Just a newbie here and hope I’m in the right place ! 2008 F 150 4.6 V8. Lots of 250K + good oil pressure, doesn’t burn any oil between 5K changes, synthetic 5/20, pulls strong, but with sub zero temperature can’t get it pressure up, no issue with sender, you can here tappits ….. weird stuff, very frustrating …. Talked to good mechanics who should know but they’ve never experienced this since it has strong pressure under regular day temperatures ….. anyone have intelligence on this !?

 

Thread moved to truck forum. More traffic here for your model specific questions.

 

Sender issue?
250k on a 4.6 in sub zero means it is now time for a new oil pump
That is AFTER you install a direct pressure gauge and determine your actual oil pressure is actually low
Glad to read you are using the thinner oil the motor needs, otherwise that could contribute to the problem
08 4.6 I would do the timing chains and guides as well as the tensioners and oil pump

 

Yep verify pressure with a real gauge first. GW offers adapters that go in place of the filter. I have the set but honestly not sure if there's an adapter for the M22 (there should be)

Even the 2Vs will have guide debris in the pan -- seen it first hand. I'm wondering if your pickup is clogged so much that the cold oil can't sneak through sufficiently. The pump pickup kinda has a "cave" then a screen and guide debris will pack in to the cave.

Perhaps an experiment is see if 0W16 causes the same issue -- theory being it can squeeze through the clogged pickup even when VERY cold. I wouldn't run the 0W16 very long, this is just an experiment.

LET US KNOW WHAT YOU FIND!!

 

Thank you Manic mechanic ! Don’t need to hook up alternative pressure gauge cause you can hear taps and lifters starving for oil …… but yes perhaps **** in the oil pump area and good advice on timing chains,guides and tensioners ….. or …. Maybe more a little down the coast where the breezes are a little warmer 😜 thanks again 🙏🏽

……

 

How do you know you're hearing lifters and not phaser noise and/or combined with timing chain slap?

See also:

I looked at my kit today and adapter #3 is M22x1.5 despite GW not listing thread specs ANYWHERE.

 

His 2008 4.6 has no phasers

 

Excellent catch, thank you!

 

I had to look it up to not advise replacing phasers too

 

Nah, I know all the '04-08 4.6 are 2V, just wasn't thinking!!

But I still question whether he's truly hearing no oil pressure. Even the 2Vs can make a lot of weird noises. It's also possible he's got a stiff roller follower, which wouldn't necessarily be oil pressure related

I'd still want to get a real gauge on it to have actual numbers, but whatever.

 

if it is OK when warm and only does it when COLD... you may have collected water ( condensate) that is plugging the suction screen or filter when COLD. (ICE).. I would drain the oil and change filter and see what happens... would be good it let it set inside garage overmight to thaw out first if possible...... if your outside, maybe an electric milk house heater and tarp for a couple hours would help..

 

I wonder if there plastic timing chain guides came apart and pieces of the plastic are stuck in the pickup screen causing low oil pressure and when the oil gets hot it can now pass by the plastic pieces in the screen. My sister's 09 navigator did same thing.

 

Indeed, I wonder..... things that make you go Hmmmm

 

Hey steve ! Thanks for listening ….did an oil and filter change, no difference ….

 

Cut apart the old oil filter and look for tiny bits of yellowish plastic in the filter and if you do see any those are pieces of timing chain guides