gasket replacement question

[ghack]

I have a 96' 4.0 Ranger that a buddy gave to me as it was getting codes and wouldn't pass inspection. I have no experience with Rangers. The dealership quoted 1400 to fix. They had diagnosed a leaking intake manifold gasket. I removed the upper gasket, and saw that the gasket was indeed bad, oil around mating surfaces. My question is, how likely is it that there is also a leak on the lower gasket. It seems like a little bit more of an operation to get that out, so I don't want to go that route if i don't have to. On the other hand, I've gone this far, and it would be a shame to put it back together with new upper gasket and find there's still a leak. Anyone have any opinions/experience with intake manifold gasket leaks?
Gary

 

[RonD]

Lower intake gaskets are a known issue with the 4.0l, so I would go all the way.

You can try just replacing the upper gasket, it can be reused several times.
Oil on this gasket would mean the PCV Valve, hose and vent hose need to be cleaned or replaced, also the oil wasn't changed as much as it should have been.

The torque on the lower(and upper) manifold bolts is not much, 14ft/lb, you might just check if some are loose, do not over tighten these, they will break.

 

[Andy D]

Lower intake gaskets are a known issue with the 4.0l, so I would go all the way.

You can try just replacing the upper gasket, it can be reused several times.
Oil on this gasket would mean the PCV Valve, hose and vent hose need to be cleaned or replaced, also the oil wasn't changed as much as it should have been.

The torque on the lower(and upper) manifold bolts is not much, 14ft/lb, you might just check if some are loose, do not over tighten these, they will break.

That is a real good thing to know, sir. I have read about loose intakes on the 4.0 often enough to see if that is the source of the Rat's high idle. Not knowing the spec, I would have likely sheared a few. Another mistake avoided ,Thank you.

 

[black_demon69]

yes do upper and lower intake.


this is the gasket set i used when i did mine for the upper and lower VICTOR REINZ Part # MIS19316 @ rockauto.com about $67 + shipping this is a master intake gasket set......

hope this helps

 

[RonD]

Yes, and if the truth be known the Factory service manual recommends replacing head gaskets and head bolts when replacing lower intake manifold gasket on the 4.0l
You are suppose to torque these three pieces down together, as a set.

I wonder if they do that at the factory or if it is just for the dealer service departments

 

[ghack]

Thanks for the input guys. I think I will go ahead and do the lower as well. I did get the master gasket set. I think it was Felpro though. About the same money from RockAuto.

 

[rfl]

Spend some extra time prepping the surfaces. Any residue will cause premature gasket failure. Lacquer thinner will break down RTV, and Acetone will clean up the lacquer thinner and any oil residue. Just be sure to not get any inside the engine.

Truth is, fixing the lower is a crap job when the intake is full of sludge. You are going to be bolting all that sludge back on to a new gasket set unless you decide to spend time and/or money to clean the intakes before it all goes back together. You would do well to strip the intakes and pay the $75 or so that a machine shop will charge to dip them before you put them back on. You can save some money by cleaning them with oven cleaner, brushes, power washing, and a lot of frustration, but not recommended.

 

[black_demon69]

Spend some extra time prepping the surfaces. Any residue will cause premature gasket failure. Lacquer thinner will break down RTV, and Acetone will clean up the lacquer thinner and any oil residue. Just be sure to not get any inside the engine.

Truth is, fixing the lower is a crap job when the intake is full of sludge. You are going to be bolting all that sludge back on to a new gasket set unless you decide to spend time and/or money to clean the intakes before it all goes back together. You would do well to strip the intakes and pay the $75 or so that a machine shop will charge to dip them before you put them back on. You can save some money by cleaning them with oven cleaner, brushes, power washing, and a lot of frustration, but not recommended.

cleaned mine at car wash to get bulk of the crud off then used purple power degreaser and let it soak for a the time it took to prepare engine for reassembly then back to car wash to rinse off . then silver aluminum paint (just for show)

 

[FritzTKatt]

Replace the lowers. It's really not that difficult. And go ahead and let the parts soak in degreaser and use a small wire brush (stainless bristle!). Seafoam also works well as a start, but the real degreaser is where it's at...

Mating surfaces are even more important. I hit them gently with a razor blade and acetone.

PCV valve won't hurt.