Hi I just recently bought a 2009 Cobalt SS about a week ago with 88,xxx miles on it. I carfaxed the car beforehand and no issues or anything were reported on it. A couple of days ago my coolant started getting low even after ive refilled it 2x it would just go low again about an hour later. But when the cars not running the coolant level doesnt go down and when I checked the oil today it looked normal. But I just wanted to know before I tk it to the shop (doing it on tuesday)how likely is it that I have the pourus block issue?

 

Whats your vin and ill check gm history. If you had porous block your oil level would be going up. Have you let it run and checked for leaks?

 

Check your oil

 

Most of the porous block guys do not have coolant in the oil.

If you are losing coolant and don't see an external leak or in oil, then it's a porous block most likely and going internally into the engine

 

Ive checked my oil today and yesterday and it looked completely fine. I also havent noticed an increase in my oil at all. But im giving the car to my mechanic today and iill keep my fingers crossed,

 

It is possible its burning it off. how much have you had to add to it the last few times?

 

This. If it's burning off, an oil sample analysis would likely tell you if it was in the oil.

Honestly there aren't many places for it to go. It either leaks outside somewhere, into the combustion chamber, or into the oil.

I'm not sure how many spots there are on the block where it may crack. If it's porous block, the crack may not be big enough for coolant to seep unless it's pressurized. Mine was and I lost coolant overnight. The loss was MUCH larger when running. I didn't get the milky oil until I took the car home from the stealership. However, I took a sample from the drain plug and it was all coolant coming out after sitting overnight.

 

I have coolant in the oil of my car as well.. took me a couple months to tear it down, get the head checked, decked & cleaned and re-assemble and found out this weekend that it's still doing the same thing. Myself, the shop, and a couple of friends all thought it was the head gasket; especially since it had indications of coolant and oil leaking around the block and the gasket being deteriorated considerably in a couple of areas. Hi boost from the turbo probably lifted the head with the stock bolts. Unfortunately, there's more to my issue than merely a head gasket. The question is what?
With no coolant, or very little in the system, the car runs like a top. As soon as coolant was forced in via pressure through the valve cover nipple, it started running worse and worse. After 3 oil changes, it was obvious that the issue is something else since the oil level on the dipstick gained by about 2".
I have a mechanic friend who says it's quite possibly the water pump.. is this even possible or do I 100% need a new block? I don't know what else it could be tbh. I've also noticed that it can have a "boiling" noise after turning the ignition off for a couple of minutes, so it seems like coolant is getting in somewhere and being boiled on the block; just my hunch anyways. When the head was off, there's no cracks anywhere on the top of the block and all cylinder walls are smooth as a baby's ass, so if it is in fact porous block, it must be hidden deep inside somewhere that cannot be seen.
I know this was somebody else's post, but I figured I'd add my own experiences with this problem to date, and maybe, find a solution.

 

i try to folllow these threads

never heard of head gasaket failure on lnf and not too many water pumps

most often its pourus block. or crack.

 

Same here. The porus block term messes with everyone, it's actually a crack in the coolant passages allowing you coolant to leak into the oil or combustion chamber.

I also have never heard of a head gasket going on an LNF or the water pump. Still trying to figure out why the water pump would be the cause of coolant in the oil. For it to leak into the timing chain area it would be a catastrophic failure not a keep running and keep the car temps at idle in check.

You need a new block end of story.

 

Lol could be.. a mechanic friend told me that the water pump is a possibility. It leaks 4L within 10 minutes into the oil pan so it's MAJOR. And, as for keeping cool, it gets hot once it dumps the coolant into the pan... 220ş+ Unless, it's running on the highway at 70mph or more, then it stays cool due to air. From what he told me, the oil cooler and water pump are the only other two causes other than a cracked block. If the block is in fact cracked, it's cracked somewhere that a person cannot see it, and it must be absolutely Huge. It's really strange because the car runs great without coolant Lol

 

I was looking at the water pump yesterday and couldn't figure out how a failure in the pump would get coolant into the oil unless there was a massive shaft seal failure. Haven't heard of an oil cooler failure but I guess it's possible.

 

negative. i had a porous block and my engine was replaced under warranty. i found out when my temperature spiked to 110C while i was doing around 70mph on the hwy on the way home one day. i pulled over and checked my coolant resevoir. empty. checked dipstick and under oil fill cap. condensation. towed.

 

qfe.

Not saying that a shaft seal failure is impossible on the cobalt water pump, but not likely. If one of the coolant passages cracks (normally the ones that crack are in the block not visible) you'll dump your coolant quickly, 4L in 10mins isn't a crazy rate for a crack. And if you've been running your car for any time at highway speeds with an extra 4l of coolant in the oil your rod bearings are damn near done by now. Just buy the LDK from ZZP and call it a day

 

Negative to you maybe, but it worked for me.. I drove the car 80kms or 50miles like that because it stayed cool from the incoming air. Without coolant, the car runs great Lol.. of course, you couldn't do that in traffic at all, but I guess on the highway, I have enough cooling to not overheat.. it's weird I know. I haven't driven it anywhere in over a year, but still... the coolant had all basically drained into the oilpan during that time.