Hello all,

Sorry if this is lengthy, but I don't want to leave anything out.

Last year, I found an oil leak coming from the back of the intake. Also, I noticed that when the car ran, smoke would come out of the breather cap I have on the passenger side valve cover (PCV is on the driver side). I verified that the PCV valve was working.

About a month ago, I started tearing the intake off. I finally finished it Saturday, got everything back together yesterday. Based on a conversation in a previous post, I also got rid of the breather cap and replaced it with a solid cap.

Today, I started the car and let it run for a few minutes in the driveway. No problems. I took it for a ride around the neighborhood, not venturing very far but drove about 1.5 miles. Came back home, everything was still fine - I checked the oil, the air in the tires and decided to take it for a longer ride. And that's when everything went to hell.

After driving about 1.5 miles, I was stopped at a light when smoke started billowing out from under the hood and through the dash vents. Luckily, the light turned green so I pulled out of traffic into a fast food restaurant and popped the hood. I saw flames and realized I didn't have a fire extinguisher with me. I ran into the restaurant, grabbed some water and doused the fire, which was small and confined to where the individual header pipes collect. There was also a trail of oil from the street to under the car in the parking lot, so I knew it was leaking.

So first things first: taking the car out without a fire extinguisher - especially considering it was the first time of the year and I had just had the intake off and the fuel lines disconnected - was beyond stupid. I would say I learned my lesson, but I knew better before hand. It was just dumb and a mistake I won't make again.

With that out of the way...I had my brother meet me at the restaurant with an extinguisher. After restarting, we were watching and the dipstick shot up and oil was spurting out of the tube, getting all over everything and collecting on the header, where it was catching fire.

I went back to my house, grabbed my breather cap and installed it, started the car - no issue. Well, no issue once the rest of the oil burned off. But the dipstick was fine and no oil was coming anywhere.

I removed the PCV valve, and the end of it was dripping with clear water - not antifreeze, but water - and was a bit foamy but working. Also, when I removed the non-breather cap, it too had water/condensation on it.

So...my questions:

1) Why the water? Was it just condensation from the car sitting for 6 months? Or something worse?

2) I assume "something" isn't right with the breathing of the car to cause an issue like this. Obviously, the quick/temporary fix is the breather cap but what else do I need to do/check? Is there a better PCV valve? Do I need to check the vacuum at the valve even though it's working?

Anything else I'm missing?

 

The opposite side of the pcv needs to be vented. Either to the atmosphere or back through the air cleaner to be burned.
it sounds like you completely blocked off the passenger valve cover?
this caused excessive crankcase pressure to build up and it found its way out...

 

I'll add that it also seems like excessive blow-by.

 

I was wondering about the blow-by as well. The engine was completely rebuilt, it has about 250 miles on it - I hope the rings aren't worn out or damaged yet.

For now, I'm going to leave the breather cap on it as it seems to have fixed my problem, I'll keep monitoring it and see if it gets worse.

 

The PCV system should keep a slight vacuum in the crankcase , thus being a "positive crankcase ventilation" . You do need a place for air to be drawn into the crankcase as the PCV valve draws air out and this is the breather you ended up putting back . Thing is , without the breather being open to allow air IN , the PCV valve should have put such a vacuum to the crankcase as to possibly even suck the china wall gasket IN and no way should a pressure have built up as you describe to be blowing oil out of the dipstick . As the other posters have well stated , you are having excessive blow by issues if the PCV system , even at idle speeds , couldn't draw enough air from the block to keep it from becoming pressurized like it did !

Where this is a fresh rebuild , I do wonder about the rings and how well or not they may have "seated" during the initial few runs ?

 

Is there - or was there - something I was supposed to do "seat" the rings? I assume at this point it's too late?

Unfortunately, I have 0% confidence in the guy that built my engine. I initially couldn't start/run the car because he had the timing marks misaligned and I had to tear the timing cover off to fix. I also had a small antifreeze leak, and of course the intake oil leak. So if I discover that something else is wrong...well, it won't be a surprise.

The two questions this leads to then is: 1) what other symptoms would the car have and 2) how do I test/diagnose for sure? I don't get smoke when the car runs, but I do have some odd hesitation issues when taking off (mostly at very light throttle), not sure what else I should look for/test.

Assuming that it is a ring problem...what is the next step? Do I drive as-is until it gets worse? Or fix immediately? If I drive as-is, do I risk breaking something else or causing more damage?

 

Were this mine , I think I'd troubleshoot and fix the slight hesitation you describe , I'd verify the PCV system is functioning properly , and then I'd drive it a while and see if putting some more miles on it may help the rings . Thing is , there are engines that have taken longer , up to 1000 miles or maybe even a few more , to seat the rings fully , and you have only 250 miles since the rebuild . Your blow by could be either the break in not really being finished at only 250 miles or it could be something more serious , but I'd like to see at least 500 to 1000 miles on it before I got too worried about it ,

 

Tell us what you know about the rebuild..

i/e did you have the machine work done, then purchase parts, then have some put it together..if so, let us know parts used...

Or did you drop an engine off and that person took it apart, took things into the shop...etc..

Did you use Chro Moly rings by chance?..I never have, but understand they need a different hone process to aid in seating properly.

