# 2017 Gen 2 Diesel Loud Clattering Start Intermittent



## Snipesy (Dec 7, 2015)

I would change fuel filter before doing anything intrinsic. If the filter is slightly clogged it can cause some startup issues, usually in the form of weird sputters, and then clears itself in an instant after the system is saturated.

Beyond that the engine is going to sound different until some stuff like the alternator and a/c engages after which the engine will need to work harder, and usually more efficiently.

Could also be valvetrain noise mixed with low oil pressure not lubricating everything. Good way to check this is to see if the noise changes with newer, of the same previous type, oil. If it dampens it’s likely just valve train noise and will come back as the oil ages.I don’t know the intrinsic of the engine but as certain components wear I.e. cam lobes, lifters, whatever they cause things to not sit right as they once did and they need more oil to more or less pick up the slack. Nothing bad will happen of this, but it adds noise.


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## oregon_rider (Jul 21, 2017)

I am.hearing the a similar thing recently and believe the EGR may need to be cleaned. 

And I just recently had my fuel filter changed. I am also running r99 diesel that has a cetane of 70.. so it isn't due to low cetane fuel...

Let me know what you find


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## Carminooch (Mar 23, 2018)

Hi please update on what you find. Take a video and document everything if you’re able to. Keep us updated with what you find

I’d love to hear the noise you’re referring to though. I’m curious if it’s similar to mine


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## MRO1791 (Sep 2, 2016)

st1100man said:


> My 2017 Gen 2 diesel, began intermittently starting loud a couple of months ago. 30K miles. It does this when the engine is cold and when warmed up, as well. Sounds really loud and clattering. Spoke to Service manager. Will be taking it in soon. Otherwise, the car runs fine.


Manual Transmission or Automatic? If manual, be advised the DMF (Duel mass Flywheel) can fail and cause noise like you describe, however it would not change much with engine temperature. 

My 2017 Auto doe at times seem a bit loud at start-up, then gets quiet. Since I have 3 Gen 2s, 2 Autos. and one manual, I have in family cars to compare to see what is out of normal. It is interesting that between the 2 autos, they do sound a bit different.. but as Snipesy pointed out, engine wear can be a factor.. my 2017 has about 24K, the 2018 Auto has less than 10K on the odo. The 2018 manual is about 28k.


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## sledstorm1 (Mar 9, 2017)

I have a 2017 auto and a 2018 Gmc Terrain. They both started doing this over the winter. The Cruze has 27k on it and the Terrain has 21k on it. To me it sounds like the starter is getting hung up on the fly wheel when the motor is first taking off. 

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## st1100man (Dec 17, 2017)

Snipesy said:


> I would change fuel filter before doing anything intrinsic. If the filter is slightly clogged it can cause some startup issues, usually in the form of weird sputters, and then clears itself in an instant after the system is saturated.
> 
> Beyond that the engine is going to sound different until some stuff like the alternator and a/c engages after which the engine will need to work harder, and usually more efficiently.
> 
> Could also be valvetrain noise mixed with low oil pressure not lubricating everything. Good way to check this is to see if the noise changes with newer, of the same previous type, oil. If it dampens it’s likely just valve train noise and will come back as the oil ages.I don’t know the intrinsic of the engine but as certain components wear I.e. cam lobes, lifters, whatever they cause things to not sit right as they once did and they need more oil to more or less pick up the slack. Nothing bad will happen of this, but it adds noise.


I changed the oil a few hundred miles ago, using Pennzoil Euro-L Dexos-2, as I used for the last oil change. So, I don't believe it is oil. old or new.


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## Cruz15 (Mar 17, 2016)

Would like to hear the noise as well.


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## sledstorm1 (Mar 9, 2017)

Does anyone have an update to this problem? My Terain does it all the time now. 

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## st1100man (Dec 17, 2017)

st1100man said:


> My 2017 Gen 2 diesel, AUTOMATIC began intermittently starting loud a couple of months ago. 30K miles. It does this when the engine is cold and when warmed up, as well. Sounds really loud and clattering. Spoke to Service manager. Will be taking it in soon. Otherwise, the car runs fine.
> 
> I've tried to add a sound recording to this blog MP3, MP4, MOV. No luck. I am not a computer genius.





st1100man said:


> My 2017 Gen 2 diesel, AUTOMATIC began intermittently starting loud a couple of months ago. 30K miles. It does this when the engine is cold and when warmed up, as well. Sounds really loud and clattering. Spoke to Service manager. Will be taking it in soon. Otherwise, the car runs fine.
> 
> I've tried to add a sound recording to this blog MP3, MP4, MOV. No luck. I am not a computer genius.



