Blow-By
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From: TX
Blow-By
Alright well I think I got a blown head gasket, every winter or any cold morning below 65 degrees I get white smoke out of the exhaust and I believe it never stops even after it warms up. Also I got that nasty white milky goo in my breather filter and the oil cap. It never seems to overheat but throughout the whole year I find I have to refill the radiator with a tad bit of water. I hope I'm not screwing up my 5.0. BTW its a 1993 with over 205k miles its expected that the head gaskets need replacement LOL. Any of you all that have experienced the same thing?
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If your only adding water every time the 50/50 mix of antifreeze is going to become less and less a 50/50 mix. If your going to top off with fluid, top off with 50.50 mix.
Now blow by and a headgasket is going be two different issues.
Blowby is oil getting by the rings of the pistions. Which could explain the oil in the airbox. Have you changed the PCV Valve lately? They are very cheap and easy to do.
Now if your oil is milky you certainly have a headgasket leak. Since the oil is mixing with the water leaking in.
Depending on how many miles the engine has on it and if you are getting both blowby and headgasket leak you best bet is a full rebuild of the engine.
Now blow by and a headgasket is going be two different issues.
Blowby is oil getting by the rings of the pistions. Which could explain the oil in the airbox. Have you changed the PCV Valve lately? They are very cheap and easy to do.
Now if your oil is milky you certainly have a headgasket leak. Since the oil is mixing with the water leaking in.
Depending on how many miles the engine has on it and if you are getting both blowby and headgasket leak you best bet is a full rebuild of the engine.
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From: Bear, DE
Before you go assuming you have a bad HG, you need to do a few tests:
- A coolant preasure test. This will tell you if the cooling system is holding the 16psi of pressure it's supposted to be. Once you pressurize the system any leaks that are there will be revealed and this COULD show you where the coolant is leaking from hence why you are adding some every once and a while.
- A compression test. This will show the condition of the head gaskets. If they are low on compression. Then its possible you blew a HG. Though HG's don't go with just milage.
- A leak down test. This will show the condition of the rings/bottom end. A quick blow-by test is pull the oil cap off while the engine is running. See if any smoke is coming out. If it is, then more then likely you have blow-by. SOME is acceptable. If it's chooching like a freight train then the bottom end is worn and needs a rebuild.
I'd clean all the "goo" up. If it returns then it's a problem to look into. How's the oil on the dipstick? Do you loose any extensive amount? Is it the same chocolate milky color as the oil cap?
I hope this helps.
-Mike
- A coolant preasure test. This will tell you if the cooling system is holding the 16psi of pressure it's supposted to be. Once you pressurize the system any leaks that are there will be revealed and this COULD show you where the coolant is leaking from hence why you are adding some every once and a while.
- A compression test. This will show the condition of the head gaskets. If they are low on compression. Then its possible you blew a HG. Though HG's don't go with just milage.
- A leak down test. This will show the condition of the rings/bottom end. A quick blow-by test is pull the oil cap off while the engine is running. See if any smoke is coming out. If it is, then more then likely you have blow-by. SOME is acceptable. If it's chooching like a freight train then the bottom end is worn and needs a rebuild.
I'd clean all the "goo" up. If it returns then it's a problem to look into. How's the oil on the dipstick? Do you loose any extensive amount? Is it the same chocolate milky color as the oil cap?
I hope this helps.
-Mike
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From: TX
Well I know my coolant to water ratio is about 70% to 30%
For sure I have blow by, not a lot but enough to notice and that's kinda my fault that its been getting worse because I still treat the engine like its new if you know what I mean lol. For the milky crap I have very little on the cap and none on the dipstick. It only happens during winter maybe its moisture maybe even a small little leak on the HG's. Also if any oil is being burned its a very little amount because I never have to fill up with oil. I use a straight 40 oil weight to reduce the amount of blow by.
For sure I have blow by, not a lot but enough to notice and that's kinda my fault that its been getting worse because I still treat the engine like its new if you know what I mean lol. For the milky crap I have very little on the cap and none on the dipstick. It only happens during winter maybe its moisture maybe even a small little leak on the HG's. Also if any oil is being burned its a very little amount because I never have to fill up with oil. I use a straight 40 oil weight to reduce the amount of blow by.
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From: Clitherall, MN.
I live in west central MN and it gets pretty cold up here. I have noticed the milky substnce on my cap if the truck doesn't get up to operating temp long enough.It won't get rid of themoisture in the engine till it does.I usually let the truck warm up for ten minutes or so just to make sure.My truckwil blow steam for awhile to till the exhaust gets warmed up too.I'm just being optimistic, but the tests they have suggested you should prolly do.They don't take too long to do and will give info. on whats up.
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From: TX
I always do 5-10 minute warm ups before I even move the truck especially in cold weather, I got fel-pro gaskets im just gonna replace them and the blow by will have to wait a little more. I might just swap in a 351 or ill rebuild the 302. It lacks no power ill tell you that but the blow by is getting me. Its always been taking care of.
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From: Clitherall, MN.
Yeah,I take pretty good care of mine but I work it too hard sometimes pullin' trailers and stuff.I used it one time to pull down an old house.Got 250k on mine and a little bottom end knock first thing in the morn. Maybe I'll go for the 351 swap also.
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