Truck is blowing out smoke but my compression&combustion test came back good

I drive a 2002 sequoia SR5 with 240k miles. RWD. I post here because it's essentially the same truck, but more traffic on this forum.

The truck started puffing out a ton of smoke on the interstate, so I pulled over and while at idle it looked like a forest fire. I looked at my oil, it was a whole quart low after just changing it 3 days before (and I'm 100% sure I filled it up with the correct amount, I had been using mobile1 religiously, but decided to change to Pennzoil after watching a project farm video ) I topped it up with an extra quart, and After deciding to drive the extra 5 miles home and chance it, the smoke stopped once I got back up to interstate speeds. But now it only blows out the smoke on start-up, I've driven it around the block once or twice to check on it. I can't figure out for the life of me why my truck is blowing out smoke on start-up, sometimes it looks blueish, other times it looks white. My oil doesn't look frothy or dirty, my coolant looks clean and full. I looked for an oil leak and couldn't find one, nor did my cardboard have any oil drops after letting it sit overnight.

When I did the combustion test the liquid stayed blue, so that's good.

Below are the numbers from my compression test.

Cylinder 1- 200/225
Cylinder 2– 165/195
Cylinder 3-200
Cylinder 4-230/225
Cylinder 5– 200
Cylinder 6– 200
Cylinder 7– 160/190
Cylinder 8– 210

I ended up running the numbers twice on the ones that were real low/high because I wasn’t sure if I actually gave it time to reach its top PSI and weirdly enough the second time on the ones that I ran that were low ended up coming back higher.

Was I wrong to run the numbers twice on the ones that seemed “off”? Part of me was just praying and hoping that maybe I didn’t tighten the compression hose in tight enough or that I didn’t give it ample cranking time.

Also, the spark plug from cylinder 3 was covered in oil, on the screw side. What does that indicate? Picture below

Here are the codes from the OBD, they all mention something about O2 sensors, the codes have been on for almost a full year now ( I know I know, not the best idea, but money had been really tight this year, and a "shade tree mechanic" told me not to worry about O2 sensors, they are "only there to help get ya' a couple more miles on a tank")
P0135
P0155
P0161

I have the truck parked until I can solve this issue, but I am at a loss of what to do next.

 

Bad advice from the mechanic. Your O2 sensors are responsible for efficiency by helping the ECU figure out the best fuel trims. When they fail, the default is rich, which ends up clogging up your cats over time. O2 sensors would cost about $60-80 each for a total of $300 or so to replace them all. Your cats are around double that a piece and there are 4 of them. Also, Getting 11mpg instead of 15mpg due to failed O2 sensors costs you money constantly. Would need more info on your smoke situation and what else has been checked to help more. Have you checked the power steering valve? Have you checked the break booster? Have you read the mega thread???

https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

 

I checked the power steering valve already with a que tip, and no liquid came out, same with the brake booster. I dont appear to have a loss of any fluids whatsoever. Also, I changed out the PCV valve, which was very dirty, but that didnt seem to help with my smoke show situation.

I am about to read the megathread now. Thanks

 

I've not experienced this with my Tundra, but years ago I had an old Pontiac and it would blow huge clouds of smoke out on startup. Issue on that car was the intake manifold gasket had gone bad. Might be a possibility.

 

UPDATE. it seems like everytime i crank up the truck there is less and less smoke. I guess thats a good sign right? Maybe at this right if I drive it daily, next week there wont be any smoke LOL... wishfull thinking

 

If that's what you're finding, that the smoke only lasts for the first couple of seconds/minutes, and is less smoke if you fire up daily vs. weekly, it could be a sign you've got a leaky injector.

That is to say, you have one injector that slowly leaks gas into the cylinder after shutting off the truck, and when you start up, you're running abnormally rich until you fully burn out the fuel, causing excess smoke out of the tail pipe.

The only way to prove/disprove this, or figure out exactly which injector it may be definitively, would be to let the truck sit for a few days, pull all 8 plugs, and use a borescope thru the spark plug openings to look for fluid in the bottom of each cylinder.

Granted, you could also just replace all the injectors with new OEM injectors and see if the problem subsides. The couple of people on here I've seen refresh their injectors after 150k+ miles have reported back that the truck runs waaaay smoother than before.

I suppose if you lack a borescope/snake cam, you could get one of those really-long Q-tip swabs on a stick, and stick it down into each spark plug hole, and if you come back up with one that's soaking wet and reeking of gasoline, and it will ignite with a flame, that could be a good indicator. But I'd prefer to see what's in the cylinder. You could also look for scoring of the cylinder walls and other such stuff.

