Hey Gurus, diagnose this scenario: Update With Video!

[gr8scott]

Hop in Bronco at 6am, start her up and get thick plumes of white smoke from left tailpipe (dual exhaust). It's not the
usual condensation/water vapor/steam that dissipates quickly. It's thick white smoke that keeps on going. What say you?

Scott

 

[sanndmann3]

Blown head gasket? What does oil look like on dipstick? And check antifreeze too... Hoping for your sake it's something else...

 

[Hozr]

Head gasket leaking coolant into exhaust? Does it smell sweet and dissipate fairy quickly?

 

[Joe473]

Hop in Bronco at 6am, start her up and get thick plumes of white smoke from left tailpipe (dual exhaust). It's not the
usual condensation/water vapor/steam that dissipates quickly. It's thick white smoke that keeps on going. What say you?

Scott

Head gasket OR intake gasket. Do leakdown. And see if rad pressurizes or get a kit to test coolant for CO to prove its head gasket.

Sent from my SM-G960U using Tapatalk

 

[gr8scott]

Blown head gasket? What does oil look like on dipstick? And check antifreeze too... Hoping for your sake it's something else...

Blown head gasket was my conclusion too. Oil was changed two days prior to this happening, no problems before or
after changing oil. Antifreeze looks good too. So I get the left head pulled but I don't see anything obviously wrong with the
head gasket. Unless I'm missing something.

 

[gr8scott]

Oh and Joe473, intake gaskets were fairly new, both looked good.

 

[Master Chief]

Had the similar issue with my original block, found #8 cylinder wall cracked.

 

[Broncomt]

Tops of middle two pistons appear discolored, almost like rust.

 

[B RON CO]

Hi, I would have done a compression test before pulling it apart. There is a test for combustion gas in the coolant which tests out of the radiator cap, using a fluid that changes color if the head gasket is blown. It is U View combustion leak test.
The last time I blew a head gasket I was losing coolant.
Now I would check the vacuum modulater on the tranny for a leak.
I am a big believer in the simple things first.
Good luck

 

[Rustytruck]

Check the vacuum line at the transmission modulator and see if there is tranny fluid in it.

 

[Rustytruck]

Blown head gasket was my conclusion too. Oil was changed two days prior to this happening, no problems before or
after changing oil. Antifreeze looks good too. So I get the left head pulled but I don't see anything obviously wrong with the
head gasket. Unless I'm missing something.

Number 8 cylinder the head gasket surface on lower left looks fubar.

 

[Boss Hugg]

I'm voting for cracked block or head. Probably visible to the naked eye.

 

[Lawndart]

Well, this just happened to me -
http://classicbroncos.com/forums/showthread.php?t=288151

 

[gr8scott]

Number 8 cylinder the head gasket surface on lower left looks fubar.

I did see evidence of coolant leaking into cylinder 8 in that area after removing the gasket.
That lowest rear head bolt didn't feel as "torqued" as the others. Could it have backed out a little?

I can see nor feel any cracks anywhere.

C4 vacuum line is bone dry. Wouldn't that show up on both sides with true dual exhaust?

I'll go ahead and reseal and go from there.

 

[Boss Hugg]

Who torqued those heads the first time? Or was it the original factory build? Is it possible someone missed it?

 

[B RON CO]

Hi, since the vacuum modulator is dry this doesn't matter, but you asked, so, if the vacuum source is right under the carb the vacuum is going to all cylinders. If the vacuum tee is on the left rear intake runner the vacuum is pull in that one cylinder.
You know you can remove the dowels in the block to make it easier to clean the deck. I use a die grinder and gasket cleaning cookies to remove it all.
I also double check all the head bolts after final torque.
Good luck

 

[Broncobowsher]

At this point put a new head gasket on and see what happens. If it is fixed, great you fixed it. Done.

If you are still loosing coolant out the exhaust now you have to dig deeper. Leak down is great for this. Even if not a real leak down, just put shop pressure on the cylinder at TDC firing cycle and watch the coolant in a full radiator. Note which cylinders the water level rises when air is applied. Now you know where to look when you take it apart again.

So what if you don't have a compression leak into the cooling? corrosion pin holes have developed in intake manifolds before. The small block Ford is not a common problem, but I am not saying it can't happen.

 

[gr8scott]

Who torqued those heads the first time? Or was it the original factory build? Is it possible someone missed it?

I torqued them down, but it's been well over ten years ago. Don't recall the the exact year though. I'm surprised the gaskets
looked as good as they did.

Hi, since the vacuum modulator is dry this doesn't matter, but you asked, so, if the vacuum source is right under the carb the vacuum is going to all cylinders.

Yeah it goes to base of carb.

I use a die grinder and gasket cleaning cookies to remove it all.

I use 2" Rolocs with my cordless drill.

I also double check all the head bolts after final torque.
Good luck

So do I. Maybe I missed double checking that one.

 

[gr8scott]

So I finally got her buttoned up today and there is no more smoke! She hasn't ran this good in a long time...

[youtube]M3yUwQ9o35w[/youtube]

 

[Boss Hugg]

Mighty fine, mighty fine! So she had a little miss because of a bad head gasket, huh?