Needing You Experts Thoughts - White Smoke from Exhaust

Hello Tacoma World Experts, I have a problem, need advice. Problem is I have white smoke coming from exhaust.

Heres a little background on my 2000 3.4 4x2 290k miles. My knock sensor code was on since 2018, I've take to shop twice for that but they said the same thing both times truck runs fine don't worry about it. About 3 or 4 weeks ago I saw smoke from exhaust, I thought maybe the cold, it then started smoking like every 3rd time I started the truck, and it stops smoking some times after about 20 minutes of driving but not always. Well, radiator fluid all fine, have had zero loss, oil is fine, a little loss but normal loss for this truck, about 3/4 quart in 4k miles. Oil looks good no milky look to it, just oil, I use Mobile One full synthetic 20k mile. No oil in radiator fluid, looks good and changed radiator fluid about 6 months ago with Toyota Red. Heater works fine. But the weirdest thing the check engine light has gone off, no code for knock sensor anymore.

I took it to the first mechanic to diagnose, he's worked on truck before, he said head gasket is blown, wanted $7k to replace it, I laughed and said no thanks. Went to AutoZone bought the head gasket tester, did test the fluid stayed blue did not turn yellow, so it's not the head gasket. Even did the bubble test, no bubbles.

Took it to another mechanic, I don't know on Sat, didn't tell him anything, just to tell me what the problem is, he said sticky valve and either blown head gasket or head cracked, if head gasket $4,800 if need heads $6,500. I said thank you but no and then showed him the test I did to see if head gasket is blown, he wasn't impressed with test.

Took it to another mechanic today, he said he would just start tearing the engine down until he found the issue, no price. I said no.

Truck runs fine, no power loss, has never overheated in the 10+ years I've owned it, just smoking, more so when colder than warmer, but it's intermittent not every time and sometimes it stops after 20 minutes. No codes any longer.

I'm not a mechanic, I can change parts, but seems no one knows what's wrong and assume white smoke equals blow head gasket. Google is tired of me googling this and they don't have an answer I can find that's right for the problem.

Any advice will be helpful, I would rather put in a rebuilt engine than spent $7k on head gasket. Also they wanted $300 for a compression test, I thought that was high so said not right now, maybe I should do that

 

Oil smoke will have a blue tint to it. The head gasket tester with blue fluid is not 100% accurate all the time. 3/4 qt of oil in 4k is alot for a Toyota. My guess is being that you ran it so long with a knock sensor issue, it may have melted a ring land on a piston.

 

My guess is your just barely leaking into one of the cylinders.....

A bore scope would allow a peep thru the spark plug hole....

if there's been water there for some time this is what u'll see....

 

If its not too bad leak......barr's stop leak can buy some more time......

 

What does your oil look like?

 

Run a compression test and leak down test.

https://www.pegasusautoracing.com/document.asp?DocID=TECH00137

You can buy the tester tools for these almost any place. If you can unscrew a spark plug then you can run the test.

 

Ok thank you all.. When I took into shop for knock sensor code first time they said it was fine, I "assumed" they were right. Definition of assume is make an "ass" out of "u" & "me", lol. But the second time I was getting timing belt replaced and water pump just bc it was due not bc of problem, a different guy said it wasn't worth changing that it would be ok. Lesson learned.

I've done blue fluid test now 3 times never turned yellow, nor any bubbles in bubble test. On oil consumption, I change the oil every 10k miles with 20k mile oil & filter, it always starts at the top of the dipstick line and ends on the bottom line at 10k miles, oil looks fine every time including now, so that was a guess for me because I put some in one time and it was 3/4 quart low.

I'll try compression test recommended by currygoat this evening. Thanks again

 

Question if i do put Barrs leak stop, will it mess up the engine if that's not the problem?

 

When used in past I wasnt worried about the engine.....however I did by-pass the heater core.....
and stuck in an old radiator......

So at the very least its gonna cost u a radiator to eventually get the ship back upright, if you go that route.....
But.....it did give me extra 2 yrs on my engine, and time to plan my strategy....

I did three treatments.....eventually after about 6mo the white smoke, and the hard hot starts would come back.......That pic I posted of the block is what we found.....#3....o'rusty..

In end of treatment #1 water got in oil.....but caught it....immeditately changed it, and still got another year out of the engine......

Got to realize my situation was I had 3rz engine that is prone to blowing head gaskets.....and I did not want that engine no more....and planned it from when I bought the truck($3K).......

The other 2 engines 2.4 & 3.4 dont seem to be nearly as bad......
so these I would just regasket the heads......if taken care these engines last a long long time.....


Change antifreeze and oil often that's the secret.......
......the pink antifreeze is suppose to last twice as long.....that's counter-intuitive.....and it maybe damaging/etching the gaskets........
If anything you want to change it more often.....

 

I would not run it too long with a bad head gaskets using stop leak or other stop gap measures. The coolant can pit the block deck.
I was in denial with my 3.4 since it only had miss on startup for 1 sec or so. Took a long time for the white smoke to show up. BTW the white smoke on mine is like steam, it dissipates within a few feet of the exhaust. Burning oil is quite different, won't dissipate that easily and I would think will be very smelly. Hold your hand at the exhaust while its smoking (while the truck is stopped only please)and you will know in a hurry if its oil or steam.

When I pulled the heads, the area with the bad gasket had some block pitting between the coolant passage and cylinder but it did not make it to the fire ring. Supposedly this is OK although I serious doubt the new gasket will last as long as the original since water will have a easier time getting into the gasket. I have heard that if you run a long time with a bad head gasket the pitting can extend all the way to the cylinder and then your ship is upside down as Silver Taco would say.

 

The best way is not what you want to hear.
When you ave a bit of white smoke that seems to come and go it could be engine coolant seeping over to the exhaust side of the head. It could be a crack in the head or a bad head gasket. You have 290 thousand miles so I suspect a worn head gasket.
As a prior poster said:
Sneak a cheap remote camera down each spark plug hole and find the cylinder that is burning off engine coolant. You can then determine which head is leaking.

 

The real Question is How many gallons of coolant do you add for 50 miles of driving??

A coolant system pressure tester will let you know if you have a coolant leak

 

I played that game....it wouldnt lose very much for long time....
then all at once you'd see the temp needle max out going down the road...
leak became inconsistent over time....that in itself may of warp the head...