Misfire on Cylinder 8 and Oil in Intake Pipe -Investigation and Engine Swap

[2001LC]

Bummer!

I was hopeful you had not top oil properly last change, and exaggerated how much oil was coming out of air pipe. But apparently you did not, and know what you're doing.

I'd scope # 8 first thing. If cylinders wall scored, I stop there, to save time. Then start looking for a replacement engine. If #8 not scored, I'd move on to compression test rapidly of each cylinder, while still hot. Then wet, followed by leak down testing. I then scope any cylinders that fail testing.

 

[awesomeissquid]

Bummer!

I was hopeful you had not top oil properly last change, and exaggerated how much oil was coming out of air pipe. But apparently you did not, and know what you're doing.

I'd scope # 8 first thing. If cylinders wall scored, I stop there, to save time. Then start looking for a replacement engine. If #8 not scored, I'd move on to compression test rapidly of each cylinder, while still hot. Then wet, followed by leak down testing. I then scope any cylinders that fail testing.

I had originally hoped I had not topped up properly as well, but once the consumption continued I knew something was serious.

I actually did scope the cylinder in question back in 2020 when I bought the truck and replaced the spark plugs. I found broken timesert threads in the cylinder with impacts visible on the piston head and scoring on the cylinder wall: Thread - Tapered Seat Spark Plug Horror

Here are the views since the links in the thread are broken:

• Cylinder Wall Scratches
• Piston Head Impacts

Here is a view of the threads I found on top of the piston.

Image from original engine with assumed blown piston in cylinder #8

Since then I have had put ~6k miles on the engine and never had any need to top up/add oil when I checked it before this trip. I guess the engine was on borrowed time already and something pushed it over the edge.

I will probably still run a compression and leak down test to confirm my assumptions and since it is a good learning opportunity. I will probably also still pull the head to look at it first hand and to confirm it is beyond repair. I am slightly anxious about finding a good replacement engine....

 

[2001LC]

Hope you got a deal, on the 2000.

 

[awesomeissquid]

Hope you got a deal, on the 2000.

It was a good price, but if I had known about the timesert or the cylinder condition I would have walked or asked for more off. Just kicking myself because I asked the shop that did the PPI to do a compression and leak down test and the mechanic talked me out of it. Lessoned learned.

 

[awesomeissquid]

Weekly update on this. Work kept me busy over the weekend so I didn't get around to testing my current engine. Planning to at least compression test and scope it tomorrow to see what I find.

On the replacement engine front, I found an interesting engine in the LA area and planning to go see it on Friday (anyone want to give me a hand looking at it to make sure I dont miss anything?). Was serviced at a dealer every 5k miles with the last service about 4k miles before a rear, side impact totaled it. Fingers crossed it is in good shape and I will bring it back home for the impending swap.

 

[2001LC]

Sound like you've found a very good engine prospect.

I do PP inspection. It is not common, to do compression testing or scope cylinders during PPI. But if a see certain service performed (in some cases. not) in history. I have on occasion recommended compression testing. Last one I recommended failed. It does cost more, and I require permission of seller. to do these test.

Number one reason I put out below spark plug alert, is risk to cylinder(s).
The common fix if they blow, is Time=Cert! More often than not, the install of time-cert will contaminate cylinder.

Ticking time bombs!

Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert!

TICK TICK TICK POP POP POP is a ticking time bomb, often mistaken as exhaust manifold crack or gasket leak leak. ALERT, ALERT, ALERT: Spark plugs are working themselves loose. "Walking Out" Then blowing out of head, taking their female threads of head with them! Very damaging! You think TICK...

forum.ih8mud.com

Spark plug blow outs, do not in themselves damage cylinder walls. It what falls in afterward. Which in case of time-cert, is all to often metal shavings doing the most damage. Just like we see in your picture @awesomeissquid. Had you shown that cylinders picture and mentioned metal found in cylinder, in first post. No doubt, many would have pointed you in that direction.

Another case developing, of time-cert issue:

I've a mud member, bough me his low miles very clean 01. He'd taken to a shop in NoCA that specializes in Land Cruiser's, just after purchasing it! He wanted the very best for his new rig> So did his homework and found and drove many hours to that specially shop. Sorry to say "they" made a mess of everything they touched. He's broken down on the road, forced to hotel it numerous times since they worked on it.

I've been sorting things out. One thing I can't do anything about is a time-cert in a BK2 cylinder head. Seems the NoCA shop replaced head cover gasket and tube seals, needlessly IMHO. Regardless, while in there, they did not replace or even check the spark plugs. It had to have been, ticking even after warm up. Sure most would think, an exhaust header leak "tick". But it was not! He blew a spark plug ~ 100 miles later. First shop a dealership after the blow out, said, new engine needed. He towed back to NoCA shop. They said no problem, "we see plugs blow all the time". They install a Time-Cert free. Nice guys, right! Only charged him for new spark plug and coil, what a deal!

