Oh that sinking feeling.
Thread Starter
|
Senior User
Joined: Sep 2006
Posts: 186
Likes: 2
Oh that sinking feeling.
1990 Ford Bronco XLT. 5.0 w/ automatic. Unknown mileage, unknown history, but always runs reliably for me, and starts with a flick of the wrist.
My only complaint was its an oily, oil leaking mess - so I pulled the engine to replace rear main seal, oil pan gasket, and valve cover gaskets. I've noticed two troubling things.
First - when I removed the air filter box I noticed the air filter was wet with oil, and there was a heavy coating of oil on the inside of the box.
Second - when I pulled the upper intake manifold and noticed the inside of both the upper and lower intake manifolds are pitch black with oil. If you run your finger tip in there it will come out pitch black, oily, and worst of all - gritty.
Is this any sort of a "classic sign" of problem X, Y, or Z?
My only complaint was its an oily, oil leaking mess - so I pulled the engine to replace rear main seal, oil pan gasket, and valve cover gaskets. I've noticed two troubling things.
First - when I removed the air filter box I noticed the air filter was wet with oil, and there was a heavy coating of oil on the inside of the box.
Second - when I pulled the upper intake manifold and noticed the inside of both the upper and lower intake manifolds are pitch black with oil. If you run your finger tip in there it will come out pitch black, oily, and worst of all - gritty.
Is this any sort of a "classic sign" of problem X, Y, or Z?
Elder User
Joined: Jan 2012
Posts: 954
Likes: 0
From: Viva Las Vegas
Usually a sign of piston rings blowing by.
While the engine is out and the pan is off do a leak down test.
Connect an air hose to the spark plug hole and fill the chamber with air (about 40-50 psi.
There is usually a small amount of air that will sneak by, but it you have a large amount of air you have bad rings, time to rebuild...
While the engine is out and the pan is off do a leak down test.
Connect an air hose to the spark plug hole and fill the chamber with air (about 40-50 psi.
There is usually a small amount of air that will sneak by, but it you have a large amount of air you have bad rings, time to rebuild...
Senior User
Joined: Sep 2003
Posts: 436
Likes: 1
From: North Carolina
A clogged or improperly functioning PCV valve could have caused excessive blow by, and also if the filter hadn't been cleaned in a long time could have accumulated quite a bit of oil. Some black oil/gunk coating over many years in the intake is kind of normal but it could be worse from the blow by issue. Hopefully it could be more of an issue like this than straight up engine wear.
Junior User
Joined: Aug 2015
Posts: 80
Likes: 0
Well at least the engine is out 
I've been talking to local machine shop and they are telling me that they see a lot of blocks from fuel injected engines with straight cylinder walls and no bad wear patterns. It's not the old days with 0.025 taper and stuff. These motors can be re-ringed and go back in service.
I'd do a compressed air leak-down test, but at this point I'd prolly just pull the heads off, ball hone it and do rings and bearings and timing set, re-assemble and drive on. Of course I'd do a new PCV valve for sure. But unless there is something else wrong, it'll run a lot longer on just that
I've been talking to local machine shop and they are telling me that they see a lot of blocks from fuel injected engines with straight cylinder walls and no bad wear patterns. It's not the old days with 0.025 taper and stuff. These motors can be re-ringed and go back in service.I'd do a compressed air leak-down test, but at this point I'd prolly just pull the heads off, ball hone it and do rings and bearings and timing set, re-assemble and drive on. Of course I'd do a new PCV valve for sure. But unless there is something else wrong, it'll run a lot longer on just that
Thread
Thread Starter
Forum
Replies
Last Post
Resendiz
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
20
Apr 3, 2017 10:57 AM
xjoedirt55x
1987 - 1996 F150 & Larger F-Series Trucks
14
Dec 15, 2006 01:13 AM
sjser
1987 - 1996 F150 & Larger F-Series Trucks
17
Dec 21, 2005 11:58 PM
TallPaul
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
12
Oct 17, 2003 01:54 PM
