5.4L Oil Milkshake - Is it definitely a head gasket?

2002 F150 - 5.4 L Triton

151,000 miles

My truck leaks a bit of oil.  I probably add a half quart per thousand miles.  It is annoying, but not bad enough for me to really dive in and figure it out.  This truck is my daily driver, and I don't want it to be out of commission if I can avoid it.  Yesterday, I checked the oil and it was a little low.  When I pulled the cap to add oil, the bottom of the cap had some milky oil on it.

Am I just lying to myself by trying to believe it could be a fluke?  Weather here has been changing a lot, and I have been doing a lot of really short trips hauling stuff around our property.  Any chance I could have condensation inside the engine?

No loss of power, no misfires, no codes, no weird sounds.  Can't smell any coolant in the exhaust.  I think the right answer is change the oil, put some miles on it, and see if anything changes, but I'd like to get either some affirmation or a slap upside the head.

Edit:  The title may be misleading.  I haven't drained the oil yet, so I don't know how bad it is.  Oil on the dipstick looked normal.  Only the cap was milky so far.

Is the oil milky or just on the fill cap? If just the cap it's condensation.

Just updated the text with clarification.  Haven't drained the oil yet, so not sure.  I've only driven about 1,000 miles since the last oil change.

It's a 5.4.  Once you start taking it apart, you will find enough worn out stuff that a fresh engine from Ford is cheaper. 

It's just condensation, likely.

I just had a very similar thread here about the same thing on a 6.8L mod motor.  It's just condensation.

About two months after I had that discussion here I wound up having to tear into my motor because of a stopped up oil pickup.  And pitted camshaft lobes.  And a stretched timing chain.  While there was a little sludge and such, there was no milkshake anywhere else in the engine.

Dipstick clean?

bigeyedfish said:

 I think the right answer is change the oil, put some miles on it, and see if anything changes

Go with the feeling. 

There is a big difference between a milkshake and some cheese under the oil cap.

Check your crank case vent system, although short trips can easily cause cheese to build up. One solution is to drive it farther and get it fully warmed up to cook all the condensate out of the oil.

The crazy cat lady's battery was low, I remind her we put a battery in it last year. Turns out battery was good, many short trips were causing the battery to not get fully charged.

Yep, cap cream is condensation. It will go away come summer. 

You need to drive it more and get the oil hot.

How is your PCV

EvanB (Forum Supporter) said:

Is the oil milky or just on the fill cap? If just the cap it's condensation.

100% this.  If the dipstick looks good, and the oil looks OK at your next change, don't sweat it.  (Sweat it?  Condensation? Get it? :P I crack myself up)

And if you really get worried, do a compression test before pulling anything apart.  Had a friend that tore down most of their engine only to realize the HG was fine, they just had lots of moisture/condensation buildup.  That was an expensive mis-diagnosis.

Can't say that the following is what you're seeing; but a lot engines run oil filler caps that are located at the top of a rather high filler neck. This, and high humidity can result in condensation building up on the cap underside.

iceracer said:

You need to drive it more and get the oil hot.

How is your PCV

That's a good question.  I bought a PCV valve to swap in because the previous owner didn't remember if it had ever been done.  I ended up with the wrong part because this truck has a heated PCV valve and I ordered the standard one.  I think I pulled  it and replaced it after making sure it was functional, but I honestly don't remember.

wae said:

I just had a very similar thread here about the same thing on a 6.8L mod motor.  It's just condensation.

About two months after I had that discussion here I wound up having to tear into my motor because of a stopped up oil pickup.  And pitted camshaft lobes.  And a stretched timing chain.  While there was a little sludge and such, there was no milkshake anywhere else in the engine.

I really liked the first half of this reply.  The second half was a bummer.  Did you get it straightened out?  I tried to buy a couple 6.8 trucks before I ended up with this one.  I wish I could have been more patient, but here we are.

bigeyedfish said:

iceracer said:

You need to drive it more and get the oil hot.

How is your PCV

That's a good question.  I bought a PCV valve to swap in because the previous owner didn't remember if it had ever been done.  I ended up with the wrong part because this truck has a heated PCV valve and I ordered the standard one.  I think I pulled  it and replaced it after making sure it was functional, but I honestly don't remember.

I'd only use a genuine Ford PCV, because they are calibrated restrictions and parts store PCVs are usually incorrect.

That said, it's not PCV related.  Plastic valve cover in the direct airflow from the fan blowing cold air at it causes water vapor to condense there.  It happens on all of 'em.

You want to see bad, check out a Mopar 3.7/4.7 with the big oil funnel thing.  Looks like someone globbed some Hellmann's in there, sometimes 

Imo, tremm nails it. And yes, I too will say "sorry about the modular Ford".

bigeyedfish said:

wae said:

I just had a very similar thread here about the same thing on a 6.8L mod motor.  It's just condensation.

About two months after I had that discussion here I wound up having to tear into my motor because of a stopped up oil pickup.  And pitted camshaft lobes.  And a stretched timing chain.  While there was a little sludge and such, there was no milkshake anywhere else in the engine.

I really liked the first half of this reply.  The second half was a bummer.  Did you get it straightened out?  I tried to buy a couple 6.8 trucks before I ended up with this one.  I wish I could have been more patient, but here we are.

It's all good and running better than ever now.  I think mine was an artifict of lack of use over its life.  Before I bought it the annual mileage only averaged 5500.  Those problems had nothing to do at all with the goop that was in my oil fill tube.  When I had the valve covers off, there was none of that anywhere but right towards the top of the fill tube. 

Basically it's plastic, it sticks up a bit, it's got that fan blowing on it, and so it just is a really good place for condensation to collect.  I never had the problem until it was cold and I wasn't running it for an hour each way to work.