Spun Rod Bearing?

Hi all, newbie here. I've got a '98 Taco V6 3.4L 5vzfe 4wd TRD Off Road w/195,000 miles. Long story short, I've got engine prob's. Husband and I have been debating heavily this week (problem started last Sunday) about what to do. Tried to convince ourselves to replace her, then realized we'd never be happy w/anything we could afford in her place, cuz we love love love that Taco. So, we've at least decided for sure we will fix her, but then deciding between the following options has been driving us insane, as we know all of nothing about 5vzfe engines, other than that's what's under our Taco's hood and it's not feeling well. Trying to read/research like crazy to educate ourselves, but it ain't easy. Complex stuff to say the least. Anyhooo, options we're considering are -

1) him attempting to rebuild engine himself - least $, biggest PITA
2) having someone rebuild it and he installs - 2nd least $, but I've read horror stories about warranty prob's when installed by someone other than cert. tech, plus still hefty PITA for husband to pull it/put it back in
3) having someone rebuild it and they install - most $, least PITA
4) having someone install a reman - most $, least PITA

It's all about time and money. And being overly attached to a truck and wanting her to be babied through whatever happens next. While he's done 90% of the repairs/maintenance on her since we've had her (bought in '04 w/70,000), dealing w/engine seems like a far cry from things like brakes, radiator, shocks, struts, tranny/4wd service, etc in terms of skill set, tools needed, time needed, zero room for mistakes, etc. So leaning heavily towards #3 or 4, and would love input on pros/cons of each of these routes. When mild lurching followed by knock/tap noise started 6 days ago, towed to Toyota Dealer, and they dx'd spun rod bearing and poss. blown HG based on a $60 diagnosis (didn't really open anything up, just listened). Naturally, after researching WTF a spun rod bearing is, we started clinging to hope that maybe they were wrong, and did some DIY dx at home. Drained oil, pretty sure we saw metal specks. Pulled NGK spark plugs, and all looked good EXCEPT #3 on coil pack side - center electrode (made of nickel) was gone. Not corroded or broken, just totally gone, and boot interior was covered in carbon build up. Borescope down bad plug's well (praying to find MIA electrode and end this nightmare) - didn't find anything except maybe a hole in piston head (we didn't really know what the hell we were looking at though!) and more shiny specks like what was in the oil.

We've gotten lots of encouragement on forums to start taking things apart to determine how bad the damage is before making a decision. But I'm confused, because it seems like if we start ripping components off the engine to see the extent of damage, we've essentially committed to rebuilding it, or at least removing it and putting in a new one ourselves at that point. Right? Or are there basics we can do to see how bad it is? From what I've described about the symptoms, is there even any point in us tearing into it to better understand the damage, if ultimately we want someone else to do the labor of fixing/replacing it? On one hand, some mechanics I've talked to have said maybe damage isn't too bad, and you won't need a full rebuild/different engine put in, but rather just certain components of it machined/replaced/etc, which could make cost go down from $4500 for reman/rebuild to $1000 - 3000 - so in that regard, it'd be nice to know for ourselves how bad the damage is before taking it in for repair, so we're not crossing our fingers that whatever mechanic we go with is honest. On the other hand, others I've talked to have said on an engine w/nearly 200,000, even if we only have a few components damaged, by the time you tear shit open enough to discover that (time and money), you'd be a fool to not go all the way w/rebuild or replace w/reman. But I guess we're scared to have it towed somewhere, sign up for a $4500 reman to go in it, then what if dealer was wrong w/their lame listening test and we didn't spin a rod bearing, and the noise and f'ed up plug are just some dumb DIY fixable issues? Am I in denial? Help. I need all the opinions I can get on that.

Wow, guess I didn't make a long story short after all.........thanks for reading everyone!!!

 

There are probably some things you should (and probably already have begun to) think about before you decide which route to take. First and foremost, how much money are you willing to put into a 16 year old truck with 200k miles on it? This is going to be the governing factor, because as you've stated, this could get expensive fast.

