2008 Chevy Cobalt SS 220,xxx miles/f.b.o./HP tuned. So it appears I have a piece missing out of the block right above the oil pan next to the flywheel. Is this fixable? Anybody have any experience with this issue? Kind of hard to see in the picture but this is the best I could come up with. It's directly right of the flywheel on the block above the oil pan. Thanks guys

 

Oil leaks are a pain to diag, I don't see anything out of the ordinary for the block

I would clean the entire engine well and add UV dye to the oil, the leak could be from somewhere completely different just running down to that area. It would also allow you to confirm it's engine oil and not transmission oil from the half shaft seal.

 

Right on ECaulk. I know it's engine oil because it's super dirty. I've been working overtime at my job & let the oil life monitor go to 20%. I was actually just about to change the oil yesterday. I'm about 2.5 quarts low. No check engine light. I checked the turbo & piping with no sign of oil. I'll give it a thorough cleaning after work today. Thanks ECaulk for your view!

 

A small leak like that isn't going to shed that much oil over its lifetime. You're likely just burning a little more than usual (it happens). Gotta make sure you're checking your oil every couple fill-ups. My Cobalt and Viper both lose about a quart every 1-2000 miles.

 

I know where you're coming from I had a wrx that ate a quart every change but this is different. I saw evidence of the missing oil underneath the car. The oil is leaking on to the half shaft & then spraying it everywhere. I was driving for an hour and a half home from work the oil runs all the way down the exhaust system(externally) down the middle of the car.

 

Interesting. Is the back side of the flywheel wet? AKA - is this a rear main seal problem?

From above, I would check the back side of the head to ensure this isn't just a leaking VC gasket - or anything else in that area.

Might be worth getting it up in the air (and level) and then just idling it, just to see if you can see anything. Might be a run-time only leak.

There's just a little metal bracket that goes there and covers the flywheel. It's more of a safety bracket than anything else though.

 

The rear main is also what I thought might be causing it, thats why I suggested the dye, you'll see quickly where the leak comes from. But you need to have a clean engine to start to make things easier.

 

When my rear seal started leaking thats exactly what it did. They actually make a pour in rear seal stop leak that is very often effective, but it takes a month or longer to work. Its worth a try. My leak stopped after about 2 months, and I just changed out the rear seal a few months later when I changed out a clutch.

 

Ya I got the clutch changed out & did the rear main seal while we were in there 40,000 miles ago. So it's a new seal. It shouldn't be failing which leads me to believe it's the beginning of the end

 

So it Turned out to be the rear main seal. The car still drives strong with the rear main seal leak. I have 215,xxx miles on this lnf engine. I bought a rear main seal & new gmpp clutch kit/ lightweight flywheel friction disc replacement as well. So I'm @ a cross road. Should I swap the rear main seal or the engine. The car drives as strong as it ever has. What worries me is that something is causing too much crank case pressure. Is there a test I could do to find out? 2008 cobalt SS full bolt on HP Tuned. Has had a pretty spoiled life so I'm leaning towards replacing the seal. Any Thoughts on the matter would be beneficial. I have an LHU engine in my eBay shopping cart just in case. I Do have HP tuners but I'm not sure how to log crank case pressure without a oil pressure sensor. I have performed the external pcv valve with catch an in line. Do I need a oil cap breather. I'm only tuned for 22 psi on stock turbo.

 

Mine just started leaking as well, I originally thought it was the pan gasket. So I replaced it but its still leaking from the arrows location, which I believe would be an indicator of a real main seal leak.

 

Yes, that is the rear seal right where mine was. Sorry you had to go thru all that with the pan for nil. Cleaning up all that sealing adhesive is a b*tch

 

Was the seal noticeably damaged? Or just oil was seeping past it.

I'm wondering what could have happen to mine as the engine was a new one from ZZP that was leaking.

 

I'm getting my rear main seal changed out next week. I'll ask the mechanic to take a look at the integrity of the seal. I think for me it was crank case pressure. Why, I still do not know.

 

In my case couldnt see the seal damaged but could see the leakage around it. Anyone doing this yourself I used a schedule 40 PVC fitting with a plug for a drive tool. Take your new seal to the hardware store, makes it a lot easier. I also had a friend tap with a small hammer while I help the seal/drive tool in place. Kinda hard to do by yourself as it wants to pop out every time you hit it till you get it started.

 

Here is what mine looked like, not really sure what caused it yet. But ZZP was kind enough to sent a replacement main seal! Clutch was a pain in the butt to remove, hopefully putting it back wont be too much trouble.

 

I would replace your intake manifold PCV. The PCV in my intake manifold wasn't doing it's check valve duty, so when I went into boost the crankcase was pressurizing with 25 psi.

LNF PCV Valve 12589440

 

Right on USMCFieldMP. I thought about that as well. I checked it already and it's good but I will replace anyway(got 3 sitting on deck). I bought a Turbo Tech Racing pcv filter housing and completed Tom's how to on a proper working catch can set up for the lnf a while back. I can check the pcv valve without taking off the intake manifold.