Following my initial post, I recently changed the fuel filter. I haven't noticed the problem since.


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## TDCruze (Sep 26, 2014)

st1100man said:


> Following my initial post, I recently changed the fuel filter. I haven't noticed the problem since.


Thats good. Must have got some bad fuel to clog up the filter at only 30k miles.


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## kroelofs (Apr 7, 2020)

I’m also having this issue again. Seems to happen 5k kms into an oil change on pennzoil euro L. I brought it into the dealership and they simply changed the oil and told me to use acdelco filters rather than fram. It was fine until I changed it next, 10k kms later. Used pennzoil again with acdelco filter and 5k kms later it’s making the same rattle at startup. I bought Mobil 1 esp to try because I believe that’s what the dealers use. Hoping that these cars simply prefer Mobil 1 and there isn’t something bigger going wrong. The car has 60k kms on it now, automatic transmission. If anyone has any ideas as to why this might be, please reply.


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## sledstorm1 (Mar 9, 2017)

Could this be a problem with the oil filters as well, I have tried 2 off brand filters in the past. The last time I changed the oil on My Terrain I used a SuperTech filter from Walmart. The clatter at start up came back right away for a couple of weeks and then stop for no good reason. My Cruze I tried a Fram Tough Guard last fall and had random clatter startups all winter. When I changed it this spring I went back to the AC Delco filter and have not had a problem since. I also use the Pennzoil Euro L oil. Has anyone used a Wix filter, I was wondering if it used the felt ring to seal to the return tube? The Frame filter I used last winter, the felt ring came off when I removed the filter. I am wondering if there is a drain back problem. The picture below is of the Wix filter, it does not show the felt ring. I am wondering if it uses a rubber ring?


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## oregon_rider (Jul 21, 2017)

I have used the wix filters on our 1.4 liter powered Buick encore. And they are an improved design with an o-ring for improved seal. No felt ...

Jeff


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## conemark (Feb 9, 2020)

We've joined this clattering club today. I'm curious to a possible answer. Oil levels seem ok, no obivous leaks to see.


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## sledstorm1 (Mar 9, 2017)

sledstorm1 said:


> Could this be a problem with the oil filters as well, I have tried 2 off brand filters in the past. The last time I changed the oil on My Terrain I used a SuperTech filter from Walmart. The clatter at start up came back right away for a couple of weeks and then stop for no good reason. My Cruze I tried a Fram Tough Guard last fall and had random clatter startups all winter. When I changed it this spring I went back to the AC Delco filter and have not had a problem since. I also use the Pennzoil Euro L oil. Has anyone used a Wix filter, I was wondering if it used the felt ring to seal to the return tube? The Frame filter I used last winter, the felt ring came off when I removed the filter. I am wondering if there is a drain back problem. The picture below is of the Wix filter, it does not show the felt ring. I am wondering if it uses a rubber ring?
> 
> 
> View attachment 288173


I ordered 2 of wix filters, they do use an o-ring. I will be changing oil on my Terrain in the next month. I will report my findings. I use the Penzoil Euro L. 

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## sledstorm1 (Mar 9, 2017)

Today I change the oil on my Terrain due the clatter returning last week. I switched to a wix oil filter and I also switched to a 5w-40 Dexos 2 oil. Even though the owner manual only specifies using 5w-30, i looked up the owner manual for an Vauxhall Astra with the same engine and 5w-40 is listed for use. After I changed the oil the difference in the noise of the engine is amazing, it is a lot quieter. No clatter after the first start up, but it was back the next morning. I called my dealer to see if there is a tsb on this issue. I have not heard back yet. 

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## oregon_rider (Jul 21, 2017)

I have noticed a clatter on startup on occasion - this clatter persists after she "fires up". If I "cycle the power" - e.g. shut it off and restart - then it doesn't present itself on the restart (at least once or twice). This led me to suspect that it had more to do with a sticky egr valve than oil or oil drainback.

jeff


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## sledstorm1 (Mar 9, 2017)

I would think if the egr was stuck open the ecm should throw a code. I know on the older vw's when the egr would stick open they started like crap do to a lack of oxygen and miss fired. I think the starter is hanging up. And when the oil is fresh the added viscosity helps to slow the engine as it is starting up. When the oil is old and the viscosity is thinner the engine is over speeding the starter preventing binding it up preventing it from releasing. That is my theory. It's just a pain in the ass to replace the starter on a Terrain with AWD. The transfer case sits under the starter. 

