Help: Metal in Oil Pan
 

Hello all! Quick background - I purchased a 65 GMC Suburban 2 weeks ago. I was told the 305 was rebuilt approx. 10,000 miles ago. The engine was running rough and was told it was the carb. I installed a new carb but still was running rough. Pulled the valve covers and found 2 bent pushrods, 2 loose push rods, and 2 stuck valves. Everything else looks new. I pulled the oil pan off to see what was going on below. Everything looks good and cranks smooth, but I found these 4 clips/retainers attached to the magnet in the bottom of the pan. I apologize up front for being inexperienced, but I have no clue what these are? Is it a sign that the engine needs pulled and completely rebuilt again? Is this something I can fix while the engine is still in? I really appreciate any input you can provide. Thank you.
Ken

Re: Help: Metal in Oil Pan
 

Those clips don't look like anything that belongs in one of these engines, I've torn into and assembled these engines numerous times and not seen anything like it.

Re: Help: Metal in Oil Pan
 

Thank you for the quick response Bigblock! Man I hope so. I've never seen anything like them. Really dumbfounded.

Re: Help: Metal in Oil Pan
 

Could it be parts of a mangled ring?

Re: Help: Metal in Oil Pan
 

They look like broken wrist pin clips, when you have full floating wrist pins.

Re: Help: Metal in Oil Pan
 

Clyde,

Thank you!!! Yep, that's exactly what they are. Unfortunately, with the spiral locks broken that floating pin was moving side to side in the piston which scored the cylinder. Not sure if it is repairable. Uggghhhh.

Re: Help: Metal in Oil Pan
 

Have you actually torn down the engine to see the damage in the cylinder wall? That retaining clip looked more like a u joint clip. All the ones I worked on and pistons sets I have look like a normal snap ring with the two eye holes. If damage is too severe on the cylinder wall it can be sleeved.

Re: Help: Metal in Oil Pan
 

Yes, unfortunately there are 4 perpendicular, symmetric gouges (2 on each side of the wall) where the ends of the floating pin would be hitting. I haven't taken piston out yet, but the gouge can be seen when the piston is at the lowest point in the cylinder. It probably doesn't make sense to just replace the clips and not fix the cylinder wall. Could a machine shop install a sleeve fairly easy without tearing down the lower end of the engine? The pistons and rings are newer, so can a sleeve be installed to match the current diameter so I can reuse the piston and rings? Thanks again for the advise!!

Re: Help: Metal in Oil Pan
 

The lower part of the engine will have to be torn down, there's machining involved to install a sleeve. As long as your piston has no damage it can be used again, I know someone with a 478 V6 that had a sleeve put in the block and used the existing piston. Check out the rest of those piston pin clips, maybe they're the wrong ones and post some pics of them, I want to compare them with what I have.

Re: Help: Metal in Oil Pan
 

What do you think caused the bent push rods? I think I would start over and check every thing. Bob

Re: Help: Metal in Oil Pan
 

Greetings fellow club member!

I hate to have to tell you this--but I do believe it would be in your best interest to tear the engine down again. what you have found in the oil pan are broken wrist pin retaining clips. This type of clip is most commonly found in agricultural or industrial type engines employing "full floating" wrist pins. Most automotive engines use wrist pins that are press fit to the connecting rod and do not use retaining clips of any kind.

Re: Help: Metal in Oil Pan
 

Another thing you might think about since you have to pull the engine anyway is just pulling it and setting it in the backyard under a tarp for spare parts. You can find a replacement 305 for about $100-300 bucks and you'll be in better shape. I bought a spare for Cecilia when I got her just in case something like this happens. Parts for a full rebuild are hard to find. Might be the cheaper route!

:goodluck:

Re: Help: Metal in Oil Pan
 

So here is a photo of the piston with the floating wrist pin and broken retainer/lock clips. Snap rings probably would have been better.

Re: Help: Metal in Oil Pan
 

That's the problem, why did whoever rebuilt the engine useing u joint retainer clips?:ahhhh: Snap Rings are normally used on these engines. I have bought 1/2 a dozen V6 piston sets over the years, one factory and the rest aftermarket yet all came with real snap rings:

Re: Help: Metal in Oil Pan
 

Because he lost the little envelope with the snap rings in it! My guess is the grove in the piston was not wide enough for the U-joint retainers and they did not fully seat.

Sorry, that engine should come apart again. Also need to find out why the valves stuck. Might not be too bad, but you don't know until you get inside of it. Sorry to hear of your troubles, sounds like a nice wagon.

Re: Help: Metal in Oil Pan
 

Bob, you're right, the snap rings that come with the pistons are much thinner than u joint retainers. Can't believe someone would compromise such a critical part in assembling an engine.:pullinghairout:

Re: Help: Metal in Oil Pan
 

Here's a pic of the correct snap rings that come with V6 piston sets. What I've noticed is not all my V6 piston sets came with the snap rings. It could depend on the manufacturer as well as being old NOS stock sometimes it may get removed for something else:ok:

Re: Help: Metal in Oil Pan
 

I have seen over a dozen different types of retaining rings for wrist pins. I have seen where the same piston manufacturer has used two different types during a production run. I have seen and used the type that looks like the snap ring for external u joint that was used in the above piston with the broken snap rings. Under light load conditions like the V6 and under 4500 -5000 RPM's most any snap ring will work if installed properly. If the rod is bent or the wrist pin bushing is wearing out then that will put an extra load and can break a snap ring.

Re: Help: Metal in Oil Pan
 

Best to use what came from the factory, I've only seen the ones I posted on factory as well as aftermarket pistons. Pistons for these engines are the same way too. OEM pistons are less prone to expansion while aftermarket pistons were prone to expansion and would score the cylinder walls, that was a real problem with these engines.

Re: Help: Metal in Oil Pan
 

Ken
Sorry to see you having troubles of this sort.

Since there are bent push rods and other issues as well as the clips, the engine needs to be pulled. There will probably be metal particles piled up in in places in the oil galleries.
It needs to be completly disassembled, cleaned, measured and inspected.

Do you have any paperwork on the rebuild or the shop name?

Re: Help: Metal in Oil Pan
 

Well the engine, I was told, was built approx.. 10 years ago and sat for a while. I am trying to track down the original owner who had the engine rebuilt. I am only guessing that it was run more recently with bad gas causing the valves to stick. Probably causing 2 pushrods to bend. I cleaned the heads up and they now appear to be okay. I am working with Rustbucket to get good running 305 to replace it. I plan to take the block to a machine shop and have the one cylinder repaired (see photo with the grooves cut by the piston wrist pin). Hopefully I will then have a working spare engine.

Thanks again for all of your responses and great advice!
Ken

Re: Help: Metal in Oil Pan
 

Greetings kcchampagne!

From what I've seen and read about in your thread, there are some people out there who should not be allowed to possess a wrench, much less be allowed to work on or rebuild engines of any kind!:pullinghairout: