I have a Cat 953 s/n 20z01274 with a 3204 motor. There are four machined holes across the intake side of the head right below the valve cover. Three of them are covered with bolts/washers with rubber seals, the washers say: “Do not use sealant - China” so I know they’re some sort of aftermarket part. The fourth hole is just an open hole that you can see into the head. Oil has been coming out and draining down the side of the engine which is how I found it. Trying to use part diagrams I think there is a plug cap that is supposed to go in the holes if it is oem: Part# 8F-6575 (part #6 in the attached diagram) So this leaves me with 3 questions: Is it normal to switch those plug caps with a bolt/washer/bushing type setup? If so, if one is missing, does that mean a backing portion of it fell into the engine? Is the cat number the correct part, and if so can I push it in from the outside or would I need to remove the valve cover anyhow? Thank you in advanced, I feel like I’m on the right track, but I am hopeful someone can give me some closure and or guidance. Thank you all!!
I’m thinking that is where the injection lines used to enter the head . There would have been an adapter with a fuel injection line attached. I guess your machine has external fuel lines and injectors. Could this head have come off of a 3208 possibly.
Yours would have an adapter box where the lines go through.
My lines go in on the exhaust side similar to the diagram you attached. The holes in question are on the intake side.
On a 3208 they go through the head you can see the holes on this picture
I have marked in red arrows the holes I am referencing in the attached image.
You should be able to put the cat ones in from the outside. If you pull the valve cover you can see how much dirt got inside and check for the missing plug.
I appreciate your replies, thank you so much.
Sounds to me it just has rubber expansion plugs in the holes that fourth one may have just fell out if the nut backed off
I did not realize these were a thing. I looked it up, that is exactly what it is. So glad to see that there’s no piece to fall in if they get loose. Napa has them for $3.70. Going to swing by and reinstall it this afternoon. Thank you!!
I think you'd want to pull the valve cover and see if any dirt or debris got in inside. Hopefully not but not worth taking a chance.