1981 f150 inline 6.
When the cold weather came I started getting moisture and yellow foam under the oil cap and in the breather hose that goes to the air filter. Probably a month ago. Some have told me not to worry others have told me to start looking for an engine hoist and a crappy honda.
I check my oil and top it off daily because almost all of my gaskets have failed. So far the rear main seal and oil pan seal have been redone but i believe the valve cover and god knows what else still leaks. The truck sat in a garage for years before i bought it and it was only run every now and then, now i drive it an hour or more daily.
I just got my oil pressure gauge working it reads consistently on the low end of the "normal" range, even after an oil change. The oil didn't seem to have any water in it. How can you tell? It definitely smelled like gasoline but it didn't have any abnormal separations, the liquid was pretty homogenous.
No notable drops in coolant levels, although i've noticed a slight leak coming from the threads on a plug on the engine that wasn't there before. I haven't seen any coolant in that damn overfill tank since july even with a new thermostat and radiator cap.
I'm not sure if all of this information applies but I thought i'd be thorough.

So is it the head gasket? If so how much time might I have? Thanks guys.

 

I'd do an oil change and see what it looks like. If the oil looks like a milkshake, that's BAD..

I seem to be repeating this in a lot of threads, but I'd start with some basic checks.

Gas in the oil is a classic fuel pump diaphragm failure, but without more details I couldn't say. I've also seen it with engines that sit for a long time.

Low oil pressure can be several things, bearings, pump, oil itself (low viscosity, low volume). If it's low normal, that is not always a bad thing.

The yellow foam thing concerns me a little, but without more diagnostics I wouldn't panic.

A head gasket can be diagnosed with compression and leak down tests, and that would be my next thing.

But that's just me..

You said just about all your gaskets have failed. Do you see oil leaks, or is it consuming oil?

Leaks mean one thing, consumption another..

 

I doubt it is the head gasket. My bet is condensation. You say you drive it an hour a day, but does it get fully warm or do you make several small trips? What thermostat did you put in? You should have a 190 or 192 degree stat in or things won't truly get hot enough to boil off the condensation that is a product of combustion.

 

I should have read it closer.. 'when started, cold, under oil cap'..

Could be condensation, etc.

Me being me, I'd still check..

The 'all my gaskets have failed' statement is one I would want to verify..

I'm also wondering where all the oil is going..

 

When I bought my truck, (which had been driven a grand total of 138 miles in the past 10 years) there was the cream-colored mess under the cap. Draining the oil, first to come out was about a quarter cup of clear water followed by a quantity of tan colored coffee milkshake, then a half hour of goo slowly oozing out (sludge). I've been driving it pretty regularly since and the condensation hasn't reappeared, and the oil so far appears to look like, well, oil. Before declaring a head gasket problem, look at whether the engine actually warms up enough to cook off the moisture inside, and check your PCV system-the oil leaks tell me you may have a faulty PCV valve or vacuum leak to the valve. ~Bill

 

It sort of depends on the oil leaks, but a bad PCV valve could at least cause some of it.

When I hear phrases like 'all my gaskets are bad', I'd do a few quick tests. That being said, I understand not everyone has the equipment, space, or time to take that approach.

Having to add oil as much as you indicate, sounds like a pretty big leak to me. I can't believe you aren't having other issues as well.

Again, if it were me I'd start ruling things out if for no other reason than to put my mind at ease.

But that's me

 

Thanks all.

I'm not too worried about this motor for several reasons 1. it runs superbly. 2. no fluid in the oil just under the cap, and 3. when it does fail in some way I'm going to have a blast taking the thing apart. I can't tell if I'm burning oil because the leaks make it difficult to gauge oil levels. I can also tell you however that I over exaggerated the amount of oil I top off. I'm at about a quart of loss per three to four week period.

Btw. my new thermostat is rated 195 degrees and I just got my temp gauge working. So far it usually reads dead center but fluctuates throughout the normal range depending on how hard I run the engine. I dont know if this is normal and I haven't taken a long highway drive yet. Someone told me these higher temps spikes are what causes my motor to occasionally diesel after shut off.

 

The factory gauges on these vehicles are notoriously bad. They will fluctuate all over the map when the temp or oil pressure never changes. That's what most of us run aftermarket gauges. Cheap and very reliable.

 

I do have after market gauges in there but they aren't hooked up.. I think the last owner just liked the way they looked or something. I haven't been able to get past the headlight switch when taking my dash out. The thing just won't come off and I don't want to break it. I know theres supposed to be a little tab you press with a screw driver or something but its either broken or i didn't try hard enough

 

Two ways to get the headlight **** off. There's a button on the switch itself that releases the shaft the **** is on. It can be a pain to get to, but will do it although you should pull the battery cable off first as it leaves the headlights on. Or, there is a little slot in the base of the **** with a tab in it that you can pull with a hook to get the **** off the shaft.