# Compression Test Procedures - Multiple Codes



## Jms2980 (Dec 4, 2016)

I just purchased a 2018 Cruze Premier with 51K miles for my teenage daughter. I owned a 2011 Cruze Eco for 7 years and drove it for 125K miles. Sold it to my nephew 3 years ago for the $3K trade-in value at the time. Trying to buy that representative car back now demands $6-7K. Given this craziness in the used car market, I took a risk and bought a 2018 with a rebuilt title - good price and a lot less miles. Flew to Philadelphia and drove the car home to Wisconsin (900+ miles). Get 3 miles from home and the car starts running poorly, rough idle, flashing CEL and service stabilitrak. Getting the following codes:

P0300 Random/Multiple Cylinder 
P0301 Cylinder 1 Misfire
P050D Cold Start Rough Idle

I've already changed plugs, swapped the #1 & #3 coils with no change. I have 4 new coils on order and also a replacement coolant temperature sensor. 

I'd like to pull a compression test next but am trying to find the correct procedures:

Obviously, 

Pull plugs
Disable fuel system
Disable ignition
Crank
What am I missing? I know some procedures require wide-open-throttle. Is that required for the LE2 engine? If so, how is that best accomplished. Any advice on any of the above would be appreciated.

PS - my 2011 Cruze was one of the first diagnosed with the cracked piston issues in the Gen 1 powertrain. GM actually flew a representative to my servicing dealership to inspect my car.

James Smith


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## snowwy66 (Nov 5, 2017)

You probably have a cracked piston.

Pull plugs and sit them on the motor so spark grounds..don't need to worry about fuel but if inclined pull fuse to fuel pump and ignition. 

I don't know what the procedure is for WOT.


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## Snipesy (Dec 7, 2015)

Cranskshaft variation learn requires WOT, but this doesn’t involve that. And it’s not even WOT you just hold the throttle.

I would go for damaged valve or head gasket failure: most likely from a bad repair job. I think cracked piston is unlikely. You can get a camera down there to look around.


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## Jms2980 (Dec 4, 2016)

Compression Results:
#1 - 45
#2 - 150
#3 - 150
#4 - 150

Anybody have experience replacing the pistons themselves? I'm assuming best option is buying a used engine. Looks like they can be bought for ~$1,000 on ebay.


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## Snipesy (Dec 7, 2015)

Jms2980 said:


> Compression Results:
> #1 - 45
> #2 - 150
> #3 - 150
> ...


I would take the head off before you decide anything.


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## jblackburn (Apr 14, 2012)

There’s a 5 year / 60k powertrain warranty. Unless I’m missing something, that’s still covered.

Edit: I guess the salvage title disqualifies it, eh.


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## Jms2980 (Dec 4, 2016)

Yep salvage title invalidates any remaining warranty. Still can't quite wrap my head around the fact I drove it 900 miles at 75+ all day and it drops #1 cylinder when I pull off the highway 3 miles from home. No other signals all day.

I'm borrowing a cheap bore scope tomorrow to that will hopefully give me some idea of what the piston/cylinder walls look like before deciding my next move. 

Anyone have access to or know where I can find the torque specs and tightening sequence for removal/install of the head?


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## Snipesy (Dec 7, 2015)

Jms2980 said:


> Yep salvage title invalidates any remaining warranty. Still can't quite wrap my head around the fact I drove it 900 miles at 75+ all day and it drops #1 cylinder when I pull off the highway 3 miles from home. No other signals all day.
> 
> I'm borrowing a cheap bore scope tomorrow to that will hopefully give me some idea of what the piston/cylinder walls look like before deciding my next move.
> 
> Anyone have access to or know where I can find the torque specs and tightening sequence for removal/install of the head?


AllDataDIY should have the 2018 by now. Which is very reasonably priced.

Do it Yourself Automotive Repair Information | ALLDATA DIY

The LUV specs are definitely around here somewhere, but idk if it's the same.

Personally, I would still suspect head gasket.... And if the head gasket does look okay, and there is nothing wrong with the bore, cyllinder, rings, etc.... Then the head is probably warped from a prior engine overheat. It can be kind of hard to fix a warped head, but some shops could definitely assist. The warped head would make a lot of sense because in those cases the head gasket tends to work until it doesn't.


