Funny cold start noise on 4.8is
 

I have my 4.8is and noticed for the past year that while cold the truck has an engine tick/knock which goes away when warmed up. But, it is not rhythmic but constant. It does not go up when I rev the motor, even while cold. Only at idle. 92k miles.

I changed oil to 5-40 Castrol, no change
Plugs appear to be original so I ordered a set of NGK 6441 plugs.

Noise is still present when I shift from P to other gears. Weird.

I removed both serpentine belts to see if it was accessory related. Nope. Still there.

Could it be the dreaded Intermediate levers? How can I check those with INPA software?

Runs great, no codes. Very smooth.

Gas mileage is a bit lower these days at 14mpg mixed, I swear it was higher a year back or so.

I tried stethoscope method, cannot isolate it.

Thanks,
:thumbup:

Sounds like this
https://www.youtube.com/watch?v=WhvQ...ature=youtu.be

sounds like vanos

Pull your acoustic covers off and feel the solenoids (the big round things half way down the engine. Clicking in time with the noise? Y/N

Okay thanks I will check that in the next few days or so. I hope they are not too tough to replace, or $$$. It is a common fail item?

I put in brand new 6441 NGK plugs. I took out the old BMW/Bosch 2 prong plugs which are now at .048 gap. Maybe it is my delusion, but the X5 seemed much quieter this morning on cold start. I will report back in days to confirm. Also I did put my hands on the big solendoids on each side, they both make noise, used stethoscope. Are they hard to change out?

I also viewed some plugs on the rear on top of each valve cover-leaking a little.

I gotta look at my records to see when last mine were done. That's a solid possibility, me thinks.


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So to update on my cold noise and MPG concern. Noise is still present, same as before. Truck is smoother though now with new spark plugs in it. My mileage mpg is up only a tinsy. So I know I have upper timing cover leak, i had valve cover gaskets changed last year: sigh sigh. But I do not think cold start noise is from gasket leak right?

I pulled the oil dipstick and the engine slightly buckled and then ran fine, so intake leak from upper timing chain leaking is looks like. I read here the engine should almost die when you pull the oil dipstick while running.

What, engine should die? Wow.


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Just googled this. Did not know this was a thing. Crazy.


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