Hey guys, my 3.4 has a "white smoke" issue. I swear it's just steam though. Anyway it only happens after the truck sits for several days. If I drive every day or close to it, no problems whatsoever. Coolant and oil hold their levels and look normal. But the other day I start it up after sitting for a few days and get the "white smoke" show and even got a couple codes, 0300 and 0420 (random misfire and catalyst/o2). I have kept the OBDI cat, also fwiw. Runs great after warm up. Codes went away on their own really quick. Sounds like a seep somewhere? Also, coolant dropped in relation to this mess, about 30 oz. Before this episode hadn't dropped at all for months. Truck hasn't sat for so long either.

So here's the other most recent thing, the heater control valve kicked the bucket a few months ago while I was up in Truckee. I was scared it was HG because the thing redlined real quick before I shut if off and the coolant ended up on the ground. Luckily it wasn't HG. It was the heater control valve, relatively cheap easy fix, plus got the added satisfaction that the mech up there ran a vacuum, compression, and chemical test on the coolant system and HG. Everything checked out great, and has run great since. Thought I had inadvertantly solved the minor coolant leak I was having right there. Until what I explained in previous paragraph.

So I am left with a couple scenarios: HG may be slowly dying, which is what most of you will probably say. But my other thought is that the "white smoke" really is just steam, really is normal, and I may have a small seep in the intake manifold, which after several days kicks a slight amount of smoke/steam through exhaust. But if that were the case, why would it take several days to show signs, instead of one or two days?

I think next I pull all the plugs, let it sit, and inspect.

Anybody have any similar issue with a 3.4?? And fwiw I put this post in the swap section because other issues with the old 3.0 stuff may be a factor, like the almost 20 yr. old heater control valve that died.

Also http://www.toyota-4runner.org/3rd-ge...ld-gasket.html that's an interesting read if anyone else is tripping out about this hard to diagnose issue. That may not be an issue. Or not.

THANKS!!!!!

 

ok ill tell you what you dont want to hear you have a blown headgasket You should see no smoke and the eating coolant issue is a big clue.... get ahold of a coolant pressure testor (harborfreight $40) and see if your system holds pressure if not guess what

 

yeah the pressure's good. already passed a few times. i swear it's not a huge obvious thing or i wouldn't be here. i just want to avoid any further issues, and am damn curious to get to the bottom of this. i think i was trippin about the coolant too btw. thanks for your input though..

well this is gonna sound dumb, cause it is. When I checked the coolant and it looked low, the truck was parked on a hill so that the drivers side was higher than the passengers. Normally when I have been working on it lately it is in the driveway, where the drivers side is slightly lower than pass. The rad. cap is on the drivers side if you get my drift. I checked the overflow res. also, and it's pretty full so hopefully the cooling system is holding tight after all. right now it's mega full. to the brim, and yesterday when it was parked dumb i did not fill it to the brim, making me think this theory is sound. told you it was dumb.

and after researching more, I am thinking the valve guide seals may be the culprit, and the white smoke steam is actually oil smoke. This stuff is hard to describe, but I think with the standard steam the 3.4 makes, especially after sitting, after short trips, the additional oil smoke kind of blended in, appearing to be coolant, or "white". and since it was leaking coolant, externally, before the hcv died, i was used to thinking it would be low.

maybe i'll start using high mileage oil or that m1 synthetic everybody seems to like, see if theres any improvement with that. just been using pennzoil 5w30 so far. based on the excellent results I got with BG 44K in the fuel system perhaps a look into fancy oil is a step in the right direction.

i'll keep you posted, but hopefully thats all there is to it.

 

also i do not lose a lot of oil, but it shouldn't take much to make some lingering smoke. also smoke shoe doesn't happen much either, only after sitting for days. so wouldn't seem like it's burning much oil anyway if that's what is happening.

 

ok good luck let us know if mobile 1 fixes it

 

If you're passing coolant pressure tests and losing a lil oil and only smoke after sitting a while thats valve stem seals that are bad.

 

but would that burn a little coolant? there's a burnin coolant smell there too.. I thought valve stem seals were more of an oil burning situation.

It has burnt coolant smell for like less than a mile, then goes away, all systems normal. It's really weird! I think maybe small lead in manifold?

For the record: No coolant in oil, no oil in coolant, no real coolant loss to speak of. Somewhere she's burnin a little bit of coolant though.

Either way she runs great, I don't think it's a quick fix issue, just gonna keep an eye on it I guess.

 

If you're smelling it, I would think that coolant is somehow making it into the exhaust somehow. You might have a small pinhole headgasket leak that seals up when you get warmer.

It is possible that you're getting a little coolant in the intake as well. You can try to a coolant system pressure test and see if you see anything. If you suspect an intake manifold leak or a headgasket leak make sure you take all the spark plugs out before cranking it after pressure testing it.