If that is milky chocolate color oil I would immediately drain my oil and see if it all looks like that. If it does you either have a blown head gasket or a crack somewhere allowing antifreeze into the block contaminating your oil. Do not drive it until you do this. If your drained oil is like this I would have it towed to wherever you are going to have it fixed at. If you aren't going to do it yourself. If its just a blown head gasket it is a relatively easy fix. Need to check the head for warp. If it is warped you will need to get the head planed. If not a blown Head gasket you may have a bigger problem.

 

Sorry if these questions are answered in the previous posts.

How long do you drive the car with oil temps "hot" (or how ever you want to identify the normal operating temp of oil)?

How cold is the weather there?

Have you done a leak-down and compression test yet?

What do the plugs look like?

Have you found oil in the coolant?

Are you getting any codes?

Do you have any scanner or other means to know what the air/fuel ratio is?

 

Coolant in the crankcase.

Your heads need to come off. Possible blown head gasket OR leakage of oil from the heads into the crankcase and vice versa.

When the heads were worked on/machined, were the spring pockets enlarged for larger diameter valve springs? The cutter may have cut into the cooling jacket on the head. I have experienced this in the past and the "cut-through" portion was small and went un-noticed initially, but that's all it takes. A cooling system pressure test and compression test on the engine can be very helpful here, but that crap-in-your-cap is NOT good.

After the heads are off, a pressure test can be performed on each head if necessary.

 

Its NOT a deal breaker. There are TOO many things to consider before you condemn the engine.

1. Was it thee before this event?

2. As manley845 previously stated all of his questions and they are relevant.

Find the source of the NOISE, and then determine the repair. Check the oil in the crank case and coolant in the tank to see how they look.

See what Stephen (ENGLANDGREEN) and Jason says as they have the hands on technical look and other facts.

BC

 

I agree with Manley and BC. I just am gun shy with blown head gaskets. The oil is easy to check and I learned my lesson about driving with a blown head gasket early in life. I just don't want to see anyone do more damage to their motor. Not jumping to conclusions just trying to be helpful. Nestles Oil is not a good sign.

 

You have a street car with a 160* thermostat. You are never getting the engine hot enough to burn the condensation in the crannkcase off. The breather you have is making the condensate issue worse. I prefer a proper working closed pvc system with a low value pop off valve that opens under any positive crankcase pressure.

You don't need a dyno tune. You need to make sure there isn't a mechanical or electrical malfunction. Then you need someone that understands the RAFIG, cracker, & follower, and getting the spark in the correct range to make it start, idle, optimize wot, and make it behave on and off throttle. It takes quite a bit of time to really dial a tune in for optimum street manners. You get a big old cam stuffed in there and you're going to have some low end weak behavior and some surging at times. You can't make a monster cam drive just like a stock bump stick.

 

Keep us posted on developments. I am interested in the outcome.

 

Yes.... I've had some of these same concerns. The builder will be back on the 3rd and I'm hoping to link up with him then. I've never understood (completely anyway), the whole idea of the 160 degree thermostat on a daily driver car. I don't think heat is a problem for these cars, even living where it gets 100 degrees sometimes. As for the car's behavior, part of it feels like my when my old school carbureted 350's were cold in the morning. As for the pcv system, I wish I could just have a stock one back. The only thing I can figure (and feel free to clarify) is that I couldn't run the stock system on an LS1 engine running LS6 heads?? Not sure, but the crankcase gasses in the interior have to go away before I die of CO poisoning!! It's really bad! I'll keep everyone posted.

 

You could run the stock LS1 PCV system with the LS6 heads.

 

Just a couple of thoughts and questions. First if you haven't yet get a hydrocarbon tester for your anti freeze to verify the leaky head gasket. You cap does not look good to me. Have you deleted your O2 sensors and running just off the tune or are you running heated O2s. If not I am sure you know you may not be getting into closed loop. Here is a quote from LS1tech
"the only way you could get the car to run without upstream o2s is with aftermarket upstream 02s feeding the pcm signal (which is upstream 02s anyhow) or with a completely standalone engine management system programmed to run constantly in open loop and never look for upstream 02 signal."
http://www.ls1tech.com/forums/conver...-problems.html

Not knowing the full extent of your fuel management situation I wonder exactly what your tuner is doing. Can you give us the specifics? The previous post about condensate is right on so you may not have a bad head gasket but too much condensate that is not going away which is why I said to do a hydrocarbon test. 161 is too cold.

Whatever it is time for your builder/tuner to get it togther I don't care how nice they may be they are not giving you what you paid for. That make me sad. You have seen the commercial with R. Lee Ermy time to go all mamby pamby on them.

 

Might give these a read if your concerned about your cap.

http://www.ls1tech.com/forums/genera...-pix-here.html

http://www.ls1tech.com/forums/genera...s-oil-cap.html

http://www.ls1tech.com/forums/genera...l-cap-wtf.html

 

Good and welcomed inputs all.. I'm on pins and needles until my builder gets back on the 3rd (damned holidays...lol). But, I'll definitely let everyone know what I find. I'm having my oil drained this afternoon to see what it looks like. Also, where can I get the hydrocarbon tester and are they expensive? Sounds like a good tool... Also, my tuner mentioned that he had turned off my O2 sensors (suspected bad by me) and will replace them when he returns. As far as I know, I only have the front two sensors and the others were deleted since I'm not running cats... As for the tuning around this, unfortunately my knowledge stops there. I'm definitely going to ask him though..

 

BTW.... Posted the following on general discussion with no inputs at all. Since it is related to my current problems, I thought I'd ask you all and see what you think... Is this a related problem??

