Car Bogging Down at Highway Speed

Yesterday I changed the oil. Checked it right after with out starting just to see. Oil all over the dip stick but read about halfway up the hash marks. Drove the car for 45 minutes or so around town and down the interstate. Let it sit for 15 minutes and checked it again. Perfectly even with top of the hash marks.

Go to a football game, drive the 25 minutes home and about 20 minutes in after dropping into 4th at about 60 mph and running it up to 85 mph and into 5th, I go to 6th, drop to 80 mph and just start cruising.

The car then begins to bog down. That is the only way I can describe it. The RPMs never vary, but the car is acting like I'm brake checking. I push the gas a little and the car goes. Shift to 5th, cruise at 70 mph for a minute, the car does it again and this time very badly. I give it a little gas and the car goes like normal.

I shifted to 4th, ran the car up to 80 mph into 5th, and when I let off of the gas to hold 85mph, the car does it again, give some gas, nothing wrong, go back to a steady speed of 70 mph, does it again. This continues all the way home.

I checked the oil when I got home, exactly the same spot as the last check. Dead even with the top hash mark. The car has been sitting all night. I just check the oil again, same spot on the hash marks.

About to go for a drive and see if I can replicate the issue. If I do, going straight to the dealership.

I checked around the oil filter, no oil observed. I used the recommend Motorcraft oil purchased at the dealership for the oil change.

Any thoughts?

I have no clue...Did anything come loose ? Vacuum hose ? Did any warning lights flicker ?

You may want to go to a dealer regardless if you replicate the issue or not.

No warning lights, oil pressure good, nothing other than a very noticeable and odd feeling of the car not wanting to go unless I gave it some gas. I am pretty sure I was no where near any vacuum lines for the oil change but I will take a look.

What’s ur fuel level? Greater than a quarter? Check your air filter to make sure it’s not loose. Do u have oil catch cans? Are they empty and connections ok?
Random thoughts from reading forums and wierd stuff happening.

Filled up with Shell 93 prior to making the drive to the game. Had about 7/8 of a tank of gas when it started to act up. No catch cans. I’ll check the air box.

These symptoms have nothing to do with oil. Its either fuel (starvation or bad fuel) or ignition issues. The ignition issues could have many potential causes, to include over-active traction control or ABS. Generally, if its an ignition issue, you will get a check engine light. If traction control or ABS are kicking in, those lights comes on (only temporarily).
If the computer didn’t cause or sense any issues (no lights or codes), fuel is a potential culprit.
Was it doing this before you filled up?

It was not doing it prior to fill up. I just drove about 50 miles over the same route as last night. I can not replicate the issue. The car ran perfect doing as close to what I was doing last night. I guess time will tell. Like Chairman said, maybe fuel is the cause. I was looking at the dash, specifically the RPM, when it was doing it but I’m pretty sure I would have seen ABS or traction control lights if they came on or even flashed.

Maybe just one of those things or fuel.

Sounds like fuel issue to me. If coils you would get CEL. Fuel/injectors can have these issues for a while before there is a code. But I agree this is not related to oil unless you did something inadvertenly while changing oil like spilling oil somewhere to damaging cables somehow.

Not my first rodeo so pretty sure I did not cover something in oil or pull something loose. Hopefully it was a fuel issue that has since burnt off. The Shell station I filled up at I have used many times in the past with zero issues. That does not mean they did not have some bad fuel.

Your dipstick wasn't fully seated. There's a seal on the top of the dipstick and if you don't get it all the way down, it'll allow air into the engine that doesn't get metered by the MAF. That'll throw the mixture off. If you'd left it, it would have eventually thrown a code.

You fixed the problem when you checked the oil again after the drive.

Interesting. I’ve notice the harder push at the end when putting the dip stick back in. Fairly certain I push it in until the click, but maybe not.

Thanks to all for the suggestions as to a cause.

That is actually a great conclusion saw this happen recently when someone pulled out the dipstick on a 15kw gas generator while it was running, they thought it was bent, when the seal was broken and air was sucked in it was quite the show.
Surprised we haven’t seen more of this here as we are all checking oil more frequently in this car, and would suspect there have been times when it didn’t get seated correctly
Add to the list of knowledge

Will be interested to hear if this is causing your problem. I had a track day with my oil dipstick not fully seated and it did not affect me at all - other than bits of oil getting flung everywhere

If it runs fine then acts up again after driving, no codes, I’d lean towards fuel as well. But I would think a lean code would be present. You can call the gas station and find out if they had any other complaints.

Throw some unleaded race gas in to see if that will help or Torco if you like orange plugs.