venom 13

iTrader: (7)

THE PROBLEM:

I need some help diagnosing my engine problems on my LS1. As some of you already know, I hurt it this past Sunday. Did 3 highway pulls, and on the 3rd pull I heard a slight funny noise, then upon cruising at a lower speed the motor started to sound and feel a little off. Got to the lake, turned engine off, and then restarted it a few minutes later. Smoke (looked white to me) began pouring out of the exhaust, and then I turned it off. Towed it back to my work, did some more trouble shooting last night.

Engine:

PRC 5.3 L heads on top of stock bottom end.
Big Cam
Upgraded springs, but have not changed them in a while
LS6 intake
Under drive pulley
105,000 miles
Never had nitrous or any other power adder.
Plugs were changed 10,000 miles ago, maybe a little less.
Mobil 1 Synthetic oil.


Symptoms:

-Oil is the color of milk chocolate, but is a right oil level.

-After startup there was no initial smoke, as car began to warm up, it started to pour smoke again.

-Smoke/Exhaust smells like coolant to me, but friend said smelled like burnt oil.

-There is a definite knock coming from motor (wasn't there before)

-Coolant in radiator seems a little low, but not much.

-Coolant reservoir looked ok.

-Yellowish film/gunk on oil cap, but I think that is just because of the high Louisiana moisture (seems to be confirmed from what I've been reading.

-When idling the car after warming up some, puffs of white smoke began coming out of oil fill tube. (Cap was removed)

Oil cap:


Picture makes the oil look darker than it actually does in person:




Here you can see some of the smoke and barely hear the knock (sorry but the exhaust is loud, but when hearing it in person you can hear the knock clearly)
http://www.youtube.com/watch?v=Htp20zYSnWo

And here's the smoke...it doesn't look like much but it starting clouding up the shop quickly
http://www.youtube.com/watch?v=jrYoAChSGIA



So the question is....how bad is it? At first I thought it would be a bad head gasket, possibly cracked head....maybe even cracked intake considering the oil is not what I would consider really milky. Now starting to think it could be piston ring or wrist pins. Any ideas?



Thanks in advance for any help.


UPDATED PICTURES ON POST # 26

BlumaroZ28

from what it sounds like to me you are on the right track with the head gasket/cracked head theroy. that does not mean that is the only problem. when you get coolant in the oil it can wash the bearings and rings causing knocks and other noises. i have rebuilt many engines that started off as a leaky intake gasket or head gasket but turned into a bad lower end as wheel form having coolant in the oil. either way it can be a pricey problem. hth.

BlumaroZ28

Car still looks damn nice though...even on the trailer!

Scott02WS6

iTrader: (8)

I agree you are on the right path with the heads theory, go ahead pull the heads off and start there. take the heads to a machine shop and have them do a thorough test/inspection of the heads.

1ltcap

either a cracked head, blown head gasket. check your plugs to narrow down the cylinder. once you know which cylinder, take the schraeder valve out of your compression tester, screw it into the plug hole, and pump shop air into it. watch the radiator.

trans_am7935

iTrader: (15)

yes i agree that this sounds like a head gasket. i would also drain the oil, and inspect it upon removal. you can also pressure test the radiator system, to see if it is leaking. if you do indeed find a foul plug, then test the coolant system pressure with the plug removed. if you hear air coming through, there is your problem.

the knock could be a rod from the coolant mixture. hopefully you can just change the oil, and the head gasket (if this is the issue) and the knock will go away

The Alchemist

iTrader: (19)

Pull the number 7 spark plug and take a peak. Let me ask, when you put on the ls6 intake, did you block the rear steam vents? If so, my guess, is you popped a ring land on #7.

trans_am7935

iTrader: (15)

i had this same fear which is why i have a cross over pipe back there, 2 LS6 set-ups

The Alchemist

iTrader: (19)

Or this could be a broken valve spring or bent pushrod etc.

513camarors91

iTrader: (5)

sounds like a head gasket like they said^

1ltcap

another note......if the oil's looking milky, then coolant has gotten into the oil. check your bearings carefully. generally once antifreeze has gotten on the bearing surface, it's only a matter of time.

bjamick

iTrader: (31)

Ya drain the oil asap. Sounds like it's just a headgasket.

c0ncEpT

iTrader: (4)

^What he said.

Probably broke a ringland and cracked the block.

The Alchemist

iTrader: (19)

I wouldn't go as far as to say cracked block, but only time will tell.

venom 13

iTrader: (7)

Thanks man.





Thank you all for the input and advice. As soon as I get off of work I will attempt some of the ideas you all suggested. I am going to go see if advanced auto has the compression tester I could rent/borrow.



After I check the plugs, I will try the pressure test that was mentioned. To futhur clarify...find plug, remove schrader vale force compressed air into spark plug hole and watch for air bubbles in the coolant?

OR

Should I just remove plug, pump air into radiator and listen by the spark plu hole?



Should I run an actual compression check as well, while I have access to the tester? (or at least just check the possible cylinder after checking plugs?)

*If I do the compression check, it is my understanding that the car must first be warmed up, and that takes a while in my car...will I be doing more damage to engine than actual good?

I will also address draining the oil.


As for the LS6 intake goes...it was already installed on the car when I purchased it, so I don't know if they were blocked or not.

Thank you for all the help so far, any further input is still welcome. I will keep you all updated.

1ltcap

you can do either way.

one more thing i forgot to warn ya about....when you put shop air into the cylinder....if it's not down at bdc, the pressure's gonna rotate the engine till it is. be careful not to have anything near any rotating parts, so it doesn't get flung.

venom 13

iTrader: (7)

Thanks for the heads up. Is there a certain psi I need to be pushing?

1ltcap

if you're using full shop air, you can regulate it down to 50psi if you want. it'll still show. you'll either see air or hear it in the radiator.

it's not necessarily the "right" way to check, but it's a fast effective way though.

91sonomast

Most leakdown testers(which is basically what you're doing here) run at 100psi via a regulator on the tester, 50psi should work but if you don't hear anything crank it up to 100psi to make sure.

The Alchemist

iTrader: (19)

Remember, during combustion, cylinder pressures are quite higher than 100psi. So even at 100psi, you're safe.