# 2015 Cruze knocking after shut down



## Rivergoer (Mar 30, 2017)

@Hass I tend to agree with your initial thought regarding Regen. Although if it’s happening multiple times a week, that seems less likely.

Regen cycles can definitely create some odd ‘bumps’ and ‘hiccups’ on deceleration/stopping/shifting into or out of Park while EGR temps are elevated above 1100 F. There’s also a distinct smell when the car is shut down during or right after Regen. The fan will often continue to run after shut down to eliminate excessive heat build up.

In my limited experience (I’m by no means an expert) Regen frequency can vary widely depending on a number of factors. In this case, the variable is a new driving pattern that comes with a different primary driver.

What’s your wife’s typical driving situation? Short trips around town, little highway?

My Regens (‘14 CTD 93K miles, no mods) happen regularly around 700-800 miles with about 2/3 of that being highway miles. I’ve noticed if I spend a few hundred miles around town, my Regen will occur around 400 miles. On the other hand, if I do an entire tank on the highway at 70 mph, it can reach beyond 900 miles before Regen.

It would be helpful to definitively know Regen status when the symptoms occur. A Scangauge or Android app might help identify (or eliminate) any correlation to Regen.

It’s possible the dealership can identify an issue IF there’s a stored code. Otherwise tough to diagnose something intermittent like this.

Good luck and keep us posted on status.


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## Robby (Mar 1, 2013)

Until you can figure out how to reproduce the concern, thereby creating a situation where you can reproduce it for a dealer, there is no point in taking it to a dealer.
You will only be creating brain damage for yourself and the shop since there is nothing more aggravating than a repair order that states 'Unable to Reproduce concern........aggravating for a dealer to write it (since they know you didn't turn your day inside out for no repair) and aggravating for you (since you didn't want to turn your day inside out either).

Keep driving.....it'll get to the point it'll be findable (I know, home made word)......I don't think it'll strand you or anything along those lines.

Rob


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## Hass (May 20, 2015)

Thanks guys.



Rivergoer said:


> What’s your wife’s typical driving situation? Short trips around town, little highway?


We live pretty far out in the country, so her trips are generally ~15-20 miles rural roads then the last 5 miles of town/village driving. Usually no less than 25 miles per trip.



Robby said:


> Keep driving.....it'll get to the point it'll be findable (I know, home made word)......I don't think it'll strand you or anything along those lines.


This is what I'm hoping, haha. I don't think it will leave her stranded anywhere either. I figured worst case scenario is that it would put it in limp mode or whatever it's called, and restricts the max speed to 55mph or whatever.


Slight development though, we got a CEL today. a P2459 "Diesel Particulate Filter Regeneration Frequency"

I spoke a bit more with my wife about it too, and she said it all started the time around I changed her oil. At the same time, when I was changing the car's oil, I noticed she had a Low DEF warning too, so I filled up the DEF with a new jug. I thought it had a sensor for poor quality DEF though, so I'm not sure what to make of that.

Edit: Looks like it's a trip to the dealer, https://gm.oemdtc.com/8470/16-na-09...nated-dtc-p2459-set-2014-2015-chevrolet-cruze

From more searching, it looks like the code is pretty uncommon in a Cruze so far, but an easy fix. It needs a state inspection, so the CEL has to be cleared anyway. Ok.


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## Tomko (Jun 1, 2013)

@Hass What oil did you use for this most recent oil change? What you’re describing _could_ be the result of the DPF being contaminated by the wrong oil, i.e. not dexos2 registered.


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## boraz (Aug 29, 2013)

Hass said:


> . I thought it had a sensor for poor quality DEF .


there is no sensor for def quality, just quantity

there are sensors to read pre and post nox, if the numbers are off, it assumes def quality issues, but its never the def, its sensors gone bad


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## boraz (Aug 29, 2013)

Tomko said:


> @Hass What oil did you use for this most recent oil change? What you’re describing _could_ be the result of the DPF being contaminated by the wrong oil, i.e. not dexos2 registered.


and/or overfill


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## Hass (May 20, 2015)

Tomko said:


> @*Hass* What oil did you use for this most recent oil change? What you’re describing _could_ be the result of the DPF being contaminated by the wrong oil, i.e. not dexos2 registered.


Same oil I've always used. Castrol 03559 EDGE 5W-30 C3 Advanced Full Synthetic Motor Oil.
Definitely Dexos 2, the blue logo not green.

API SN/CF, ACEA C3, BMW Longlife-04 , *GM dexos2*, MB - Approval 229.31/229.51, Renault RN 0700/0710 , VW 502 00/505 00/505 01

I checked oil levels, and it's in between the knurling. Definitely not over/under.


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