Nstyc6

Hey all,

I just built an LS2 for my C6 and I've got a bit of an issue. As the title says I was alerted when my oil pressure was down to around 25psi, when I've been sitting a bit higher than that. Then it dropped to 0 on the freeway while I was test driving it and I immediately killed the ignition, and drifted off to the side of the road.

I​​​​​​ had a full 5.5 quarts of oil in the car a few days ago and now there is no reading on the dipstick. There is a ton of oil in the exhaust tip and on my rear bumper, with no visible leak around the engine bay. Therefore, this engine just drank 5 quarts of oil. I know the title says 10 minutes, I truly have no idea how long it's been leaking, but I had good oil pressure one minute and none the next.

This is my first engine build so I think I know where to look but I'd like some expert advice. Due to work I won't be able to tear into things for a little but can you guys tell me if this sounds correct, and if there are ANY other possibilities?

This car has PRC stage 2.5 243 heads, which means the intake rocker arms bolts all penetrate the casting of the intake runner. I used black Rtv sealant on all intake bolts but I'm thinking one (or more) of them is leaking and pulling in oil through the intake runner in the head.

1. Pull spark plugs and inspect for oil, they are under a week old so that should be telling.
2. Pull valve covers and inspect for any obvious signs ?
3. ?????

If that is the issue, what would work better than what I've done ? More Rtv? Different solution?

Can anyone think of other possibilities for me to look at?

Edit** There is only oil coming from the driver side exhaust. The passenger side header is free and clear internally.

Thanks all.

G Atsma

Sounds like you either wiped out a ringpack or oil seal(s). On the driver's side.

KCS

iTrader: (20)

I don't think it's the rocker bolts. RTV should seal it up just fine and if not, oil would be coming from both banks.

There's a number of possibilities, but based on the limited info, I'd lean towards rings installed upside down. If you put those Napier second rings in upside down, you're going to lose oil quickly.

Darth_V8r

iTrader: (4)

Agreed. You think a compression test would help isolate or verify that?

pdxmotorhead

Leak-down Test... If its pulling that much oil and its ring related you'll find it quick..

For this purpose the cheap harbor freight leak down tester will do and a small compressor works fine..

Nstyc6

I should have clarified that I did not touch the pistons or crank on this motor and those are OEM installed by GM. Everything on this motor is new except for the oil pump, rotating assy, timing chain, and the block.

The stock motor configuration ran and worked just fine.

I'll see what I can find out there, but based on those parts being untouched from the factory I'm sort of skeptical. Sorry for the confusion!!

KCS

iTrader: (20)

So what parts did you change then?

brandon6.0

iTrader: (32)

Pull intake and look into intake runners in heads. See if oil has puddled. Also maybe bad valve seals. Last check for leaks.

Nstyc6

Not sure if I'm forgetting anything but Heads, lifters, pushrods, front cover, water pump, harmonic balancer, cam, cam sprocket, timing chain tensioner, heads have new everything including rocker arms, springs, valves, new valve seals, retainers, etc. I'm running cometic head gaskets and anything that I crossed paths with received a new gasket. TSP did the valve job and CNC porting. Sorry if there was any confusion, just trying to get to the bottom of this safely!

I figure that would be the best first step. I'm betting that one intake runner has an oil stain in it currently but I won't know until tomorrow until I can take a look.

Nstyc6

Also most bolts ( such as the rocker arm studs ) are new.

Che70velle

iTrader: (6)

If you have oil actually coming/running out of the exhaust, this car must have smoked like the batmobile. I can’t imagine someone building a head and forgetting to put valve seals in, but it sounds that extreme. What valve covers are on the engine?

Crf450r420

iTrader: (1)

CNC on bad casting and the intake port has a hole, maybe?

Valve stem seals are not needed to run a race, just inject about a quart every time you gas the car. So, unless the guide has fallen out of the head it is most likely something else.

You say all oil, but did you add to it and find out how much? Only lose about 2 quarts and the oil won't show on the dip stick most times.

Nstyc6

I didn't get that far but I did get 0 psi reading on the dash. Will follow up.

Also, The car has OEM valve covers on it.

03EBZ06

Is the oil filter tight? bell housing? someone put that crank seal in backwards, valve seals come to mind since its in the exhaulst, but d*** thats alot of oil? I've had those sensors go out to btw. you may have multiple issues.

BlwnLs1GTO

iTrader: (12)

If it was anything that would cause the engine to burn the oil, you would have known this within seconds of driving.

Get under there and look around every where for some sign of oil loss. Fill it back up and let it sit idle for a while if needed.

Or, put your drain plug back in j/k.