Plastic in oil what to do.
 

I pulled my valve covers the other day and notice chunks of plastic sitting on the heads. I read its usually the timing gear that failed. The motor was running fine but is it possible to just clean out the motor and replace the timing gears and chain and be OK or should I be more concerned there is more damage. I'm not to happy but I'm hoping everything is alright.. Thanks

Re: Plastic in oil what to do.
 

Are you sure it's not failed valve seal umbrella pieces? I'm trying to picture how large chunks of timing gear would get up there without going through the pump and getting filtered out. Maybe they could bounce and work their way backwards through the drainback passages between the valve covers and timing chain area and bounce up into the valve cover area? I don't know. I don't want to doubt your observation; I'm just brainstorming to see if it's something else. Something easier.

What color are the plastic parts? Valve stem seal umbrellas are usually dark and nylon timing teeth are usually off white.

You might be luckier than you think. If it's not the timing chain then you could get by with just a cleanup and new seals and gaskets for the heads.

Re: Plastic in oil what to do.
 

Did you happen to take pic of the pieces? What color were they?

Personally I don't see how they got by the oil filter. Might be something else like broken pcv.

Re: Plastic in oil what to do.
 

Valve seals. I would clean it out and keep driving until the puffs of smoke become too much of an annoyance to you.

Re: Plastic in oil what to do.
 

It is chunks of black plastic smaller pieces I’ll post a picture.

Re: Plastic in oil what to do.
 

sounds like valve seals..thats about the only thing that would be under the valve covers...does it smoke a little when you first crank it cold?

Re: Plastic in oil what to do.
 

After you guys mentioned it I am certain that what it is. No pics at the moment but what I see online that’s it. It’s hard to tell the exhaust dumps under the truck but I’ll look next start after I clean it out.

Re: Plastic in oil what to do.
 

Most of the plastic timing chain gears I've seen were whitish that turned brown after years of use. They stopped putting those in engines many years ago.

Also, about 4-5 years ago I removed the valve covers on a 1977 Corvette engine I had bought. I found small black chunks of plastic that turned out to be totally dried out and brittle valve stem seals (as mentioned above). I used compressed air to remove the valve springs and replace the stem seals.

Re: Plastic in oil what to do.
 

Definitely agree it's valve stem seals. I recently replaced the worn out timing gears on my '68 so I know all too well what that looks like. I dropped the pan to replace a leaky rear main seal and was greeted with a pan full of tiny plastic pieces. The oil pump was also jam packed with bits. I had no clue what to think of this until I did some searching here on the forum and realized my truck had plastic timing gears!

https://farm5.staticflickr.com/4190/...04eb268c_c.jpg

Re: Plastic in oil what to do.
 

Wow that is bad! Yeah the chunks in mine look different you can tell that is from the timing gear on yours.