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Topic: Head Gaskets - General Question (Read 1250 times) previous topic - next topic

Head Gaskets - General Question

I had my 1984, Cougar, 3.8L. motor rebuilt (about 2000 miles ago).

Just noticed traces of what looked like a little antifreeze on the driverside bottom and oil on passenger side bottom.  Took back to AERA rebuilder (there now) and indicated just needed to retorque heads.

Question:

Since there are leaks should NOT the head be pullled?

(Seems to me if you just retorque, you might trap oil (or worse yet the antifreeze) between the engine and gasket or head and gasket which would pit the metal over time and cause a larger leak.)

Head Gaskets - General Question

Reply #1 –
well.................................IN MY OPINION ONLY..................

YES.,, but...Its possible the head being retorqued could solve the issue.  There are many secondary worries to this assumption as you read on.


Head gaskets have this natual way of sort of adheasing themselves to your block and head.  This is called the seal.  Actually there are three parts to the sealing pattern so bear with me so you understand whats happening.......

The headgasket itself is about 2 layers of metal back to back sorta with some fancy adhesive stuff on both sides of each layer.

there is a ring made into the headgasket which matches the circuference of each cylinder and upon being crushed,, they are able to crush to the surface shape of both the block and the head.  they also add to sealing the combustion chamber off from the outside world because the rings re of a metal that can withstand the temps and live a long life.

the headgasket has other holes in it which insure that the water ports can pass water from the intake, through the head and through the block without bleeing over to the combustion chamber.

the remaining holes insure water does not get into the oil pan or PCV system.

VIsa Versa, any one combination of the three trying to infultrate thier way into unauthroized areas will cause the engine to run poor or not at all.

Now,, pop quiz time........................
what were the finding of the shop upon diagnosing this "retorque"?

they need to share with you compression test numbers to verify cylinders are within limits of eachother.

They need to share with you if the heads required suface milling or "UFO" cut as some call it.
They need to share with you thier findings on head warpage during the original rebuild.
Your heads have a .006 diagonal surface warpage tolerance and a .003 width warpage tolerance if my memory serves me correctly.
They need to share with you the dospoogeents supporting they used New head bolts.
Your engine has bolts that are "technically" not reuseable.  They stretch as they are torqued and experience heat for the first time.  Usually after the first go around with aluminum heads and odd compression or leaks are detected, or better yet-nothing found at all, the heads are retorqued.  These fancy bolts are for your specific engine and the like out there with aluminum heads are called "TTY" bolts - torque to yield.
They need to share with you the compression numbers on the rebuild
They need to share with you when the heads were retorqued on the initial install.
They need to share with you the compression numbers after the retorque.
sometimes engines require a little head bolt snugging here and there on all four perimeter bolts surrounding a cylinder that shows signs of low compression.  Its my guess that a retorque and a second compression test was not performed.
they should share with you if water was in the PCV system.
They should share with you if water was in the intake
They should share with you the condition of the spark plugs.
They should go into each cylinder with a boroscope and verify piston and or cylinder washing. (if water got into the cyl, it will dilute lubrication on the walls and quickly increase wear and increase compression ring end gap. Compression ring end gap increase means lower compression. Lower compression means your foot must be more heavy on the gas to produce the same vehicle speeds.  A heavier foot on the gas pedal means higher gas costs and lack of dependability or feasability the car is providing cost effective transportation.  Also, it will assist in sending too much fuel to the engine which will likely not get burned up completely and any excess will leak past the worn rings to the oil pan thus thinning out your oil and thus your efforts of a rebuild is fruitless as your bearings wear more quickly due to lower viscosity of the oil.  If all that becomes a non issue, the the water in the oil will do the same thing because water sinks below the oil.  Since the oil pump sump filter in the pan sits low, water will be the first thing the engine circulates for lubrication throughout all your oil ports upon startup until if finally mixes with your oil slightly.

Concerned yet?

If,, they cant provide you with the information in bold,, you have a valid issue but others may have a different opinion.
IF the shop says we did a retorque,,,,,,,,,,,,,,ITS A FULL STOP AND INVESTIGTE THE >OVERSIGHT<,, key word here is oversight on thier part.
Keep in mind, the depth of your pocket may have effected how much time /talent they could feasbly contribute to the rebuild from a buisness perspective.  Coming to the defense of the shop for a moment,, you do get what you pay for and if offers for a certain level of rebuild was rejected, you dont have a leg to stand on.

AN engine re-ring kit doesnt really qualify as a full blown rebuild but does fall in a "freshen up" rebuild.  In a re-ring kit, a lot of old parts get reused including pistons, crank cam, typically cam bearings, timing gears, valves bla bla and the list goes on depening on how much you could pay. 
Post up a scan of your bill of materials for the project.

