Join Our Ford Truck Forum Today

Document your Ford truck project here and inspire others! Login/Register to view the site with fewer ads.

coolant out tailpipe

kevin9

New Jersey Chapter member
38
2
hey guys,i have a 51 f3 flathead that was just rebuit from the ground up.started it up,smoked for about 20 seconds then stopped.ran good even test drove in the driveway,parked back in garage and saw coolant leaking out of the passenger tailpipe(i rigged two small exhaust tubes one for each side as temporary exhaust) so i performed a compression test,all cylinders were120 psi so im pretty sure i dont have a gasket issue,the block was sleeved and pressure checked by a reputable machine shop any ideas?im thinking cracked head on left side ,i did use sealer on the bolts and they were retorqued twice.any ideas?
 

mtflat

Flatheads Forever
2,559
147
Sorry for the misfortune. I don't mean to sound stupid, but the liquid running out is coolant-colored? It would be normal for a good bit of condensation to run out, but that should be clear.

With all your pre-cautions and checks, the only other thing I can think of is a crack in the head, but that should be pushing compression gasses out into the radiator not the other way around.

Only time I've had coolant out the exhaust involved a crack from the intake valve-to-cylinder.

If you pull the head you should be able to see where the coolant is coming from. Is there any chance you have a head gasket flipped end for end? I did that once - they leak.

Anything else you find, the pressure test should have picked it up. I'd be on the phone with your machinist that did the testing.
 
Last edited:

kevin9

New Jersey Chapter member
38
2
coolant issue

hey,thanks for responding.the fluid is definitely prestone green.i am a professional mechanic but dont have much experience with flatheads,i am only 37 but my heart tells me it is a cracked block.otherwise i would have compression problems.do you have any other suggestions on repairs or am i looking for a new block?i will post some pictures of the engine when i get a chance.thanks for all your advice knowledge is the best tool i have,kevin
 

mtflat

Flatheads Forever
2,559
147
Flatheads are really simple. I'll post a link where you can find some cut-away pics.

http://www.vanpeltsales.com/FH_web/flathead_home.htm

I'd pull the head and see if there's evidence of coolant in the cylinder. The other possibility is a crack in one of the exhaust runners between the valve and the manifold - they run thru the coolant passage.

If you find a crack, it depends where it is. Some can be fixed - best solution is to pin them.

As with any other engine - there's no evidence of foaming in the radiator or milky oil??

If you want to talk to mechanics with years of tech experience, here's the site you need. I'm a moderator there so let me know if you need any help. The techno page has tons of archived info that we're in the process of improving access to. You'll need to register to participate, but it's worth it. These guys are the best on the internet.

http://flatheadv8.org/phpBB/index.php?sid=ab7c28968be0614617c89cc0df187592

I'll follow your progress.
 
Last edited:

kevin9

New Jersey Chapter member
38
2
coolant

thank you for your help.it is nice to know there are still good people out there.if you need help with any late model problems feel free to ask.i have a well run shop that i work at and i have lots of resources available.again thanks,kevin
 

mtflat

Flatheads Forever
2,559
147
Thanks Kevin, I may take you up on that offer. I need to pull the 5.4 out of a wrecked Expedition this weekend so my son-in-law can haul it home to swap into his. If I hit any bumps in the road I'll let you know.

Just out of curiosity, where are you located?
 

kevin9

New Jersey Chapter member
38
2
coolant

i live in southern new jersey about 15 miles from philadelphia.are you a mechanic by trade?
 

mtflat

Flatheads Forever
2,559
147
No, only by hobby - and I have greater than ever respect for professional mechanics. Trying to get that 5.4 out of the wrecked '01 Expy Eddie Bauer edition today is one of the toughest I've ever done.... course most of what I've done is 48-90's stuff.

After working most of the day we finally got the throttle body off and are ready to pull the intake manifold... hoo boy. Had to cut our way thru a lot of mangled sheetmetal and are taking time to salvage the few things that are any good, so its taking a little longer than if we were just wrenching.

But still, it's nuts how tightly packed things are - you guys earn every penny you make and my hat is off to you!

I'm a old carpenter/contractor by trade and a full-time pastor by calling.
 

kevin9

New Jersey Chapter member
38
2
tim,yeah those expeditions are tough even with a lift.some of the diesel f series we pull the whole cab off just to access the motor.i was a carpenter for a couple of years too.then i decided to try the marines for about 8 years.i worked on fighter jets it was a cool experience.i admire that you are a pastor,i have been searching for my spiritual side for a long time.nice talking to you and thanks for the advice.kevin
 

kevin9

New Jersey Chapter member
38
2
coolant

well finally got the right cylinder head off to inspect for a cracked block.found a crack in the upper water jacket dumping coolant into the exhaust port number 2. i am goimg to jb weld it because i think that will seal it up.any other suggestions would be welcome
 

mtflat

Flatheads Forever
2,559
147
Upper water jacket... Do you mean the crack in the head or the block? JBWeld might do it. Let me know how it goes.

re: marines. Thank you for serving! God bless you.

re: searching for your spiritual side. For me, spirituality is the opposite of religion. If you get a chance, find a copy of a paperback titled "The Shack" and when you read it, let me know what you think. I love the way the author describes the relationship God wants to have with us. Religion is rules and regulations, but a relationship is just knowing you are loved and cared for - not for what you do, but just because. It takes all the pressure off and might sound too easy. Enjoy your search, but remember God isn't hard to find - we just have to get out of our own way sometimes.
John 3:16 and Ephesians 2:8,9 are a couple of awesome verses.
 

TexasNomad

FTFS Designated DRINKER!
Eeew sounds nasty, send some pics.
 

kevin9

New Jersey Chapter member
38
2
crack

the crack is in the block.i will try to get some good pictures.tim,in regards to the spirituality,thanks for the suggestions its nice to hear that point of view.as for the block i am going to try jb weld this week,i will keep you posted.
 

Ford Truck Articles

Top