I'm losing coolant have, excessive white smoke coming from the exhaust, and rough idle. Doesn't over heat or even try to overheat. The oil fill cap looks brownish white. It drives fine other than extremely rough idle. I know how to check a blown head gasket with the combustion gas test.

From what I've read blown head gaskets on 4.6 fords are fairly uncommon but a blown intake gasket is fairly common. How can I tell the difference?

 

Is it missing? compression check most likely will tell you

 

Two possible ways are the exhaust manifold temperatures at the ports and a Scanner to look at the misfire monitors.
A third is a look at the spark plugs for signs of coolant.
A forth is look at the front Ox sensor actions.
The one getting the coolant will act quite different than the other side.
None of these will tell the difference between an intake leak or a head gasket but tell you what cylinder/bank is involved.
The results of either shows up in the cylinder and exhaust.
Exhaust gas detected in the coolant will only be a head gasket.
Out of all these you should make a pretty good diagnosis.
Good luck.

 

I don't have a check engine light on. So in guessing it's in the early stages. It runs just as it did a few months back when it had a severe vacuum leak at the pcv valve. So I'm guessing there is no easy diagnosis for a blown intake gasket.

 

you probably can not tell the difference between manifold and head gasket failure. Sometimes you will have an external leak also on the gasket which might help narrow it down. Otherwise, you have to pull the manifold and look for a damaged gasket. If you find it , you have to make a decision to repair or keep going to look under the head....... If you don't find a damaged manifold gasket, your in for a bigger job.

 

I say that because I had a manifold gasket blow out and I had some overheating issues with continued operation ............ long story short, I think once it overheated and small damage to head gasket... I fixed the manifold as time permitted, but did not realize I still had a very small head gasket problem... for the next 2 years... I managed it with BARS copper sealer.

 

Well I swallowed my rouse and took it a mechanic yesterday.

 

Rouse?! Darn auto correct!!!

Got the word from the mechanic shop today. A mechanic I trust. Anywho, told me it's definitely a head gasket. I'm losing coolant into cylinder number two. Looks like I'm going to put it up for sale as I lost my job last month and haven't found another one yet and can't afford to have it fixed. They quoted me $2000 to have it fixed plus what ever else they find wrong. Anyway thanks for all the input and help.

 

Professor... you might look at the BARS LEAK COPPER head gasket sealer.. For $10. its worth a try. You have nothing to loose.

 

https://www.ford-trucks.com/forums/1...g-coolant.html

 

Yeah that's what I was considering just as a band aid. Talking to my dad he thinks we should get back from the mechanic and do a motor swap.

 

Depending on the size of the leak, your success can vary from "helping a little bit", to " several months of not leaking"............ your mileage will vary depending on the severity and type of leak.

 

It wasn't bad but it's getting worse. It blows a lot of white smoke out of the exhaust and sometimes it doesn't.

 

Technically, the coolant is ruining the cats on that bank.
What you see as smoke is not smoke but liquid that has changed phase like water to steam because the coolant does not burn.
Good luck.