coborn35

The other day when I was accelerating I noticed a very audible vibration as the engine revved up. It would get higher, but then quiet down as soon as the transmission shifted gears. I didn't notice it at lower speeds or cruising, only when I gave it a good amount of gas. On start up I have heard a small vibration, which I attributed to something or other being loose. This morning on start, I opened up the hood to check and the vibration seems to be coming from somewhere on or right next to the engine, and I also heard a rattle, like a small plastic bb or something was moving around. I am concerned that this could be the start of something bad....

Vitals:
2005 F150 FX4 85,500 miles
I am running 10W30 in Minnesota, but about 7 out of 10 starts it is either warm or plugged into a block heater. Should I switch to 5W30? I changed it recently (October) but if its too thick I will change it.

I have a video but having problems uploading right now.

Tommy J

Get unerneath and check out your heat shields first. They sound horrible when loose or rotted

coborn35

Heres the video : Rattling

Was rattling (the bb noise) on startup but was gone when I got home. It was a 10-15 minute drive and the engine got up to operating temperature. I will check the heat shields for vibration when I get a chance.

coborn35

I should have time to look on Sunday, any other ideas?

coborn35

So I have it in the garage at work right now, and I can't find any issues with the heat shield. No dents or broken welds yet. It honestly sounds like a small bb got dropped into the oil fill. It's coming from that area. I highly doubt anything got in there seeing as I changed my oil in October or November and didn't notice this until January, plus I'm not an idiot. I'm worried it could be pinging or detonation, from googling. It's not really metallic, literally like a plastic bb rattling around in the oil fill area. I'll keep looking for anywhere a rock could have snuck under. Any help is greatly appreciated as I don't want to go to a shop unless I need too. When I pulled the oil fill cap off there was some yellowish gunk on the cap and a little ways down the throat. Is that normal?

powerranger262

I'm not sure what that noise is, but the gunk is from short trips with the truck not getting up to operating temps.
My wife used to work roughly a mile away from where we lived. Everyday she'd fire it up and go. You should have seen the crap under that cap.

Tommy J

Stuff under cap is normal, I thought I read it could be from moisture but can't remember exactly, my truck has it. It almost seems like something is loose from what you describe but the location is weird. I highly doubt its a rock or pebble. I"ll state the obvious- did you grab and try to move stuff when engine is running. If its in the oil cap area then you can't move the oil stem but can you tap it with a screw driver or something to see if it changes or goes away. I think that would drive me nuts too. I thought I read about something like this before but I can;t be sure it had the same symptoms but it just sounds familiar to me. Sorry

Tommy J

Listened to the video. Thats def not heatshield. How does it drive otherwise? Can you buy a cheap stethoscope and really try to pinpoint the sound. Its hard to tell where any of these noises are coming from with the engine running. I don't know if thats the start of something bad or not. At least if you have to take the valve cover off its the easier side

HulluCorn

Honestly, a big screwdriver will be similar to using a stethoscope too.

coborn35

Just got a call from the shop. 4 (I believe) tensioners had their bearings shot, and they were rattling so bad it sounded like bb's in there. Quoted me $180 for parts plus $50 in labor. Hopefully this will solve the issue. Excuse me if my terms are slightly off, we just had a quick discussion.