Sick of Smoky startup - can I change valve seals with heads ON THE CAR?

No unmetered air enters through the oil cap. Just allows pressure out. There is a huge difference between installing a breather in the PCV and installing a breather in the oil cap. Look into it. My mirror is ruining great,.and no smoke, no hassles.
 
bolson,
I'm sure it's not a lot but any time you allow air in to or out of the crank case, it's 'unmetered'.
I think you're saying that the breather that some have linked to only lets air out if the PCV system can't 'suck it up' fast enough but that air is blow by - which came from the intake - which was metered at some point.

Not trying to split hairs here but there is a reason why the crank case is a sealed system on EFI cars - and it's so that all air that goes through the MAF eventually goes through the exhaust - even if it loops the PCV system a time or two.

This may not be a big deal on NA cars but on my supercharged Mustang, I was told that under no circumstances should my blow off valve let air out of the system. Instead it is looped back to the intake right behind the MAF (so it's not metered twice).

On the MM I'm betting that the O2 sensors have enough leeway so that if a little air escapes or enters the system that's unmetered, they can have the computer adjust the A/F ratio - so it's all good.

Personally, I'm going to try the oil separater first - I can set it up for under $25 with a Harbor Freight separater: (http://www.harborfreight.com/air-tools/air-tool-accessories/12-standard-air-filter-68279.html). On my Mustang I removed the 'push button' drain and installed a regular threaded drain. No problems so far.

Thanks!
 
Ozz said:
Greetings,
My '03 300A MM just passed 105k miles and instead of smoking on start up a half dozen times a month, it smokes like it's on fire every time it sits for over an hour.
As the norm, it only smokes for a few seconds (and I think only on the left side) but it's kind of embarrassing and I'd like to see if there's anything I can do WITHOUT REMOVING THE HEADS.

My guess is that I can remove the cams, etc and, if it's anything like my 5.0, I can hold the valves closed with air pressure while I carefully remove the springs and faulty seals.

I'll do a compression and leak down test prior to attacking the seals but assuming they are both fine...

Anybody ever tried this or am I just dreaming about a cheap solution that doesn't exist?
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You aren't dreaming.

Smoke at start is caused by worn seals. Auto-Rx http://www.auto-rx.com/ will clean and recondition them, without taking off the heads. No more smoke on start. Yes get a good oil separator for the PCV afterwards.

There are a lot of other Marauders that could benefit from this.
 
babbage,
I have used Auto-RX. It's been awhile since I did a full treatment though. I usually add 2 oz. when I change oil.
It did seem to work the first time though.

CBT,
Nice idea. What is that thing?
I'll look into that too.
 
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Ozz said:
bolson,
I'm sure it's not a lot but any time you allow air in to or out of the crank case, it's 'unmetered'.
I think you're saying that the breather that some have linked to only lets air out if the PCV system can't 'suck it up' fast enough but that air is blow by - which came from the intake - which was metered at some point.

Not trying to split hairs here but there is a reason why the crank case is a sealed system on EFI cars - and it's so that all air that goes through the MAF eventually goes through the exhaust - even if it loops the PCV system a time or two.

This may not be a big deal on NA cars but on my supercharged Mustang, I was told that under no circumstances should my blow off valve let air out of the system. Instead it is looped back to the intake right behind the MAF (so it's not metered twice).

On the MM I'm betting that the O2 sensors have enough leeway so that if a little air escapes or enters the system that's unmetered, they can have the computer adjust the A/F ratio - so it's all good.

Personally, I'm going to try the oil separater first - I can set it up for under $25 with a Harbor Freight separater: (http://www.harborfreight.com/air-tools/air-tool-accessories/12-standard-air-filter-68279.html). On my Mustang I removed the 'push button' drain and installed a regular threaded drain. No problems so far.

Thanks!
Click to expand...