You should be able to determine the extent of the damage yourselves without too much difficulty, if you are fairly mechanically minded and have some space to work on it. If it comes down to taking it to a shop, you'll need to tow it anyway (I wouldn't recommend driving it with possible spun rod bearings), so you might as well tear it apart on your own. That being said, be extremely careful with organization of hardware, wiring harnesses, etc. Ziploc bags with labels, electrical connectors taped and numbered, take your time with seized fasteners (PB Blaster is your friend), and you'll thank yourself later.

Based on the preliminary diagnoses you mentioned, it shouldn't be terribly difficult to figure out what's going on. The self-destructing spark plug is most likely what was causing lurching (dragging a cylinder), and as long as it didn't destroy the threads in the head, and you can get all the pieces out of the cylinder, that's an easy fix. Not sure why that would cause a hole in the piston though, and it would burn oil like crazy once you get it running again if that's the case (which may help the diagnosis). Also, if the head gasket was blown, you'd most likely be burning coolant, which would make huge clouds of white smoke out of the exhaust. Again, that can be quickly seen once the motor is running again.

That brings us to the most serious problem, the rod bearings. You mentioned that there was visible metal in the oil, which means you'll want to drop the oil pan regardless to get all that out. Once the oil pan is off, the crank will be visible, and you can assess the condition of the rod bearings. If you have access to a factory service manual, it should have tolerances for the bearings, which you can check with a feeler gauge. If the bearings are toast, as long as they haven't damaged the bearing journals on the crank, you'll be able to replace them without pulling the bottom end of the motor apart. It sounds like you stopped driving very soon after the problem arose, so hopefully there is no damage.

At this point, depending on what you find, it's easy enough to put the wheels and oil pan back on and get it towed to a local mechanic to begin repairs, if that's the route you want to go. If you've been thorough with your disassembly procedure, it shouldn't be hard for them to pick up where you left off. Maybe they'll look at it and say it needs a new bottom end and it'll cost $1500. Maybe just rod bearings and it'll be $400. At least then you'll have some information to base your next move off of.

 

Hi drr, thanks for the reply. We've gathered lots more info since my initial post, and now know we have a hole in the piston below that plug, plus obviously there could be more damage beyond that to the cylinder head, etc.

We've been beating our heads against the wall reviewing all the options since this started nearly 2 weeks ago. Any input you can give would be appreciated. There's a very LONG thread about all of this on the 1st gen Tacomas area of this forum, if you're so inclined to check it out.

We've ruled out taking our engine apart, because we know we don't want to rebuild it/have it rebuilt, due to time/space/skill set/not a huge cost savings over other options anyway.

We ruled out replacing the truck because we love it. It's got all the features we want, and that is tough to find in a newer version of it for less than $20K. And we can't afford more than that. Even that would be a serious stretch.

We've examined the remanufactured engine option under a microscope big time. And due to hearing bad stuff about "assembly line" reman's and their poor quality but perhaps slightly lower prices, we are 99% sure that if we go w/a reman, we'd go to (EDITED - SEE BELOW). This would be the most expensive option we're considering @ $4500, but our impression is that he does very high quality work, and that price includes all swap labor, OEM parts, 2 yr warranty, and hopefully a very very high quality dressed long block. Lots of people think we're nuts for considering spending that much on a 17 yr old truck w/200,000 miles, but it's actually in very good condition, and like I said, there don't seem to be many Tacos floating around w/all the features it has for less than $20K, unless there's something shady about them. We've discussed things like, what if the tranny goes out next - and we feel like this would still be worth it to us, even if faced w/a $3000 tranny issue right away, because at the moment the tranny is fine, and the rest of the truck is good. And other than the tranny, my husband can handle most, if not all other repairs. So even $5K on engine + possible $3K on tranny seems worthwhile to us, compared to replacing w/a truck that lacks some of this one's features, or trying to break the bank every month on an insane payment amount, while living in fear of spilling coffee or getting dog hair inside such an expensive truck.