 

Burning oil, smoke at start up, good compression and nasty looking plug sounds like a valve seal to me. You could always do a leak down test and try to find where the air escaping (intake, exhaust or air bubbles in coolant lines).

 

I forgot to mention as well. That the smoke starts off blowing blue for about 10 seconds, then it stops blowing for about 5 seconds, then it begins blowing out white smoke

Also, is replacing injectors a job that a beginner would be able to do? I have tools, but i only know the basics.

 

Blue would be oil, white would be gas. You may be in over your head, that’s ok. Trouble is. Trustworthy mechanics are hard to find. Shop hours are how they make money, and they are very stingy with taking time to diagnose something that isn’t a CEL triggered solution. Actual mechanic work. Oil in the combustion chamber can come from a number of places, worn rings, bad valve seals, head gasket etc. leak down test can help determine that. The white smoke leaking fuel into the combustion chamber only comes from one place. Injector. This is assuming you’ve ruled out the PCV, the power steering valve and the brake booster as possible sources of oil ingestion.

 

Well I just put a new PCV valve in, and still having issues

So at this point I need to do a leak down test.

I took a que tip and stuck it inside the vacuum hose on the brake booster, it came out dry. Is that enough to test out the brake booster or is there something more i should be doing?
I did the same thing with the power steering valve, stuck a que tip into the 2 hoses, they both came out dry. Is that a good enough test?

I do have an appointment with a mechanic in town who has a great reputation with Toyota drivers. But in the mean time would love to do as much "digging" as possible (and hopefully even fix this problem myself so i dont have to waste money at a shop)

Let me know what you would do in my shoes.

 

Valve steam seals are worn. Blue smoke on startup that quickly goes away is the usual sign.

Change oxygen sensors, they are vital, especially upstream ones.

 

poor o2 sensors are probably caked in oil and soot....not to mention the cat converters too.

 

In order to “probe” your brake booster, you need to get a “dipstick” down inside the booster body, not just into the tube or opening. Many use a zip tie as it’s flexible, but rigid enough to direct.

 

So take the vacuum hose off the brake booster/master cylinder (sorry they are the same to me since they are connected lol I’m a beginner) and stick a long zip tie as far as I can into both openings (the hose and the metal hole) and check zip tie for any liquid?

 

The zip tie will go into the booster and point down towards the bottom to see if any fluid is pooling down there

 

My trucks been sitting all day long, should I check it now or after a short drive?

 

Is it possible that all this smoke could be caused by o2 sensors

 

Now is fine.

 

I don’t see a correlation. Upstream sensors measure the exhaust contents once it leaves the block to understand if the engine’s air/fuel mixture is OK. Speaking generically, if reporting it’s too lean, ECU will add more fuel or less air. If too rich, the ECU will cut back on fuel or add more air. There are other working parts here, like if the MAF is reporting the correct amount of air coming in, and the ECU can correctly read the throttle plate position, speaking at a high level.

O2 sensors wouldn’t explain blue and white smoke for me. It also wouldn’t explain what looks like a considerable amount of oil on that one plug, which is the cylinder likely responsible for all that smoke if i had to guess. That’s oil, not gas, right?

 

Check engine light is burned out, I scanned my codes here they are
P0135
P0155
P0161

 

Sorry, yep, i just scrolled up to read that. And i edited the last paragraph of my post with more thoughts in response.

 

That is oil on that plug yes. That plug also was so worn down the ring thing ….uhhh, WASHER (sorry I’m still learning) came off it

 

And yes, you should probably replace the upstream and downstream sensors with new Denso brand sensors. But I wouldn’t spend that $200-300 on sensors (parts only) before understanding what’s happening in the engine. Hell, if you pull the negative battery cable for 10mins to reset the ECU and force it to re-learn, then unplug the upstream sensors before starting it, if the truck will start, and it continues to blow smoke, it has nothing to do with the O2 sensors.

 

I unplugged the battery resetting it after compression test and it didn’t blow smoke. But that’s thing the, the smoke is completely random. Usually yes it’s on start up, but sometimes not. Also it will randomly smoke show when driving (usually right after getting off the interstate or while still on interstate driving)…
the smoke is like my alcoholic father, shows up whenever it feels like it

 

Not at startup. O2 sensors are not relied on during open circuit (cold start up) status.

