• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Need help


Nickvincent987

New Member
Joined
Jan 31, 2019
Messages
6
Reaction score
0
Points
0
Location
Ct
Vehicle Year
1988
Make / Model
Ford
Transmission
Manual
I have a 1988 ford ranger and it keeps burning valves in the same cylinder the timing is good and there is no vacuum leaks it’s not running lean what else could cause this
 


alwaysFlOoReD

Forum Staff Member
TRS Forum Moderator
TRS Banner 2012-2015
TRS 20th Anniversary
Joined
Apr 13, 2009
Messages
13,868
Reaction score
5,029
Points
113
Location
Calgary, Canada
Vehicle Year
'91, '80, '06
Make / Model
Ford, GMC,Dodge
Engine Size
4.0,4.0,5.7
Transmission
Manual
2WD / 4WD
4WD
What engine?
Any codes?
 

pjtoledo

Well-Known Member
Supporting Member
U.S. Military - Veteran
Joined
Oct 5, 2007
Messages
5,337
Reaction score
2,906
Points
113
Location
Toledo Ohio
Vehicle Year
20002005199
Make / Model
Fords
Engine Size
3.0 2.3
corroded or clogged cooling passages causing hot spots near that valve? that's a long shot, but it's the best I can do this late at night.
 

Nickvincent987

New Member
Joined
Jan 31, 2019
Messages
6
Reaction score
0
Points
0
Location
Ct
Vehicle Year
1988
Make / Model
Ford
Transmission
Manual
Brunt valves

There are no codes and it’s a 2.9l
 

adsm08

Senior Master Grease Monkey
Supporting Member
Article Contributor
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
34,623
Reaction score
3,613
Points
113
Location
Dillsburg PA
Vehicle Year
1987
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Tire Size
31X10.50X15
Exhaust leak at the manifold gasket can burn exhaust valves.
 

Bird76Mojo

Well-Known Member
V8 Engine Swap
Joined
Jun 28, 2009
Messages
2,633
Reaction score
1,264
Points
113
Location
IL
Engine Type
V8
Are you using the same head and just having it rebuilt every time?

Burning the exhaust valve only?




GB :)
 

Nickvincent987

New Member
Joined
Jan 31, 2019
Messages
6
Reaction score
0
Points
0
Location
Ct
Vehicle Year
1988
Make / Model
Ford
Transmission
Manual
There is brand new gaskes at the manifold and the but the heads are brad new and yea just the exhaust is valve
 

19Walt93

Well-Known Member
Ford Technician
V8 Engine Swap
Joined
Nov 13, 2018
Messages
4,473
Reaction score
4,409
Points
113
Location
Canaan,NH
Vehicle Year
1993
Make / Model
Ford Ranger
Engine Type
V8
Engine Size
351
Transmission
Automatic
2WD / 4WD
2WD
Total Drop
3"
Tire Size
235/55R16
My credo
If you don't have time to do it right will you have time to do it over?
Loose valve guide? I've seen 2.9's crack heads under the valve cover and the coolant ends up getting sucked into the cylinders by the pcv system.
 

Bird76Mojo

Well-Known Member
V8 Engine Swap
Joined
Jun 28, 2009
Messages
2,633
Reaction score
1,264
Points
113
Location
IL
Engine Type
V8
There is brand new gaskes at the manifold and the but the heads are brad new and yea just the exhaust is valve
Well, it's hard to make sense of this but I'm seeing: new exhaust manifold gaskets, heads are new, and just the exhaust valve is burning?


Besides a leak at the exhaust manifold, there can't be a lot more reasons to keep burning the exact same exhaust valves on brand new/rebuilt heads.


I do know the 2.9 is known to have problems with the cam journals/bearings wearing in an odd way if the mileage is high enough.

As mentioned by Walt, the 2.9's are very well known for cracking heads as well. It's usually in the same exact spot too. I've cracked/changed/cracked half a dozen heads on my old 2.9's and all cracked in the exact same spot. On 2 different blocks.

I suppose you could closely inspect your rockers and see if something is funky there. Also have a good look at your hydraulic lifters. Comparing measurements of your pushrods might also point to something.

Still, I'm thinking something's funky with the fuel system, or the cooling passages near that valve.



GB :)
 

RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,290
Reaction score
8,291
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Did you get new rockers with the heads?

Valves rotate each time they open
For exhaust valves this is very important so they don't get hot in one spot
A worn rocker can cause valve to stay in the same place and result is............wait for it......lol, yes burnt exhaust valve.
 

Nickvincent987

New Member
Joined
Jan 31, 2019
Messages
6
Reaction score
0
Points
0
Location
Ct
Vehicle Year
1988
Make / Model
Ford
Transmission
Manual
I motor only has 80,000 miles on it could an injector giving to much fuel burn a valve I didn’t get new rockers with the engine what should I look for
 

Nickvincent987

New Member
Joined
Jan 31, 2019
Messages
6
Reaction score
0
Points
0
Location
Ct
Vehicle Year
1988
Make / Model
Ford
Transmission
Manual
No new rockers the motor only has 80,000 on it coin a back ingector like that isn’t misting more like putting out a dribble of duke cause it to burn a valve because then I would have the right air fuel ratio making it run lean because it’s not a mist?
 

RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,290
Reaction score
8,291
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Since there is only one O2 sensor for all 4 cylinders then it is possible for a cylinder to run leaner or richer than the others, computer just opens other injectors longer to balance exhaust for oxygen level

But there would be other signs of a Lean burn, pinging/knocking would be heard often
And head chamber and piston top would show signs of that, pitting

Burnt exhaust valve is because the valve is not sealing the cylinder when it closes on its valve seat, simple as that.
Explosive gases, when cylinder fires, start to exit at that opening which eats away at the softer metal, the valve
Eventually no seal is possible and cylinder starts to misfire

Yes, lean burn causes higher heat in that cylinder, that's what causes the Pinging/Knocking
That heat can soften the valves BUT.....intake valve usually take the brunt of that because its softer metal than exhaust valve, it "tulips" from the heat, which does happen on the 2.3l


If bevel on valve seat and valve are not the same then poor seal happens(i.e. Valve job)
If valve seat is not being cooled by head coolant circulation, it can get a hot spot, causing poor seal
If valve isn't turning it can get a hot spot, causing poor seal


Valve stem should be flat on top, rocker should also have flat area so valve stem is free to turn, and roller rocker needs to be flat, if it sits at even a bit of an angle it will prevent valve from turning, like its pressing sideways on the of the stem not straight down

Weak valve spring is a long shot but not a no shot, lol
 
Last edited:

Nickvincent987

New Member
Joined
Jan 31, 2019
Messages
6
Reaction score
0
Points
0
Location
Ct
Vehicle Year
1988
Make / Model
Ford
Transmission
Manual
So the fact i have it straight pipes with holloes out cats probably isn’t helping and the pipe I have is like 3 inches so I should probably get a pipe that is more stock size
 

Sponsored Ad


Sponsored Ad

Staff online

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Truck of The Month


Kirby N.
March Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top