Topic: Weird pitch change at higher temps

[NGalaxyTimmyo]

This started the other day on my way home, it sounded like the power steering was low. It almost sounded like a supercharger whine, but I think low power steering would be a closer sound. I knew I was low since I checked it the day before and stopped to get some. Drove home with no other problems. At that time it seemed like the power steering was at the top of the tube when I looked inside.

Today went out on a Kappa cruise and heard the sound again, only this time is wasn't when turning. It seemed like it started around 3k RPM, but only when the cars temp was above 220. We took a quick break and when I got back in the car the temps were back down to 190, and the sound was gone again, only to return once it started to get closer to 220. It started to rain and the temps dropped again and even after the rain stopped and I could listen again, I couldn't hear the sound anymore.

I know my fan has a small chunk missing, so it's off balanced and loud at full speed. Usually I'll hear it when I have a car next to me and it's above 210 degrees, but I did not hear it. I have a new fan I just got the will be going on tomorrow, hopefully it'll solve my issue, but it doesn't make sense to me that the pitch change follows RPM, and not fan speed. I was thinking maybe an air bubble in the power steering, but it's not like the pump ever went dry, just the reservoir. None of the Ecotecs I've had had VVT, so I was thinking maybe it was that due to changes with RPM, but I would assume it would throw a code. The last thing I was wondering was if it could be the water pump. Temps were going high, and it was always with an increase in RPM.

Thank you for any assistance.

[Sol Asylum]

So what are the details on your Kappa, red line, GXP, NA?  Manual/ auto trans?  How many miles are on it?

I can't say I have seen my temps come close to 220 so the cooling system could be something to look into.

[NGalaxyTimmyo]

I'm sorry, I did leave out all of that. I have an 08 Sky Redline with about 34,500 miles on it. It's a manual.

I did add in the one way valves for the coolant system today when I was replacing my fan. It was close to midnight by the time I finished, and I have to get up early for work tomorrow, so I haven't had a chance to drive it yet to see if it continues/if it still overheats. This was only the second time I've seen the car get above 220.

[Sol Asylum]

If you are still hearing it check what your boost indication is showing.

[NGalaxyTimmyo]

Boost has been fine, hitting around 23lbs.

I went out for a drive today and didn't hear anything, but the temps never got above 198 degrees. It was a much cooler day, around 78, instead of the 94 we had when it was giving me issues.

[Uranium-238]

The trans got enough fluid? If it sounds like a supercharger, I think gear whine. Check your rear diff too.

[wilson0x4d]

Your water pump might be on its way out if it has never been replaced. Nominal idle temps for a fresh WP are 173-180 at 75-80F ambient, under "spirited driving" conditions it shouldn't be going above 212-223, or, it should be dropping back down to a cooler temp fairly quickly once you return to idle.

At around 238 you risk engine failure.

Now and then you can find them cheap ($50) but they generally run a price tag of 150-250 depending on who is selling them, and how many they need to get rid of.  Draining coolant and removing everything necessary to swap the pump is not fun, but, better than overheating. My advice is to return your tune to something closer to stock and see if the problem continues. Also, to see if your idle temps change.

Non-idle temps are harder to work with, high idle temps on a stock tune are pretty much a dead giveaway if you have a cooling problem.

Water pump is chain-driven, in case it needs to be said.

I've had a WP fail, so I keep an extra on-hand. A royal pain to "experimentally" swap for diagnostic value, but better than overheating.

[Gentleman Jack]

Any new details OP?