I recently acquired a 460 and C6 through some trading with a buddy and swapped it into a 1977 swb F100. I swapped radiator, hoses, and everything. The engine had been sitting for 5 years or better and supposedly has low miles since a rebuild. All this "history" is here-say and I don't really know any of it for a fact.

It runs great, holds great oil pressure cold and hot, and will really pin you in the seat. The problem is that it appears to be overheating though the gauge doesn't show it. Let me explain: Installed the engine and trans, hooked everything up and started it. Had about 4 feet of exhaust pipe on each side with no mufflers yet. Took it down the road and back maybe 1/2 mile and brought it back to the shop. Ran fine but it was WAY loud as you can imagine. Ordered mufflers and welded an exhaust system under it Friday night. Drove it Saturday a little more - smoked some tires and had a little fun on the roads around the house. When I pulled back up to the shop, I could hear what sounded like water boiling and gurgling around the front of the engine even though the temp gauge showed everything to be fine. I assumed it just needed to be topped off so I left it sitting for an hour or so and topped off the coolant. It was maybe a half gallon low. Drove it down the road and back, gauge looked fine, but it still made the same unhappy water noises when I got back.

I removed the thermostat, started it back up and topped off the coolant again. After a couple of minutes of idling it started to make the noise again and I could feel it in the radiator and the hoses when it gurgled and popped. Everything felt relatively cool by hand except the front of the cylinder head on the passenger side. I let it cool and got out the heat gun. I started it again and as it started to make the noise after a minute or two, I started taking readings with the temp gun. Basically when the radiator and the rest of the engine was around 140-150°F, the area of the front of the cylinder head/block on the passenger side was reading 210-220°F. This was also where the noise was coming from.

I did lots of searching but couldn't find symptoms like this. My guesses would be: head gasket installed backwards or water jackets in the block full of junk and not letting water flow properly in this area?

Has anyone experienced this issue and determined the cause? I also read something about purging air from the block via the heater hoses when filling with coolant? The heater core is bad in the truck so there is a hose connecting the 2 fittings together and it is kinked . I assumed this wasn't the issue since when the heater would be switched off there would be no flow through the core anyway?

Any help would be greatly appreciated guys.

 

Running it without a tstat is a bad idea. I would first get a psi checker and pump it up. See what it does.

 

From you description the is a blockage on the right side of the engine. Oh and marka is right, never run without a thermostat. Whay temp thermostst are you running?

 

No clue what temp the T stat is - I just pulled the housing and removed it to see if it made the issue go away ( I assumed it was stuck since it was making overheating noises while sitting there idling).

Been researching some more and the most likely culprits seem to be a blockage in the water passage(s) in that area of the engine, a head gasket installed backwards (would that make the front of the engine heat up quickly or the rear?) or air in the system?

Everything comes up to temp nice and evenly - radiator, hoses, and engine - except for that one area where there is obviously some very hot water or steam in there. I couldn't really tell if the problem was in the block or the cylinder head. They both seemed to be hot.

I assume that unless someone chimes in with a 100% certain cause, I will start down the list with the easiest first. That being said, where would air be trapped and how would I purge it? I assume revving it with the cap off (which I had been doing) doesn't cut it.

Also - what is the best way to flush the block out in the vehicle? Or would that even do any good? Heck - I can have the thing out and back on the engine stand in a couple of hours and really clean it out if needed.

 

head gasket leaking compression into the coolant will have a similar effect. 1000 degrees and gasses cause those symptoms..

 

I was thinking along those lines too, but I suspect the radiator cap would end up dumping those combustion gasses eventually and the OP didn't mention boiling over.

 

Okay guys - had a chance this afternoon to mess with it some more and take notes of the details. Here goes:

80° outside. Truck hasn't been touched in 3 days. Installed 195° thermostat.

Cut loop of hose connecting the 2 heater hose ports. Filled the heater hose that comes from the intake with coolant until it started coming out the heater hose from the water pump, then plugged the water pump hose.

Filled the radiator until coolant started coming out of the intake heater hose and plugged that hose.

Filled radiator to about 1" below full and started engine with radiator cap off and let idle. No flow and no bubbles as expected.

After approx 1 minute running both heads measured about 95°F on the front face.

Installed 16lb radiator cap. About 30 seconds later had to take a phone call and killed the engine for about 5 minutes.

Measured temp on both heads before restart - about 132°F on both heads.

Restarted engine and noted the following over a course of 5 minutes or so:

1 minute - 135°F on both heads - upper radiator hose limp - removed cap - no pressure - no bubbles or flow.

2 minutes - 145-150°F on both heads - upper radiator hose and tank cool to the touch.

2.5 minutes - 165-170°F on the left head, 175-180°F on the right head - puked a stream of coolant from the overfolw hose (maybe a few ounces). Radiator and upper hose still cool to the touch. ODD.

3 minutes - 170-175°F on left head, 185-190°F on right head - radiator cool - upper hose cool and firm.

3.5 minutes - 165-170°F on left head, 190-210°F on right head - puking a steady stream of coolant from overflow hose, radiator getting warm to touch.

4 minutes - 165-170°F on left head, 210-220°F on right head - puking stopped - no odd noises - radiator now hot indicating thermostat opened - radiator top tank 175°F on inlet side and 150°F on outlet side showing 25°F gradiant across radiator.

4.5 minutes - 165-170°F on left head, 230-240°F on right head - some puking from overflow hose - no odd noises that I could hear.

5 minutes - 165-175°F on left head, 235-245°F on right head - puking from overfolw hose and boiling/popping noise from right front of engine (unhappy water) - shut engine off.

