Bigfutz

Well, the cap color is more accurate than anticipated. The Prestone DexCool (left) is definitely orange, and what’s in the reservoir(right) is pink.

Thank you! Why the cap and colors on the jug wouldn’t match the contents boggles the mind. Am I the only one who thinks of antifreeze in terms of color?

If you unplug the line and it “fixes” it, that doesn’t mean your brake booster is bad. But if this is a new symptom, I can’t think of anything else that would be the culprit. You should expect to see the Rpm’s react slightly to the brakes, but it may something else. Does it do the same thing when you’re idling and turn on/off the AC?

So I guess I need to break the seal on a jug of Dexcool and compare the two. Is there a pink coolant? Going by the label color, maybe Mercedes coolant? I don’t want to mix types and I don’t want to use the wrong type... everything says use Dexcool, so I guess I’m flushing if it’s not a match.

Replace your TPS. Easy cheap and will probably fix it.

Bought a used 2017 Suburban awhile back. Noticed the coolant was a little low, so I bought some Dexcool compatible as recommended by my LAP store. Before I added it, I pulled a sample and what’s in there is as pink as pink can be. The Preston Dexcool is orange. Did I buy the wrong coolant, or did the previous owner/dealer put in the wrong stuff? Do I just need to flush and fill with orange?

What do you mean sounds like the starter is going bad? If it’s spinning but you’re not getting ignition, it’s probably not the starter. Let it sit overnight, turn the ignition on but don’t start it. Listen to see if you hear the fuel pump running; if so, wait for it to stop, then it should start right up. If that is the case, and the fuel pump runs for more than a few seconds before turning itself off, you have a fuel pump or fuel line problem.

Mine was clogged with rust crumbs. I couldn’t find a suitable replacement hose at my LAPS so I removed it and wallered it out with a coat hanger. I also ran some Evaporust Coolant System Cleaner through the system (per instructions). Good stuff - gets the rust out, but plan on doing lots of flushes. Coolant runs nice and green now. (1995 Tahoe)

Is the RPM going down at the same rate as your speed, meaning do the speedometer and tachometer follow each other? If so, I think that’s the way low (1st) gear is supposed to work. Are you using the brake or just letting off the gas?

That’s a fuel saving feature, not a bug. I recently rented a Malibu (work related travel) and the dang thing cut off every time I came to a full stop.

So after warming up, cut it off, then it won’t start? Or does it cut off on you while running on the interstate?

Delayed and hard shift from 1-2 while under normal acceleration might be the TPS which is cheap and easy to change.

ECM? Have you hooked it up to a data logger? Sounds like you need a proper diagnosis before throwing more parts at it. Who changed the motor and why?

I think there’s also deep vs shallow on at least one, don’t remember which. Seems like my Haynes manual has some info. Or maybe lmctruck.com