1-2 Second Engine Knock Upon Start - 3.5 EcoBoost

[Joleat]

How many of you guys have experienced slight knock upon startup of your 3.5 EB? To me, it sounds like a low oil pressure knock, which is why it only lasts 1 or 2 seconds until the engine builds pressure. I've tracked it over my last 3 oil changes (15k miles total) and it happens every morning for the first start and every evening when I leave from work. It does not happen if the car has only been shutoff for an hour or so. For the first of the last three oil changes, I used Mobil 1 5w30 EP and a Mobil 1 filter. For the second and third of the last three oil changes, I used Pennzoil Ultra 5w30 and a Purolator PureOne filter.

It's a quick "thud, thud, thud, thud, thud" and not a "tap". I usually count somewhere between 5-10 thuds and then it's nice and quiet.

I searched the ol' internet and it seems that quite a few people are experiencing this knock. One person even had their long block replaced under warranty. Some think blame the direct injection pump, but most others seem to think it is a normal characteristic of the 3.5 EcoBoost and don't feel that it is any reason to worry. With almost 50k miles on the odo, I'm ready to install a tune to spice things up a bit. I just want to make sure the engine isn't about to succumb to a catastrophic failure before I proceed with my plans!

Discuss.

[BiGMaC]

Nothing like this on my '13 SHO... stock tune

[SHOdded]

Try Motorcraft filter next time.  Non-Motorcraft filters have been found to create these brief startup sounds.

[Joleat]

That's my next step. In my research, I noticed several people placing the blame on the oil filter valve. I just thought it was unlikely since I've used two different high quality filters. With that being said, I ordered an oil filter, air filter, cabin air filter, and spark plugs (534s) earlier today. All items are Motorcraft.

[SwampRat]

Try Motorcraft filter next time.  Non-Motorcraft filters have been found to create these brief startup sounds.

Most Motorcraft Oil Filters are made by Purolator .
I use Fram Ultra Guard , I don't have this  "problem"  and use full synthetic Valvoline 5w30 since my SHO was new  ( 1st at 2500 miles ) and just changed All for the 4th time at 17250 miles . Never had an issue with Fram or Synthetic Oil either .

[SHOdded]

Try Motorcraft filter next time.  Non-Motorcraft filters have been found to create these brief startup sounds.

Most Motorcraft Oil Filters are made by Purolator .

Yeah, I don't know why.  Maybe certain engines are just off-spec enough to be sensitive to this issue?  In any case, just because Purolator manufactures a filter for Motorcraft doesn't mean the filter sold under their own label will be to the same spec.  Still high quality, no doubt, but ...  Will have to look to see if there is a direct comparison out there, maybe on BITOG?

And this may not mean anything, but if they have a TSB out on cam phaser mechanism possibly causing a lubrication bottleneck, it may be more prevalent than is assumed.  Something else to dig into!

[IHeartGroceries]

Reminds me of a common issue found on the Mazda MZR, which was due to a faulty lock pin in the variable valve timing actuator - number one symptom is a loud ticking/clacking for only the first couple of seconds at start-up. And it was due to slack in the timing chain, and the chain slapping against the underside of the valve cover very briefly.

Always began on cars with around 50-75K miles on the odo.

Sent from my SM-N900V using Tapatalk

[Brucelinc]

I have never used anything but Motorcraft in my MKS and never had the problem.  However, I did have this issue occur with my wife's Taurus (non-ecoboost) when I used a Purolator filter.  I thought maybe that particular filter was defective but I am not sure.  Even though Purolator is a great name and they make Motorcraft filters, the specs could be different as SHOdded said.

[Needmoreboost]

If my car has been sitting for a while (week plus) I do the cold start prime method.  I hold down both the brake and accelerator pedal (to the floor) for 3 to 4 seconds.  The engine just turns over without starting until (priming the oil into the cylinders) I then let off the accelerator and car fires right up.  Might test that and see if your knock goes away.  FYI

[SwampRat]

If my car has been sitting for a while (week plus) I do the cold start prime method.  I hold down both the brake and accelerator pedal (to the floor) for 3 to 4 seconds.  The engine just turns over without starting until (priming the oil into the cylinders) I then let off the accelerator and car fires right up.  Might test that and see if your knock goes away.  FYI

I learn something new everyday ...

[n8rfastback]

Mine has had a slight knock on startup for as long as I can remember it, it drives me nuts but hasn't caused any issues that I can tell.... I may try a different filter and see if I notice a difference

[futat2]

I use Motorcraft filters on all my fords, believe it or not they make a top notch filter. Yes they are manufactured with a different company but to there specs. I would put one up to a K&N or Moble1 filter any day.

[TSS]

I also only use Motorcraft filters and don't have that issue. Even at negative 13 degrees this morning. 

[REDSHOCGO]

I hear a slight tick at power up bit it goes away within a minute or two sounds like valves

[elund126]

I had a 2005 F-150 with the 5.4 liter. It had the cam phaser knocking which I had repaired. However, if I remember right, the opinion of all the forums I was on was to use Motorcraft filters only because there is a valve that keeps the oil where it needs to be when the motor is shut off.

However, on my 2010 SHO, I also have the knocking noise on cold start up. It hasn't gotten any worse and it has always been there, so I don't think it is hurting anything.