[XtremeRevolution]

How-To: Replace the Valve/Camshaft Cover (1.4L Turbo)
​

Overview
The valve cover of the 1.4L Turbo engine houses the PCV system. Whether due to a leak in the gasket or a failure in the PCV system, this valve cover may need to be replaced. It is covered under the 5 year, 100,000 mile warranty from GM, but you may choose to perform the service yourself under certain conditions. The valve cover was at one point redesigned due to a high rate of failure. As my dealership is a significant distance away from me, it is more cost-effective given the value of my time to order this part and install it myself. In addition, I like to replace known defective parts ahead of time as preventive maintenance.

The following image compares the primary cosmetic difference between the old design and the new one. The old design is on top, new design is on the bottom. The new design has a ramped vent.

Part Number & Cost
GM part number 25198874 (Camshaft cover with bolt and seal), Available on Amazon.com. The valve cover comes as a kit, which includes gaskets and bolts pre-assembled. You will also need some RTV silicone or engine sealer.

Required Tools
Flathead screwdriver
T-30 torx screwdriver/bit
E-10 socket and ratchet (Available on Amazon.com)
In-lb torque wrench (Available on Amazon.com)

Procedure
The procedure is in fact rather simple, but I will walk you through it step by step.

The first step will be to remove the ignition coil cover. It's that piece of plastic on the top of your engine that "ECOTEC." Once you lift it off, you will see the ignition coil assembly. Remove the two torx screws with a T-30 torx bit/screwdriver.

Once you remove the screws, set them aside in a safe place. You will need to remove the coil assembly. This has to be done carefully as it can break. Do not use a screwdriver. Grab the assembly with two hands as shown, and lift evenly. Apply a very slight see-saw motion as you lift if necessary.

Once you have the coil bar removed, you will need to disconnect it from the wiring harness. To do this, you will need to slide back the connector lock. This will be an orange tab on the connector. Be careful while sliding this out as it can break easily. Once you have slid back the lock, you should be able to press down on the tab to disconnect the connector from the harness. The following image shows the connector with the lock slid back.

On the rear right of the engine, lift the harness out of its seat:

When you reach the left side, you will need to wedge a screwdriver in the snap retainer to free the harness.

Underneath the snap retainer, there is located a plastic vacuum line. Remove this as well. It will simply pop out of its retainer.

On the left side of the cover, lift the harness out of the retainers:

Below the harness, there will be a plastic bar that holds some additional wiring. You will need to use the screwdriver to hold back the retaining clips so you can remove this. It took me a little while to figure out which way to push the tab, but once you have it right, the bar should should lift up and out.

Using an E10 socket, loosen all of the bolts until they can be lifted.

Remove the oil fill cap and dipstick:

 

[XtremeRevolution]

Once you have all of the screws loosened, lift the valve cover off. If it does not come off easily, you can use an interior trim tool remover to wedge the valve cover up off of the cylinder head. Whichever tool you use, be very careful not to scar the cylinder head gasket surface. If you have to, you can remove all of the bolts from the valve cover, but it isn't absolutely necessary. It will be easier to remove the valve cover if you lift from the front so you don't snag the wiring harness with the rear. Once you have the valve cover off, this is what you'll see:

My particular Cruze had ~35,500 miles on it at this time. I took some pictures of the various valvetrain components:

Here, you will see the PCV ports inside the cylinder head:

After you're done admiring your shiny valvetrain (or recovering from the horror of the sludge you found from using a crappy oil), remove the snap retainer from the old valve cover and put it on the new one.

IMPORTANT: use compressed air or brake clean to blow out any oil that may be inside the bolt holes. Oil is not compressible and will cause you to strip the threads while tightening if left in there.

Before installing the valve cover, you will need to clean off the old engine sealer at the two joints between the timing cover and the cylinder head, and apply a bead of sealer at those points, shown here:

Check the valve cover to make sure the gasket is still snugly attached to it. Put the new valve cover on. I recommend sliding it in at an angle so you can tuck underneath the wiring harness.

Tighten the bolts down by hand with just the socket end until they are snug. Once you have them all even and snug, go around in as star-like of a pattern as you can and tighten them until they are snug but not tight with your ratchet. Unlike valve covers of the past, these actually have a sleeve, and what you tighten down is the sleeve. The gasket acts as a spring for the valve cover itself, and the sleeve holds it down. The correct torque spec for this is 71 inch-pounds, NOT foot-pounds, so these really don't need to be very tight at all. Just snug.

Once you have all the bolts snug, start putting everything back into place. Start with the plastic bar you removed earlier. This should just slide right back in and lock with a snap.

Secure the harness with the snap retainer. Don't forget about the plastic vacuum line underneath!

Get the rest of the harness tucked inside the retainers:

Before you put the coil assembly back in, look inside the spark plug boots and check the springs. Those like to snag and bend inside the boot. Wiggling the boot around a bit usually frees them up. Make sure they're all straight, then evenly press the bar back down. Reconnect the connector, and push the connector lock back in.