Well, after reading history. I recommended we check compression. Sure enough, time-Cert in a BK2 cylinder, now has low compression (20PSI lower than average of others). I also found #1 spark plug tube seal (blue after market) leaking badly. It was not fault of shop, it blew a spark plug. But really, they see a lot of "spark plugs blow" (their words, told to me) and put in many time-Cert all the time. WTF! They should have checked the spark plugs while coils out, IMHO. I'm mean really, they'd not yet figured this out. Denso are walking out of the 4.7L. I know that shops reads the forum and regular post in mud. I'll not give out their name, so don't ask. But if I hear, of a pattern from this shop. I 'll let their their name be known. Everyone has bad days. I hope that all this was.

I've had this owner watching fuel trims. Unfortunately, seems BK2 is changing, for the worst. We may go down same road as you @awesomeissquid.


Here's the Tube seal caught on spark plug tube I mentioned above. Seal is sliced and pushed out above tube. Can't see well, but color is blue, OEM ore not blue.

 

[awesomeissquid]

Scoping the new engine. Seeing a bunch of carbon build up. One or two minor scratch makes on two cylinders but can still see the crosshatch. Thoughts? Photos from cylinder 5

Images of replacement engine pre-purchase.

 

[awesomeissquid]

Images of replacement engine pre-purchase.

Cylinder 7

 

[awesomeissquid]

Those are two of the worse ones. The rest have some carbon but not seeing any scoring. All cylinders seem to have very good crosshatching visible.

 

[awesomeissquid]

Realizing I can’t really do a compression test by hand. Got two cylinders to 90psi but couldn’t get it any higher. On the third I got it to 60psi. Lost track of counts and didn’t have the energy to keep trying. Going to find out more info about the warranty and thinking about taking it back home to connect it to a battery to compression test that way.

 

[2001LC]

Looks good! Not perfect but good. May look even better after you run the engine a few 100 miles.

BTW: What scope are you using? Looks better than my for sure!

 

[awesomeissquid]

Well went for it! All wrapped up and packaged.

Got the engine with all accessories for $2k. My dad and uncle are pushing for me to pull the heads off to remove as much of the carbon buildup as possible and to get a better look at the piston heads so we can see if any of those or the rings need to be switched. Going to ponder that over the weekend. Now the fun begins with figuring out what to replace and what to swap over. Fun times for sure.

Tomorrow I’ll take some more pictures of all the cylinders to post.

 

[BnvS]

Good luck buddy.. sorry for the pointing you down the wrong tree.

 

[awesomeissquid]

Ended up getting back way later than I thought I would last night so today was spent setting up. Picked up an engine stand and engine hoist. Then just as I was getting ready to unload the engine I realized I needed bolts for the bell housing. They are M12 with a 1.25 thread pitch if anyone needs it. After picking those up it was too late for any other work so more to come tomorrow.

Picture of the nice present all unwrapped.

Looks good! Not perfect but good. May look even better after you run the engine a few 100 miles.

BTW: What scope are you using? Looks better than my for sure!

The scope is a Vividia VA-980. It’s pretty good but definitely doesn’t compare to the more expensive options I have tried. I think I also got an older model and the newer one is suppose to have a slightly higher resolution.

Good luck buddy.. sorry for the pointing you down the wrong tree.

No worries at all! I really do appreciate your suggestions. It can’t hurt to try anything that might be a solution. It’s all a learning experience for me and I’m having fun so that’s all that matters in my eyes.

 

[awesomeissquid]

Spent some time with the replacement engine tearing it down and inspecting it some more over the past week. Drained the block of any remaining oil and coolant. Oil looked like oil and the coolant looked like a fresh pink color which makes sense since it was shown as replaced at the dealer 2yrs/26k miles ago.

Here it sits minus the wiring harness, some of the timing belt covers, and some other stuff. Planning to sell the wiring harness, throttle body and any other unnecessary parts after this is over. Timing belt is a Toyota branded one.

Found the RH cam seal leaking a bit, but the LH side looked pretty good. Will take care of that one when I pull the heads.

All the injector grommets looked pretty rough so those will need some care. Still undecided if I should send the injectors out to get serviced.

As expected, all the valve cover bolts were loose and barely hand tight. This caused some of the oil leaks I found. One of these leaks was causing the cylinder 1 exhaust port to be coated in oil. Must have been causing some smell, and I was surprised to find it given the previous owner was at the dealer for service every 5k miles. The color of the manifold at the elbow makes me think it got pretty hot.

Some of the Toyota branded parts I acquired with the engine are a power steering pump which might be original that looks better than mine and an original alternator. The AC compressor is branded Denso so that must have been replaced at some point to deal with the LA heat. The starter is a Toyota branded Denso remanufactured that was replaced 7yrs/100k miles ago. Ill plan to inspect and rebuild it as needed. It does look to have some oil on a lower boot connection so not sure where that came from...

Next up on the agenda is to scope each of the cylinders again and to run a compression/leak down test.

 

[awesomeissquid]

Made some progress on testing the current engine that is in the truck and oh boy is everyone in for something special.

