Help for possible Broken Piston Rod please.

Hello all. I was driving my 2005 4x4 2nd gen 4.0 about 70mph when I heard the clatter from right side of engine, I slowed down and engine died. Car would not crank over, locked up. Took it home and after turning the crank back, heard a and forth, heard a "clank" it then freed up and would start up and run but with clatter and shaking. Mechanic friend said indicated timing was off, but sounded to me too bad with clatter and so told him to I turn it off quickly. I took off the cam covers and fan etc and checked timing chain alignments via marks and all was good. Then I checked the piston movement via spark plug hole in cylinder 1 and it is not moving stuck at top (all others are OK). I was hoping maybe a valve had broken and was inside and I could find pieces but no movement of piston.

So I have a broken rod or maybe more likely the rod cap ( I haven't taken off the oil pan yet. My questions are, when the rod breaks and piston is stuck at the top and valves are still opening, is there enough clearance for valves or is there a good chance I damaged and broke a valve also?
The second question is for this job, is it possible if it's only the rod on this side (and my crank, block, or cylinder wall isn't damaged)... to replace just the rod, can I do this with block still in the truck, or is it necessary and/or much easier just to pull the engine? Thank you.

 

A used engine would be my next step in your situation.

 

Full rebuild or replace the motor.
Good luck with your truck.

 

Typically when a rod lets go there's a reason for it, often times it's from a spun bearing due to oil starvation. Did it have enough oil in it?

Either way it would probably be cheaper to put an engine in it rather than rebuild that one unless your really lucky and the crank & block didn't get trashed.

 

teardown and inspect

sometimes rods and rod bearings can still be done with engine in

 

The dip stick was at half way between the marks, so I think that's 1/2 quart. I have been driving it 3 years with 1 link off on the crank timing chain so running it advanced maybe 20 degrees, as it was installed by me off and I never got around to tearing it back down to fix it. It has driven fine, just I could notice a sluggishness going up hills with acceleration, but the engine has been pretty clean inside. I was passing a lot so petal to metal multiple times on that trip before it broke. Not sure if that could have caused it with the timing being off like that driving it hard.

 

I replaced a piston on a race car at the track with the engine in the car. The engine lasted a quarter mile, probably wouldn't have made it another quarter.
Realistically, you need another engine.

 

If a rod let go inside the engine, the entire engine is toast. So much debris gets scattered about I wouldn't even fathom trying to rebuild that. A replacement 05-11 engine will be less of a headache in the long run.

 

Used engine

 

Hello, OK thank you all for all the replies so far. I live in Costa Rica and there are very few 4.0 Taco engines here, however much more likely I can find a used V6 Diesel out of a Toyota Hilux as a very common truck here. Is it possible or difficult to switch my 4x4 truck over to Diesel from my 4.0 on my 2005? Thanks

 

It won't be a simple swap, you will at a minimum need the ECU and harness out of the donor truck as well as quite a lot of additional work and misc parts. The few shops that specialize in diesel swapping Tacomas get $$$$$$$ (20, 30, 40k) for the conversion depending on details.

 

I visited Costa Rica in 1978. I love those little Toyota diesel trucks.
Buy a Tacoma with a rusty frame in the US. Have a surfer drive it down, swap engines.

 

Update for anyone interested. I pulled the engine, took it apart and the problem was a spun rod bearing on Piston #1 causing the rod to break and that caused the front counter balance weight on the crank to totally break off and so was in the pan. In addition one of the flying pieces also bent rod #2 and damaged the lower part of piston head. The block has some deep marks in it, but I think its rebuild-able. Cylinder #1 has some scratches in the lower cylinder that I think will come out and most sit below the ring level so no big deal. I was shocked the valves didn't get touched by the damage with piston sitting stuck at the top, but they both look fine. Now to find a crank, pistons and rods, condition the heads, get some gaskets and put it back together. I may put a new oil pump in it just to be sure. I was noticing the past month the lifters too noisy when first start up. Also timing chain wasn't too bad but will do it anyway since I have 161 K on the motor.

 

Was it ran low on oil at some point?

Bearings typically only spin from a lack of lubrication.

No damage to cams or main bearings?

 

Well I think what happened was I replaced the timing chain 3 years ago and the engine will full of crud. So I cleaned and flushed motor as well as possible then also been running Marvel mystery oil in it as maintenance. I never ran it lower than half dip stick down between marks and it doesn't get driven too much but the humidity in the tropics collects inside the crank case with short trips and so gums up the oil faster. I think you are right on the oil... and that it was simply accumulation of the crud that lead to it causing oil starvation. All of cam and other bearings look fine. Only other issue I had noticed at the back was main seal had been leaking some over the past 2 years. When I pulled heads off I noticed two of the exhaust valves were stuck open (lifters down) and I was able to tap them shut so they were sticking in the guides probably due to the internal crud. Need to pull all valves out and inspect to be sure they are all OK and springs are fine. I need to find a machine shop that can vat the block and heads to give them a super cleaning next.

 

Sorry, but I foresee another blown engine in your future.

I hope not, but....

 

Seriously you’re throwing money away if you rebuild it.

 

This makes me think of one of my favorite youtube channels.

Where do y'all think rebuilt motors come from? If the OP has the tools, and if he has the skills, and if the core isn't trashed, there isn't any reason why he couldn't rebuild his engine. That's a lot of "if's" though. If it were me I'd buy a long block that had been redone by a reputable shop. Shipping to Costa Rica might sting a bit though

 

Thanks for the inputs. However due to my location out of the USA and lack of funds to just buy another vehicle or engine I don't really have any other budget options. I took valves out today and have the 2 intake on cylinder 1 bent, so will probably just replace all the valves. I''m no pro, but I have rebuilt a few engines years ago. Actually I used to specialize in the RX7 rotary engines. Those are really tough because you have 1 hour to get the entire block back together all torqued together before the glue sets up. But that's a different forum... For this motor I need 2 stock rods and pistons and the crank with all bearings, rings, new oil pump, timing chains & valves etc. I can lap in the valves myself and maybe get a machine shop here to spec the cylinders and if good hone it for me and I should be good to go. I don't think it will cost too much and not sure why so many think the motor will blow again after a rebuild and that its a waste of money. I thought that's what everybody did here...

 

Man, i’d say the overwhelming majority of us buy tacomas so we DONT have to rebuild engines But it sounds like you have a solid head on your shoulders as far as the repair goes. Wishing you all the best, man. Good luck! Update the thread when you get it back up and running. routing for ya!