Okay, so I was looking at my car (2001 coupe with LS1/mods) and noticed some smoke, condensation or something coming OUT of the oil fill port with the cap off.... However, this isn't the weird part... I was looking at another guy's modded C5 Z06 last night to see if he had similar gasses coming from his oil fill port (here's where it gets weird).... Instead of puffing anything out, his was pulling so much vacuum that pulling off the cap was like opening a new jar of pickles or something... I replaced the cap for a second and repeated it with the same results. Now, my question is this..... Is my engine the normal one (blowing air out of the oil fill) or is his the normal one with the vacuum?? Of course I know that engines create a vacuum and that big cams can decrease this vacuum, but in this instance specifically, should the engine be expelling air or sucking air from the oil fill/valve cover?? Do I have a vacuum leak someplace or something?? Thanks and I apologize for the seemingly stupid question, so be gentle,but this was kinda puzzling for me to see the opposite on these two cars and I'm wondering who has the issue....him or me???

 

The O2's are potentially one of your issues especially in a header car they may not get hot enough to turn on thus you are running in open loop dumping gas with no feedback from them.You can run without them but drivability will suck and your tune must be dead nuts at various RPMs with the A/F ratio corrrect. If you thought they were bad that may be why. Heated O2's fix that issue and yes you only need the upper 2. The hydrocarbon test most shops have them you can call the parts stores tell them you want to test the antifreeze for oil.

 

as far as pressure
http://www.ls1tech.com/forums/genera...erts-come.html

The LS-Series engines are prone to excessive crank case pressure build-up resulting in oil blow-by, oil consumption, and oil wetting of the intake manifold. One of the first changes from GM to help resolve this issue was the bay-to-bay “windows” placed in the main webs of the blocks. Any increase in cubic inches places more demand on the PCV system, regardless of the engine type. GM has made several changes to the PCV systems over the years and many consumers have a mismatch of parts and components. It is imperative that you inspect your PCV system and make certain that it functions properly. If you are using a factory PCV system it is required that you use a new “fixed orifice” PCV valve for routing your pressure relief hose from the valve cover. This valve is included with all custom XXXX LS-Series short blocks and engines. The GM part number for this item is #12572717.

http://www.ls1.com/forums/archive/in...p/t-92556.html

Short answer is yes they should be some pressure how much is up for debate

 

Do you have a catch can installed? If so did you eliminate the PCV valve by accident? I see people installing atch cans all the time and throwing out the PCV hose, replacing it with the open hose from the kit. This is incorrect.

 

Good information, but not sure on one point... So, is the short answer that air should "blow" out of the oil fill when the engine is running or "suck" in?? Our two cars couldn't have been more different in that regard with his like breaking the vacuum on a new jar of food... Can't wait to check on the other stuff tomorrow (no work!!). As for the pcv system, I can't for some reason post this pic on here directly, but as far as I know, this little "breather element" is the ONLY ventilation I know of for the entire engine. The builder has ordered and is supposed to install something else to relocate this venting somewhere forward, but I'm not sure what it is. He said he doesn't like catch cans, but I'm up for whatever is (and I stress this) PROPER for this engine to make it RIGHT and not band-aid fixed. All I know is the fumes in the cabin are wicked to say the least. Here is the link to the pic of my "breather" filter....

http://i552.photobucket.com/albums/j...ownload070.jpg

 

Think of it this way when the cylinder fires the air and gas expands. If the rings are good there is a tight seal in the cylinder but not perfect so a miniscule amount goes past the rings this is called air blow by (oil blow by is the oppisite when pressure is so high in the crank case it pushes oil up past the rings into the cylinder). That creates positive pressure in the crankcase. The more wear on the rings and cylinder walls the looser they get allowing more blow by and more pressure build up. How much pressure is acceptable I do not know I am not really an engine builder but there should always be a little IMHO I could be wrong lets see if anyone disagrees.

I suspect his engine has an operating PCV system that removes the pressure and sucks it into the intake so yes he has a vacuum you don't because you do not have an operating PCV system.

 

im running a TR Trak cam (231/234, .598/.648 112lsa) with stock heads upgraded valve train and an ls6 intake. everything else is stock including the pcv system. I dyno'd at 396 and tuned it myself with HP tuners, i just pieced together a bunch of uploaded tunes from their repository with people running the same type of mods. i still get 28-29 mpg highway but my city mpg dropped to around 18 from 23.

my advice is: with the cam you have (and i thought mine was a monster) and aftermarket heads, you should be running way more hp and it should be decently streetable with an lsa of 113. fire your tuner, raise hell and try to get some of your money back.

my .02

 

With the PCV system in place on an engine that's essentially stock, the vacuum will be much higher than a big cam engine. In the OP's case, with the PCV system either removed, or negated by the install if a breather, there cannot be any vacuum in the carnkcase. Even if the PCV were fully operable, engine vacuum wouldn't be as high as the oem car.

My suspicion is that the Z06 with apparently high crankcase vacuum doesn't have a pcv valve in place or something isn't right with it either. None of my LS engines have had a noticeable vacuum on the engine when removing the oil fill cap at idle.

There's so much speculation here about what the problem(s) might be w/o knowing much at all about the build and current configuration that it's just too much. However, seeing noticeable blow by coming out the open filler at idle is not a good sign. That issue would concern me.

About the discoloration under the oil fill cap. That doesn't really concern me. It looks old to me. Likely occurred before the new build. The oil fill cap is the highest point on the engine and condensation accumulates there in a closed system. That isn't going to happen on an engine with a breather installed.