Then there's the used engine option. I was totally against that at first, due to not knowing how it was treated before you acquired it, short (if any) warranty, and horror stories we've read/heard about people taking this approach and going through 2 or 3 motors before getting one that actually worked. But, the obvious upside is spending a whole lot less than $4500. Taco fans on the other thread convinced me to at least spend a little time considering/researching this option by making a good point: our engine problem is rare, as typically this engine type is pretty bulletproof, so a high miles used engine shouldn't be feared, and essentially the risk factor is the same as buying a used car, which is what we did when we bought this Taco w/70,000. They've coached me on things to look for when selecting a used engine, but honestly it's still quite overwhelming, as there are so many places selling them, so many factors to look at to select a good one, so much fine print in the warranties, so much to consider in terms of making the swap (husband w/neighbor's help vs. a mechanic). And pending who'd do the swap, and the price of the used motor, and how many parts we'd want to replace that could be worn on the used motor (timing belt, HG, etc), the margin of savings over the reman option could narrow quite a bit. Definitely would be a savings no matter what, but at this point seems it could be as much as $3K saved, or as little as $1K, pending those factors.

Can you tell I'm confused? I'd love to know if you or anyone you know has ever heard of (EDITED - SEE BELOW) and if so what they think. So far he has really impressed me w/his knowledge and professionalism - he's either a really good actor about being super anal regarding quality, or he really is that serious about it. All he does is Toyota trucks, mostly engines. A machine shop I called recently (when we were considering rebuilding ours) recommended him, plus I've seen lots of good stuff on other Toyota forums and Facebook, and have only found 2 bad reviews.

Thanks for reading!

EDIT: I've deleted the name of the business that replaced our engine from this post, because problems developed with the truck after the work they performed, and those problems are still in the process of being diagnosed as of today 2/4/15. Until I have a full clear picture of what these issue are and what caused them, I do not want to recommend or speak poorly of their business. Thanks.

 

I have heard of [deleted], and all good things, but only in passing - I've never seen their work. That certainly seems to be a safe bet if you're set on replacing the engine, although you could do a used engine for cheaper if price was an issue. Also, I'm only seeing the dressed long block from [deleted] as $3300, are they doing the installation as well?

I saw the other thread about this in 1st gens after I replied - I couldn't believe no one was answering your questions. Makes sense it was in the bigger forum though.

It sounds like you're looking to get the work done by an outside source - I'm a DIY kind of person, so my recommendation would be to buy the motor (whether from [deleted] or a junkyard) and swap it in yourselves, but I can understand that it might not be easy for everyone to do that. I'm interested to see where you guys go with this, I'll try to answer any other questions if I can.

 

Hey drr! Thanks for the reply, didn't realize you'd posted til now!

They are doing the install as well......we towed our Taco there Tues morning. Thinking our total will be ~$5K, including dressed long block, all labor, plus some extras, like power steering pump and drive belts, possibly a flex plate, and definitely cleaning or even replacing fuel injectors, plus possibly coil pack(s), pending what they find when they inspect it. Hoping no core charges apply or that number will go up more. It's great to know you've heard good things about them, hurray! I've heard a whole lot more good than bad about them, which is a lot more than I can say about some of the other mechanic options we've looked at. They've been nothing but super professional and knowledgeable so far, so crossing fingers that we made the right choice.

Yep, it's surprising that no one else in NW forum replied, but I'm quite grateful that you did! Nice to get feedback from someone that runs a Taco in the same climate, as I'm guessing we experience similar issues related to that! Actually, right now there's a debate on the other thread about fuel quality. Do you know anything about whether there's funky stuff in the fuel in Oregon? I've heard that before, that due to environmental regulations or something like that, we have some additives in it, or maybe that it's missing additives that other areas have?

At the moment I'm obsessing over what could have caused the hole in the piston, and it seems like the majority of people think a lean fuel condition. We dug out an invoice from 2007 where the Toyota dealer found that same plug (at #3 cylinder) carbon tracked, along with the coil pack and wires. Those were replaced, and fuel injectors cleaned, and now it appears that was an 8 year band aid to some sort of underlying issue at cylinder #3. So I'm super curious to see what the (EDITED - SEE BELOW) mechanic finds, hoping he'll be able to get to the root cause of why a very similar problem recurred at that same cylinder 8 years later - so that we can fix whatever it was and be sure the problem doesn't repeat when our new $5K engine is in!!!

