to get home. Less then a week later I have a ever so slight knock at 3K RPM. I believe that the bad rod bearing is the one closest to the PTO side of the motor and furthest away from the oil pump. It's good to know that I can do it in the car. I'll let everyone know what I find.

Hope it does work out for you. Its a pretty cheep fix if it does...but while your down there check them all to make sure...including your mains as well...may as well be sure what is gone. even if you replace every bearing and a pan gasket, it should run you less than a hundred bucks if you can do it your self...
I use to build V8 race engines and the whole kit of clevite bearings used to run around a hundred bucks.
And for your sake...don't get the caps order mixed up. Remove and check one at a time.

Good Luck!

Nytemare wrote:

It knocks because your crank journal is not round anymore.
All be it you cannot see it with your naked eye. It may only be out by a few thou of an inch. This "out of round" condition is what is fixed by a machine shop on a rebuilt crank. The journals are ground down and they supply you with undersized bearings.

Just be sure its a bearing prob and not a wrist pin.

Just pull the pan and make sure it is a bearing prob before you drive just in case it is a wrist pin.

I plan on measuring the crank with a mic to check it for out of roundness. According to my Haynes manual the oil film spec is .0001 which is a very tight spec to say the least. That being said the crank is ALOT harder then the bearings so I would venture a guess that the crank will eat the bearings alive unless it spun the bearing, and if it did that the engine will need alot more then a rod bearing.

I hope it's not a wrist pin too. I'll be dropping the pan today to see whats up. It doesn't bother me at all for you to assume that I have very little experience, I know my way around engines/cars, but there is alot of people out there that know a heck of alot more then me. So far on this Sunfire I have done

Power steering pump at 70K
Clutch at 90K
Water pump at 98K (that job sucked and took about 8 hours)
Replaced a blown tranny at 110K (I'm getting good at taking that thing out and can drop it in about 3 hours now)
Clutch MC at 113K
Rod Bearings at 114K ... we'll see how that goes.

The Sunfire is my winter beater / tow vechile I got it at 55K for 4.5K, even with all the wrench turning that I have done it's been a good car. It would need less wrenching if I didn't subject it to "severe duty".

--Emery

just a quick ? on the topic..... i'm rebuilding a 97 2.4 to put in my 98 2.4 ...... found a decent amount of metal flakes when i dropped the oil pan, so i'm going to replace the rod bearings. My ? is, can you get these at your local parts store or do i have to get to the dealer for this too. already have to go to the dealer for a complete gasket kit anyway.


thanks
Jason

Well 114K with towing a trailer ain't bad....I assume thats Miles...I'm from Canada (km for me)
Seeing as how you are good at engine work. Even a complete rebuild wouldn't be expensive as long as all your internals are good.

Keep us posted.

Hott98Z wrote:just a quick ? on the topic..... i'm rebuilding a 97 2.4 to put in my 98 2.4 ...... found a decent amount of metal flakes when i dropped the oil pan, so i'm going to replace the rod bearings. My ? is, can you get these at your local parts store or do i have to get to the dealer for this too. already have to go to the dealer for a complete gasket kit anyway.


thanks
Jason

The bearings are $9.99 a rod at NAPA.

I found lots of metal slivers in the pan (some of the filings were big enough to get caught in the screen, and their is lots of evidence of grindings in the pan too. Problem is I can not tell where they have come from. From what I found in the pan I expected it to be obvious where the problem was, but so far it looks lfine in there. Rods 1 3 4 have some side to side play. Rod 3 was the worst so I pulled the rod bearing, but it looked OK for 114K. I'm going to pull more rod bearings tomorrow. The crank seems to be tight too, but I might pull a cap and still take a look. Can the crank bearings be changed through the pan also? I forgot to look and I don't have the engine here in front of me. Any suggestions?

if the bearing looks like this

and the crank looks like this

and the rod looks like this

not much hope left
btw thats a 2.2 with 185000 miles and hard driving

They may be able to be changed. If there is enough room to slide in a new bearing from where the old ones came out.
Metal filings could be from anywhere, If you take a sample of the oil and have it analyzed they should be able to tell you what type of metal it is. Or even swish a magnet in it for a couple min. If nothing sticks to the magnet than its non ferrous...bearings, most likely.
If s#!t sticks to the magnet...that could be a really big prob.

Never thought about it before but you said you held it at 6k rpm for like 7 miles...you could have a little valve knock.

Nytemare wrote:They may be able to be changed. If there is enough room to slide in a new bearing from where the old ones came out.
Metal filings could be from anywhere, If you take a sample of the oil and have it analyzed they should be able to tell you what type of metal it is. Or even swish a magnet in it for a couple min. If nothing sticks to the magnet than its non ferrous...bearings, most likely.
If s#!t sticks to the magnet...that could be a really big prob.

Never thought about it before but you said you held it at 6k rpm for like 7 miles...you could have a little valve knock.

I've thought about the valves, but there isn't much up there that would cause a knock and metal slivers. Gonna go tear it down some more today.

Dropped the main and rod bearings and they were ok. Where the damage is isn't obvious. The motor will need a complete tear down. So for the mean time I went and bought a 06 cobalt today, wow what a step up from the old j-body platform. I still plan on bringing the GT back to life after doing a rebuild on it. So my fleet is now up to 3 cars: 06 Cobalt, 01 MR2 Spyder, 97 Sunfire GT.

That sucks about the J man...but you should be able do most if not all the rebuild your self.

On a side note...what does the cobalt look like...pics??
does it have the 2.2 or 2.4?

Nytemare wrote:That sucks about the J man...but you should be able do most if not all the rebuild your self.

On a side note...what does the cobalt look like...pics??
does it have the 2.2 or 2.4?

Yeah I should be able to do all of the rebuild myself. I'll have to figure out how much it'll run in parts.

Black coupe with a spoiler, 2.2L. The spyder is fast enough for now, buts sooner
or later the cobalt will get some mods.

And on a plus note...its warrentied. and brand new...
So is the ride tighter than the J. I think i heard it is built on a delta platform like the Ion.
I had an 03 Ion out when I bought my 04 cavi..the ride was prety good...I found it more responsive than the cavi...
but I got an 04 for less than the 03 in the end...so I went with that.

Nytemare wrote:And on a plus note...its warrentied. and brand new...
So is the ride tighter than the J. I think i heard it is built on a delta platform like the Ion.
I had an 03 Ion out when I bought my 04 cavi..the ride was prety good...I found it more responsive than the cavi...
but I got an 04 for less than the 03 in the end...so I went with that.

I/m not saying the J-bodies are "bad". You can just tell that the 23 year old platform is easily out classed by the newer delta platform. The delta chassis is much more rigid. Even it it's old age the 97 GT felt more connected to the road over 80MPH.... even though she squeaked alot. However I think the delta platform will hold up better over time because of it's increases rigidity.

--Emery

Never had the Delta over 80...sales person was in the car..lol
In the end I like my Cavy more than the Ion anyway....unless it had been a quadcoupe....and there are more aftermarket parts for the cavy too.