Modkart554

Need a bit of help! 04 CS 146,000 miles, about 3000 miles ago I noticed a slight ticking- drivers side front/top of motor near AOS but in front.
Verified location using a stethoscope which I have checked all over the motor, top, bottom, sides.
This ticking totally disappears at approximately 2700 rpm and up-verified with stethoscope.
It has not gotten any louder, and I have zero oil loss, power loss, or codes thrown.
Did oil change 2500 miles ago, switching from my normal 0-40 Liqui Moly, to my summer 5-40.
Always use Ceretec. Owned since 98,000 miles, car had lived its whole life in so-cal, and every service, recall, coolant pipes etc done by the dealer previous owner bought car at (Rusnak).
I do live in a colder climate, and I installed an oil pan heater before first winter. There is room if you are creative and have small hands! On average the heater warms oil to approximately 90 F in sub-zero weather.
I have Borescoped all cylinders and see zero evidence of anything but perfect cylinder walls, again zero oil loss or change in level.
Correct me if I’m mistaken but wouldn’t scored cylinders have had an increase in the ticking?
and would it also be constant and increase with rpms?
Also according to the survey, this would be the highest mileage case to date by a long shot.
I have done a Colorado-California trip with this ticking, and did not baby it at all, no change in anything.
Any ideas?
Going to pull belt tomorrow to rule out anything on front of motor, if that is unsuccessful, I’ll pull valve cover and see if I may have excessive timing chain play.
I have cycled the cam position sensor(under the AOS) with a 9volt battery and get a resounding think indicating it’s working properly.
Hoping I don’t turn into another scoring story, but I’m doubting that is the issue.
Thank you all for any advice in advance.

v10rick

You do not have the typical bore scoring symptoms, reported on this forum.

Isolating the cause, by removing the serpentine belt briefly, is an excellent start.

Please provide updates.

Dilberto

You have noisy lifters. Rest assured there is no scoring, which is characterized by warm start smoking and oil loss.

oldskewel

I agree with your doubts - it does not fit with the standard symptoms of bore scoring, in many ways. Still, I'd be doing all the same things you're doing - try to get whatever it is figured out, in case it leads to a bigger problem. BTW, I have a 2004 S with 103k miles, about 55k of those on the second engine.

To specifically answer this question (to maybe be corrected by the experts, which would be good to know), the ticking/knocking/slapping should be synched with engine speed, occurring on every second revolution of the crank. So it should be at engine RPM divided by two.

Modkart554

Thanks guys. I should clarify that the tick does follow engine Rpm, but totally goes away at 27-2800 rpm. Using stethoscope at the area of tick, having an assistant rev the car.
Bore score noise should not go away at all if I’m not mistaken?
Headed home now to attempt further isolation of said noise. Will advise

Modkart554

Nothing on front of motor is the culprit.
Ran over whole engine top to bottom again with stethoscope and it is isolated/loudest right at the drivers side cam chain location.#5 cylinder I believe?
Time to dig deeper

J'sWorld

Check the cam deviation before you start taking things apart.

Rod Croskery

You'll find your engine ticking a lot more if the fingers which cover the coils and fuel injectors are removed or loose. They dampen a great deal of engine noise. Any chance one is unscrewed a bit?