Engine Blow By
Thread Starter
|
Freshman User
Joined: Mar 2002
Posts: 29
Likes: 0
Engine Blow By
Good day,
I've always had some problems with blow by on the Truck (82, F150, 351W, 2WD). Most of the time it just filled the PCV Filter in the breather. I'd empty and clean the filter every couple of weeks. I just changed the oil, and now its making a huge mess in the engine compartment. Its blowing up the DipStick, rolling down it and smokin' on the exhaust manifold.
Its also been blown off the dipstick, and most of that side of the compartment is slicked with oil. I've always used a brand name oil, however whatever was on sale. This time it was castrol GTX, and I did make sure to get the 10W30. I put 5.4L of oil in when i changed it. The manual called for 6L. I shouldn't have overfilled the crankcase.
I'm well aware that this problem is a sympton of wore rings. What I'm curious about is why it just started to blow out of the dipstick. I've cleaned the PCV Valve, and it didn't help. Aside from running a vacumn hose from the dipstick to the under the frame, what options do I have ?
gm_monzaAThotmail.com
I've always had some problems with blow by on the Truck (82, F150, 351W, 2WD). Most of the time it just filled the PCV Filter in the breather. I'd empty and clean the filter every couple of weeks. I just changed the oil, and now its making a huge mess in the engine compartment. Its blowing up the DipStick, rolling down it and smokin' on the exhaust manifold.
Its also been blown off the dipstick, and most of that side of the compartment is slicked with oil. I've always used a brand name oil, however whatever was on sale. This time it was castrol GTX, and I did make sure to get the 10W30. I put 5.4L of oil in when i changed it. The manual called for 6L. I shouldn't have overfilled the crankcase.
I'm well aware that this problem is a sympton of wore rings. What I'm curious about is why it just started to blow out of the dipstick. I've cleaned the PCV Valve, and it didn't help. Aside from running a vacumn hose from the dipstick to the under the frame, what options do I have ?
gm_monzaAThotmail.com
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
Engine Blow By
The engine is wearing out, or you've got a blown head gasket. Do a compression test. The PCV system is only designed to handle a specific amount of crankcase air, and that much compression getting in there easily overwhelms it. Compression test.
Thread Starter
|
Freshman User
Joined: Mar 2002
Posts: 29
Likes: 0
Engine Blow By
I've done the compression test. They range from 95 to 105 psi. The valves chatter, and oil pressure readings of near zero are common. The engine needs a rebuild. When I changed the oil on sunday, I had no blow by from the dipstick. I've owned the truck for a year, and its never done that. I was looking for ideas, as to why I would change the oil, and the next day it would start blowing out the DipStick.
>The engine is wearing out, or you've got a blown head
>gasket. Do a compression test. The PCV system is only
>designed to handle a specific amount of crankcase air, and
>that much compression getting in there easily overwhelms it.
> Compression test.
>The engine is wearing out, or you've got a blown head
>gasket. Do a compression test. The PCV system is only
>designed to handle a specific amount of crankcase air, and
>that much compression getting in there easily overwhelms it.
> Compression test.
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
Engine Blow By
A 351 only making 105psi? 
That means your highest effective compression ratio is only 8:1. I think they're supposed to be 9:1, but I'm not sure. Sounds like you need to face the fact that the engine is dead. 
That means your highest effective compression ratio is only 8:1. I think they're supposed to be 9:1, but I'm not sure. Sounds like you need to face the fact that the engine is dead. 
Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
Engine Blow By
Castrol Oil is well known for it's cleaning ability, which is why I use it. It probably took out the last bit of carbon in the cylinder walls that was causing a seal. Either that, or by strange coincedence, a piston holed, or the pcv tube collapsed at the same time.
Jared
Jared
Thread Starter
|
Freshman User
Joined: Mar 2002
Posts: 29
Likes: 0
Engine Blow By
Well I just finished another compression test on the motor. Did it the proper way this time, pulled all the plugs at the same time. Got better results. Varied between 110 and 125 PSI. I'm going start looking at replacing all the PCV components.
>Castrol Oil is well known for it's cleaning ability, which
>is why I use it. It probably took out the last bit of
>carbon in the cylinder walls that was causing a seal.
>Either that, or by strange coincedence, a piston holed, or
>the pcv tube collapsed at the same time.
>
>Jared
>Castrol Oil is well known for it's cleaning ability, which
>is why I use it. It probably took out the last bit of
>carbon in the cylinder walls that was causing a seal.
>Either that, or by strange coincedence, a piston holed, or
>the pcv tube collapsed at the same time.
>
>Jared
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
Engine Blow By
In addition to pulling all the plugs, you should have the throttle blocked full open during the whole test. If you get a low reading on one cylinder, you should put a couple of drops of engine oil into that cylinder, spin the engine a few times, and retest. If the oil makes a substantial difference, you'll know it's the rings & not the valves or head gasket.
Trending Topics
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
