[revjpeterson]

I dont believe the dpf is recoverable but prove me wrong. It's tucked in there and iirc the manual has you move some stuff like egr cooler bits. You dont need to do that but it'll make handling the pressure pipes easier.

Realizing neither of these might be the actual regen issue, should I be looking at testing / replacing downstream NOx? Or, worse yet, has anyone actually replaced the dpf and what's involved? I haven't looked closely at it, but is it a bolt-on or welded?

Removal of the DPF is relatively easy. Nothing mechanical has to be removed to uninstall it--only stuff like heat shields, engine cover, underbody shield, etc. The two most difficult steps are reaching some of the heat shield bolts, and removing the V-clamp that holds the turbo and DPF together. If your flange bolts on the bottom of the DPF are badly rusted, that could be a trouble point. If you want to be really safe, having new flange nuts and a new Turbo-DPF gasket on hand wouldn't be a bad investment at less than $20 total for parts you're not likely to find in-stock locally.

From there, the question would be whether there's anything you can do to physically clean it or not. I have no experience with reinstalling, but I imagine it's a straightforward reversal of the steps. The one spot I could see being challenging would be reconnecting the differential pressure sensor lines to their tubes on the DPF in the space available. It could also be interesting figuring out which line goes back on which tube unless you labelled them before removing.

 

[Snipesy]

The one spot I could see being challenging would be reconnecting the differential pressure sensor lines to their tubes on the DPF in the space available.

It's easily the most difficult process. There is not much wiggle room. The hoses do not go on easilly, even lubricated. And every time I've done it the clamps had to be replaced as they just lacked any sort of tension and slid on and off.

You definitely don't need to label which is which. They will not fit any other way.

 

[jalias]

Fork in the road today... got the egr and tb all cleaned up went to install and found coolant where egr installs. I had stuffed shop towel in the cavity just to keep crawly or other things out while off for cleaning and the toweling was soaked with coolant. Normal when egr removed?

 

[Snipesy]

Fork in the road today... got the egr and tb all cleaned up went to install and found coolant where egr installs. I had stuffed shop towel in the cavity just to keep crawly or other things out while off for cleaning and the toweling was soaked with coolant. Normal when egr removed?

No.

I’m not sure where you are referring to.

A common failure point is the two hoses which connect to the EGR cooler. These little connector pieces are replaceable.

If it’s an internal seal well... GM only sells the entire EGR cooler assembly. It’s very expensive to the point a donor engine starts looking appetizing.

 

[jalias]

No.

Crap. But didn't think so anyway.

I’m not sure where you are referring to.

The hole/cavity left exxposed when you remove the EGR. I had a wadded shop towel stuffed there to prevent things falling/getting in that area while EGR removed. Was soaked with fluid and when I wrung it out, appeared to be coolant.

A common failure point is the two hoses which connect to the EGR cooler. These little connector pieces are replaceable.

Source for a good pic or diagram? I see the one and it appears to be ok but can't see a 2nd in the cramped space... but I could be looking right at it and not recognizing it.

At any rate, everything's back together and running and driving but holding off on a force regen until I can source the coolant leak. Again, thanks so much for all the help... your knowledge of these is amazing

 

[Snipesy]

Crap. But didn't think so anyway.

The hole/cavity left exxposed when you remove the EGR. I had a wadded shop towel stuffed there to prevent things falling/getting in that area while EGR removed. Was soaked with fluid and when I wrung it out, appeared to be coolant.

Source for a good pic or diagram? I see the one and it appears to be ok but can't see a 2nd in the cramped space... but I could be looking right at it and not recognizing it.

At any rate, everything's back together and running and driving but holding off on a force regen until I can source the coolant leak. Again, thanks so much for all the help... your knowledge of these is amazing

Emission Components for 2015 Chevrolet Cruze | GMPartsDirect.com

www.gmpartsdirect.com

#7 and #8 in that diagram are the little connectors which hook onto the coolant pipes.

 

[jalias]

Back on the CTD after a few long work days. Try a forced regen with BiScan again with same results.... regen initiates, runs 5-6 minutes then ends prematurely with a diesel engine shut down soon msg.

What should my EGT's be reading going in to and during the regen? I'm seeing EGT1 at 240-260, EGT2 270ish and EGT3 starts in the same ballpark but gradually climbs to 640-645 before the shut down msg.

 

[Snipesy]

Back on the CTD after a few long work days. Try a forced regen with BiScan again with same results.... regen initiates, runs 5-6 minutes then ends prematurely with a diesel engine shut down soon msg.

