Cold Start Clatter


#1

Video of Noise:https://www.youtube.com/watch?v=NtgpG8THUNA
Sorry for the AC Fan in the background

I am getting the above noise on startup, it goes away after 5ish minutes. I am in Texas, so it isn’t exactly cold out. So I don’t think its the oil viscosity. Its not a bad oil filter flow back valve, and its way longer than the oil lifters should make noises. I don’t think it is a cracked manifold, I think the noise would be different. I am out of ideas, you guys have any?


#2

I would suggest that you take a look at the belt pulleys.
We have no idea how old your vehicle is, or how many miles it has on the odometer, but I think it is very possible that the bearings in one or more belt pulleys have gone dry and a pulley (or two) needs to be replaced.


#3

Would that go away after the engine warmed up? I didn’t think it would, so I hadn’t looked into bearing issues.


#4

I’d have to agree with @VDCdriver. It definitely sounds like pulley bearing noise. Valve lifter noise would never sound like that.


#5

Ok, will check out the pulley bearings. I hadn’t just didn’t see how the engine warming up would make a bearing stop squawking at me. Any one in particular to start with?


#6

I’d start with idler and tensioner bearings. I’ve heard this type of bearing quiet down after warming up. A little info on the make, model age & mileage would be helpful.


#7

Jeep wrangler 2005. 4.0L, ~99k Miles


#8
I hadn't just didn't see how the engine warming up would make a bearing stop squawking

It’s pretty common. In fact I have a box fan for ventilation where I live that does this. Makes various clicking and clanking and squealing noises for a few minutes after turning it on before finally quieting down to a soft purr. I don’t know the reason. I suppose it could be the bearings expand with the friction heat or the lubricant gets heated and flows to where it is needed.


#9

Huh, I guess so. I guess it depends on what is going bad within the bearing itself. Your electric motor box fan does this as well? That is interesting.

My other thought was that this might be a idler or timing slap. But bearing sounds more likely, will have to diagnose over the weekend.


#10

Sounds like your idler puller or belt tensioner has a bad bearing. I heard the same noise last winter and found the idler pulley to be bad. I replaced both pulleys because it’s was cheap and easy. They are simple to check when they are cold. Be sure to release the belt tension first.