Gasket Issues?

[Automobilie]

It'd be harder to explain, so here's a video for your viewing pleasure and understanding.
http://www.youtube.com/watch?v=GpWbg4eQMcY&feature=youtu.be

Basically, I'm getting a small amount of back pressure into my radiator.

 

[ddranger]

i would have a cylinder leak down test done. it will tell you which cyl is leaking into radiator. but either way it's just telling you what you already know. you either have a cracked head or a head gasket leak.

 

[BRUTUS_T_HOG]

It'd be harder to explain, so here's a video for your viewing pleasure and understanding.
http://www.youtube.com/watch?v=GpWbg4eQMcY&feature=youtu.be

Basically, I'm getting a small amount of back pressure into my radiator.

You need to remove the cylinder heads and have them pressure checked. No way around it. At least you know what the cause of overheating is.

I use that same tester multiple times per week

 

[aspevacek]

Run a compression test on the cylinders and see where your numbers are both dry and wet. Then do a cylinder leak down test and see which cylinder or cylinders ar eleakin gdown the most. based on those numbers I would decide to pull the heads or not. At least if you do those tests prior to breaking it down you will have a good point to start looking.

 

[RonD]

You can do the glove test for free.

Drain a bit of coolant out of the rad, 2 or 3 inches.
Remove all but 1 spark plug
Remove spark plug wire from that 1 plug

Get a latex glove and rubber band, remove rad cap and place glove over opening and use rubber band to seal it.
Remove overflow hose(next to rad cap) and block that hole, a vacuum cap off the intake or short hose with bolt in one end works.

Turn over engine and watch glove, it will dance around if the cylinder that has the spark plug has a leak into the cooling system.
Remove spark plug and put it in the next cylinder, repeat until all cylinders have been tested.

The glove will dance, this won't be a slight movement.
This will ID which cylinder or cylinders are pushing air into the cooling system.

Instead of a spark plug I use a compression tester so I can also get the compression PSI of each cylinder as I go along.

You can also do the glove test with all spark plugs in place, with wires removed, it will tell you if you have a cracked head or head gasket issue, it just won't tell you which cylinder.

 

[aspevacek]

You can do the glove test for free.

Drain a bit of coolant out of the rad, 2 or 3 inches.
Remove all but 1 spark plug
Remove spark plug wire from that 1 plug

Get a latex glove and rubber band, remove rad cap and place glove over opening and use rubber band to seal it.
Remove overflow hose(next to rad cap) and block that hole, a vacuum cap off the intake or short hose with bolt in one end works.

Turn over engine and watch glove, it will dance around if the cylinder that has the spark plug has a leak into the cooling system.
Remove spark plug and put it in the next cylinder, repeat until all cylinders have been tested.

The glove will dance, this won't be a slight movement.
This will ID which cylinder or cylinders are pushing air into the cooling system.

Instead of a spark plug I use a compression tester so I can also get the compression PSI of each cylinder as I go along.

You can also do the glove test with all spark plugs in place, with wires removed, it will tell you if you have a cracked head or head gasket issue, it just won't tell you which cylinder.

He has done th echemical leak test and it changed colors so I was leading him to narrow down where the leak is. The problem is even with the chemical test the color is very slow to change so it is an ever so slight leak. The test results from a straight compression test and leak down test will lead him to the cylinder where the issue is. I personally would suspect a head gasket with how slow it is responding and does not change faster based on engine temp. The expanding and contracting of the iron at different temps would create mor or less of a leak based on temp if it was the head. The gasket will hold at a specific expansion and contraction becaus eof the materials used in it.

 

[RonD]

My 4.0l didn't show which cylinder had the leak with the compression test, all were within 10%, average was 170psi.
The effected cylinder was actually one of 3 closest to the average.
It was a cracked head, standard 4.0l issue, crack was between intake and exhaust valve seats.

The glove test showed which cylinder it was, so I retested compression a few times and it still averaged 170.
Yes, leak down would show it but glove was easier

Many DIYers don't have pressure gauges or even compressed air, so you work with what you have.

 

[Automobilie]

Well, had a hydrocarbon test done after mine didn't come out consistent enough. it was positive with ~500ppm, so a small leak, but a leak. Right now I've got everything down to the heads off including the head bolts, but the exhaust manifold bolts won't come out. Already stripped two of them and a socket so I'm probably going to try at the manifold to pipe bolts. They're larger and the threads look more exposed.
I don't know why I'd have a crack though.

 

[RonD]

4.0l heads are known for cracking between valve seats, it is a weakness in the casting.
My guess would be a running lean condition or EGR issue that causes a cylinder to run a little hotter, or a failed water pump or coolant leak which caused an overheating situation, anything that causes an over expansion in the head metal and the weak point shows up.

Just for future reference, if I have a running vehicle and plan on having to remove any exhaust parts, i.e. manifolds, cats, etc....
I take it to a local muffler shop tell them what I am doing and have them remove and reinstall/replace any exhaust bolts I will have to deal with.
Usual cost is $25-$50 so not too expensive
All they are doing is loosening and tightening bolts and nuts, to make sure they are not frozen, so it can be a pretty fast job.
And if there is a frozen one(almost always, lol) they have all the tricks and tools to get these stubborn nuts and bolts loose, they do it every day, so are fast and have replacement nuts and bolts in stock.
I did have one broken manifold bolt once, I told them not to replace it since I was pulling the head and could do it myself.

 

[Automobilie]

About to go out and see if I can't get those bolts out. If it is a crack, can I get it ground out and welded? I was looking and rebuilt heads are around$300-400. My dad's offered to pay for parts, which I'm really grateful for, but if I don't have to go all out and get new ones that'd be fine. Also, the truck only has 90,000 miles on it

Edit: No luck , might end up getting it towed to a shop to get it busted off with their tools. The mechanic gave me a bit of acetone/ATF to set on it over night and I bought an extra quart of acetone and ATF if it works.
On the other heand, got to take my minibike across town cop passed by me once, looked at the bike, but never said anything.

 

[aspevacek]

I have a set of extractors made for stripped nuts and bolts they are a loose thread on the inside and as you turn them to remove the nut/bolt they walk down and grab the surface. Had very godo luck pulling hte exhaust bolts on my dads 86 F250. I had neve rtried them prior to that but will give the big thumbs up for completeing that project.

 

[Automobilie]

I've got a set of those too actually, but I can't get at teh bolts very well and they're very stuck.

 

[RonD]

You couldn't get the header pipes off?
So pull the head with manifold attached

Worst case, I would cut the exhaust pipe at a spot where you can pull it out with head and manifold attached and then after reassembly drive it to the muffler shop and have them weld a sleeve over the cut, you can get/make a clamp on sleeve for temporary use.

if head is cracked I don't think a weld would hold, could but I would be leaning towards getting another head

 

[alwaysFlOoReD]

I was trying to remember and finally did, it was panama expat that mentioned welding a cracked head in another thread.
www.therangerstation.com/forums/showthread.php?t=136006

Richard

 

[Automobilie]

Got one off with the ATF so the other's are soaking. Need to get an extension in town to get the others.
So it sounds like the head cracked, should I try and get another iron head or an aluminum one? How prone are these things really? And if only one has a crack should I expect the other to crack soon?