Skidaddalin00

I have a 2000 Silverado 5.3 just freshly rebuilt except for pistons and crank. Which was all fine cylinders still had hatch marks from factory. Tsp 224r .600/.600 lift 110lsa, PAC 1219 single beehive springs, chromoly pushrods, new valve seals, 862 heads with a valve job, not ported and polished, long tube headers, roller timing chain, new oil pump, 2800 stall converter. Nothing extreme. Problem is, started up for first time Sunday and have oil coming out of driver side header. Only ran it for around 10-15 mins if that. It’s not tuned yet. Seems like cyl #7 isn’t firing as all the new header pipes turned a goldish tint except for cyl #7 still looks new. Removed the header yesterday no oil in exhaust ports. No oil on plugs, cyl#7 plug smells like straight gas. Kinda wanted to find out where oil is coming from before firing back up or to get tuned. Codes thrown were p0300 multiple cylinder misfire cause no tune and the computer is freaking out, egr which is deleted. O2 sensors bank 1 sensor 1 which was in the driver header probably what caused excessive fuel on driver side, and the 2 after cats which are no longer there anymore. All help greatly appreciated. Any questions please ask. I’m sure there’s something I forgot to say.





5 & 7 cylinder

1 & 3 cylinder

Header off truck turned on side

wretched73

iTrader: (1)

Well, Valve seal is most likely why you have oil in your exhaust.

Check to make sure you are getting spark on cyl 7

That p0300 isn't because you haven't tuned it. Its because cyl 7 isn't firing.

Skidaddalin00

Will check the valve seals again. The machine shop installed them, Only thing I didn’t do. Just hoping it’s not the rings. Was thinking maybe dumped too much fuel in cyl #7 fouled the plug and maybe washed the cylinder which may be where the oil came from? Will check spark also. Thanks

RedXray

Like posted check the valve seals on seven. I'd also make sure sevens injector is not dumping fuel fouling that plug. That may be a mix of fuel and oil in the collector. Number seven gets a lot of oil drain back from it's rearward location. Swap that injector with number one, five or three and see if the fouling follows the injector... after replacing that dead spark plug.

Skidaddalin00

Will do that also. Just a little skeptical on firing it back up after seeing oil in the header lol if it was the exhaust valve seals wouldn’t there be some sort of oily residue in the exhaust ports? Just wondering.

wretched73

iTrader: (1)

If there is oil in your exhaust, one or all of your exhaust ports should have oily residue.

That's the only way it can get there

Skidaddalin00

Probably can’t tell from the pics but there’s none. They’re all bone dry. One reason why it’s puzzling.

RedXray

I'd get that cylinder firing and if it's smoking out the exhaust then I'd look for where the oil is coming from. Usually bad seals causes the engine to smoke on initial startup and clears up after reaching operating temps. You may have a seal damaged during install that's not wiping oil off the valve stem.

arthursc2

iTrader: (5)

P0300 is random misfire

you may have more things to look at, but absolutely put effort into getting the obv 7 hitting

Skidaddalin00

Just pulled injectors and cyl 7 injector port was full of fuel. Interesting find.