It appears I have an engine oil leak coming from between the exhaust manifold and head on the passenger side of my 1997 Ford Ranger with a 4.0 liter OHV engine. What could be the possible causes of this? Cracked head? Bad valve guide seals?

 

Valve guide seal leakage goes right into the combustion chamber, so I'd rule that out.
Since there's no oil passageway from the head to the exhaust manifold, I'd guess a crack is possible.
Could an oil leak from elsewhere simply creep into where the manifold and head contact? ..like a PCV system drip or valve cover leak?

 

I am still investigating the valve cover leak possibility, I need some uv dye...

 

Is there a maximum runout limit? Like, to measure for warped or distorted stamped steel valve cover? I have looked everywhere for a specification, but have not found anything. Is there a rule of thumb for valve cover runout for warpage/distortion?

 

I've never seen a spec for "valve cover trueness".
Were I in your situation I'd eyeball it and simply "bend it back" if I could.
You might want to cut a piece of scrap plywood so it touches the entire mating surface of the cover. Check for high spots.
Make sure the plywood is flat by setting it against a piece of window glass or flat marble.

Did you go the UV dye route yet? If not, remember, you need the shop UV light to see the leak.

 

I have a question....

What is up with #14? Apply a 1/8" ball of sealer to valve cover bolt holes on exhaust side of cylinder head? Is anybody able to elaborate on why that differs from the left or driver side? What is going on here and what kind of sealer is recommended and/or advised? Please and thanks in advance.

 

no uv dye, but some thorough investigation?

 

In the #14 step an 8mm ball is described as (1/8"), or 0.125".
8mm = 0.315", which is considerably larger than 0.125".
I'd use Ultra Black or red RTV

 

will a mazda 4.0 liter ohv engine gaskets work on my 1997 ford ranger 4.0 ohv application? I am cross referencing parts on Rockauto... the cylinder heads for a mazda 4.0ohv and ford 4.0ohv are the same, but the lower intake manifold is only available for the ranger, not the b4000, although the upper intake manifold crosses to both applications. Both applications also utilize the same gaskets according to fel pro numbers and part numbers. Basically, can I utilize a b4000 lower intake manifold gasket, along with upper intake and plenum gaskets with valve cover gaskets all from mazda dealer for my ranger, as long as I use Mazda B4000 4.0 liter OHV parts and gaskets?

 

Everything I've ever read says they're the same vehicle.
It's good that parts are available.

 

Thanks for all the help from this forum. I got my valve cover gasket to take and seal. It only took, the FSM listed information (above), a snap on torque wrench and supplemental rtv sealant on felpro permadry gaskets....

https://www.felpro.com/technical/tec...y-use-rtv.html

 

Having to redo the valve cover due to one spot seeping engine oil. Quick question on torque specs: When the torque spec is listed as 3ft/lbs. to 5ft/lbs. (36in/lbs. to 60in/lbs.) doesn't that mean to start at 3 ft/lbs., then 4 ft/lbs., then, finally, 5 ft/lbs? Following the tightening sequence for each torque value to "creep" up to max value? Correct me if I am wrong, please.

 

 

Just shoot for the 4 ft.lbs..
The VC gasket isn't one of multi-layer construction like a head gasket.

 

I torqued the vc bolts all down to 3ft/lbs. following the tightening sequence. Put it all back together and ran it until operating temperatures. Would it hurt anything to tighten to the 4ft/lbs. from here?

 

Likely not....don't overthink it.

 

SO, how important are the valve cover bolt reinforcement plates? When I disassembled for my valve cover gasket job my reinforcement plates for the valve cover bolts were not present/gone. I never had them.... Does anybody know where to get the reinforcement plates for the valve cover bolts? Please and thanks in advance for reading.

 

Ha, I suppose their importance has diminished as gasket materials' and sealing products' quality have improved.
I bet they reduce 'spot overtightening' when used correctly on stamped steel covers.
Are these reinforcements a legacy technology which the engineers adopted back in the day of cork gaskets?

 

I searched the forum archives along with the "RangerStationForum" archives. Apparently, RonD is advising the usage of cork gaskets with the stamped steel valve covers (I used felpro permadryplus valve cover gasket, which I am beginning to suspect my culprit in this leak/seep issue), along with the usage of spreaders or bolt reinforcement plates.

 

Thank you for the advice and easy reading.

 

To display proper forum etiquette, I would like to let forum know that I found a tweaked valve cover that I had to replace (that was a replacement for my originals, from my lower intake manifold job, bought them used). Long story short, IF you are going to be doing any kind of engine building, PLEASE get yourself a machine straight edge and a good torque wrench.