Light ticking/knocking noise

[rpiereck]

My 9-5 has in the past few weeks developed a light ticking/knocking noise when idling. The noise goes away when I rev past 1300-1500 rpm. I am trying to pint point the source of the noise on the engine itself bu so far no luck.

I think it's about time I buy a tool like this :Amazon.com: TEKTON 5888 Mechanic's Stethoscope: Home Improvement

The car currently has 236,000 km, 146,000 miles. It happens when the car is cold or warm, with cold or warm weather. Seems to be stronger when the engine is cold. What could be the source of the noise?

[nordwulf]

What kind of oil are you using? The 2.3T engine seems to run quieter and smoother for me when using Castrol 5W-40 instead of Mobil 0W-40. Ticking or knocking sounds unusual though.

There was this post with common causes for lifter and valve noise: http://saabworld.net/f9/saab-2005-95...457/#post47737

6. Noise occurring after a short period of idling when the engine is hot. If the engine is
run at 1 500 rpm or more, the noise will disappear after a while. The cause of this
noise is low oil pressure in the hydraulic valve tappets at idling speed.

[Tweek's Turbos]

Have you dropped the sump lately, could be oil starvation.

[rpiereck]

Not really, saw the sump through a bore scope when I first got it, all seemed pretty clean from there.

[photousa]

I wouldn't trust looking through a bore scope and trying to evaluate the condition of the sump. The sump and oil pickup screen are too important to ignore. Usually when owners report that they are hearing noises like
valve ticking, it's turned out that they are using the wrong oil or their oil pickup screen is partially clogged. What you should really do is to run an oil flush product, then drop the sump and clean everything out, following, use a full synthetic oil like a 5W-30 that meets A3/B3 specs, you'll most likely see the noise go away.

[rpiereck]

I'll be dropping the pan next week, as we go into holiday schedule here, we are working half days only.

[rpiereck]

Well, it seems that in a slip of the mind at the last oil change I put Mobil 1 5w30, which is NOT A3/B3 compatible; I hope that is what is causing the tick. There is a box of empty Mobil 1 5w30 bottles in my garage, which points to that oil being in the 9-5 since I use dead dinosaur juice on the 900.

Tomorrow I am draining the 9-5 and doing a change with A3/B3 compatible Mobil 1 0w40. I couldn't find Castrol 5w40, so Mobil 1 it is, hopefully the noise will be gone. I was going to drop the pan tomorrow, but alas I forgot to buy gasket material, and since all the shops are closed tomorrow I am out of luck (I hate that about Germany). If the noise is still going on after the change then I'll probably do the pan drop on the following weekend, if not then some time in January.

I told my wife that if the 9-5 is still ticking after the oil change then we will ride to my sister's home, a 2.5 hour drive, on the 900. She has never ridden in the 900 yet, and the first question she asked was "does it have a heater?" Bless her heart, I laughed, of course honey, all Saabs do! Then she asked me if the car is safe, to which I said, for a 1987 car without ABS or airbags it's as safe as it gets!

But I do hope the 9-5 isn't ticking tomorrow after the change. Wish me well!

[Saab Story]

Hi Frank,

5W-40 viscosity isn't approved for use in our engines per the owner's manual. What are your thoughts on this? Also, what effect does the 5W-40 have on your engine that the approved viscosities don't?

Thanks for any feedback on this Frank.

[nordwulf]

Don't always go by the owners manual or what Saabs recommends. They always said never to use any oil additives and now Saab Parts NA is promoting and selling additives.

There really isn't much difference between 5W and 0W. Saab did specify 5W-40 for all gas engines but may have been for different years. http://saabworld.net/f144/saab-9-5-o...ication-27619/

I go by the A3/B3 spec for choosing engine oil and both Mobil 0W-40 and Castrol 5W-40 have those. Perhaps it is all in my mind but you often read Mobil is a bit overrated. I think there are a few oil threads around..

[Saab Story]

That sounds like good advice to me. I'm gonna look for Castrol Full Synthetic 5w40 then.

Thanks Frank!