x5 knocking on startup

[subieworx]

The beginnings of rod knock would definitely go away after a few seconds. I have seen it dozens of times.

Take it to a qualified mechanic and have it inspected.

[740ilDuke]

Both of my 4.4's do it at random. My X5 sat for several months and was quiet at start up. Other times it makes the knock type noise that quickly goes away.

My X5 has 183,000 miles on it and my 740il has 129,000. Both have 5W-30 Mobil 1.

Keep your oil topped off, too.

[Gary92]

i've been hearing this same knock in my 2003 4.4i since i bought it in 2006. took it to the dealer when i did have warranty and they told me its normal

i never hear the noise on a cold start, only when the engine/oil is already warmed up

[ezrax5]

Originally Posted by subieworx

Rod knock. What you are hearing is the beginnings of a rod bearing failure. The clearance between the bearing and crank shaft has opened to the point that when oil drains in to the crank case after sitting there is too much gap for that initial start up period. During that startup period there is a second or two where very little oil is present at the bearings as it has drained out. It takes the engine a second or two after starting to build oil pressure and distribute that oil through the engine. This is not heard on an engine in good shape as the bearing clearances are tight enough to prevent the knocking.

I'm not sure if the X5 will do this, but most drive by wire throttle cars can be cranked without starting if the gas pedal is held down to the floor. This is a good test to see if what you are experiencing is a bearing issue. On cold start on cars that are capable of this, one can crank the car for 5 seconds to build oil pressure then start as normal. If the knocking sound is not there after cranking for 5 seconds then it is definitely bearing related.

Is there any way to make the car turn over with out is starting to build oil pressure?
2001 e53 x5 4-4 133,000 miles