donbrew

When the EVAP purge activates the vacuum will take a dive.

11hhrlt

I'll have to check that out. However, it's more than the vacuum dropping. It's very consistent in that the needles starts bouncing
all over after warm-up and is steady under load. The only problem is what I'm seeing on a gauge. All else seems normal. So again,
I don't know if it's actually a "problem". I'm looking forward to 843 putting his 11/2.2 on a gauge to see what the results are.

11hhrlt

Went to the local auto parts place yesterday. No codes showing and/or stored. Battery has not been disconnected for as long as I've owned it (a few months).

843de

No codes stored, that's a good thing.

Glad you had it checked, and my apologies for not recalling if you'd ever had any codes pop up. With all of the posts I read every day, and all of the HHR's here, my "Thinker" will forget who has what going on.

11hhrlt

Geesum crow, I was just thinking about that - how Site Administrators handle all the traffic. With all the meet & greets, conversations, changes, updating, trolls, security, etc., I think I'd lose my mind in about a week.

Then, of course, you have to contend with guys like me, just all over the place, going outside the box, mixing it up, getting off topic and stuff. I can appreciate what you're doing.

843de

OK, thanks to yesterday's all day rain, I had to wait until this afternoon to hook up a vacuum gauge to my 2011.

First the variables....

2.4L vs. 11hhrlt's 2.2L (My 2.2's are 2006 & 2007 L-61's)

Mileage at the start of the "tinkering" 59,929

Ambient temperature 55 degrees Fahrenheit.

Barometric pressure 29.94 in HG steady.

At start up in "Open Loop" mode I measured 18 inches of vacuum with no fluctuation at idle.

To bring the engine up to full operating temp, I disconnected the gauge and took a quick run from our garage to Landis, NC and back. That brought the mileage up to 59,940.

In "Closed Loop" mode with an engine temperature of 190 degrees Fahrenheit observed via the DIC.

Vacuum at idle again measured 18 inches, with occasional momentary drops to 16.75 inches, which I attribute to operation of the EVAP Purge Solenoid, or "Dithering" due to the operation of the VVT system.

The only thing I couldn't measure with exact certainty was when the ECM commanded operation of the Purge Solenoid, thanks to my Tech II being out on loan to a local engine builder.(Yes he knows how much it cost, and what I'll do to him if he breaks it)

Based on what I saw today, even factoring in the extra 200cc's of displacement, I don't think you have any reasons for concern.

Oldblue

Now that is what this site is all about, helping out fellow members, nice job, Mike!!

843de

Heck, it was a good excuse to "tinker" in the garage while my Wife and Mom took our boy "Shopping" at the Hobby Lobby.

Poor kid isn't even two yet, but he already hates going to Arts & Crafts stores.

11hhrlt

Thank you! I owe you one - somehow.

Looking over your results it seems there is a significant difference.

Yours: stable at 18 with occasional drop.
Mine: constant bouncing between 15 and 20.

Still might not be a issue (hopefully). I'll have to get it to my mechanic to be sure.

Thanks again.