Check the throttle valve (aka...throttle body) top cover piece. It can go loose and cause the map to fluctuate. (This happened to me) Loose fasteners always happen. More common when you mod. B.

 

What is the preferred method to check the fit of intake to heads? Modeling clay or something?

Would a vac. leak be enough to pull oil out of the valley into the intake track?

I have a stock intake we could try as well? i just need to port to 58MM first - I know.

 

Can you spray carb and choke cleaner around the intake gasket and watch / listen for a change in idle? Is oil all over inside the intake? Is the pan on the bottom of the intake? Were those plugs removed from the under side of the intake? If so, were they reinstalled w/ GMS, silicon or equivalent? Maybe air and oil are getting up through the threads.

 

Thanks for the repiles.

The heads are going to a machine shop for an inspection. It'll be a week or two...or three, until I'll have enough time to finish removing the heads.




Want to sell it? I'll need to have it milled, and I don't want to alter it if you're wanting to use it in the future.


I used a butane torch (sans flame) around the intake gasket area and I noticed no difference in the idle. Butane would get a reaction similar to carb cleaner, right? There is oil inside of the intake. The pan is on the bottom if the intake and the plugs have never been removed. The intake has seen several hours in an oven at 420F...but that was like 6 years ago and it didn't leak previously. I do plan on removing/reinstalling the plugs when I remove the intake this time. The plugs are NPT, right?

 

The plugs are NPT...

I think you told us already but what are you doing with your PCV set up? Stock?

 

All stock, new parts.

 

That might be part of where the oil is comming from. Its not uncommon for the stock system on an LTx motor to push oil thru and into the intake.

 

What options are available other than stock?

 

You can go old school and delete the PCV and just run a breather or 2 in the valve covers. Or a bit more expensive if done nicely... run a nice catch can set up with stainless lines off of each cover... or big expensive and run a crank case vacuum pump.

Anyway you go will eliminate crankcase venting thru the intake. It was an emissions thing. burn the crank case fumes. To do that they used a PCV system to send the fumes back to the intake. Its not uncommon to carry the oil vapors all the way back to the intake as well.

I'm kind in the same boat. On the dyno I kept pushing some oil ou the dipstick cause the stock PCV system cant vent the crank case well enough.

 

Don't really want to sekk, I have plans for it but if need to borrow it I'll do that.



I've plugged TB and ran a hose from the valve cover to the air cleaner ( now I need a catch can ) but this is pulling enough pressure out if the block so that now i'm pushing oil out under boost.

 

Sometimes the intake leaks from the lifter valley. That can cause a number of really stupid problems... Id pull the intake to see if you have oil in the intake runners.

 

Thanks for the info. I've seen the pump on some engine before...hopefully I won't need one. If so, I think the catch can idea seems like a happy medium. The first time I filled the oil with 7qts and was getting oil out the dipstick tube. Chad Golen told me that it was too much and I should only use 6. Using only 6 stopped the oil coming out the dipstick tube, but I thought that one benefit of the Canton pan was to increase capacity. Oh well, that's a topic I will worry about later.


Thanks anyway. Sinistr on sd.org said that has one for sale.


The first time I pulled the intake there was oil inside of the intake. I didn't pull the intake for the second time just yet, but w/ the TB off it is clear that there is oil inside. I hope to remove the intake in the morning. The first gasket set had a good pinch and I am thinking that this time will be the same. When you say it might be leaking from the lifter valley, do you mean oil from the lifter valley getting past the gasket? Or through the bottom of the intake?

 

I have been trying to get in contact with you for about a month now.

 

Ever think I just have ran out of suggestions? I written you probally 25 emails since you've started this engine for the first time so don't act like I haven't been any help. Sorry if my correspondance hasn't been to a reasonable level for you. I have also sent you 3-5 chips on this new engine.

I would like to know how this mysterous vendor plans on tuning out such a huge split BLM problem.. Which by the way is not just at an idle like most big cam LT1s suffer from... It happens while driving also. Prehaps the right bank needs 15% more fuel.... but only some of the time? Not to sound like an *** but maybe this mysterous tuner can tune out your vaccum leak!

 

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