Nissan VQ35 external head gasket leak

[Headgasket]

We have an out of warranty VQ35, and it has what I've learned is the pretty common external head gasket weeping issue. I have no idea how long it has been doing this, but based on the variety of dried crust that I can see in the valley, probably a while. There's not much down there, but it's various shades of old-looking white-ish green. I am going to send the oil off for an analysis to make sure that it's clean, but there are no symptoms aside from the occasional smell of coolant when walking in front of the car (and the dried crust). The oil is clean, no smoke, no overheating, no noticeable coolant loss. Everything points to this being an external leak, and not an internal oil/coolant issue.

Now, I'm not really inclined to do this, but what do you all say about the Subaru coolant conditioner as an attempt at a "fix"? I know it's just rebranded Radweld, but can it cause any issues, aside from maybe simply being a waste of $3? It's supposed to react to the air, right? If that's the case, it seems reasonable that it may work to seal a leak to the atmosphere. Maybe. I don't really want to spend $3k to get the head gaskets replaced, as the car is probably only worth $10k, and it's not like they're anything but a smelly annoyance at this point. On the other hand, if it's been doing this for years or even since new (as seems to be the case with a lot of VQ35s), it may be OK to just leave it as it is and keep an eye on the coolant level... but I also don't want a catastrophic failure at some point.

Thanks for any help.

 

[Eddie]

I used the Radweld for my Subaru HD that was weeping and it solved the problem. I felt confident that Subaru did some real research into this product. Ed

 

[cptbarkey]

sounds more like an intake manifold gasket leak. i became extremely intimate with a VG33E and there were MANY opportunities for coolant failures in the manifold, I would imagine the same with the VQ.

 

[Headgasket]

Thanks for the replies. I'm fairly certain that it's the head gasket(s), because I can see some buildup on the block/head seam. I guess it could be dripping down from somewhere else and catching there though. Maybe I'll dig a little deeper.

 

[CBR.worm]

Hmmm. I'm not familiar with that problem, but since new my G35 has always had the smell of coolant floating around it when hot, but not enough was lost that I have to add any between 50K coolant changes. Now I'll have to take a look.

 

[Headgasket]

I'll be curious what you see. I saw my issue by shining a flashlight behind the radiator cap and into the valley under the intake manifold. There's not much room to see, but it was enough.

 

[Headgasket]

Update: I ended up springing for the $2.30 bottle of Subaru Coolant Conditioner. I used half of the bottle, and after 300 or so miles of various conditions and using the full range of revs several times, no more smell. There's also no change in coolant temp, checked by both the dummy gauge and a Scangauge II.

(I also just noticed that there's a cooling system and additives section on this forum... whoops)

 

[cptbarkey]

Interesting. All you may have done is plugged a cracked cooling line. keep an eye on it.