EDIT: I've deleted the name of the business that replaced our engine from this post, because problems developed with the truck after the work they performed, and those problems are still in the process of being diagnosed as of today 2/4/15. Until I have a full clear picture of what these issue are and what caused them, I do not want to recommend or speak poorly of their business. Thanks.

 

Interesting that you've had a recurring problem with a specific cylinder - makes me think there was a manufacturing tolerance/quality issue that arose. It may have leaned out if you had a clogged injector or something along those lines, hard to say really. As far as fuel issues go, the only thing I know of is in the winter months the EPA requires higher ethanol content (up to 10% or so, I think), which effectively dries the fuel out, and affects the energy content (makes it run slightly leaner, generally).

I imagine [deleted] must be about done with your truck by now, I'm curious to hear how it all turned out. You guys should have a sweet rig when they're done with it!

 

Thanks drr! Yep, they think this week maybe, so we are really excited to get it back!

We found out 2 of our injectors were clogged, which caused the lean condition that led to the spark plug exploding and the hole in the piston. So, 2 replacement injectors, and the other 4 were cleaned/tested. It's still a mystery as to why #3 had carbon tracking in 2007, and now #3 was the problem again. All I can think is maybe that injector has always been slightly defective, or something about how the fuel flows in that area makes that one more prone to clogging or something?

I've been reading about fuel/ethanol content, and found some interesting stuff in this article, about how stuff separates when temps drop suddenly.... http://www.popularmechanics.com/cars/alternative-fuel/biofuels/e15-gasoline-damage-engine
I know the morning this all started, it was ridiculously cold, and it was one of those all of a sudden temp drops - it'd be hard to believe that didn't play some small part.

I've heard lots of different opinions about gasoline, and I'd love to hear yours too, especially since you likely have very similar options on where to fill up, and deal w/similar climate, etc. Some have said go for more reputable stations to get higher quality gas (Shell instead of Arco, etc), others have said it makes no difference. Some have said higher octane is better, others have said it makes no difference. Also, people have different views on using fuel injection cleaner (some say it could actually lead to clogging, others say it's good to use). And I never paid any attention to what the heck was in the fuel I used, but now realizing that ethanol's virtues are being debated, I'm curious what you think about seeking out stations that offer ethanol free fuel vs. not bothering? We fill up at Freddie's 90% of the time, then occasionally Costco, cuz those are the best prices around. But now that we're spending $5K on an engine due to fuel injector issues, it's definitely got me thinking about the quality/content of the fuel we use and how worthwhile it would be to spend a little more on it if it would benefit the Taco...

I'm curious, how often do you change your Taco's fuel filter? And have you ever had your injectors cleaned/replaced?

We're having the mechanic install an AFR sensor, which should forewarn us in the future if we're ever running lean again. Not exactly sure how it works yet, but hopefully it'll be fairly straightforward and ease our minds from being paranoid about injector problems!

 

Everybody's got their opinion about gas and fuel system cleaners, just like oil, tires, etc. I'm sure after you're done with this ordeal, you'll have your own opinion! Personally, I have always run 87 octane from the cheapest place I could get it, and never had a problem. That being said, I change my fuel filter every year (or two), although I know people who have 200k miles on the original fuel filter with no (major) problems. The way I see it, the fuel filter is cheap, easy to change, and could potentially prevent a situation like yours from arising.

I've never had a "professional" cleaning of my fuel system, but I occasionally run injector cleaner through my gas, as well as seafoam. I also romp on my truck every once in a while (getting on the freeway, long open roads, etc) just to get it hot. Some people think that reduces carbon buildup on the valve seats, top of piston, etc.

I think any big name gas supplier (Costco, Fred Meyer) is going to have just as good quality gasoline as Shell or Texaco. I might shy away from the no-name places unless that's the only option, but I don't think in general that paying more for gas means you're getting "better quality."

 

I like your point about the fuel filter being easy/cheap, so why not change it often in case it helps prevent major prob's. We last changed ours in 2010 - and it's getting changed now too!

