Engine Blow By

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Just curious but I heard a lot of people talk about "blow by" in an engine and I understand how it occurs, but what are ways to slow it down? I've heard people say to run 15w40 etc. What are ya'lls thoughts? Or a high Moly oil, which now what Dino oils are high in Moly?
 
you can't really "slow it down". At that point, it is time to start looking for a new ride, a new engine, or parts to rebuild it.

But I guess that's just me, I'd rather fix the problem ASAP rather than play the odds that are against me.
 
Good point. Some close friends have a 2000 Ford Winstar and at around 150k it started having slight blow by, he was told to try a HM oil and add Lucas Oil Stabilizer. I remember him telling me that he hadn't noticed anymore issues with it, and since then they have put over 50k on it. His wife still drives it everyday with over 200k. I guess it depends on how bad it is.
 
Originally Posted By: Chris142
All engines have some blow by. As wear increases so does blow by. Using thicker oil wont do much to improve things.


It help`s some. Buy`s some time if nothing else.
 
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Lots of diesels have substantial blowzy and still run well. In a gasser, no such luck. If it's bad, look for a new engine.
 
Originally Posted By: RegDunlop
Can somebody explain "blowby?"

What causes it?

How do you know, what are indications it is occurring?



"Blow by" refers to combustion gasses escaping past the rings and into the crankcase. ALL piston engines have blow-by, that's what the PCV valve and plumbing is for- to suck it away and burn it before it creates excessive deposits in the engine (and the EPA likes it because it keeps it out of the air, too).

Blow-by tends to decrease as a new engine breaks in, then slowly increase again as an engine wears out. It is only "excessive" when the volume of blow-by is more than the PCV system can remove. You know this because the engine starts venting vapor out the oil fill hole at idle (a visible grey mist when you run the engine with the oil fill cap off) and/or soaking the air filter with oil mist that gets pushed out the crankcase air inlet pipe that usually attaches to the air intake plumbing.
 
like stated above engine is showing its age but, I woudn't run a thicker oil or stabilizers it will not help a thing and actually cause more wear in other parts of your engine like bearings etc. Trying a high mileage is a good choice to help with it some but, use your recomended grade. Thats about all you can do until its rebuild time.
 
For what it's worth, the 1.5L Mazda I have... we bought it with 147K... some time after that I realize that the engine has significant blow by... But I keep up with it, change the oil and add more when it burns off, the engine is now at 175K and still going fine. Yes, it would have been better if the PO hadn't neglected it, but if I can get it to 200K I'll consider it good.
 
Excessive blow by can be caused by actual cyl wall and ring wear, or in most cases,I believe, may be caused by ring coking from oil change abuse where the rings coke solid and can't expand to the cyl wall as designed with carbon from oil that is way pasted it prime. Synthetic oil can help prevent this. I have done 10K OCIs for many years and have never experienced ring coking with synthetic oil.
 
If the rings are sticking and causing the blow-by an engine cleaning product like Kreen "could" help. Please note the word "could" help, MMO "could" as well it just takes longer. When using one of these products just keep on eye on the oil level because it could drop faster with the addition of either product. If the blow-by is caused by wear Schaeffers #132 might help.
 
Originally Posted By: 440Magnum
It is only "excessive" when the volume of blow-by is more than the PCV system can remove. You know this because the engine starts venting vapor out the oil fill hole at idle (a visible grey mist when you run the engine with the oil fill cap off) and/or soaking the air filter with oil mist that gets pushed out the crankcase air inlet pipe that usually attaches to the air intake plumbing.


Bingo and even engines with excessive blowby can run tens of thousands miles as long as they are closely maintained... Mainly with this condition it's important to keep the oil fresh, as the blowby will quickly shear the oil and worsen the issue or possibly lead to additional problems... Of course most are going to take the attitude, it already has problems, why bother with a regular OCI...
 
It doesn't really mean a whole lot as long as the engine runs well. Their are a lot of low compression older motors out their still chugging along.

Oil has very little to do with it, its wear. The only fix is a rebuild.
 
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Originally Posted By: hattaresguy
It doesn't really mean a whole lot as long as the engine runs well. Their are a lot of low compression older motors out their still chugging along.

Oil has very little to do with it, its wear. The only fix is a rebuild.


Such as my 226K mile buick century with its 1/2 shot burnt/chipped valves..
 
yeah, I have an old ford f150 w/302 that has lots of blowby. It has run for years like that and still going strong. Just use a HM oil and accept it. You'll know when the engine is done if it ever gets to that point. I've put another 50K on it since I noticed it and expect to get another 50K easily.
 
Mine is actually a 2azfe, my tablet had an error where I couldn't see what I was typing so I'm not sure if I just posted or not but I could to see and it was filled with typos and I'm not sure if I pressed send or not. Regardless, disregard that. So is it Blowby or the valve stem seals and is this a major problem or no and would a high mileage oil be able to fix this?

On an unrelated note, I go to Detroit often now and there's often a lot of empty parallel parking spots where there's broken glass or shattered beer bottle glass. Is thst bad for your tire and would cause a flat? During the day, you can see it, but it can be hard to locate these glass shards at night so what if I accidentally parallel park at a location where there are these glass shards? Will it hurt or no or definitely cause a flat?

I got my windshield fixed by safelite and they told me their glass doesn't cause flats, but what about beer bottle glass or window class in houses? Or are standard non run flat tires unable to put up with the glass shards?

Is this smoke on startup a major problem and would likely cause a head gasket to fail or am I fine with its, the car drives like it used to and drives better than some new cars as I drove that rogue of my family members and in all honesty, the camry drove and felt better!

I also heard the camry's problem may be the valve seals, should a mechanic inspect it or how can you inspect it? will maxlife or high mileage oil fix this?
i dind't have the smoke on startup until i switched it to synthetic last year on the car at 145k miles but i have historically used synthetic blend in the car too at my tire place

and another time 2 years ago,the car smoked on startup but that was due to the valve cover gastket going bad an a minor oil leak
i don't notice any oil leaks or low oil level,so is this the valve seals? if you need work on that, is it expensive or major or not really? i heard it's ok in the short term but the smoke on startup won't be good for the long term and i'm trying to drive this car till 2025 with 300k miles (twice it's current age, or about twice, and its mileage)
 
and i dropoped power bait in my crankcase in my taurus
that should be fine right and it will dissolve or am i screwed and should pull the valve cover and fix it? thanks
 
how do you add pics to these posts? i want to post my oil analysis results (with personal info removed) here, how did you guys do that? i don't see an attach file option!
 
Originally Posted By: tig1
Excessive blow by can be caused by actual cyl wall and ring wear, or in most cases,I believe, may be caused by ring coking from oil change abuse where the rings coke solid and can't expand to the cyl wall as designed with carbon from oil that is way pasted it prime. Synthetic oil can help prevent this. I have done 10K OCIs for many years and have never experienced ring coking with synthetic oil.


tig1, you got nearly all of them...there's another mechanism that can be infuenced by viscosty, and it's akin to ring flutter. A change to viscosity (higher or lower, depending on what the cause is) can help.
 
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