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## oregon_rider (Jul 21, 2017)

A knock or click is indicative of a stuck closed or blockage on EGR. The engine will run hotter without EGR. This can lead to pre-detonation. That is my general understanding after looking at it for a few minutes - I am a "senior engineer" with more of an emphasis on "senior" versus "engineer" at this point in my life!  

A p0401 code would be triggered - insufficient flow on EGR - but the threshold at which it is triggered versus when you might "hear" the problem might not be deterministically calibrated.

My car is in the shop right now - but I have a fresh EGR valve to install - I just suspect that it needs to be cleaned - so I am going to install a new one and clean the one I remove to put on the shelf.

I am running renewable diesel now - so I will have zero egr soot accumulation going forward. It has a cetane of 80+

My daughter drove our diesel for about 12 months at college and it was used for very, very short trips - it got "clogged up" and had a "cat replacement" last year. So the probability of a dirty egr on my vehicle is high.

jeff


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## Barry Allen (Apr 18, 2018)

oregon_rider said:


> pre-detonation


How does a diesel engine get pre-detonation?


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## sledstorm1 (Mar 9, 2017)

oregon_rider said:


> A knock or click is indicative of a stuck closed or blockage on EGR. The engine will run hotter without EGR. This can lead to pre-detonation. That is my general understanding after looking at it for a few minutes - I am a "senior engineer" with more of an emphasis on "senior" versus "engineer" at this point in my life!
> 
> A p0401 code would be triggered - insufficient flow on EGR - but the threshold at which it is triggered versus when you might "hear" the problem might not be deterministically calibrated.
> 
> ...


Jeff i could see your explanation happening while drive when the engine is hot, but not when its a cold startup and it has been sitting for 3 days. 

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## oregon_rider (Jul 21, 2017)

Barry Allen said:


> How does a diesel engine get pre-detonation?


 True that.

I was thinking of the pilot injection. It is finely metering fuel pulses and expecting a given amount of oxygen for combustion. With the egr not operating properly this may no longer be optimal. Result could easily be a diesel "clatter" like days if old.

Jeff


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## Barry Allen (Apr 18, 2018)

oregon_rider said:


> I was thinking of the pilot injection. It is finely metering fuel pulses and expecting a given amount of oxygen for combustion. With the egr not operating properly this may no longer be optimal. Result could easily be a diesel "clatter" like days if old.


Diesel engines always run lean, even at full power. That's why the are such good candidates for heavy use of EGR: you can have lots of EGR and there is still plenty of oxygen for combustion.

For pilot injection, it's a very, VERY small amount of fuel injected into the cylinder that does two things:
1. It puts a little bit of pressure on the piston to completely seat it on the wrist pin for the combustion stroke. This is a good part of what used to give you that diesel clatter in old days: the huge, all-at-once injection of fuel gave you a high pressure combustion event and it would "hammer" the piston onto the wrist pin and contribute to some noise from the engine.
2. It adds more heat to the cylinder temperature so that the larger fuel injection events that come during the power stroke will ignite faster and combust more thoroughly.

Even if you had EGR running at very high percentages, the pilot injection would still combust without much trouble. It's such a small amount of fuel that it doesn't need a lot of oxygen to combust.

Even if you had 0% oxygen in the cylinder because you had EGR flow that returned completely, totally spent exhaust to the cylinder? You wouldn't get any diesel clatter because you'd be injecting fuel that would evaporate and WOULD. NOT. COMBUST. because of the lack of oxygen in the cylinder. You'd get no diesel clatter at all because you couldn't have combustion.


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## oregon_rider (Jul 21, 2017)

Thanks for that great explanation Barry...

jeff


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## Barry Allen (Apr 18, 2018)

oregon_rider said:


> Thanks for that great explanation Barry...


Some time ago it was piezoelectric injectors that were the new technology. The ability to make unbelievably small changes to injection timing and quantity enabled engine designers to control the injection of very small quantities of fuel. The description I remember is that the newest piezo injectors could control injection of a quantity of fuel the same as the amount of ink it takes to print a period on an average newspaper sheet, so we are talking picoliters or nanoliters of fuel quantity injected.


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