engine trouble
Thread Starter
|
New User
Joined: Mar 2013
Posts: 13
Likes: 0
engine trouble
I bought a 1993 Bronco, The owner told me that it has a stuck valve, How can I test for this and is it worth repairing or replacing the engine, I have found a junk yard motor for $300 with a 30 day replacement warranty.
PS: I have tried tuning it up and think the old owner had the wrong firing order but could have been my fault, there is a lot of exhaust smoke coming out of the breather.
PS: I have tried tuning it up and think the old owner had the wrong firing order but could have been my fault, there is a lot of exhaust smoke coming out of the breather.
Lead Driver
Joined: Sep 2002
Posts: 9,182
Likes: 12
From: Gateway to the West
First question... "Breather"? The only location where the crankcase is open to the atmosphere in that model year is UNDER the air filter INSIDE the filter box. If there is exhaust coming from the crankcase you have problems far more serious than a stuck valve.
To test for a stuck valve you will need to perform a compression test on each cylinder to determine which cylinder is affected. Compression in a cylinder with a valve stuck open will be zero. A valve stuck open usually has tell-tale rhythmic chatter unless it is stuck just slightly open and the top of the piston doesn't smack it as it reaches TDC. Still, if a valve is open there will be some noise from the rattling of the pushrod and rocker arm for that valve. A valve stuck closed will either bend or break a pushrod or rocker arm. Either will yield obvious noise from the engine.
To test for a stuck valve you will need to perform a compression test on each cylinder to determine which cylinder is affected. Compression in a cylinder with a valve stuck open will be zero. A valve stuck open usually has tell-tale rhythmic chatter unless it is stuck just slightly open and the top of the piston doesn't smack it as it reaches TDC. Still, if a valve is open there will be some noise from the rattling of the pushrod and rocker arm for that valve. A valve stuck closed will either bend or break a pushrod or rocker arm. Either will yield obvious noise from the engine.
Thread Starter
|
New User
Joined: Mar 2013
Posts: 13
Likes: 0
They oil was dirty but good we currently are flushing the oil.
Thread Starter
|
New User
Joined: Mar 2013
Posts: 13
Likes: 0
First question... "Breather"? The only location where the crankcase is open to the atmosphere in that model year is UNDER the air filter INSIDE the filter box. If there is exhaust coming from the crankcase you have problems far more serious than a stuck valve.
To test for a stuck valve you will need to perform a compression test on each cylinder to determine which cylinder is affected. Compression in a cylinder with a valve stuck open will be zero. A valve stuck open usually has tell-tale rhythmic chatter unless it is stuck just slightly open and the top of the piston doesn't smack it as it reaches TDC. Still, if a valve is open there will be some noise from the rattling of the pushrod and rocker arm for that valve. A valve stuck closed will either bend or break a pushrod or rocker arm. Either will yield obvious noise from the engine.
To test for a stuck valve you will need to perform a compression test on each cylinder to determine which cylinder is affected. Compression in a cylinder with a valve stuck open will be zero. A valve stuck open usually has tell-tale rhythmic chatter unless it is stuck just slightly open and the top of the piston doesn't smack it as it reaches TDC. Still, if a valve is open there will be some noise from the rattling of the pushrod and rocker arm for that valve. A valve stuck closed will either bend or break a pushrod or rocker arm. Either will yield obvious noise from the engine.
Hotshot
Joined: Jul 2002
Posts: 14,285
Likes: 12
From: Bend,OR
what about the noise??? you havent answered that question.
is the oil milky or discolored at all? its possible that you have a blown headgasket if there is no noise.
I would drain the oil, put in a delo or rotella diesal grade oil 15w40. install a motorcraft, wix, purolator oil filter and run the motor. I would also recommend installing a new pcv valve which should be located on the passenger side valve cover in the back.
is the oil milky or discolored at all? its possible that you have a blown headgasket if there is no noise.
I would drain the oil, put in a delo or rotella diesal grade oil 15w40. install a motorcraft, wix, purolator oil filter and run the motor. I would also recommend installing a new pcv valve which should be located on the passenger side valve cover in the back.
Thread Starter
|
New User
Joined: Mar 2013
Posts: 13
Likes: 0
what about the noise??? you havent answered that question.
is the oil milky or discolored at all? its possible that you have a blown headgasket if there is no noise.
I would drain the oil, put in a delo or rotella diesal grade oil 15w40. install a motorcraft, wix, purolator oil filter and run the motor. I would also recommend installing a new pcv valve which should be located on the passenger side valve cover in the back.
is the oil milky or discolored at all? its possible that you have a blown headgasket if there is no noise.
I would drain the oil, put in a delo or rotella diesal grade oil 15w40. install a motorcraft, wix, purolator oil filter and run the motor. I would also recommend installing a new pcv valve which should be located on the passenger side valve cover in the back.
Trending Topics
Thread Starter
|
New User
Joined: Mar 2013
Posts: 13
Likes: 0
what about the noise??? you havent answered that question.
is the oil milky or discolored at all? its possible that you have a blown headgasket if there is no noise.
I would drain the oil, put in a delo or rotella diesal grade oil 15w40. install a motorcraft, wix, purolator oil filter and run the motor. I would also recommend installing a new pcv valve which should be located on the passenger side valve cover in the back.
is the oil milky or discolored at all? its possible that you have a blown headgasket if there is no noise.
I would drain the oil, put in a delo or rotella diesal grade oil 15w40. install a motorcraft, wix, purolator oil filter and run the motor. I would also recommend installing a new pcv valve which should be located on the passenger side valve cover in the back.
#2 There was some milkyness on the cap but not on the dip stick - I think this is do to the truck sitting for a few months and condensation build up (hoping)
#3 changed the oil using an engine flush - used Mobil 5000 and a Purolator filter, have not changed the PVC valve - will do that today
Thank you for all the help so far
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
The Southernmost Mod
Joined: Dec 2004
Posts: 6,902
Likes: 21
From: Caracas, Venezuela
You didn't find the cause yet, you better take a harder look into it, because it will come back, I would seafoam that engine to clean it further, do a search for seafoam and seafoaming.
New User
Joined: Jun 2010
Posts: 9
Likes: 0
Thanks for the reply, I both seafoamed the crank and fuel yesterday,
Thread
Thread Starter
Forum
Replies
Last Post
lexasgs400
6.0L Power Stroke Diesel
30
Feb 20, 2012 11:27 AM
SteveInMs
1967 - 1972 F-100 & Larger F-Series Trucks
6
Aug 12, 2009 05:20 PM