1978 F350 2wd 460 all stock as far as I know except MSD Ignition, Cloyes straight up timing set, Holley 4160 with alum. adapter to stock spread bore manifold. Still has egr and evap.

Early in the week:
Harder starts, 4-5 cranks instead of the normal 1-2 hot or cold. Idling rougher that normal.

Thursday:
Took a (1) hour round trip to a job site, once back in town at idle started smoking noticeably looked white to me.

Saturday:
Still smoking but not quite as bad found a cracked vacuum cap replaced that and checked for other vacuum issues, check timing, vacuum reading was at 16.5 steady, idle better but still smoking smelled like exhaust and fuel, don’t realty get what the “sweet” smell should be like indicating coolant.
Oil looks fine no odd color, coolant looks fine.

Sunday:
Pulled plugs and they were all badly fouled some worse than others but all bad, oil on the threads and crusty build up on the electrodes. Last plug change was 5/12/14 just before smog test, all of them looked good except #7 was slightly oily, (passed test easily if that matters)

Compression test:
(4) 130 (8) 155
(3) 145 (7) 155
(2) 140 (6) 135
(1) 145 (5) 150
Front

New plugs, fire up and HUGE smoke cloud goes up, again looks white to me, got less but never really stopped.

Monday:
Cold start, rough idle, white smoke but now spitting oil residue enough to splatter the ground.

From what I can find the white smoke indicates head gasket and coolant getting into cylinder, but oil is clean and plugs are fouled which I think indicates valve guides or other head issue?

Also how are those compression numbers? After searching around the forum I was expecting 110/120, operating temp pulled all plugs full charge on the battery, cranked 8 times each.

Seems like the next step is pulling the heads and having them re-done, any other options and what else can I expect to run into? If we are talking pull heads have them machined and re-install what kind of time should I allocate? Need to plan this out to minimize down time as much as possible.

Thanks!!

 

I dont know what part of california you are in, but the Los Angeles and Inland Empire Craigslist has several 460 heads listings.

 

You think I am better off getting another set built and then doing the switch instead of having mine done?

Thanks,

 

Make sure it's the head gasket .
AGCO Automotive Repair Service - Baton Rouge, LA - Detailed Auto Topics - Symptoms of a Blown Head Gasket

 

Oil burns "blue" white and antifreeze burns white. Hard to think the guides would all go bad at once.
I have seen heads gaskets go bad and no oil end up in my crankcase.
Id have mine rebuilt unless you can't have the down time while at the shop.
Now a days you don't know what your buying. Might be worse than what you have.
Every shop is different but id expect two whole days at the metal shop.

I just reread your post and oil spatering the ground doesn't install confidence in this being a simple problem...

 

That was an interesting article, sounds like any number of symptoms can be any number of problems

Mr7.50headsup: good point on the guides all going at once, all of this came on pretty quick. I drive it at least a little every day, and went form running great to this over a couple of days time.

Down time is rough but can't really drive it like it is. Looks like my only option is to pull it apart and see if I can get any more info.

Two days might not be too bad if I can time it. You are so right on not knowing what you are getting, I am thinking if possible working what I have is a better choice.

Thanks for the thoughts.

 

What transmission do you have? If you have an automatic is it shifting properly? A bad modulator can cause the engine to suck ATF creating white smoke and a vacuum leak.

 

Bothers me that this all happened suddenly and affecting both banks, all cylinders. The transmission suggestion is valid, as would be a power brake booster leaking. Check the fuel pump weep hole if that oil spatter is on that side. PCV system clogged/valve stuck, even the EGR. All of these things are simple to check and I would rule out before tearing off the heads.

 

check your carb adjustments, to much fuel will also emit white smoke ( gas smoke ).

 

Thanks for all the suggestions guys, really appreciate it:

Fordworth: c6 was shifting smoothly prior to this issue

gfw1985: PCV is fine, but did not look at the EGR I can do that next.

emeraldcoupe: re-built about a year ago, first think I checked when things went haywire was timing and mixture which were both fine. What about a stuck float could that be an issue? Sounds possible though, I will do a little more investigation with the carb before going farther.

Question on the head gaskets would it be something that started slowly and got progressively worse or would it go all at once?

Probably won't have time to look at until Thursday/Friday but will post up any new information then.

Thanks again!

 

Even if the trans was working properly I would still pull the line off the modulator and check for fluid. A buddy of mine had that happen on an old galaxy and the tranny worked fine until one day it consumed in a fluid that it just stopped moving.

 

Definitely worth checking out, I will do that first chance I get

Thanks

 

Each stroke of the piston is a compression pulse eroding any weakness .. What starts out as a little weakness becomes bigger quicker the harder you run the motor .. My experience is it may not become apparent until 1-2 weeks down the road and that depends on how well you kept up on the head bolt torque specs .. When an engine is freshly rebuilt it is important to retorque the heads shortly after it has been run for the first time .. This applies to head gasket replacement also .. A step that is often overlooked ..

 

My last response may have been confusing the carb is the only thing I re-built.

A couple of months ago I replaced the timing chain, gears and water pump. The timing set was already a straight up set so I know that had been messed with don't know about anything else.

Sounds like a head gasket would have gotten progressively worse not come on all of the sudden as this seemed to.

Any thoughts on how the compression plays in? 130-155 so less than 20% differential, seems pretty good would that lead one direction or another?

Thanks

 

Yes that has been my experience ..

I would make sure you are confident in those numbers by doing the test a couple of times so your confident .. Engine must be at operating temp and roll the motor over 7 or 8 times until it won't go higher with all plugs out .. The reason I say this is I would be a little concerned with the 20 % difference so being confident in your numbers is important .. If it is head gasket related I would identify the weak cylinder and during a compression check on that cylinder remove the radiator cap and see if bubbles appear as your rolling the engine over ..