Started by pulling all the coils/spark plugs and removing the drive belt. Then went to town with the borescope to document the condition of each cylinder, piston, and the associated valves. Here is the view of the cylinder 1 and 5 piston heads and the cylinder 5 valves. All the others (besides cylinder 8...hint hint) looked pretty similar.

Images from original engine with assumed blown piston in cylinder #8.

Cylinder 1 Piston Head

Cylinder 5 Piston Head

Cylinder 5 Valves

Everything was really caked in oil which makes sense given it consumed like 5 quarts over the ~150ish miles as I tried to limp home. As a bonus, cylinder 5 had some intense polish marks 180 degrees opposite each other. I'm assuming this was from the engine running low on oil at one point causing extra wear. If anyone wants to chime in if this is right or another cause I would love to learn more.

Cylinder 5 Polish Mark 1

Cylinder 5 Polish Mark 2

Now for the real treat, cylinder 8, where some real messed up stuff turned up. At first look, the piston appeared cleaner than the others, so at this point I'm assuming the head gasket leaked some coolant into the cylinder and steam cleaned it just a bit, maybe? The valves also looked different from the rest so idk .

Cylinder 8 Piston Head

Cylinder 8 Valves

Without much else that I can investigate without pulling the head I decided to go forward with a compression test and a leak down test. Since I was lazy and didn't want to reassemble the engine to heat it up to operating temp to take it apart again I decided to do the compression test cold. Before starting, I pulled the EFI fuse and relay to ensure no fuel got delivered; it worked. Cylinder after cylinder came back looking pretty good until I got to cylinder 8 and got a big fat zero. Here's a full breakdown of the compression numbers:

Cylinder #	Pressure (PSI)
1	210
2	205
3	190
4	203
5	189
6	200
7	210
8	0

Moving on to the leak down test for cylinder 8 I set the cylinder to TDC and pulled the radiator/oil filler caps and pressurized everything to 90 PSI. Surprisingly no bubbles in the radiator neck, but I did hear a ton of noise coming from somewhere. Opening the throttle body valve and noise could be heard there, so maybe a stuck intake valve. But, I still was hearing a ton of noise near the cylinder itself. Feeling around in the area, I believe I found air leaking past the fuel injectors. Pretty sure this makes sense since the fuel injector is inline with the intake valve. At this point there really isn't anything else I can do so I pack up.

Reviewing the pictures at the end of the day, something just seemed off on cylinder 8... Did you notice anything? Lets try another view:

Cylinder 8 Piston Head Closeup

Well that large black space shouldn't be there! Seems some of my piston head has disappeared.

Looking forward to disassembling this to get a first hand look.

 

[ClassyJalopy]

Love this kind of investigative work! 2UZ -FE don't just give up and quit easily so this is a very good insight into a rare failure

 

[2001LC]

I'm surprised at the high cold numbers. I get ~150PSI cold, hot engine ~185 PSI, in the Miles high city.

Likely, you'd hear air blowing from your oil fill cap tube.

 

[awesomeissquid]

Love this kind of investigative work! 2UZ -FE don't just give up and quit easily so this is a very good insight into a rare failure

Happy to put my unfortunate series of events on display for others to learn from.

I'm surprised at the high cold numbers. I get ~150PSI cold, hot engine ~185 PSI, in the Miles high city.

Likely, you'd hear air blowing from your oil fill cap tube.

Agreed, it was a bit higher than I would have expected. I think there was still oil from driving it a few weeks ago around the top of the piston rings since I saw some glistening as I was manipulating the borescope, so I guess this could have been considered a wet test.

I did check the oil filler cap tube and did not hear anything escaping from there. I agree that with the chunk missing I would expect to hear some serious air leakage from that. My running assumption for now is that with the intake valve being open and the spark plug tube seals being leaky, all the air is escaping through those two avenues before it makes it to the oil fill cap tube.

 

[2001LC]

If valve burnt (can't see whole valve in above picture), should see with your great articulating camera easily. You may need to be on intake/exhaust stroke, to have their valves open, if minor newer leak of valve or it's seat.

One very difficult part of leak down test. Is setting target cylinder to TDC compression stroke. I do by feel, keeping air pressure lower as I turn crank. Around 30 PSI I can just barley turn crank with 1/2 ratchet, as I come up on TDC compression stroke of a good cylinder. If I stop a little to much before TDC (BTDC) of target cylinder, and kick up pressure to 90 PSI. Crank may turn CCW, as piston pushed back down from pressure. Pasted TDC, crank may turn CW. Hit that just right spot and crank holds as air pressure increased. If I can turn 720 degrees, at 90 PSI with no back pressure on ratchet, I've a bad cylinder. One can turn crank 720 degrees, while just listening at oil fill tube, in that event. I always hear some air sound at oil fill tube, when valves closed even good cylinder in a cold engine. When rings not sealing as they should, a bad cylinder at TDC Compression, I hear much more air sound than I do from the good cylinders.

By looks of piston and cylinder wall of #8. I would have "bet" you'd hear from oil fill tube.