What should my EGT's be reading going in to and during the regen? I'm seeing EGT1 at 240-260, EGT2 270ish and EGT3 starts in the same ballpark but gradually climbs to 640-645 before the shut down msg.

Back on the CTD after a few long work days. Try a forced regen with BiScan again with same results.... regen initiates, runs 5-6 minutes then ends prematurely with a diesel engine shut down soon msg.

What should my EGT's be reading going in to and during the regen? I'm seeing EGT1 at 240-260, EGT2 270ish and EGT3 starts in the same ballpark but gradually climbs to 640-645 before the shut down msg.

Huh. And it otherwise runs fine? No other DTC? Like any? Like not even something silly ?

 

[jalias]

Other than the P2463 and P144E codes, no, nothing. And yes otherwise it starts runs and drives seemingly fine - but with "reduced engine power". I also keep a close eye on PIDs when attempting the forced regens so for 5-6 minutes and what I can see appears normal. It needs new tires but I don't think that's affecting it

Do you know what's a normal range for EGT2?

 

[Snipesy]

Other than the P2463 and P144E codes, no, nothing. And yes otherwise it starts runs and drives seemingly fine - but with "reduced engine power". I also keep a close eye on PIDs when attempting the forced regens so for 5-6 minutes and what I can see appears normal. It needs new tires but I don't think that's affecting it

Do you know what's a normal range for EGT2?

above 350C.

 

[jalias]

Is the EGT 2 sensor the lowest of the 4 that are mounted through the front heat shield?

 

[Snipesy]

Is the EGT 2 sensor the lowest of the 4 that are mounted through the front heat shield?

It’s kinda just sticking in the dpf midway. Makes a 90. Not the big boy that’s the O2.

Regardless even EGT1 should be reading higher. So something there is going wrong. Glow plugs or injectors maybe. The 6.6L does use a glow plug to heat the injector so it’s possible the Cruze uses a residual glow as well. Such a process is not documented in the service manual, but it wouldn’t be the first time. No codes though.

Injectors you would think would have some drive ability issues... Failling fuel pump or clogged filter would set off a code....

MAF is an interesting issue. If the MAF reads low it will demand more air. More air is less temps... But you would think that would set off the O2 sensor at least
but it’s possible the active Regen is inhibiting the O2 sensor.... Interesting...

Beyond that I’m at a loss.

 

[jalias]

What should EGT 1 be reading? I might need to invest in alldata or a service manual set because I'm missing alot of the tech specifics for this engine.

I was going to pull EGT 2 to test it. What made sense to me was that after force regen initiated and car rev'd to 3k rpm, ECM diagnostics looked for EGT 2 to hit a certain temp by a specified time before it actually started the regen process. When the temp is not reached within that time, it canceled regen request and shut down engine because of low EGT (hence the P144E)

Made sense to me EGT 2 could be at fault given EGT 3 temps were where they should be... I mean if there was a fault further up the process... MAF, fuel, etc... all 3 EGTs would be low wouldn't they?

 

[Snipesy]

What should EGT 1 be reading? I might need to invest in alldata or a service manual set because I'm missing alot of the tech specifics for this engine.

I was going to pull EGT 2 to test it. What made sense to me was that after force regen initiated and car rev'd to 3k rpm, ECM diagnostics looked for EGT 2 to hit a certain temp by a specified time before it actually started the regen process. When the temp is not reached within that time, it canceled regen request and shut down engine because of low EGT (hence the P144E)

Made sense to me EGT 2 could be at fault given EGT 3 temps were where they should be... I mean if there was a fault further up the process... MAF, fuel, etc... all 3 EGTs would be low wouldn't they?

during a Regen you should expect EGT 2 to be slightly higher than EGT1. As for how much higher is kind of up in the air and honestly it doesn’t matter if it’s less than EGT1 just as long as it’s in acceptable ranges.

It will be generally more as some unburnt fuel will burn in the DOC while the remaining will collect on the front of the DPF and burn there. Hence why EGT 3 is the highest as at that point, after the DPF, all fuel should have combusted.

The fact EGT3 is actually climbing tell me something is stopping the exhaust stream itself from becoming hot enough. As it needs to be hot else the catalyst and dpf will not be able to burn the fuel optimally. But the injectors themselves are properly dumping fuel and that fuel is making it to the exhaust.

