joshtried

So, this is kind of a weird issue, that i am not sure if it is an issue or not. I have an appointment saturday to get this checked out, but wanted to run it by the forum first..
So: '19 pretty well base model stingray.. (+ nav)

During the break in period, The electronic tach has a "redline" of 4500 rpm, with blue up to around 4000, then yellow to 4500, and red above.
Once i hit 500 miles, blue all the way up to 6500 rpm, then red beyond that (i assume break in was complete here).

Now for the issue..... Every time i start the car, it reverts back to the pre-break in 4500rpm redline. Sometimes it lasts 15 seconds, this morning it lasted maybe 10-15 minutes.. Has anyone else noticed this? is this supposed to happen while the car warms up?

JMII

Correct until the engine gets up to proper operation temp the redline is lower. I normally drive with the Sport gauge and it has yellow, orange then red. As the car warms the yellow slowly goes away, then the orange and finally you left with just the red.

Not my picture but this shows the warning colors from 3.5 to 6.5

DTOM

Cancel you appointment.

This is normal behavior.

As the car warms up, the RPM line will move accordingly.

rb185afm

As stated, absolutely normal. It’s the car reminding you the oil is not
up to temp.

Bishop4142

I'm curious why there is a 6500 redline when my M3 V8 had a 8000 redline.

Bill Dearborn

Different design. GM V8s have a larger displacement and don't Rev as high although they generally make more power for physical size and weight of the power plant. They don't have overhead camshafts so don't have all of the weight and space required to house/drive the cams.

Bill

joshtried

I have an appointment for other reasons (clunking on start up). but i am glad to know this is normal. I thought that might be the cause, but have not had opportunity to check it while the vehicle is warm.

DTOM

Clunking or slight ticking?

joshtried

clunks, like shifting into gear. The whole vehicle jerks with it. They were unable to replicate it on saturday after letting it sit for a couple of hours (i guess it is only on cold start), so i will be leaving it over night on thursday. One tech said it might be the torque converter draining.

Elk

It is actually based on water temperature. The engine considers itself warmed up when the water temperature reaches 175 degrees F.

X25

Are you sure? You might be right of course, but It looked more like it waits for 100 degrees oil to me. Have you read that somewhere?

Elk

I am certain, but admittedly by observation only by monitoring oil and water temperature, together with the incremental steps advancing the redline.

rrsperry

It actually has to do with peak piston speeds. The BMW engine is a shorter stroke design, (S65, 92 bore, 75.2 stroke, ratio 1.22:1, 8400 red line) whereas the C7 (lt1 b4.065, s3.622” ratio 1.112:1). The higher the ratio the more it can rev. A Yamaha R1 (79x50.9. Ratio 1.53:1) has a red line of 14,500...

also your S65 eats rod bearings if you visit redline often. Then again so does the S54..

X25

Unfortunately, I'm yet to see a reliable high revving engine, except Honda S2000's engine. When run hard, they all fail. Perhaps some of Porsche's high rev GT engines are good, too, but people just don't use them enough at the track (they usually sell within a year) to come to a conclusion.