Rebuilt Motor - Failure. Hypothesize (1 Viewer)

[concretejungle]

This is a tuff pill to swallow and I'm still kind of in shock over this. Took my cruiser to a friend of mine for a "tune-up" since I've noticed that she is not running right. Ruff idle, hard time starting it, loss of power, even worse gas mileage than the already horrible gas milage. I thought maybe I had an intake or exhaust leak or something minor. I'm a lot more busy these days with my career and don't have the same time to mess with it on my own like I used to have. He called me to tell me the bad news, he said he did a compression check and my compression numbers are between 60 and 130. He did a leak-down test and we have air coming from the exhaust, the intake and the oil fill. So rings and valves are leaking.

Back story is about 10 years ago I completely rebuilt the motor with the help of a friend who had tons of motor rebuilds under his belt. Took the block to the machine shop to have it "cleaned up" and plained since the machinist said the block was in great shape and you could still see the hatch marks from the factory. He cleaned up the head because he said the valves didn't need to be re-ground. Put a cometic HG on it with ARP fasteners. Sent the injectors off to be cleaned. New water pump, all OEM parts, ect.... After that I put a TRD supercharger on it.

Have made 4 trips across the country and many, many trips in NC and the east coast. Never had a hotter water temp than 205 degrees, changed the oil like clock work, always run premium fuel. I figured that this motor rebuild should outlive me!

So I'm trying to speculate on what could have happened to cause this?! Why would the rings and the valves be out this soon? Even though there's 10 years on the rebuild the milage is probably only around 50,000 miles. He said he noticed the plugs were very dark with a lot of carbon indicating that it was running rich.

Could the supercharger be to blame? Contemplating what mistake, if any, was made and trying to avoid it in the future. Right now there's no real good "cheap" fix. A rebuilt motor isn't cheap, then add the time and labor to remove mine and put the new one in. Replace with a used motor, I don't think that's the best option because I rely on this truck to take me to remote places and get me home. Spoke with Cruisers and Company about a new motor plus turbo. Considering a new motor and putting my supercharger back on. Just not sure what direction to go at this time, but I can't help but wonder if the supercharger deserves blame or what.

 

[COYS]

I’m bummed for you dude. I’m at 27k miles into my 1fzfe (100% new OEM from bottom to top) and I sometimes wonder if this unit will reach the og factory assembled 278k/24yr benchmark.

I placed my money/bet on not mixing with any aftermarket parts whatsoever and not reusing anything except for the valve cover.

Good luck! This too shall pass.

 

[family80]

Just clarifying the head wasn’t rebuilt just cleaned? Did the pistons and rings get changed?

 

[concretejungle]

Just clarifying the head wasn’t rebuilt just cleaned? Did the pistons and rings get changed?

Correct. The pistons got new OEM rings when I did the rebuild.

 

[SHIfTHEAD]

He said he noticed the plugs were very dark with a lot of carbon indicating that it was running rich.

If it was running way too rich then the cylinder walls could have been washed down from oil which could either burn them up or cause low compression, I believe.

The head needs to come off to really know what's wrong, IMO. Or at the very least get a camera down in there to inspect the cylinders and valves.

 

[concretejungle]

If it was running way too rich then the cylinder walls could have been washed down from oil which could either burn them up or cause low compression, I believe.

The head needs to come off to really know what's wrong, IMO. Or at the very least get a camera down in there to inspect the cylinders and valves.

That is a theory that my mechanic brought up and I think that's pretty valid. the more brain juice I put into this I feel like since valves and rings are out, must have been a lubrication issue. If it was running rich then I could see the oil being "rinsed" away so it was not doing its job.

Dumb question but why would it run rich? I can't adjust the fueling in the computer (at least if you can I did not).

 

[leonard_nemoy]

Could the supercharger be to blame?

Yes, I don't know why anyone who wanted a reliable rig to take them to remote places and back would want any kind of forced induction. So many more things to go wrong and more stress and heat for the engine...

I really hope you get it sorted out and it isn't as bad as you think once you get the head off.

Goodluck

 

[SHIfTHEAD]

That is a theory that my mechanic brought up and I think that's pretty valid. the more brain juice I put into this I feel like since valves and rings are out, must have been a lubrication issue. If it was running rich then I could see the oil being "rinsed" away so it was not doing its job.

Dumb question but why would it run rich? I can't adjust the fueling in the computer (at least if you can I did not).

Well a stuck injector can cause this, but I can't think of a situation where the ECU is putting in so much fuel it would cause this if it's working as expected. Adding a supercharger, especially OEM, I wouldn't think could cause this. But what I don't quite understand is the low compression from the rings and the valves. What I would bet is that if it started running rich, and this is a long shot mind you, then you started building carbon in the cylinder. Maybe you've got a valve that won't seat now and the rings aren't shot, just need a film of oil to seal.

 

[SNLC]

You check ring gap when they were installed? How about the oil pump? And bearings?

Toyota inline six engines are known to burn exhaust valves.

Cheers

 

[concretejungle]

I did check ring gap and valves before completely buttoning it up.

possible stuck injector? In hindsight I will say that every time I put new plugs in, the old plugs were black! Maybe some kind of issue with the front O2 sensor?

