heads

[Edgefevah]

So guys I have had a head gasket leak for quite some time now, been putting off changing gaskets and now I can finally afford the time and money to get it done.

My question is should I spend the money to get the head(especially the drivers side) checked for cracks?It has been leaking for about 3,000km now. But round fine, doesn't overheat or leak into the oil at all.

the local machine chop charges $110 per head to check for cracks and see if the valves are seating properly. the truck runs absolutely fine except for having to add coolant every once and awhile. they then charge $70 for resurfacing.

I would really appreciate some experienced advise on this as I don't exactly know what to do about getting the heads checked.

 

[RonD]

That sounds a bit high, I am in Vancouver and it was $220 to have the heads cleaned, surfaced and pressure tested, they also installed the new valve guide seals I provided from the head gasket kit.
'94 4.0l OHV

Cracked head on the 4.0ls usually happens between the two valve seats, and easy to see.

Yours sounds like an unusual head gasket issue.
Glove or balloon test works well to see if there is a crack or leak from a cylinder to the cooling system, and you can even ID which cylinder has the leak with this test, which makes tear down inspection easier, i.e. is it a gasket or crack issue.

Here is a video of a "glove test", member didn't use a glove though
http://www.youtube.com/watch?v=vFGquUimXro&feature=youtu.be

Losing coolant without visible leak is not always a head gasket issue.
I had a crack in my overflow hose where it ran over the top of the rad.
Engine would warm up and send coolant to overflow tank, some would leak out the crack and evaporate pretty fast because rad top was hot, so no dripping or other signs of a leak.
Then at cool down, the crack would allow air to be sucked back into the rad, so when I checked coolant level when cold rad would show low level.
So leak MUST be in the engine cooling system.......oops, wrong, chased my tail a bit on that one, lol.

 

[Edgefevah]

Yeah I'm am 60% sure it is an unusual headgasket problem, no antifreeze in the oil either which is the main resin I do believe it to be just an external leak. I can also see the green antifreeze building up on the outside too.


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[RonD]

Wouldn't be a cracked head then.

Coolant in the oil can happen with a head gasket issue but usually only 10% of the time, so it is not as common as cooling system to cylinder leak.

Cracked head would at first cause cooling system pressure to increase, overflow tank would bubble and coolant would be sucked into a cylinder on intake stroke and then burned on power stroke causing a white vapor in the exhaust that smells "sweet" like coolant burning.

You could have a cool seal issue which is not common and usually caused by a warped head.
When engine cools metal contracts that can allow coolant to breach the head gasket at the edge of the head, where it cools faster, so you get a leak of coolant just below the head.

Surfacing the heads will fix that.

 

[PlumCrazy]

You probably just have a leaky lower intake gasket.

If it was a head gasket you would be putting pressure into the cooling system and popping a hose.

4.0 OHV motors are notorious for lower intake gasket issues. Do a compression test to rule out the head gasket issue.

 

[Tbarnes93]

You can have them for straightness but you can spray some wd 40 on the head and leave it out and with the dew and sunlight a crack will have rust on it no rust head is not cracked. Warped on the other hand needs to be checked. I changed my head gasket a few months ago its a job that's for sure

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