 

[Snipesy]

Looking at some old data logs... Exhaust should get progressively hotter for first 5 minutes.

2 minutes after regen start EGT 1 and 2 should be roughly close to each-other around or above 700F / 350 C. EGT 3, doesn't matter at this point but its around 500F or 250C.

From this point EGT2 will start climbing quickly to about 900F / 500C. This will take about another 2 minutes. EGT 3 will be slowly rising but not above EGT2. EGT1 kind of just sits at its 700F to 800F temp.

At around 4-5 minutes EGT 3 will climb past EGT2 to a standard regen temp of somewhere between 600C and 700C. It kind of bobs around a little until regen completes. And then it just cuts off. Doesn't really do any special cool down process.

 

[jalias]

Finally had some more free time to look in to this. Took a closer look at components to think through the process and gather my thoughts and noticed a couple of "that-aint-right's"... would any of these have a hand in the original problem (failed regen)? Or maybe I should start another thread...

1 - Discovered the EGT 1 sensor location is actually using an EGT 2 sensor part GM55581305 instead of the correct GM55598259. Any difference between the 2 besides maybe cable/connector length?...

2 - The engine appears to be missing the part in the picture below (maybe vacuum line? marked with "Turbo <-----"). What is this, was it on all models (like not introduced after a specific product date or discontinued), and if it should be there why the heck would someone remove it???

Also don't know why I missed it before but noticed many of the factory connectors are not where they should be, non OEM zip fasteners, etc. Clearly some work was done here before. With what I see moved or altered, it'd have to be a big front component like radiator, radiator fan or even dpf I don't know.

At any rate, any advice is appreciated. Thanks all!

 

[Snipesy]

Finally had some more free time to look in to this. Took a closer look at components to think through the process and gather my thoughts and noticed a couple of "that-aint-right's"... would any of these have a hand in the original problem (failed regen)? Or maybe I should start another thread...

1 - Discovered the EGT 1 sensor location is actually using an EGT 2 sensor part GM55581305 instead of the correct GM55598259. Any difference between the 2 besides maybe cable/connector length?...

2 - The engine appears to be missing the part in the picture below (maybe vacuum line? marked with "Turbo <-----"). What is this, was it on all models (like not introduced after a specific product date or discontinued), and if it should be there why the heck would someone remove it???

Also don't know why I missed it before but noticed many of the factory connectors are not where they should be, non OEM zip fasteners, etc. Clearly some work was done here before. With what I see moved or altered, it'd have to be a big front component like radiator, radiator fan or even dpf I don't know.

At any rate, any advice is appreciated. Thanks all!

That’s the VGT vacuum actuator control. Sometimes incorrectly referred to as wastegate control with the manual.

As you can imagine that’s a very important component and if it was even slightly not working you would get insane under boost error codes.

Having said that a non-OEM vacuum line can be out of spec. A line of the wrong length will cause the vacuum control to not work correctly. It could potentially be the cause of “too much air” like I mentioned earlier. However I fail to see why it wouldn’t set off a DTC.

 

[Snipesy]

As for the EGT that’s really sloppy and I would never have it that way. I don’t know. The sensor itself is likely the same but they go to a computer module which may or may not be the same. One of those modules is on the side of the air box.

 

[jalias]

Dude. You aren't going to believe this... ok maybe you will

Shortly after my last post, I went ahead and pulled both EGT 1 & 2 sensors. I discovered they were installed reversed. And yes they are different... EGT 2 probe is about twice the length of EGT 1. Also, EGT 2 sensor has a female connector end where as EGT 1 has a male connector end. Of course they match up with corresponding male & female connectors on the harness. Can you guess where this is going?

Whatever idiot did last work on this car not only swapped the install location of EGT 1 & 2, they were also connected the only way you could so that meant this whole time the ECM was reading EGT 1 data from 2's location and vice versa.

That would explain the P144E code and hence the regen failure.

I am so friggin HAPPY right now. After wiping off excess soot and reinstalling them correctly, I had an oh so successful forced regen and now sit at 0g soot mass! Took 37 minutes run time but kept a close eye on things the whole process and I am just giddy with the results.

Also kicking myself for not paying closer attention from the start.

And yes there is a simple rubber vacuum line in place of the OEM vacuum actuator control so I'll get that ordered & replaced.

Thanks soooo much for your expert help!

 

[WillL84]

Glad it was something simple! Sad to see some hack was clearly in there before though. Hopefully they didn't screw anything else up 🤦‍♂️