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## Jms2980 (Dec 4, 2016)

Replacement head on Rock Auto ~$1100. Better to go used engine route if head is warped. I had both cracked pistons and warped head issue on my Gen 1 Cruze.


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## snowwy66 (Nov 5, 2017)

Alldata doesn't have a single subscription anymore.

I couldn't find it anyways. 

If he had a bad gasket the engine should be overheating and blowing vapor out the exhaust. Or leaking coolant.

The gen2 has the standard temp thermostat. Not the hot one the 1s have. 

At 51k and the piston being a common problem. Although 18 was supposed to be improved.


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## jblackburn (Apr 14, 2012)

snowwy66 said:


> Alldata doesn't have a single subscription anymore.
> 
> I couldn't find it anyways.
> 
> ...


Once repaired, OP should use an oil with better LSPI protection and >87 octane in the tank to try to help avoid it happening again. GM redesigned the pistons and the tune to reduce the likelihood of this happening, but still can't avoid 100% of the events (and neither does their own oil spec)


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## Jms2980 (Dec 4, 2016)

So was quoted $3500+ by local indy and $4300+ by local dealer to repair (assume teardown and replace all 4 pistons per the tsb). Decided to go used engine route - just ordered from salvage dealer replacement engine with 14K miles delivered for $1100. Going to tackle the engine swap myself. My time is limited to weekends so hopefully have it done in the next 3-4 weeks. I'll post my experience with the process when I'm hopefully back up and running.


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## CRUISE-CRUZE (Nov 8, 2010)

Jms2980 said:


> So was quoted $3500+ by local indy and $4300+ by local dealer to repair (assume teardown and replace all 4 pistons per the tsb). Decided to go used engine route - just ordered from salvage dealer replacement engine with 14K miles delivered for $1100. Going to tackle the engine swap myself. My time is limited to weekends so hopefully have it done in the next 3-4 weeks. I'll post my experience with the process when I'm hopefully back up and running.


I did a swap for the MT ECO, yours will be different a little bit but the steps should be the same, follow my post:
How-To: Engine Swap - 2011 ECO MT to 2014 ECO MT | Chevrolet Cruze Forums (cruzetalk.com)


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## Jms2980 (Dec 4, 2016)

So I ordered a replacement engine and began the process of removing the old engine. I don't have a lift so put the car up on car ramps (all 4 wheels) and that gave me enough room to work underneath etc. My dad and I had the engine pulled in about 12 hours. Took our time, took a lot of pictures and labeled the wiring harness as we went along. Dropped the replacement engine in without much trouble. Got super lucky lining up the flywheel/flex plate and the torque converter bolts. Hooking everything up took about 4 hours. It starts! Haven't driven it yet - should be tomorrow. Now for some additional trouble shooting:

Tachometer doesn't work. Instruments do the full sweep when starting but tach sits at 0.

Remote start doesn't work. Parking lights flash but nothing. Though I don't think I tested it before I tore the car apart. 

Service Stabilitrak light is still on.

Still have the following codes:

P0300 - Random/Multiple Cylinder Misfire Detected
P050D - Cold Start Rough Idle
P0335 - Cranshaft Position Sensor "A" Circuit

According to my scan tool (Blue Driver) these codes can't be cleared with a scan tool.

Lastly, reading various information in ALLDATA, it looks like I need to have the ECM reprogrammed for proper performance. Anyone have more information on this requirement? I'm planning to have the reprogramming done per the TSB for the LSPI issue anyway.

Overall pretty happy to get it this far, now to just finish the troubleshooting.

James


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## Jms2980 (Dec 4, 2016)

So after reading quite a bit last night about crankshaft position sensor and need to perform a variation relearn procedure, I decided to check the part number on the sensor installed since there are two different part numbers. Well I found the 1 connector I missed in the whole harness. Swapped sensors, plugged it in this time, started the car. Car ran good, tach works, service stabilitrak light/warning is off and no other CELs. Finished putting everything back together and test drove. Everything seems fine so I drove it 45 miles home (shop I was working in was that far away). Seems to run "perfect". Fuel computer says 37 MPG on the drive home in 10 degree weather. So will just keep driving it for a while and monitoring for codes.


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