New problem ! Head gasket ? *** !

[dsltech83]

I looked at an 87 f250 today .. It's actually pretty clean . It's a 4x4 with a 5spd . We agreed on $750 and I'm picking it up tomorrow . I'm either going to toss the engine in the 90 or drive it while I change the head on my 90 . Would an 87 be a 6.9 or 7.3 ? I couldn't read the sticker .

87 should be a 6.9, look at the exposed head bolts, 6.9's are smaller than 7.3's.

 

[homelessduck]

I picked the head up today .. it's not cracked Soo , I obviously have an issue with the block . I know blockworm usually affects the rear cylinders , and mine is leaking in the #2 cylinder , so I don't really know what to think .

...

 

[redmondjp]

I picked the head up today .. it's not cracked Soo , I obviously have an issue with the block . I know blockworm usually affects the rear cylinders , and mine is leaking in the #2 cylinder , so I don't really know what to think ....

Sorry to hear about that. You can check the deck for flatness w/o removing it from the truck, but that won't necessarily confirm or deny anything - if you find out it needs to be decked, the block has to come out anyways, and at that point the first thing is to clean up block and check for cracks and pinholes before any more $ is spent on machining . . .

On the plus side, you've got a good head to start out with!

 

[homelessduck]

The engine is already out . I don't have the time to tear into it any farther than I have . I will probably have to put my 6.9 in it.. I can try to diagnose it further , and I will today , but no matter what the issue is with the block it would have to be stripped down so I could have a machine shop check it out .. which I don't have the time or money to do . At that point I would only reassemble it after doing a complete rebuild . It will have to be a later project . Right now I'm thinking my only option is to pull the 6.9 , freshen it up and toss it in .

Anyone need a head ? I have (3) 7.3 heads that have been hot tanked and mag'ed..

 

[hesutton]

I'm sorry to hear that man. I too worry that the deck may be warped. That sucks and will require a good machine shop to fix, plus, the special Mahle pistons for decked blocks.

I hope the 6.9 is good.

Keep us updated. Hang in there.

Heath

 

[homelessduck]

I think I'm going to have the head mag'ed again .. just to be sure . I'm still in denial .

 

[hesutton]

I think I'm going to have the head mag'ed again .. just to be sure . I'm still in denial .

Did the machine shop say if the head surface was warped? If they didn't check, it'd be something to look at as well.

Heath

 

[homelessduck]

They checked the surface while I was there and said it wasn't out of spec .

I took the head to another machine shop today . He mag'ed it ; no cracks . He checked the surface and said it looked fine but it is hard to tell when it's warped on the ends . I looked closer at the block , gasket and head . It obviously made very little contact right below the water jacket , maybe an inch from the wet cylinder . There is no sign of it mating in that spot on both the head and gasket , though the rest of the head sealed well . The block deck does not look warped , it actually looks really flat . There are no cracks in the block that I can see , and from the amount of coolant in there it should be noticeable I would think . I'm thinking about tossing a new HG on and doing a leak down test on it .

This has me totally confused and unsure of what to do .

 

[redmondjp]

They checked the surface while I was there and said it wasn't out of spec .

I took the head to another machine shop today . He mag'ed it ; no cracks . He checked the surface and said it looked fine but it is hard to tell when it's warped on the ends . I looked closer at the block , gasket and head . It obviously made very little contact right below the water jacket , maybe an inch from the wet cylinder . There is no sign of it mating in that spot on both the head and gasket , though the rest of the head sealed well . The block deck does not look warped , it actually looks really flat . There are no cracks in the block that I can see , and from the amount of coolant in there it should be noticeable I would think . I'm thinking about tossing a new HG on and doing a leak down test on it .

This has me totally confused and unsure of what to do .

Get a 18" or 24" precision-ground straight edge and check the deck for flatness using a set of feeler gauges. Make sure all of the high spots are taken off first (residual gasket, etc).

 

[hesutton]

Get a 18" or 24" precision-ground straight edge and check the deck for flatness using a set of feeler gauges. Make sure all of the high spots are taken off first (residual gasket, etc).

I agree. I few thousands of an inch is very, very difficult to see with the neaked eye. But it will be obvious with straight edge and feelers. It's a time consuming process, but important. If the gasket didn't seal there, something is going on in that area of the deck.

Heath

 

[homelessduck]

Get a 18" or 24" precision-ground straight edge and check the deck for flatness using a set of feeler gauges. Make sure all of the high spots are taken off first (residual gasket, etc).

That's how I checked . That is why I am so confused . Maybe I accidentally missed the the head bolts on that end when I was chasing the threads .. would that cause this issue ? Most parts stores carry the glow plug adapter for pressure checking the cylinder right ? 9/10 they say they don't have something that they actually do have , and vice versa .

 

[suv7734]

They checked the surface while I was there and said it wasn't out of spec .

I took the head to another machine shop today . He mag'ed it ; no cracks . He checked the surface and said it looked fine but it is hard to tell when it's warped on the ends . I looked closer at the block , gasket and head . It obviously made very little contact right below the water jacket , maybe an inch from the wet cylinder . There is no sign of it mating in that spot on both the head and gasket , though the rest of the head sealed well . The block deck does not look warped , it actually looks really flat . There are no cracks in the block that I can see , and from the amount of coolant in there it should be noticeable I would think . I'm thinking about tossing a new HG on and doing a leak down test on it .

This has me totally confused and unsure of what to do .

Have the machine shop pressure test the head. That is the only way you're going to find out if there are any other problems. They can only tell so much if they just magnaflux it.
Here's a pic of a 7.3 head that had a lot of machine work done to it by a "reputable rebuilder". Short version of the story is they cut too far down when replacing the intake seats and cut into a water jacket. Once the seat was installed everything looked great and it would not show up even if you magnafluxed the head. After the failure (hydrolock) the heads were pressure tested and the leak was found, seat removed and problem diagnosed.

Just something to think about before you go to all the trouble of putting it back together and?

 

[ih8minimumwage]

Use that straight edge and a flashlight to find the warp. There was NO way I could've found the tiny warp in the head that kept blowing gaskets with the naked eye. I wasn't even sure it was the warp until I compared with the good head I ended up swapping in.

 

[homelessduck]

Have the machine shop pressure test the head. That is the only way you're going to find out if there are any other problems. They can only tell so much if they just magnaflux it.
Here's a pic of a 7.3 head that had a lot of machine work done to it by a "reputable rebuilder". Short version of the story is they cut too far down when replacing the intake seats and cut into a water jacket. Once the seat was installed everything looked great and it would not show up even if you magnafluxed the head. After the failure (hydrolock) the heads were pressure tested and the leak was found, seat removed and problem diagnosed.

Just something to think about before you go to all the trouble of putting it back together and?

When I bought the engine and pulled the head I could tell that it had recent work done to it . The machine shop pointed it out as well . That is an interesting thought .. My plan is to buy another head gasket and install my other head that is without a doubt good . Then I will pressure check all of the cylinders before installing anything else . That way I can rule out the head. I'm doing that today , assuming I can find a GP hole adapter..

When I checked the block deck I used a flashlight and a feeler gauge .

 

[homelessduck]

Well , I can't find a pressure tester spark plug - GP adapter.. I guess I will have to order one and wait