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· Registered
2013 Cruze LT
4,284 Posts
Discussion Starter · #1 · (Edited)
Ok, after a long period of contemplation, I have decided to go ahead and make a thread documenting my 2013 Cruze LT 1.4L. I will name it a build thread, but don't really consider it that. This is just something that I work on and improve as time and funds allow. I like to tinker and find different ways to do things as well as maximize performance. I do all the work in my enclosed garage and have a decent amount of tools. Most if not all of the modifications will be bolt on.

Maintenance/work list:

Window tint 12/1/2018 54k
New tires 55000 discount tire
Paint correction and wax 55k
Dorman thermostat 4/25/2019 55k
Transmission fluid drain and fill valvoline 55k 5/10/19
Front rotor resurface 55k 5/10/19
BNR tune purchased and installed
New plug boots rock auto standard brand 55k 5/17/19
New battery (larger size) and negative cable OEM and mechanical boost gauge 55k 5/23/19
Transmission fluid drain and fill AC Delco
56k 6/28/19
Oil change and filter 56,048 7/12/19 super tech synthetic
ZZP downpipe 7/15/19
Installed black vinyl over emblems
New ac delco ceramic brake shoes front 56,300 8/23/19
New driver window motor and tint 9/4/19
New belt tensioner and belt ac Delco 11/24/19 | 56,500
digital boost gauge 12/14/19 56,600
Fixed turbo outlet line coolant leak and installed new water pump. New antifreeze 56,700 1/9/20

Changed oil penzoil ultra platinum 5w30
57,322 3/22/20

Compression right to left
180,200,195,205 Psi

5/5/20 57,541 new oil gm, oil pan reseal, ac Delco turbo oil line 89in lb, 22 ft lb, down pipe reinstalled
Brembo brake rotors 6/15/20

Bnr wastegate actuator 6/20/20
AC Delco spark plugs default gap 8/17/20
Ac Delco water outlet new prestone dexcool antifreeze 8/28/20 57,922

Dorman intake manifold 9/20/20

New purge valve OEM, BNR throttle body spacer, boost leak test passed 9/30/20 58008
New MAF Ac Delco 10/21/20 58106
New FCS front struts 58,500 1/18/21
New FCS rear shocks 58,600 2/23/21

Oil change pennzoil plat ultra, BNR LS7 coils 58669 4/12/21

New GM water pump and gasket
58,700 4/28/21

BNR Intake manifold spacer, new driver CV Axle, Cardone reman.
59,000 11/6/21

Rotated tires
59,111 11/20/21

ZZP V3 Turbo, used 1500 miles
59,300 04/02/22

Oil change Pennzoil Platinum
59,360 04/03/22

ZZP Ported intake manifold, PCV 3.4 fix kit
59,450 04/22/22

And the story begins:

When she was pretty new, she was full of swirl marks and scratches. This is after a professional paint correction that I did myself with the pictured Meguiars and harbor freight DA. Tons of work and it took days. I went panel by panel.


Next, got some new shoes (Continental Control Contact) These things are great, so much softer than the old Michelins

Shortly after, it was time to start fixing leaks. This was the first one, I fabbed up a piece of rubber tubing and put a heat shield on it. It has lasted almost 2 years now with no leaks.


Had a transmission fluid leak that was likely from an overfill, did a drain and fill X3 with AC Delco fluid.


Next was a rich condition, which I finally narrowed down to the cooler NGK plugs I installed, Don't go with the 8's... unless you like unburnt fuel

Next up is oil leak time, the oil cooler and pan were leaking. The dealer fixed the pan and for some reason painted it all with silver spray paint... I did the oil cooler a month or two on my own after. More to come in next post


continued below...

· Registered
2013 Cruze LT
4,284 Posts
Discussion Starter · #2 · (Edited)
Oil cooler teardown and fix (this is the most challenging repair I have done to date)





Removed the PCV fix kit as it always leaked, unsure as to why, but I don't prefer them really... Installed the revised Dorman manifold



Digital boost gauge

After this I went with a BNR throttle body spacer as the gasket on the DDM one was melted. It is MUCH better quality

continued below...