I think you're confusing a blow-off Valve with crankcase blow-by. A blow-off valve redirects fresh pressurized intake air, from after the supercharger, which has been measured by the MAS. In contrast, the PCV system allows crankcase pressure (aka. blow-by, aka burnt exhaust gasses which leaked past the piston rings into the crankcase where the motor oil is splashing about) to vent somewhere. The reason the PCV system is closed is to prevent raw exhaust gasses exiting the engine compartment at the front of the vehicle, where it might enter the cabin. Also, these gasses have bypassed the catalytic converters, and may be high in hydrocarbons. Sending these gasses back through the combustion cycle gives them a chance to burn more completely, sparing the air we breathe.
No air enters the crankcase during normal engine operation. Some air might be pulled in while running very high vacuum, such as a high-rpm closed throttle condition, but this would be minute amounts that aren't going to affect the air/fuel ratio in any significant way.
Actually, air entering the intake tract from the PCV system is technically 'unmetered', since it's not being measured by anything. However, since these gasses displace fresh air, the MAS will see correspondingly less air passing through. Redirecting the PCV to atmosphere should result in a slight increase in MAS flow, and a bit more fuel flow to match. I don't know if it would be significant enough to notice, though.
Air is measured ('metered') so the computer knows how much fuel to send via the injectors. Blow-back air is fresh air and the computer WILL send the fuel necessary to match what it measured. If your blow-back valve vented to atmosphere, you'd get severe dips in the air/fuel ratio each time it happens, possibly sending raw fuel out the exhaust if there wasn't enough air to burn what the computer thought was the right amount of fuel.

I hope that clears things up a bit.
 
Perhaps we agree but for different reasons. I say that all the air - even the recycled PCV air, that replaces some of the fresh inlet air, has been accounted for by the MAF and should remain in the closed loop system for optimal performance.

That said, this air will be oxygen poor and hydrocarbon rich which will tend to skew the combustion event toward the rich side.
Exactly what we want at WOT I guess! ;)
 
Considering you have a 03 300A, It is very likely it is valve seals, I had them go bad on my 1st 03 early build, Not a simple job either.
 
bolsen said:
Replace the stock oil cap with the breather.
Click to expand...

You have to remove the PCV to run a breather like that as you will otherwise draw in unmetered air into the engine. If you remove the PCV you need some other type of crankcase ventilation, a road draft tube or a vacuum pump.
 
Chevyguy said:
You have to remove the PCV to run a breather like that as you will otherwise draw in unmetered air into the engine. If you remove the PCV you need some other type of crankcase ventilation, a road draft tube or a vacuum pump.
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Chevyguy,
I'm with you on this but there was some discussion earlier about PCV air not being 'metered air'. I say it is, others say no. My logic tells me that if it's not metered air when it goes back to the engine a 2nd time, then it should go through the MAF. It does not and therefore has already been accounted for by the computer.

On a completely different subject - I thought 300A's were ONLY the early 2003 cars... With adjustable pedals, dash clock, pouch on front of seat, no traction control, no heated seats... you say your '04 is a 300A but it has heated seats. Can it be a 300A? I could be wrong but I don't think it's an A.
 
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IIRC 300A were made in 2003, then part way through manufacturing they started making 300B. Then in 2004, all MM were 300A
 
I'd trade my seats with pockets for ones with heat any day...
I bet you don't get much use out of bun warmers in south Fla so I can see why you'd want pockets back.
 
Ozz said:
I'd trade my seats with pockets for ones with heat any day...
I bet you don't get much use out of bun warmers in south Fla so I can see why you'd want pockets back.
Click to expand...


I'd don't have pockets or heat on mine. :alone:
 
CBT said:
I'd don't have pockets or heat on mine. :alone:
Click to expand...

Well , that's not right... I always thought it was a trade off - lose pockets, clock, etc and get heated seats and traction control.
Must have been an option later on.
I don't think there were any options on the 300A's in '03.
 
http://mustangboards.com/modular-4-6l-tech/41020-pcv-system-questions.html

OK looks like PVC/crankcase air is definitely metered. So some variation of closed filtration is the way to go.

Seems oil airation may be causing the problem. Mine was so day and night because of the larger pressure changes/faster revs/higher power.

Still not ruling out the breather, I will bounce it off of JDM as they are in on this. Ordered the steeda. I'm not always under the hood so the clear bottom will remind me to dump the waste. Hasn't smoked on start in a couple of weeks, but I'm sure it will be back if this isn't the problem. I'll post to this thread post install if the smoking persists.
 
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