White smoke! Help!

I have a 1997 4x4 manual trans taco. I am a decent shade tree mechanic. I replaced the valve covers and cam seals and half moons 5,000 miles ago. Sadly, it started spewing white smoke at 244,000 miles. I took it into the shop to have them diagnose which head had the problem but they told me both heads hold pressure (?) and they suspect cracked head or cracked block and also said an oil ring seal was bad. They also said rust on the frame looked like it was pretty bad and told me I should sell it. My question is, what should I do? Should I try to fix it? What could i get for a taco in such pitiful shape? I will post pictures when I get the truck back.

 

As a rival full sun mechanic, I don't have a ton of experience with head or block failure, but white smoke makes me instantly think head gasket.
Given the reputation for being bulletproof, I'd be surprised if the head or block cracked. If you're comfortable doing so, I'd say tear it down to the gasket and see if you find anything along the way.

Frame rot is notorious on these pretty much everywhere but the desert. Post some pics of that and we can tell you how bad it is. That alone may be the deciding factor on keeping or not.

 

What does the 'smoke' smell like? Antifreeze is usually pretty obvious.

 

The exhaust smelled a bit like anti freeze for the past 10,000 or so, but no smoke. This smoke smells nasty. like burning rubber. That's what has given me pause... I feel like a blown head gasket would smell like coolant... then again I've never smelled a blown head gasket.

 

Clearly something is wrong in the engine. If you tear it apart and find a problem you're probably in for at least $500 in parts and labor, not to mention the other stuff that is worth replacing while you're in there.

So lets assume the engine is toast.

What's the rust look like? If its not too bad, you could swap in a new engine and be on your way.

 

Do those engines have a PCV valve? I had one go on an old Accord one time. Was fine when I parked it one night, blew smoke so bad the next day I'm surprised no one called the fire dept. Took it to a mechanic who gave me some horrible diagnosis and said it needed a new engine. I researched it and decided to replace the valve and it was fine after. Valve was less than 20 bucks.

 

I'm sorry, but this is just plain silly. This is like a doctor saying, "Pain your abdomen?" "Right, let's just slit you from neck to nuts, rummage around and see what's doin'!" As mentioned, this will cost you $500 in parts & gaskets and may well not be anything that you can see (can you "see" excessive cylinder wear?)

First of all, is it white or light grey? If it's light grey it's likely oil-related, and if it's white, as mentioned, likely anti-freeze. Start by doing a compression and leak-down test, do a cooling system pressure test, and do a "sizzle test*" on your oil. These are all easy, drive-way tests with inexpensive tools that you can either buy (or often borrow from parts stores at no cost) and will give you a probably 95% certain diagnosis of your engine condition, and altogether will take about an hour.

*Take one-two drops of oil off of your dipstick and drop them onto a VERY hot metal surface (top of a heater, empty pot on the stove, w/ burner on high, etc). If the sample just smokes, then it's pure oil, if there's any water (ie cooling system) then you will also get 'sizzle' and steam as the water flashes off.

 

^^^ What he said.

Start by checking if there is coolant in the oil and oil in the coolant. Does the oil look like chocolate milk? Is their oil floating on the surface of the coolant when you pull the radiator cap off? If so you have a probably have blown head gasket or cracked head. Then pin point by doing a compression/leak down test to isolate the (intake valve leak, exhaust valve leak, coolant leak, ring leak).

But if the frame is toast as well as a blown head/gasket, then I would just part it out.

 

Just where has the truck lived?

How much coolant have you had to add in the past few days .

I guess my nose got educated over the years quite easy for me to smell the difference between coolant and burning oil .

lots of white smoke to the point all you see is a big cloud behind you ?

 

Pull your spark plugs and see if they look normal or have a lot of gunk on them. Check your dipstick and see if your oil level is low, or as mentioned, the colour is milky.

Major rust on the frame is defined differently in high road salt areas and nice dry places like the desert. Those who have never seen real rust sometimes overreact to what is really minor surface rust.

Post pics of your frame and the dipstick. To me, the smoke from an engine burning oil is faintly blue/pale grey. And if you have no oil in the rad or antifreeze in the crankcase, and the smoke doesn’t smell like antifreeze, it’s not a cracked head or head gasket. If the smoking started suddenly, not gradually, it could be a ring problem or it could be valve seals.

 

If its costing you $500 for a new head gasket which should be replaced anyway after 200k miles and some new head bolts, I envy the shops selling you parts. Yes, you can see cylinder wear..... have you ever taken an engine apart?
OP seemed willing to get his hands dirty, so I was just going along..

 

Some people have yet to learn how to see things that after years is quite obvious .

Then those neat inside Micrometers tell so many stories.

It is always a learning experience to pull a engine apart

 

I’ve taken many engines apart (and successfully put most of them back together again). I don’t think $500 is too far off what you would have to spend if you take the ‘bull in a china shop” approach, no. Why not perform a logical series of diagnostic tests and have a decent starting point?

Willingness to get one’s hands dirty is commendable, but my assessment was that if the OP asked the questions he did, he may not have had the experience to assess cylinder condition by looking at it, and probably didn’t have a good set of inside micrometers, dial gauges and the other specialist measuring tools needed.

 

Definitely do a combustion leak test (turkey baster looking tube with fluid) on your radiator. You can rent the tester at a local O’Reillys or autozone but you have to buy the fluid for $10 or so. There’s videos on YouTube how to do it, it’s a good starting point and could save you time and a few bucks vs getting diagnostics done. I just recently did mine and here’s my sad result, the liquid changes from blue to yellow = hydrocarbons in your cooling system (exhaust fumes which means a bad head gasket)

 

I recommend doing this because popped head gasket doesn’t always immediately mean milkshake or anything. Thankfully I caught my bad head gasket early on before it milkshaked or started smoking but I was losing water fairly fast without it leaking from the radiator. I believe the water was going into the cylinders because it would have rough idle at start and eventually cleared itself out and smogged with the cleanest numbers yet, lower than the average range (probably because it was basically water injection lol)

 

Maybe it is worded wrong but if your losing coolant fairly fast but it does not come from the radiator ( cooling system) just where does it come from??

Using straight water no antifreeze??

 

@Wyoming09 Sorry if i worded it kinda weird. I had coolant in it, when the head gasket left the chat, I was on the trail and only had a couple Jerry cans of water so I was using that to get off the trail and get back home. There was no obvious leaks or cracks in the radiator or the hoses which lead me to believe it was a head gasket and not a bad radiator or hose. And by losing coolant fast my overflow was dry and I could see the top ribs of the inside of the radiator within hours. Over the course of the weekend trip and the 3-4 hour drive home it used about 5 gals of water.

 

Ok that sounds much better

 

yeah. White/light grey smoke in a big cloud that leaves a trail behind me. Much worse when giving it gas. The smoke smells bad... like burning rubber or plastic or something. Mechanic told me he did a misfire test and 3 and 6 were misfiring. I think I'm going to pull the heads this week, or next. Take them to the local machine guys and have them deck and check them. I will replace the head gaskets, timing belt, water pump, all other belts, then give the entire bay a good cleaning... anything else I should do while I'm in there? If I have to get a new head it's my understanding I will have to do some shimming? Anyone have any experience with that process? Planning on following worsethanchigger's steps for the head removal, as well as getting a haynes manual delivered. Link to the video series. https://www.youtube.com/watch?v=voLBRDZL9fE&list=PLUdzuNFw-6nlCcguzhKhFyHgQ6PEud5o1

 

I have watched that entire head gasket video series. One of the best mechanical videos I have ever seen. I learned so much.