I was enjoying a few weeks of a nearly silent engine, after adding Rotella and replacing all the pullies.

Now i have a new tick that disappears at north of 1500 rpms or so. It sounds like a very small, thin piece of metal. Almost like a rhythmic scraping. Not audible at idle when warm. At cold start definitely audible.

I will pull things apart this weekend, but any ideas where to start? I am thinking a PS pump or something. It is engine speed, not vehicle speed dependent. Does it under load or at idle. Does it with our with out the AC on.

Fluids are good. No impact on performance that I can tell.

I appreciate the advice.

 

Before you tear it down, remove the serpentine belt and run the engine for 30 seconds and very max for 60 seconds and note whether the noise disappears .......... or not. (I believe the belt only drives the ancillaries but switch off all the power consumers and A/C and to be mega safe disconnect the alternator wires).

 

You can use the dowel rod diagnosis. Get a dowel rod. Be VERY, VERY careful not to get tangled in the serp belt or fan. Hold one end to your ear or the bone right behind your ear, the other end to the power steering pump, then AC compressor, etc. until you've worked your way CAREFULLY through the potential noise makers. You should be able to locate the source that way if it is a source powered by the serp belt. Did I mention to be careful?

All the standard disclaimers apply.

 

Might want to check your idler pulley bearings, just a thought.

 

If you can lay your hands on a mechanics stethoscope even better, but as David says, be careful 'cos it's damned hard to pick ya nose without any fingers.

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I actually got a stethoscope from Harbor Freight.
I noticed that it picks up all sorts of noises. It has not been obvious to me when I had a problem. They all sound the same.

Wish me luck.

 

Good luck.

You'll soon identify each noise and when you hear the one causing the distress, which will be the loudest, you'll know you're on the money. Admittedly, at first it is difficult to differentiate the sounds with a stethoscope but with practice it becomes easier. In all honesty I wouldn't be without my stethoscope, it helps identify anything from unusual engine noises to faulty bearings in the gearbox or even wheel bearings. One of the best few £££'s I ever invested many, many years ago.

 

I pulled the belt off and the engine is quiet again. It is hard to isolate the noise with a stethoscope.

My guess is the ac pump.

The pulley feels smooth with no play in it. Leading me to believe the problem is internal. Or, could it still be the clutch and I should try a clutch repair kit?

I suppose taking the pulley off and seeing how the spindle for the compressor spins would help. Although if the A/C is off and it still making noise, the pump should not be engaged and the noise is coming from the pulley/clutch assembly.

Does that sound right?

Also replace an SAI valve to try and fix my p1415. Part was donated by a member here.

Thanks,

 

Re-attach the belt and turn the A/C to off completely. Note the noise with the stethoscope and then turn the A/C on and check any change in the noises. If it starts to make a noise you'll know it's the A/C clutch assy. Whilst you are checking also check the alternator, idler pulleys, water pump etc. At least now you know it's not the engine and costing you mega $$$$$$ . Good luck.

 

for the hell of it, check your Fuel purge valve. I thought the worst when I first heard the ticking, finally found the source and $25.00 later, it's gone.