1980, F350 2bbl, 400z
https://www.ford-trucks.com/forums/1...l#post10483846

Had truck for like 4 years and it overheats every year spring through fall.(anything over 70*). I originally thought it was just vapor lock but 99% sure it's the block overheating. I'm hoping it's not a head gasket but at this point I just want it fixed. Oil and coolant are not mixing, but I was told the head gasket can leak on the "exhaust side" and saw someone describing similar problems.

I've changed the gas cap like 3 times, flushed radiator twice, pretty sure I did the rad cap, changed the fuel pump 4(?) times, all fuel lines(vapor lock concern), changed the carb, distributor, timed it, and today I pulled the thermostat(changed at least 3 times) to make sure it was moving water-it was.

Ctbutis advised a pressure and leak down test. The pressure test showed no bubbles in the radiator, but when I got to the last cylinder (6) I noticed air coming out of the hole in 5.

2 weeks ago I went out of town and cracked the hood to allow more flow while doing slow (5-10mph)driving and stopping but the gauge went up to the highest point in the safe range and stayed there. I got out of the truck and went to open the hood so it would cool while I was busy elsewhere. As I went to the front of the truck I heard PPPFFFFFFFFFFF, and when I popped the hood, the overflow hose was spewing water and steam into the reservoir. This hasn't happened since, but the truck always gets hot if I stop too long.
Also, because it gets so hot, I have a hard time starting as I'm sure the bowl evaporates after turning the truck off. Now I actually have to let it die on me 2-3 times before it will stay running or I have to tap the gas pedal a bunch of times and hold it lightly before it warms enough to stay running. (saw a video where a hard start similar to this was a head gasket)

I had it look like oil out blew out the side of the block (once then not again)


And There appeared to be water leaking down the back of the block which slowly washed old fluids down which ran off the middle of the axle and the very front of the transmission.

I got the head off and these are the pics
Again. I had no mixing of oil/coolant.

*Red- 3 round spots left by the gasket, all 3 look filled in on CTB's block pics. also the square at the top right looks filled but there is a hole on the head.
*Yellow- I think oil was leaking from cylinders 6/7
*Blue-This hole (only the gasket, not the hole)was actually completely covered with calcium/silt/whatever that white stuff is. (pic below)
*Green-Obvious
*Pink-I think this is where the water was leaking down the block.


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*Purple- This lines up with the non-existent square on the block.
*Blue- Looks like a chip out of the head?



I didn't get a chance to clean the head yet, but I'm pretty sure I need to replace it (mechanic also told me that he's thinking head problems from the gasket).


Still gotta do the other side. Any advise, ideas, questions greatly appreciated.

 

Here's the other side of the block. Everything looks pretty much the same except the small hole directly above cylinder 2 (between it and 3) looks kinda clogged and the lower circle hole just under the square opening looks like it needs cleaned.



Here's the passenger side Head, fowler in plug 3, no plug in 1.




I think the oil is because I didn't drain the block before removing the heads it was on the block but I wiped it off before I took the pic.

Here's the Gasket



I'm still learning so if you see something I missed or if I'm thinking nothing is something please let me know

Edit: My brother said that oil shouldn't be there.

 

One of the big problems is the timing chain is wore out after 40,000miles or sooner. Causes crossfire within the distributor. Then it causes a lean condition and then everything starts to run hot. On the valves that are dark on the intakes I'm wondering if intake gasket seeping. Did you compression test the engine? this is the big thing any decent mechanic needs to know when guesstimating your situation. The heads might not need to be replaced just rebuilt if not cracked. Didn't see anything odvious but need to magnaflux the block and heads will tell the story. Good luck and hope I've pointed in the correct direction for you. Tim meyer sells some cool products for this engine and it will run strong if willing to spend some time and money. great guy to know with the ford stuff.

 

I can't believe I forgot the intake gasket.... I had a concern when I pulled it and mentioned it to my brother...






Is that oil on the sides just where the head opens to the intake, or is that a sign?

The truck shows 67,000 miles but I'd think it to have turned over.
I remember that my truck has in the past (only 1 time this year) hiccuped or missed at highway speed. It's very rare on the road, but happens a bit in town. Lately when I come to a stop, it will stall a bit- not every time, but enough to point it out. Also if I accelerate to around 60mph or higher, I do hear a small hum from the the front of the truck so I try to stay under. I have poor acceleration up hills.


From here:
https://www.ford-trucks.com/forums/7...ssageways.html


Anything there? I saw in my other post that I had bad buildup on spark plug #8 and some on #4, both the back cylinders.

Edit:when we took the heads in, I noticed burned oil around cylinder 4, Valve cover gasket I assume, but it's in the area of the oil in the head gasket, and I don't see how it could get there...

 

As you scroll down you pics the first head gasket you see there IS the problem.
The holes at the end where you have pink and blue arrows.
ONLY one hole on one end of the gasket should be there.
The hole that was near the front of the block was letting coolant bypass that head.
Look at a new head gasket and you will see it only has one hole on one end.
Those holes MUST be in the back of the block.
NEVER in the front.

 

Yup.

Great call, rep points for that.

Skrilla,

Here is a pic of my engine with the head recently removed, notice how the front water passageway 80broncoman is referring to is blocked off:

 

Unfortunately, that hole was in fact blocked. I took this picture after I showed the mechanic at work. When I was showing him, I voiced a concern that it was blocked, thinking it was caked up with silt/rust/scale (name?) . He agreed and used his thumbs to break it up, but it was there.

I noticed that it was blocked on your pictures too, but I figured it was before you removed it and maybe it was part of your problem. I noticed on Oreilly that they have 3 different HGs, 2 are totally blocked off there and 1 has 2 pinholes there.
Here's a link to the one with holes
Fel-Pro High Performance 1013 - Cylinder Head Gasket | O'Reilly Auto Parts

 

That Felpro 1013 is for a 4bbl head. The correct gasket for a 2 bbl head would be the Felpro 8347PT-1.

 

Great catch on the head gasket being on backwards.

The holes being at either end of the block sometimes confuse one, but they shouldn't.
Looking at the gasket and the block, there is only an opening for the upper passageway
back to the T-stat at the front of the block, it's closed at rear. Only one way will gasket
allow coolant to flow out of head back to T-stat and thus, radiator.

That truck's been serious hot!

Also, when putting her back together, make double sure using the correct style T-stat
with the hat that blocks the bypass route more as it opens. Like Robert Shaw 333-180
or 333-192. It's important for these motors.

 

Heads came back and they passed all the tests, didn't even need resurfacing(saved $150 lol). Now I gotta get it back together.

CTB was talking about needing a different thermostat. I have that Rt139-180* but obviously that didn't help, so I will look into the Shaw ones.

I was afraid I had a clogged radiator, but I will definitely give this Tstat a shot first.(I can feel the water get hot at both hoses on the rad after a bit and I've flushed it twice in 2 years).

The head gasket was on the correct way, and the hole was blocked when I removed it (labeled in first post). The mechanic at work broke the hole open when I showed it to him. The pictures in the first post are of the driver's side and the 2nd post are the passenger side(Head, block, gasket) as they were taken on different days.

There is a little fluid around the transmission dipstick, I was told it's probably the o-ring there?

Thanks guys!

 

There's one thing I would do, I would pull that radiator and have it checked at a local shop. I've seen plenty of these things look like there flowing ok when there being flushed but not doing so well going down the road. Just having that peace of mind is worth it, at least to me.