Reinstall the oil cap, dipstick, and coil assmebly cover, and you're done!

As a precaution, start up your car and let it idle. With a flashlight, check the edges of the valve cover to make sure there are no leaks.



Important note: be careful not to get any dirt or oil into the bolt holes. If you do, oil doesn't compress and neither does dirt, and you can easily strip the thread or break the bolt. If you suspect you got any dirt or oil in those holes, blow them out with compressed air. You should be able to screw those bolts in by hand freely until they need to be tightened. If you can't and you start finding a significant amount of resistance, you have debris inside and you need to use a tap to clean out the threads. Just something to be mindful of when you're doing this.

 

[trevor_geiger]

Great write up, this should be really helpful for plenty of members here. Thank you.

 

[JCarlson]

Awesome write up! Good clear pictures makes it easy to follow!


Sent from AutoGuide.com Free App

 

[sx sonic]

Excellent write up. Top notch DIY.

Here's a good supplemental link for anyone that wants to understand the PCV setup on our cars and what happens when they fail.

1.4T PCV Explained - Chevy Sonic Owners Forum

 

[Robby]

Good write up Andrei,

What failed to require replacement?

Nosey,
Rob

 

[NYCruze2012]

Great step by step Andrei! Actually I am kind of curious also. I would like to know why the replacement was needed.
Actually, disregard that. I just saw where you wrote that you did it as preventative maintenance because of the high failure rate. So I guess there's my answer.

Sent from my last surviving brain cell

 

[XtremeRevolution]

Good write up Andrei,

What failed to require replacement?

Nosey,
Rob

Preventive maintenance due to a high failure rate with the old design. It's easier and less time consuming for me to replace the part at my convenience than have to deal with the problem and my dealership when the part fails in the future.

Sent from mobile.

 

[Nobody]

Nice write up! Do you have the part number for the ease of other DIYers?

 

[XtremeRevolution]

Nice write up! Do you have the part number for the ease of other DIYers?

Part number is listed above under "part number and cost."

Sent from mobile.

 

[cruzer1026]

Awesome write up! I'll be doing this in the near future.

 

[Nobody]

Part number is listed above under "part number and cost."

Sent from mobile.

Embarrassed I totally missed that second paragraph of text. I should have known coming from you...

 

[CruzeEcoBlueTopaz]

I would like to point out at 100k my original valve cover was leaking air and was replaced. I dont know for certain if this original valve cover was the older design but I imagine it was considering my eco was built 1/12. Now I can say for sure the leaking original valve cover was replaced with a newly designed valve cover which just so happens began to leak air at 180k and was replaced. So basically my original possibly older valve cover design lasted 100k and this most recent newly designed valve cover lasted 80k. ???

 

[XtremeRevolution]

I would like to point out at 100k my original valve cover was leaking air and was replaced. I dont know for certain if this original valve cover was the older design but I imagine it was considering my eco was built 1/12. Now I can say for sure the leaking original valve cover was replaced with a newly designed valve cover which just so happens began to leak air at 180k and was replaced. So basically my original possibly older valve cover design lasted 100k and this most recent newly designed valve cover lasted 80k. ???

The newer valve cover is supposed to be an improved design that doesn't fail as easily. I don't know why your second one started leaking at 80k. Some people reported their original cover failed as early as 30k miles. Keep in mind your driving conditions are far lighter and more consistent than that of everyone else.

I am curious to know the cause of failure.

 

[XtremeRevolution]

I took a quick poll of people on the Trifecta FB group and asked who had their valve cover fail and when did it need replacing. The mileage reports were:

51k
25k
48k
30k
72k

 

[prince_bigd]

count me in for 2 different valve cover replacements under 30k miles. However I believe the first one was botched as upon inspection a lot of sealant was visible around the valve cover in the back and I was pushing a huge amount of oil through the turbo, eventually led to turbo failure. It was done before I bought the car though and I missed that on my inspection. Now Im pushing much less oil through my intake just the normal amount that most newer GM cars do. Both were the newer design btw. First one was done somewhere under 20k miles as It had around 20k on my car when I purchased it.

 

[Nobody]

At the risk of sounding stupid... how do you your valve cover has failed?

 

[sciphi]

At the risk of sounding stupid... how do you your valve cover has failed?

IIRC the car throws a lean code, and stumbles while driving.

 

[Calintz]

This only happens with the 1.4T? I have 62,000 miles and everything seems to be fine. Should I replace mine as a precaution? I have the 1.8L

 

[AutumnCruzeRS]

I took a quick poll of people on the Trifecta FB group and asked who had their valve cover fail and when did it need replacing. The mileage reports were:

51k
25k
48k
30k
72k

Had mine replaced around 36k. Oil was leaking out top circle under coil pack cover.