Ok, some times when I start my truck ( 06 F-150 XLT 5.4L 2X4 ) it makes a really bad noise, reminds me of a rod knocking almost.

Its only done it 3 times now, over 2-3 month time frame.

I notice it happens when,

1) I first start my truck after its sit all night
2) after I turn the truck off and then back on 20-30 mins later, but never after a few hours.

I also noticed its always cold when it does that.

Trucks has just now got to 33K miles, I run full syn 5W-20 motorcraft and I dont run my truck hard at all, in fact 90% of the time it never sees 2,500 RPM.

I wont lie though, I have ran it hard a few time, 4 that I can recall after I bought it in april with 20K miles.

I do not take it off road, and only have towed a small 4-wheeler trailer for about 100 miles.

ideas?

 

Had the same noise in my 05. I call it a startup rattle. Mine happened during the first start of the morning and didn't happen again all day. I took it in and was told it was normal under factory warranty. Took it in under ext warranty after frequency became greater and they blamed it on cam phasers. noise went away for about 2 months and then it came back. One day driving down road my motor locked up. Diagnosis was oil pump quit working @ 51K miles. No warranty coverage. Moral of story: get everything check out and in writing.

 

It's the timing chain adjuster bleeding off. When the oil pressure builds back up at cold startup (morning start for example) the noise goes away. Mine does it sometimes.

Check the flat rate link in my sig, it'll teach you a lot about the VCT system on these 5.4 3v engines.

 

I have the same rattle on my 04 Scab Lariat 5.4 (85K miles) at cold startup. It started doing it after about 60K miles. It only does it after sitting overnite. From what I've been told and read, it seems to be a normal condition. I don't know if this would cause any long term damage though.

 

Steath -
Wow. Just checked out the 27 min. video on the VCT theory & operation. Most of that stuff was waaay over my head. Kudos & props to all you guys that understand all that stuff.

 

What oil filter are you using?

 

Motorcraft , why?

it only seems to do it when the engine is cold,or when its sit for a while, I guess over the summr it nevr got cold enough to do it, but no that tmeps drop over night to the low 20s-40's its starting to do that.

I hope its not a serious issue, my factory warranty ran out and I didnt have the money to get a extended one, and right now I dont have the money to replace or fix the truck.

thanks for the answers.

here is hoping its not serious.

 

Because some filters like the Fram allow the oil to drain back, meaning in the morning you get a dry start that sounds terrible. Just like you mentioned. The MC FL 820S has a good antidrainback valve which does not normally allow this to happen.

 

Mine started doing this too. I blame the Express Lube and their junky oil filters. I'm going to start getting all my service done at the local Ford service department.

 

My dealer does oil changes cheaper than the quicky oil change places.

 

Had what I think is the same knock as you do when I still had warranty left the dealer had my truck for several days while waiting on drive shaft parts had service manager go out and start it every morning because they couldn't repeat the problem the day I brought to them. I thought I had a bad lash adjuster because the knock was when the engine was cold not warm when most cam phaser noises show up. well they ended up replacing the lash adjusters and phasers on both heads been quite ever since.

 

+1 You get a Motorcraft filter and 7 qts of semi-synthetic oil and they check the vehicle over. You really can't beat it. I just had and oil change and tire rotation done @ my local dealer yesterday for $45.00 and I never had to get dirty. To top it off, the owner of the dealership came and shook my hand and thanked me for the business.

 

Yep. I even get coupons in the mail to make things even cheaper.

 

I think I get something about once a month, but I always forget to bring them.

 

well, she has been quiet as a mouse this month, haven't heard that noise since a few days after I posted this, guess thats a good thing.

Should be getting 4 new tires and a new SI/DO Flow master with in the next 3-4 days.