Head Gaskets - General Question

Reply #2 –
Thanks for response JCassity.

Like most things it is a control issue.  When you do it yourself you meet the level of your expectations.  If you are a perfectionist and "surgically" clean and torque everything, you expect that same level of diligence from others. 

Fortunately / Unfortunately, even though the owner and shop may have a high standard, that doesn't mean the person doing the work has the same standard or may even had a bad day.

I picked a shop that IMHO was super clean, had all the equipment needed (mills, magfllux machines) etc. and worked on high price cars and boats.  Whether my vehicle got the same due diligence is ??.

On first return I found alot of things externally mounted which were lose and definitely not even close to torque spec.  I took care of these myself.  On second pass (just got vehicle back) was informed back corner of valve cover was what was leaking oil -- indicated this is common problem with steel value covers so they made a bracket -- about a two inch long piece of metal with a hole -- to increase the clamping distance of the value bolt.  We'll see. 

Re: Antifreeze (driver side) indicated retorqued head bolts.  Didn't provide any paper work so hoping for best.  Even if they provided paperwork on retorque, only way to verify is to tear everything apart and recheck myself -- not only alot of effort but "if ain't broke don't fix it"  -- This is what I paid good money for -- a good job and so I didn't have to do the work myself.

Bottom line for me next time is either pull the engine myself, take it apart, have all parts individual worked on, verify everything to spec, put it all back together myself

 OR

buy a new car.

Head Gaskets - General Question

Reply #3 –
that flat plate they made is not a bad idea,, you see it a lot on valve covers stock and HP.  On the 3.8, the valve covers did not come with the clamp down plate washers.

the reason is the factory rubber gasket had these metal steel eyelets made into the gasket.  the bolt would snug to the valve cover and compress the eyelet to the under side of the valve cover and on the head surface.  This means is possible the rubber gasket can get blown out if the holes on the valve cover are not banged flat again our beveled.

On second thought,, if the mech did not flip the valve covers upside down and re-bevel the holes with a downward strike using a large round punch / hammer, the existing holes will be slightly beveled down ward while viewing the hole from the top.  This means the gasket can slip around in there and not make a seal.
If you were supplied with the blue rubber gaskets,, shiznit can them for cork ones for sure.

the bottom bolts need to be tighter or dominate by comparrison to the top ones.    Common sense that shiznit rolls down hill so make sure the lower side of the valve covers are tighter than the top.

Head Gaskets - General Question

Reply #4 –
From appearance looks like they use Felpro rubber.  One that is rubber coated with a hard body.  Had these before and never liked them as seemed they leaked.  Hopefully new bolt holddown will do the trick.
If not, back to cork.

BTW:
Any idea where to get:

1) Spiral Tubing Wrap in rolls.  I want to redo some wiring.
2) Alternator Insulators (Rubber caps that go over terminals) especially Stator and Field Terminals.

Head Gaskets - General Question

Reply #5 –
You should be able to get spiral wrap at most industrial supply stores. Grainger probably has a good selection, possibly in different colors.

Head Gaskets - General Question

Reply #6 –
Get them to tighten the head down first cause Ford Motors are nutores for un sealing on the head when be driven hard and 9 out of 10 times all u need to do is just tighten the head down, basicaly the head bolts come undone. When they do it make sure they re thread Lock the bolts. If that doesn't work than the Gasket was put on wrong Probley.

When they re tighten the heades make sure that there are not two differnt size head bolts. I know that the 80's carb 5.0s have two differnt size head bolts and the I believe the short ones go in the outside and the long ones go on the inside so if you looking at the the the two outside bolts get I believe short ones and the two inside are the long ones is been a while since I put head bolts in so not sure bout the size goes but tightenem by hand and if they feel like they are cross threading then the go to the other side. So if u put for intense u put a bolt in the outside hole and it feels like its cross threaded take it out and thry the inside hole.

Head Gaskets - General Question

Reply #7 –
i would never lock tight my head bolts,,silicone yes but even at that, you change the torque value due to the add lubrication.

Theres no way in hell the inside and outside bolts could be flipped around.  the inside ones are not only longer but shanked.

Head Gaskets - General Question

Reply #8 –
Well my friend did that.

Head Gaskets - General Question

Reply #9 –
Quote from: 88TurboCoupeman01;236093
Well my friend did that.


Its a decent idea,, I just have too much time behind a blow torch cooking out the red lock tight in order to not break off a bolt im trying to remove.

Head Gaskets - General Question

Reply #10 –
Thanks all for input.

Thunderhawk -  Found 3/8, 1/2 and 3/4 in 6 foot rolls at Pep Boys.
Will check Grainger (wouldn't thought of them for this) for larger.