· Registered
2013 Cruze LT
4,284 Posts
Discussion Starter · #3 ·
Next up we have a used set of BNR LS7 coils (these things are sweet!) Cleaned them up and saved over $200 off retail


You may have noticed by now a Forge Atmospheric bypass valve and BNR (Forge) wastegate actuator

Always the best oil

Recent water pump replacement, (3rd one)



Coolant leak test to sum things up

· Registered
2013 Cruze LT
4,284 Posts
Discussion Starter · #4 · (Edited)
BNR Tune review:

Other tune reviews by others here Gen 1 Tuning Comparision Thread

I want to start this off by saying this is my opinion and an unbiased and honest review.

BNR Autocal Tune $600: BNRTUNE-CRUZE14-BNR Tune 2011-2016 Limited Chevrolet Cruze 1

2013 Cruze 1LT
195HP on auto cal, assumed 170WHP
ZZP downpipe | Forge wastegate actuator | Forge atmospheric bypass valve | MSD Coil | ZZP Big 3 kit

I have the older BNR EFILive BNR tune, they now offer HP Tuners. They are the same tune, but different technologies. To start off with, they send you a base tune. You flash this onto your vehicle and gather a log to send back to them. They will then analyze the log and make changes if needed. I didn’t need to have any done. The base tune makes a ridiculous amount of power over stock and your butt dyno will immediately know.

They offer retunes for no cost as well as for mods. My experience when requesting custom tunes has been about 50/50. I requested a higher PSI tune and it worked ok, but went into limp mode/overboost a lot. Enough to not be drivable enjoyable. The Eco tune I requested though is great! I noticed quite the increase in misfires on their tune versus stock, I assume this is due to timing and them advancing it to get more power, they assure me it is no issue. It’s usually under mid acceleration or after letting off the throttle from wide open.

I get better MPG on all of their tunes versus stock, even pushing 20PSI. I currently am running their normal canned base tune and it’s fine. If you floor it, it will spin the tires a bit in first and bark the tires when shifting to second (2nd gear scratch). Which to an automobile nut, is quite desirable 😃

Their response time on tunes is normally at least 2 weeks and all the way up to a month. To some this is an acceptable window, but to me it really isn’t. I love the power, but the tune replies are pretty much rushed and lacking. You can’t ask quesitons and just receive a new file and are told to load it up. I get it they’re busy, but a little more smoothness around the edges would be nice; as well as a faster response time. If you are marketing yourself as offering updates for free, they should be a bit more timely.

In the end they get the job done, and that is how some companies operate. I am not disappointed in any way, but likely would have went with another company knowing what I know now.

Next up on the to do list is get the limp mode resolved with the tune as well as install a bigger turbo. Undecided on which brand I will end up going with. That is more of a longer term plan/if I get a good deal. Also keep trying to find out why it idles a little rough on cold starts.

Just cleaned up after an engine bay wash due to water pump replacement.


· Registered
2013 Cruze LT
4,284 Posts
Discussion Starter · #24 ·
Still can't figure out the largely negative and jumpy ltft... swapped to another set of OEM injectors and same issue. Seems when the engine warms up more it gets worse... Based on a search negative ltft can be:

  • Leaky or chattering fuel injector
  • Defective fuel pressure regulator unable to maintain fuel pressure or restricted fuel return line.
  • Restricted air intake system or clogged air filter.
  • Restricted exhaust because clogged converter, crushed exhaust pipe or plugged muffler.
  • Defective oxygen sensor or its wiring.

I have installed a new OEM front O2 sensor, air fitler only has like 1k miles on it, injectors have been swapped, I don't have a cat converter. New MAF. Boost test passes with flying colors. They of course go negative when I let off the gas as I have an atmospheric BOV... so air is being vented and not recirculated, but this is happening even with the cruise control set to say 35. It seems to run ok, but it's driving me nuts because it seems there's an issue. Fuel pressure is always 44-50 PSI or so. Out of sight out of mind? Someone on BNR facebook mentioned to test the barometric sensor... as cheap as they are I could put one of those in too. Isn't there two?

Green line on graph. Orange is duty cycle.

· Registered
2013 Cruze LT
4,284 Posts
Discussion Starter · #30 ·
Also, to confirm, the second O2 sensor isn't factored in other than to measure catalyst efficiency, right? It has not been replaced.

Lastly, I was thinking of opening the airbox and taking the filter out and or leaving it slightly open and driving around just the neighborhood. Curious if more air cures the issue.

· Registered
2013 Cruze LT
4,284 Posts
Discussion Starter · #32 ·
Also, isn't this weird... seems the O2 sensor cuts out momentarily and no fuel trims are adjusted... Spark is also retarded a ton there... idk...

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