[scooter500]

I'll by confessing up front that I don't have any experience with newer Northstar engines.

Now this particular engine looks clean (how can it not with the admittedly nice plastic cover?) but there is a slightly audible ticking coming from the drive belt near the center of the engine. Other than that the engine very quiet. Is this slight sound normal? Am I concerned for nothing?

Regarding this noise, the sales manager though this sound might be possibly be coming from a high pressure direct injection system, if this engine had such an item. Good guess on his part, but does the 2011 Northstar engine have a direct fuel injection pump in this area (top center of engine)?

Last new guy question... what's that belt near the center of the engine bay going to?

 

[BlueAngel#07]

Generally these cars are quiet. They run a little rough at start up in colder weather. Some cam noise (lifters) can happen from time to time, a tick...not so much. It might be nothing, or someone might have put an additive in it and it's got sticky lifters. These engine don't like or need additives ,(I've learned over time.) I had that problem on my 2007 and it eventually went away. Make sure the oil level is where it's supposed to be.
I think the belt you are talking about is for the power steering pump.

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Mine has 36000 and it is relatively silent.

 

[thellmer]

The belt on the drivers side of the engine is the water pump. The belt on the passenger side drives all sorts of things - alternator, ac, power steering, etc.

 

[scooter500]

Generally these cars are quiet. They run a little rough at start up in colder weather. Some cam noise (lifters) can happen from time to time, a tick...not so much. It might be nothing, or someone might have put an additive in it and it's got sticky lifters. These engine don't like or need additives ,(I've learned over time.) I had that problem on my 2007 and it eventually went away. Make sure the oil level is where it's supposed to be.
I think the belt you are talking about is for the power steering pump.

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Mine has 36000 and it is relatively silent.

Thanks, BlueAngel#07! I am swearing off engine oil additives now... even before purchasing the car!

Your post led me to research (and search) on the topic of lifters more. I heard the very minor tapping when the engine was cold, and I don't think many miles have been put on the car the past few months, so perhaps it will go away after another test drive and/or oil change? Honestly, the noise was very quiet, especially compared to my wife's '95 4.L. The 4.9L is purty good but it gargles with every acceleration.

Here's one of the posts your comments led me to search for: http://www.cadillacforums.com/forum...-dirty-lifter-dirty-valve-tapping-sounds.html Everyone's comments from that post helped, plus Submariner409's pictures helped too (thank you!) My understanding now is that a 2011 DTS uses a typical fuel pump back by the tank and typical fuel rails, but no "cold fusion" as suggested by the sales manager.

That's an interesting place to locate a power steering pump. It's all good as long as it works!

 

[danog]

If sales manager knew his product he would know the DTS doesn’t have direct fuel injection system.

The fuel pump is in the gas tank.

 

[mwilson]

I would want to make sure that the water pump itself or the belt tensioner were not responsible for the noise. Easy enough to for them to check BEFORE you buy.

Make them pop the water pump belt off and then start the engine briefly while you are standing there. If the noise goes away then tell them you want a new A/C Delco water pump, tensioner and belt installed or no deal.......

If this vehicle is not under warranty then you don't need a $900.00 repair shortly after purchase and I guarantee that nobody at that dealership will remember any discussion what so ever about a noise...."What noise?"