Does leaking coolant into the oil always mean bad head gaskets?
 

Hey guys hoping someone out there could point me in the right direction. I did a brief search but everything seems to point in a few different directions.

Backstory and history of the car:
Just bought my girlfriend a 2012 G37x in July. The car currently has 60k miles on it and we bought it with 54k miles. The previous owner mentioned it had over heated and he had 1 of the head gaskets replaced. I was weary of the purchase but we reluctantly went through with the purchase (stupid I know). I've noticed a slight antifreeze smell lately and seen the overflow tank losing coolant. I told her all summer to keep and eye on the temp gauge and she said it never climbed anywhere close to overheating during our ownership. So I did a oil change tonight after seeing a slight milky residue on the bottom of the oil cap, sure enough....it's mixing. She works less than 5 miles from home and seeing as it's winter I see this could cause this milky residue in some cases (it's not bad like pudding caking under the cap and nothing on oil dip stick out of the ordinary, just I figure any residue can't be good). The car doesn't smoke at all and the exhaust doesn't smell sweet. The antifreeze smell comes more from front of the car. I'm hoping maybe there is a issue some of the ogs on here have dealt with before I go and replace these head gaskets. Just between not fully knowing the history of the heads in the past I don't want to deal with this issue down the line. So now I'm worried like maybe he warped a head, or maybe his cheapness got us in the long run from the original over heating issue and only replacing one gasket? Just trying to bounce some ideas and any help is greatly appreciated. I also didn't see anything out of the ordinary leaking from radiator hoses. Could I be over looking something? Maybe water pump or oil gallery gasket(see these are common to fail pre 2013) or something? Idk Ive never personally had to deal with this issue in my experience with two vq35de's or my vq37vhr. So I'm kinda at a loss? Thanks again

So I've had the same thing. Smell could be coolant being expelled from the coolant overflow tube. Mine does that somewhat often. The white gunk is probs just bc the oil isnt getting to near-boiling temp and boiling off the water.

Or I've been driving around with leaky head gaskets. Either or.

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That's what I'm worried about. I'm going to Napa friday to get a headgasket tester. Wasn't sure if a thermostat or water pump could be the culprit? I'll post results. It's just weird it doesn't smoke at all/smell sweet exhaust end. Also, it's not throwing codes so it's not fouling sparkplugs.....at least yet. And I'm pretty sure antifreeze is definitely mixing. Idk it's annoying for sure though.

Ok so doing a leak down a d the block tester keeps sucking antifreeze into the pump....I've taken the top radiator hose out and tried draining a good amount. Idk if people still use this forum orrrr? Again, literally any help is appreciated.

Well, headgasket is indeed blown. These motors are kinda trash imo. I had a idea after seeing the mixture of green after the last oil change but wanted to know 100%....and unfortunately now I do. Car only has 62k miles.

You have an uncommon problem. Hence, the dearth of replies.

I understand this, but close to 500 views and no insight. My frustrations kind of got the best of me also. Sometimes seems like a dead forum unless you're one of the ogs who post every day. It's whatever though I figured it out.

You have an 09, how man times have you changed out your coolant ? As coolant ages it turns corrosive and will eat at the softer metals / copper head gaskets. Even though your antifreeze will keep your radiator from freezing doesn’t mean it’s good. :twocents:

This is actually my girlfriend's 2012 G37x with 62k. I never changed the coolant since we have only owned the car for about 6 months. I've never had a issue with my 09' and I drove that hard from 15k to 65k with no issues. I don't know I'm at a loss. I'm actually just going to post it locally for sale. It's not something were really looking to get into honestly. I definitely appreciate it. Next used car we will have to just look over alot better.

On a side note to others doing these types of block tests.....drain your antifreeze wayyyy down. The waterneck(I'd assume this is what it's called) where the upper hose goes into the block is so shallow it pulls alot of antifreeze into the tester and contaminated the test a bunch of times. I've done these tests before, this was just one of the more complicated motors I've done one on. Also the over flow coolant hose, take that off completely and blow compressed air through the tube to get all the coolant out. You'll be good after you've checked those things for a clean thorough test....otherwise, you're going to have a hell of a time.

Generally VQ engines don't have cooling issues and work well for a long time.

^^^
Too bad you missed that red flag. Also, it is a little odd that only one head gasket was replaced.... or maybe no head gaskets were replaced and then you purchased the car as the seller wasn't telling the truth.

Yeah, I looked it over good. I'm starting to think he used a sure seal headgasket kit. That was my fourth VQ and I have never had an issue like that before. Unfortunately though we drove four hours away and my girlfriend really wanted the car. I figured I've done the right thing by pointing her in the right direction of a solid car. It's all good we traded it in yesterday for a CPO Camry. The dealership didn't even notice the head gasket either..... It's destined for the auctions now. Still even got 9k for it. It's really put a bad taste in my mouth with the VHR honestly. Also, to be fair earlier models kind of did have a issue with needing a oil cooler it's all good though you live and you learn.

That sucks man. Unfortunately, you have only yourself to blame. I hope you at least got a really good deal initially and then most of your money back when you traded it in.

For the record, these VQ motors are pretty damn indestructible. If they are taken care of. A blown headgasket at <55K miles indicates that was not at all the case and should have been a huge red flag to any potential buyer.

In the future, never buy an Aluminum block engine that has over-heated. Old-school, cast iron blocks can often handle over-heating without warping or cracking; not so much with an Al block. Plus, with the tight clearances of modern engines, it doesn't take long to do irreparable damage to rotating parts.

Yeah, it does suck. Luckily I didn't get turned around in a loan since I paid cash. I still think the motors are trash sorry if I hurt any feelings. I lost a grand in 8 months. I've spent money in worse ways.