I know this is a 12 year old car, but....When it is first started and is cold there seems to be a slight tapping noise. It is a metallic sound and I am sure is not the injectors. I am pretty sure that it all but goes away when the engine is warmed up. the car has only 72,000 miles. Any thoughts? I don't remember my previous 850 making this type of noise. I will mention to the mechanic when I speak with him tomorrow.

 

That sounds like the lifters and I believe it is pretty normal for these cars. Always keep an eye on your oil.

 

Oil pan o-rings.

 

At what point would you consider this to be a problem? Is it just an annoying thing about these cars or is it something that eventually has to be addressed? I find it happens more if the car has been sitting for a few days. Otherwise it doesn't happen. Thanks.

 

If it gets to the point of not going away get it checked.

 

What does it cost to have the oil pan O rings replaced? What exactly do they do and what happens when they go bad? Thanks

 

It will cost a little to get them replaced.
Some pull the entire subframe then remove the oil pan.
The o-rings get either hard and deformed and then leak or they get really soft then swell and break.

 

If the O rings are bad would the car be leaking oil? Mine is not. How do these relate to the tapping noise? I am not quite sure I understand the relationship. Thanks

 

No it will not leak oil. They Seal the oil pan to the engine. The oil pump is mounted to the front of the crankshaft. When the o-rings go bad the seal for the oil pump to the oil pan is broke. Causing a slight loss of oil pressure.
When the car sits over night the Hold oil pressure is lost. Causing the tapping on start up. They might only be a little bit bad now. Most people wait till it taps all the time to replace them.

 

Thanks Tech, Now that you explained what is going on, I am less concerned about addressing this right now. Thanks again

 

I spoke with my mechanic today and he said he has only replaced oil pan O rings twice in an 850 for a tapping problem. He said that the problem most often is caused by varnished or sludged up lifters. He said he puts a cleaner in with the oil before changing it and runs the engine for a period of time, drains the oil and replaces the filter and oil with new. He said this almost always takes care of the tapping on start up. He said on occasion he has done this twice before the tapping has stopped. We'll see tomorrow.

 

Keep us posted.

 

Well I got the car back and have been driving it for about five days. It still taps on start up when cold but goes away. I don' think it is bad as it was. The mechanic said he will try the cleaner and fresh oil one more time. As was said in aprevious post it does go away when the engine warms up so at this point I am not going to worry about it.