Mechanic found issues w/our fuel regulator (in addition to the 2 failing fuel injectors), so he's replacing that as well. Makes me very suspicious about the quality of the fuel we've been using. Who knows, maybe there's no issue w/the fuel we've used and it's just normal stuff to be giving out at this many miles (nearly 200K). We typically fill up at Freddies, but I may start making a point to fill up at Costco instead, just in case. I noticed a sign in Costco the other day about how their fuel has even higher levels of detergents than what standards require - plus their prices are always low.

Will definitely be asking mechanic a laundry list of questions about his opinions on everything from best fuel to whether injector cleaner is good or bad and a million things in between! But it's also great to gather lots of opinions on those topics on forums - the more info the better! Thanks for your input! : )

 

Is this the same mechanic at [deleted] who did your engine swap? I would definitely be curious to hear his answer to those questions as well - I'm sure they know a hell of a lot more than anyone on this forum about these subjects.

Let me know how it all turns out, and if you roadtrip your new rig up to Seattle, I want to check it out!

 

Hey Drr! Yep, we went w/(EDITED - SEE BELOW) for the engine swap.

Picked it up Friday midday, and she drove BEAUTIFULLY, but was having problems w/hot soak starts. Started right up if sitting cold (overnight, 12+ hours); started right up if she'd only been shut off for 5 min or less; but long crank time if sitting ~30 min since last running. This was something our mechanic noted before we picked up, and he tested back pressure on fuel system, and replaced fuel regulator as a result of the tests. He thought/hoped that solved it, but unfortunately it didn't. So we drove it back there Saturday, and that final time we started it to head up there, it had been sitting ~2 hours (so at least somewhat cold), then it BARELY started - cranked a super long time.

Good news is, we have been extremely impressed w/mechanic so far, so we're hopeful & optimistic that he'll get this sorted out quickly and we'll be back on the road soon! Just tough right now - it was such a tease to get her back for a short time, especially running so smooth/powerful/perfectly, then to have to take her back. And of course now, it's impossible to not speculate ourselves to death over what it could be. Fuel regulator, fuel filter, and 2 faulty injectors were replaced. Pump hasn't been yet. We did have him install that air/fuel ratio gauge - wonder if that's causing some funky something? Current theories are either fuel pump, evap system, a sensor that wasn't hooked up correctly in the swap, or leaky fuel injector(s). What's your guess?

EDIT: I've deleted the name of the business that replaced our engine from this post, because problems developed with the truck after the work they performed, and those problems are still in the process of being diagnosed as of today 2/4/15. Until I have a full clear picture of what these issue are and what caused them, I do not want to recommend or speak poorly of their business. Thanks.

 

Jeez, sounds like it could be any of the above. If it's losing fuel pressure slowly, could just be a fuel line connection, but that doesn't explain why it fires right up when cold. I'm not even sure if there is a fuel pressure sensor, but that would be the first culprit. Those sensors go through a reset cycle when the truck is off for a certain period of time, and if they haven't reset when you try to start the truck (~2 hours or so) then perhaps they think there is full fuel pressure when there isn't. That's all speculation though - the fuel pump went out on my last truck and it took me three days to figure it out, so I'm not exactly an expert about fuel systems.

 

Hey there drr! Sorry I disappeared, been posting mostly on that other super long thread. We're still waiting to find out what's causing the hard warm starts, and after going back to our engine mechanic 2x to try to diagnose, we finally (last night) dropped it at a Master Mechanic's home garage, actually quite close to us. The guy is a good friend of our neighbor, and our neighbor has assured us that he has all top of the line diagnostic equipment, and is a diagnostic genius, so we're crossing our fingers that he has good luck. He's supposed to look at it this morning, so we're hoping to have some answers later today maybe! On the other thread, I'm offering to ship truck cookies to the person(s) who guesses the correct culprit for the hard warm starts. Feel free to head over there and cast your vote if ya want, you're the ONLY person on this thread that's actually tried to help us, so you certainly deserve your chance at truck cookies! They're super yummy! See ya, thanks for all of your help! : )