Who's got experience in old 'yota trucks? Or...better mechanics than I...

[Spyder]

Ok, I've never been good at diagnosing problems. I can FIX anything, but sometimes have trouble figuring out just what the hell the problem is. Learning...and every time I figure something new out I know how to diagnose and fix one more thing.

'86 4Runner.
Smokes sometimes, just started, from under the hood. I thought it was a power steering leak that I had never gotten around to fixing, dripping down onto the exhaust. Leak is fixed, still smokes. It KINDA smells like hot brakes, and there is sometimes a 'clunk' from the front end when I step on the brakes at speed, so I thought maybe something had come loose in the brakes and they were getting hot and smoking. Just finished pulling them all apart and inspecting everything, it all looks kosher. The rubber boots on the CV joints are shot, which I know needs to be replaced, but they only turn when the front axle is engaged, right? I'm pretty sure that the half-axles don't turn on this thing unless the front axle is being used...so that couldn't be the clunk OR the smoke issue. The alternator has been acting up lately, because of the power steering leak, which dripped into the alternator. Like I said, the leak is fixed but the smoke is not. Could it be leftover power steering fluid, leaked into the alternator, causing trouble? The alternator just crapped out on me tonight, on my test drive, so that's tomorrow mornings project...I've got a spare that's going to go in, but is it plausible that the alternator has power steering fluid leftover in it and THAT is what is smoking?

Any other ideas of what could be smoking? It doesn't smell electrical, there is no leak in the engine bay other than power steering, which the upper one is now fixed (there is a minor leak down low in the power steering system, but there's no way it gets into the alternator or onto the exhaust), the CV axles shouldn't be turning when 4wd is not engaged and the brakes seem to be just fine.

What else should I check out, what are the chances its alternator-related...?

[Playdrv4me]

Due to your description of the "hot brakes" smell, it sounds electrical, and could very well be unburned fluid in the alternator. Obviously I dont need to tell you that could be a fire hazard of course.

Besides that maybe valve cover gaskets.

[Night Wolf]

auto or manual locking hubs?

If auto lock, front axle only turns in 4wd

is manufal, and unlocked, front axle will never turn, even in 4hi/4lo (which would then be 2wd lo)

If manual and locked, then they will turn all the time, even in 2hi

it COULD be residual, but I would think it would have burned off by now.... who knows, when you replace the alternator I'd see if its still there.

I too have a power steering fluid leak on the Isuzu.... durring one of my off-road adventures I was a bit hard on her.... went thru a huge water "puddle" and stuff... something jared something around cause now my p/s pressure hose squirts fluid out one of the crimped couplings... its not that bad, I just have to top it off about once a week. I did buy a new hose, but haven't gotten around to changing it yet.... it runs fine and besides just adding fluid now and then, works fine, so I've got other things to worry about right now.

p/s fluid is basically ATF.... does it smell like ATF when burning? Also, IIRC ATF burns white.... what color is the smoke?

[Spyder]

Originally Posted by Playdrv4me

Due to your description of the "hot brakes" smell, it sounds electrical, and could very well be unburned fluid in the alternator. Obviously I dont need to tell you that could be a fire hazard of course.

Besides that maybe valve cover gaskets.

Haha, yeeup. I've always had a fire extinguisher with me in the truck. Now it rides shotgun instead of behind the seat.

Originally Posted by Night Wolf

auto or manual locking hubs?

If auto lock, front axle only turns in 4wd

is manufal, and unlocked, front axle will never turn, even in 4hi/4lo (which would then be 2wd lo)

If manual and locked, then they will turn all the time, even in 2hi

it COULD be residual, but I would think it would have burned off by now.... who knows, when you replace the alternator I'd see if its still there.

I too have a power steering fluid leak on the Isuzu.... durring one of my off-road adventures I was a bit hard on her.... went thru a huge water "puddle" and stuff... something jared something around cause now my p/s pressure hose squirts fluid out one of the crimped couplings... its not that bad, I just have to top it off about once a week. I did buy a new hose, but haven't gotten around to changing it yet.... it runs fine and besides just adding fluid now and then, works fine, so I've got other things to worry about right now.

p/s fluid is basically ATF.... does it smell like ATF when burning? Also, IIRC ATF burns white.... what color is the smoke?

Manual locking hubs, IFS front end. Hopefully its residual. Just got the alternator warranty'd, gonna replace it after work, where I'm heading now. I must say this town I live in is one of the most bike unfriendly I've ever lived in...bastards tried to kill me about 18 times on my ride to the parts store just now!

[dkozloski]

Where you from, boy? A old pickup is supposed to smoke. If it ain't smokin' it ain't runnin'.

[Spyder]

Haha...its not old...just getting broke in! Four hundred thousand miles and counting!

So, after replacing the alternator, push starting it up in front of the house because I drove it last night till the battery died, running it around the block and bringing it home to idle in the driveway, it died. Wouldn't start. No spark.

Decided now is as good a time as any to replace all the wiring I've been meaning to work on for the last six months. Ripped it all out, rode my happy ass up to the parts store with a backpack on, bought battery cables, wire, a new battery...etc etc etc...came home, replaced a bunch of crap, pulled a plug wire to see if I had spark and yanked the boot off. Break time!

Found ALL kinds of loose connections and bad wiring that is now replaced. Ground wire from the alternator wasn't tight to the block, which I'm assuming, now, was the original charging problem. Oh well...brand new alternator didn't cost me anything, replaced under warranty. Only took my time and effort and sweat and curse words. It's hot outside and I've drank a helluva bunch of water.

MacGuyver'd it back together enough to drive it to the parts store for a set of plug wires, now letting it sit in the driveway to cool down and eat lunch. Got stung by a fawking yellowjacket, cussed and swore some more, rode to Lowe's, bought twenty bucks worth of wasp killer and went on a seek and destroy mission. There's more flying around, but I can't find 'em. Later, I'll finish the job.

Seems to be running peachy, havn't noticed any smoke in the short drives I've done so far. Hopefully it WAS the alternator/power steering fluid fiasco...

[DILLIGAF]

Make sure and replace those cv shafts soon! Do not just put new boots on,if the rubber is cracked the bearings are to far gone.Are you downshifting when hard braking?Stock motor mounts?400,000 miles is asking alot of that transfer case too,they used to be rather easy to find.Most suspension clunks on toys will show itself real quick on your tires.

[Spyder]

Yea...I've been needing to replace them for QUITE some time... Motor mounts are a possibility for the clunk, I'll check that out... Tires actually seem to be wearing rather well, even and not-too-swiftly. I can't see any funny wear patterns on them...

I don't expect the thing to last forever...if it breaks to the point where its too much to fix it, I'll sell it off and buy something else. Newer, preferably with a warranty. Until then, a hundred bucks every two months is about all I'm willing to spend in repairs!

Seems to be better. Drove it about fifty miles today with no smoke and no alternator trouble...rewiring job looks beautiful, in comparison to before. Clunk is still there in the suspension/brakes, but that'll be for another day.