Gmachine

I pulled the engine on Monday, but had school so I wasn't able to do much else. You'd think college's would have Labor day off!

One thing I found was that the back motor mount bolt went through the motor mount, but not the ceter hole it was suposed to. Leads me to think this motor's been out before.

I pulled the tranny yestday and found that my throwout bearing is shot, and one of the four springs on the clutch disk was loose and had been spinning loose for a while.

Pulled the oil pan , but haven't gone any further.

This is all due to good oil pressure in the block and half of what it should be in the head!

I hope to find something.

Gmachine

Upon dumping everything out of oil pan yesterday I found a 1" long piece of plastic, slightly curved, 1/2 tall, 1/8" thick. I don't know what this is from. I'll have pics up by tomorrow. I also pulled the head. WOW, the carbon! I looked like a sun burn gone bad! Think layers of carbon pulling away from the tops of the pistons.

I'm guessing the oil passage leading to the head is in the middle of the head twords the intake? There's no o-ring in the groove as I'm guessing there should be? Maybe the cause of low oil pressure. I'm also pretty sure that it's been open before as some scribed marks were on the cam holder plates. I can't imagine Honda did this.

Gmachine

So I'm almost finished pulling everything out of the block now. I only lack the crank and one balance shaft.

So far I haven't found anything other than lots of carbon! I believe the cylinders will need bored and honed as I don't see any hatch marks at all.

I did find this odd piece of plastic in the oil pan that I have no idea about??

I also found some wear on the oil pump, but haven't been able to get the cover off the back to look at it any more. I'm guessing I'll take it to work and drill the heads out.

Sorry, webshots, so I couldn't post em!

http://rides.webshots.com/album/553992581gTTKiq

Killer_Vtec

The plastic piece was in the oil pan the whole time

hustler904

man you werent kidding about the carbon buildup

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Chung

Gmachine

I pulled the pan and let it sit under the engine over night so when I drained it I found it in there. I pulled it at my parents place and i don't think my dad would have dropped it in there or have any idea where it would have come from.

Yeah, the carbon is BAD!

I'm not sure why, but I now know why I kept throwing a rich code. I'm thinking of having the injectors cleaned and flowed while it's apart. I'd first like to diagnose the oil pressure issue in the head. So far I haven't found any schrapnel any where that would cause any kind of blockage. I haven't pulled the head apart any more than what you see.

Any ideas on why the carbon build up is so bad?

hustler904

all i know is all 5th gens run rich,i've only got 45k miles on mine and everyone who drives behind me says it smokes pretty bad,been doing it for awhile too,doesnt burn any oil,just shoots out alot of carbon,i think the motors just need to be leaned out

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Chung

NotoriouSH

For a Prelude not to burn oil and run rich is rare. I installed a catch can on the PCV line, so I can see a fair amount of oil is lost through that, but I'm still losing some oil otherwise that isn't dripping out (the engine is amazingly clean, Honda definately builds them right). As for running rich, when I reinstalled factory parts (oem exhaust, Type S intake) and ran the engine long enough to let the ECU establish a good map with long term fuel trim, my gas mileage is terrific and I have zero black soot on the bumper. Back in the day when the car had power mods, the bumper would accumulate a layer of black soot on it within hours of driving.

marcucci

Sure the plastic wasn't from something that fell in when the pan came off? There is no plastic in the motor, only stuff that wraps around it (timing cover, IAB controls, etc.). Looking at your pic

The oil supply to the head is in between the #2 and #3 cylinders on the intake side- it looks like a bolt hole for one of the head studs. There is no o-ring, the head gasket takes care of sealing this port.

The carbon buildup you have is normal with a high-mile engine. You may be a little worse if you were throwing a rich code, that will definitely cause more buildup & can cause increased oil consumption. If you were throwing the code I would definitely have the injectors checked or just get new ones.

As for the oil port, check it in the head & remove the plugs and inspect the gallies. I suspect you will find one plugged or constricted. If that plastic was indeed in the oil pan, there may be something else in there. Someone may have done some work on the motor & left some crap in there that was beat up & somehow ingested. Check the pickup screen and make sure it's not plugged.

Gmachine

Yeah, the pick-up screen looks good along with everything else so far. I'll look more into those oil ports tomorrow.

I'm also thinking that this piece of plastic came from something else, not from internals or even sitting in the pan