 

I just dropped it off this morning with a mechanic that’s got a good rep in my city for working on Toyotas. He said after I explained to him, that he thinks it’s a head gasket failure. (I guess the blue liquid test lied to me lol)

anyways, if it’s really a blown head gasket, I honestly and simply put, do NOT have the $6000 to fix it (that was the quote I got) even if it’s a grand or two cheaper, I still won’t be able to afford that, no matter how hard I try… that is why I’m about to ask the next question…

what would be the best head gasket sealer to get me another few months out of the car while I save up for another? I know I know, they are all snake oil and can mess up your car even more. But Chris fix has a video where it helped his dad’s jaguar last another 2 solid years.

trust me if I had a different option I would take it, im stuck in this predicament even though I took great care of of the truck. I did everything right, changed the water pump and timing belt, changed the LBJs, religiously changed the oil every 5K with high quality synthetic… the list goes on…

now back to the head gasket sealer, there are so many options. I’ve done a bit of research, and blue devil sounds good. Chris fix used barrs in his dad’s car, but the barrs was because the car was over heating and needed one that could work quickly. But my cars not overheating so maybe there’s one that’s better for my situation?

 

That would make sense, head gasket, given the alternating smoke colors, and variability of it all. I didn't want to be the one to say it, though. Mostly because, if (A) your oil and coolant levels are remaining the same, and (B) you don't have oil in your coolant or milky oil, head gasket doesn't make a ton of sense. If you're burning/losing either into the cylinders, or into one another, at least one or the other's level has to change, right?

Head gasket failure can happen for a number of reasons, but on the 4.7L and 5.7L, if you look at the head or its gaskets and see proximity of water passages to cylinders (see pic below, 4.7L block, note the blue circles) there's not much gasket material separating coolant/lubricant from the cylinder, which isn't necessarily uncommon. The head gasket is multi-layer too, as the other pic below that shows. The Toyota guy, CarCarNut, his professional opinion is, doing ignorant shit like using old coolant or the wrong coolant erodes that thin section of head gasket and the rest is history, you've got stuff leaking into the cylinders..

Head gasket sealers aren't snake oil, not like cat cleaners are. What they are, really, is a point-of-no-return. A self-destructing crutch. A stopgap that gets you by long enough to swap the engine. They often do irreversible things to the engine that will permanently affect it (at best) and ultimately kill it eventually. If you use one, you MUST change your driving habits, because doing something wiley like jumping on the gas, can cause the repair to blow out. Any product that Bar's sells (Bar's Stop Leak, Bar's Head Seal, etc.) is something you can generally trust, but the main thing I'd impart upon you is this: Read the directions and follow them to the letter. Once you add it, there is no turning back. Using it is only a stopgap measure to get you through until you can swap the engine. Don't be a fucking asshole and sell the truck to an unsuspecting victim as if it's OK (you may be legally liable depending on your state laws). If you honestly need this truck to last you a few more months, you MUST change your driving habits and baby the truck. I wouldn't do back-to-back treatments if it fails 2-3 months from now.

EDIT: Actually I'm stealing a 4.7L block pic from another member here, VVTi based on the (red circle) mount points for SAI pump. This will give you a better idea of how few millimeters there are between the passages and the head. Looks like you have as little as 3mm of gasket separating you at some points.

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OP, can you maybe just keep all of your questions and posts about this to just one thread? It's hard to figure it all out with the 6 different threads you have going on.

 

Makes solving the puzzle more challenging, but not more interesting, or more engaging.

 

I truly do apologize. I'm having a bit of a panic attack with all that is going on. Most forums the threads go dead and you have to make a new one if you want answers, im finding out that this website is different and has some very great and knowledgeable people who are willing to help. Sorry, its hard not to sit and wonder all day long about what direction my life is about to turn. I'm not in the position to afford a another car, let alone a head gasket repair.

it looks like I will need to use a head gasket sealer to get me by for the next couple of months. the thing about that is, I have no idea what brand to use. So many conflicting opinions online about which brands are good and which brands will ruin your engine.

Can someone please suggest which brand would be best for me? here are a few details that might help sway your decision one way or another

1:My truck is NOT over heating
2: The coolant is full, and appears clean (I checked from the top. the revivor, and from the bottom by draining some out)
3: The oil appears clean, I've checked several times. the oil fill cap is clean as well

Another few questions, I heard that I should "block off the heater core" when doing the sealant treatment, how do i go about doing this safely? Please explain to me like I'm a true beginner because I am. Does this go for every brand of sealant or just some?

I was also told to remove the thermostat. That's easy, I've replaced the thermostat in my truck a few years back, so i guess just simply remove it before doing the sealant than after the treatment replace it?

Do I need to turn my heat all the way on full blast while doing the treatment?

Any and ALL advice/tips are welcome and greatly appreciated. I hope I run into you guys one day in person because id be buying everyone lunch or a round of drinks.