I did have an O2 simulator put in for the rear O2 sensor since I went with a new exhaust and magna flow cats. But my understanding is that the front sensor helps decide fueling and the rear is more just for emissions, so the simulator in the rear shouldn't affect the fuel mixture?

 

[SNLC]

I don’t like the speculate much. If the tests are correct a tear down is in order.

I am running a single cat on mine, 12,000 on an all new engine. No issues.

Cheers

 

[Jeff Elliott]

possible stuck injector? In hindsight I will say that every time I put new plugs in, the old plugs were black! Maybe some kind of issue with the front O2 sensor?

I have an AFR sensor on my rig since it's forced induction as well (Wit's End Turbo). I noticed an off and on rich condition not on boost that persisted even after off throttle (think AFR's in the 11s and 12s). It would eventually reset itself to 14.7 but I didn't like it. Changed the O2 sensors and problem went away. I'd check your front O2 at minimum just for piece of mind.

 

[concretejungle]

I don’t like the speculate much. If the tests are correct a tear down is in order.

I am running a single cat on mine, 12,000 on an all new engine. No issues.

Cheers

I understand that, however I'm trying to figure out the path forward. I'm a little hesitant to "tear down and rebuild" and go back with what I had if this happens again. Also considering just sending the truck off and having someone else fix it and if I do that I need to know what the plan is. Do I put the supercharger back on without figuring out what happened? Do I sell the SC and try a turbo? Do I swap a V8 in?

 

[SHIfTHEAD]

I understand that, however I'm trying to figure out the path forward. I'm a little hesitant to "tear down and rebuild" and go back with what I had if this happens again. Also considering just sending the truck off and having someone else fix it and if I do that I need to know what the plan is. Do I put the supercharger back on without figuring out what happened? Do I sell the SC and try a turbo? Do I swap a V8 in?

IMO, forced induction is another layer of complexity and problems. If more power is what you want/need then I'd say start looking at what another powerplant costs. There are lots of LS swaps out there, and plenty of knowledge around it. But it's going to cost you a lot in money and time, if you do it yourself, or A LOT more if you don't DIY it. For me, my 80 series is what it is with the 1FZ. It does need more power, but when I've really needed that power, and there have been times, it was only at highway speeds on steep inclines and higher elevation. Not a normal day for me, by any stretch. So really the stock power does the job for me 99.9% of the time, and so the cost vs benefit for me isn't there. It just what you need vs what you are willing to spend, ya know?

 

[concretejungle]

I'm not going back to stock. If that's the case then I'll sell it and move in another direction. With the weight for long trips plus a RTT and larger tires, stock just isn't in the cards for me.

 

[SHIfTHEAD]

I'm not going back to stock. If that's the case then I'll sell it and move in another direction. With the weight for long trips plus a RTT and larger tires, stock just isn't in the cards for me.

I get it, my 80 is pretty slow. I have a 100 and a Tundra with the 5.7. Lots of power in the Tundra, but it's no where near as tough as the 80. Looks like you have a lot invested in the 80, so I'm guessing you like it. I would find out what is wrong with the engine before I sell it off. At least pull the head and inspect what's going on in there. If it were me, I'd put a few squirts of oil in each low cylinder and see what happens, got nothing to lose. I still don't think an OEM supercharger should cause this kind of issue. The 1FZ is pretty bullet proof. And your friend, is he a mechanic or someone who is handy? And even if he is a mechanic, people make mistakes. I guess what I'm saying is get a second opinion.

 

[leonard_nemoy]

I forsee a ls v8 in your future.

 

[concretejungle]

I forsee a ls v8 in your future.

looking at that too.

Unfortunately I have really bad thoughts in my head of getting a tundra with a slide in 4wheel camper or alucab camper..... I am trying not to go there.

 

[sbman]

I understand that, however I'm trying to figure out the path forward. I'm a little hesitant to "tear down and rebuild" and go back with what I had if this happens again. Also considering just sending the truck off and having someone else fix it and if I do that I need to know what the plan is. Do I put the supercharger back on without figuring out what happened? Do I sell the SC and try a turbo? Do I swap a V8 in?

Your previous go around wasn't a rebuild, more like a minor refresh, the valves looked ok so they were left alone. Rings were put into a honed cylinder instead of bore and new pistons and rings. When I did mine it was a 'partial rebuild' which included line bore, rod resizing, new +1 sized pistons, new rings, all new bearings, new oil pump bushing, a 'full valve job', timing chaing components, injector service, cometic gasket, arp head bolts, all new hoses, etc...

On mine the machine shop hosed up the 'full valve job' which caused the engine to burn oil and after only 50K miles, a premature failure. They did so by not bothering to check spring pressure. They also didn't mention that the exhaust valve guides were worn. The worn out valve springs didn't provide sufficient seat pressure for valve cooling which caused the valve faces to erode and loss of compression. So I had to do a head job after only about 50K. This required all new OEM valves, all new OEM valve springs, and new OEM exhaust valve guides. The proper head job cost over $2K on it's own, plus I had to replace the cometic head gasket.

So my point is, that if you want OEM original, like new reliability, you have to go all in. If you do it half-way your results may vary.

 

[60 toy ota]

We also haven't talked about what your break-in looked like for the new rings/old walls. if those new rings didn't seat right on the cylinder walls you can expect some of these issues.