 

Again, sorry for the long post but I want to provide as much info as possible:

The engine builder - he was an electrician that retired from both Ford and GM. Had always built cars, since retirement he did it for other people on the side. He built a 400 engine for my brother-in-law's Trans Am, it came out great. I met the guy three times, I visited his shop (a large pole barn) where I saw a bunch of his cars, got to hear them run, etc. Sat down and discussed options, sizes, etc. I told him the basics of what I wanted (383, around 400 HP, streetable cam, aluminum heads, etc.) and he gave me a price. Once I accepted, he provided me with a list - small block, pistons, cam, crank, heads, etc. I also got the printouts from the machine shop that balanced the crank. However, I think he got ill during the construction because when I delivered my intake to him he looked rough, and the final delivery was a bit later than we agreed upon. Then, after install, I ran into all kinds of problems. I don't remember what type of rings he used, and he provided the block. Other than buying the intake, I didn't have anything to do to with the main part of the engine build.

Miles - I'm guessing at the 250 miles. In reality, it's probably closer to 100 than it is to 250. I took it for one long ride, but other than that it has been mostly shorter trips (10 miles or less) as I've spent a good deal of time working on other things.

Break in - this is probably where I screwed myself. After reading a ton of posts about it and having conversations with people on this forum, I decided to start it with...well, I don't remember now. I want to say a light weight diesel oil? Rotella, maybe? Anyway, that was the oil I had in it when I couldn't get it started (timing marks were misaligned). After playing with the car for a month, maybe longer, I finally fixed the timing issue and got the car running. I ran the car for a few hours (but very few miles) on the oil, then drained and replaced the filter. But...I put synthetic in it. I'm reading now that probably wasn't very smart.

Hesitation - Ugh. I've been trying to figure this out for a year. When you take off really slowly, the car "chugs" or hesitates. It's odd because while it's doing that, the RPM's don't change, at least not much or in conjunction with the "chugs." It's like if you cut the gas off or something. I've data logged multiple times and sent the files to the people that burned my chip, they say they can see nothing. I changed plugs, too, but the original ones didn't look bad or wet or anything.

 

Did you go with a roller cam or flat tappet?...that's really the only concern on initial start up...to break in the flat tappet cam/lifters correctly.

Curious, what heads and intake did you use?

 

Full roller cam, a mild one. Edelbrock Performer RPM heads (I don't remember the model #) and the Holley Stealth Ram intake. Overall, it's a pretty good setup - sounds good, runs good with the exception of the hesitation/chugging at partial throttle.

 

Where your breather is on the pass valve cover, mine goes to the TB.

When you fire it up with the breather off, put your hand over/above the hole and feel why kind of pressure is there.


Unsure if your surging is related or not...but the plugs are burning clean, no ash/oil deposits on them?

 

So the breather you have has a port for a vacuum hose? And that goes to the TB? Where do you have your PCV valve hooked to? Right now, my PCV valve is hooked to the port on the bottom of the upper intake.

When I took the first set of plugs out, they were a little wet...but I had been trying to start/run the car with the timing gear a tooth off. I replaced them and ran the car for...X amount of hours, then pulled a few of them again and they were clean. Not wet, no oil or ash.

 

Pretty sure my PCV (driver side) goes to the plenum, but will check in a bit...mines not a breather, in fact it looks like a PCV, with nothing inside it...in effect, just a plastic elbow running to the TB.

Edit:

My PCV runs to the intake manifold.

 

In my situation, would a setup like this help or hurt me? If I plumb it like you did, wouldn't that create a vacuum on that side, thus not giving the pressure anywhere to escape from? Or is the idea that the vacuum would cause the pressure not to be there in the first place? I'm not opposed to trying it - I know I have a port on my throttle body that is currently blocked off - to see what happens, but I don't want to create a repeat of what happened yesterday.

By the way, thanks for all the replies & advice.

 

I think you'd be better off running it to the TB, it would also eliminate oil films/stains on the VC...you may not have blow-by, but may have just had pressure build up...if you have blow-by, it would be evident at idle as well.

All good.

 

Good call. I'm going to go and pick up the pieces I need.

As for the oil, I was planning on doing a change soon since I had the intake off. Should I switch to a conventional oil for now, or is it too late to worry about and just stick with the synthetic?

 

I'd say yes, Put a few thousand miles on it before put'n synthetic back in.....

 

Will do.

One more question. I started doing a bunch of research and found a ton of posts on here about running a setup like 8Mike9 suggested, some have a PCV valve in each side and others have 2 PCV valves AND a breather. Seems like a PCV valve in each side would fight each other, right?

If I go with a PCV valve in one side and just a tube in the other, does it matter where I get the vacuum from? If one comes from the bottom of the upper intake and the other comes from the TB, will that be an issue?

 

PCV valve gets it's suction from the lower intake in stock setup. You have it in the plennum, which should be ok.

I think your issue is the fresh air supply on the passenger's side valve cover. It needs to get it's air from the port on the throttle body. That port is UPSTREAM of the throttle blades so the pressure will be higher to allow airflow through the crankcase. The other reason the fresh air supply is located there is because the air has already been both cleaned by the air filter, and metered by the MAF.

 

That makes sense. I went to four auto parts stores last night, couldn't find the right sized elbow to plug into the valve cover. A breather cap that has the vacuum hose port on it is the same thing, right?

Going back to the oil question, is regular 10w-30 a good oil to use for break-in?