After shutdown - 170-175°F on left head, 240-250°F on right head - still lots of unhappy water noises that continue for a minute or two. Upper radiator tank showing 205 on inlet side and 180 on outlet side.

There's my data. Sounds like a head gasket or head issue to me. Anybody care to confirm or deny before I tear into it? Hopefully all this will help someone in the future.

 

Good job on your data acquisition Broncos. I know the head gaskets are marked "Front", for the heck of it I broke out the book How To Rebuild Your Ford V8 351C-351M-400-429-460 By Tom Monroe. Tom sez "If you get the gaskets on wrong, you'll be wondering why your cylinder heads are melting and your idiot light/gage [sic] is not indicating trouble. The problem is the water passages in the heads will be blocked off so coolant can't flow through them."

Sound familiar? I say pull it and change the head gaskets, crankshaft/valve seals, freeze plugs and everything else that will **** you off if you don't do it now, especially that PITA bypass hose! Good luck bro.

 

Tore into it last night and removed the right cylinder head. Unfortunately, I couldn't find anything wrong. The gasket was on correctly I think (front water passage blocked, rear passage open). I could not read where it said "front" on either end. The water passages in the front of the head and the front of the block appear to be unobstructed. I did not check the back half of the head or block on that side yet. I did not check the water passage in the intake or look closely at the intake gasket for anything weird. I did notice that the exhaust valve and spark plug in the front cylinder were lighter than the others. The head gasket did not appear to be blown or leaking in any way as far as I could tell. I'm at a loss guys. I think it has to be a coolant flow issue in that side of the engine. I guess I'll investigate further tonight.

Anybody have any other suggestions of where to look or anything odd to check for? Something to do with the water pump not feeding that side of the engine properly? Rusted out backing plate?

That would be my luck - pull a cylinder head because I have a water pump issue......

 

Any progress?

 

Not yet. Ended up having to work about 13 hours yesterday and had no time. I plan to be back to it in a couple of hours. I keep coming back to thinking it has to be a lack of (or very poor) circulation in that side of the engine. I'm going to look closely at water passages in both the head, block and intake. If I can't find anything, I guess I 'll remove the water pump and check out the passages to the block as well as the impeller and backing plate. It has to be obvious once I find it I would think - unless it's a tiny crack in the head or something.

Any other ideas would be much appreciated. I'm ready to get this thing on the road!

 

FOUND IT!!!

After finding nothing at all wrong with the water passages in the head, intake or block, I removed the water pump and found this:

<a href="http://s138.photobucket.com/albums/q261/southarkhunter71701/?action=view&current=waterpump1.jpg" target="_blank"><img src="http://i138.photobucket.com/albums/q261/southarkhunter71701/waterpump1.jpg" border="0" alt="Photobucket"></a>

<a href="http://s138.photobucket.com/albums/q261/southarkhunter71701/?action=view&current=waterpump1.jpg" target="_blank"><img src="http://i138.photobucket.com/albums/q261/southarkhunter71701/waterpump2.jpg" border="0" alt="Photobucket"></a>

I thought I was just being funny when joking earlier about someone using WAY TOO MUCH silicone - never actually thought it would be the cause of all this issue. WHO DOES THAT???? I really did remove a cylinder head to fix a water pump issue. Wow.

Anyway, the entire water pump cavity on that side was blocked as well as the passage through the timing cover into the block. It's obvious that there was way to much silicone used, but what is the other stuff? Kind of vaseline colored....Like big crystals until you mash it hard, then it becomes almost like thick grease. Doesn't really have a smell. Looks like this:

<a href="http://s138.photobucket.com/albums/q261/southarkhunter71701/?action=view&current=waterpump3.jpg" target="_blank"><img src="http://i138.photobucket.com/albums/q261/southarkhunter71701/waterpump3.jpg" border="0" alt="Photobucket"></a>

<a href="http://s138.photobucket.com/albums/q261/southarkhunter71701/?action=view&current=waterpump4.jpg" target="_blank"><img src="http://i138.photobucket.com/albums/q261/southarkhunter71701/waterpump4.jpg" border="0" alt="Photobucket"></a>

<a href="http://s138.photobucket.com/albums/q261/southarkhunter71701/?action=view&current=waterpump5.jpg" target="_blank"><img src="http://i138.photobucket.com/albums/q261/southarkhunter71701/waterpump5.jpg" border="0" alt="Photobucket"></a>

<a href="http://s138.photobucket.com/albums/q261/southarkhunter71701/?action=view&current=waterpump6.jpg" target="_blank"><img src="http://i138.photobucket.com/albums/q261/southarkhunter71701/waterpump6.jpg" border="0" alt="Photobucket"></a>

An obscene amount of stop leak? Some weird chemical reaction between something and something else? Aliens? (just kidding) No clue. I'm just glad I found it and that's all it was.

Oh yeah - my "free" 460 that had supposedly been recently rebuilt.....it is a standard bore block that hardly has any ring groove at the top of the cylinders, doesn't really have any residue in the water jackets, hardly any sludge in the lifter valley, no sign of being into before that I can see (other than water pump (with EXTRA silicone) and the normal stuff) and the heads look good. Maybe this is going to turn out to be an awesome deal after all. I smell .030", some more stroke and some some aluminum heads......

Guys - thanks for your inputs and suggestions of things to check. A perfect example of what the forum is all about. I hope I can return the favor one day.

 

Wow, that is ugly and yes, you called it! Glad you found it. Are you going to dig in deeper? Replacing the oil pump and pickup would be a good idea :-)