Classic case: Belt broke, engine overheated. What are the chances I damaged my 1GR-FE?

So my belt broke on my 2006 Toyota Tacoma TRD Sport V6 6-speed today

I was exactly 1.6 miles away from home when it happened. I was at a traffic light. I turned off the engine, jumped out, ripped out what was left of the belt, and got right back in to pull out of the way of traffic.

I decided to do the 5 min drive home, turning the engine off at lights to prevent the battery from dying. At one of the lights my check engine light came on and I discovered my temp gauge was at max (a duh moment because I should have known better that the water pump wouldn't work)

I turned up the HVAC heat and turned the engine off to coast the remainder of the downhill trip to my street. Only needed to turn the engine on for a quick second to turn into my driveway. I saw the thermostat needle begin to slowly go down below the max level during this time

When I got home I discovered that the coolant pressure had released out of the safety pinhole all over the engine... as to be expected

So MY QUESTIONS

1: Despite the water pump not having a belt, will convection cause the coolant to circulate through the engine? even poorly? or is the stopped pump a complete blockage

2: What are the chances that my engine would have permanent damage?



It's not like I drove the engine with NO coolant. There was coolant in the engine and obviously the heat dissipated through the fluid enough to heat up the reservoir, so the engine didn't get THAT hot right? These 1GR-FE engines are known for their reliability but I am very worried that I may have caused damage (which I have no evidence of)



Truck only has 156,000 miles. Belt was previously preemptively changed at 75,000 miles

 

Lots going on here. Belts don’t just break... I have over 200k on my belt on my 08 1gr. Anyhow does this start right up now? Coolant won’t flow without the water pump spinning. It’ll flow out of the weakest link ! Metal head gaskets and aluminum everything else which don’t like excessive heat.

 

Belts definitely do just break.

 

Not without some kind of noise and such... I’m speaking Toyota oem... it’s possible an after market belt may just give up.

 

Iv got 404k on my 08 and changed the belt once with oem

 

As long as it's not knocking you should be ok. Make sure you change the oil before you drive it again. The oil breaks down when it gets too hot.

 

I overheated my 2tr once when I changed the antifreeze and didnt put enough back in due to a air bubble in the block. I've got around 50k miles on it since then. It did crack a coolant tube going to the heater but they are pretty fragile anyways and the v6 wouldnt have that.
Check for excessive play in every pulley and make sure they spin. Put a (quality) belt back on it fill it up with antifreeze and fire it up.
You could do a coolant pressure test on it before hand. But if it ran when you parked it, didnt stall out or anything and it really only went a mile its probably stil ok.

I like bando brand belts because I heard that's the OEM supplier to toyota so I use them. The one I have was either made in Japan or usa, its not chinese junk.

 

Fix it and see what happens. My guess you are fine sounds like you did all the right things

 

Also double check your pulleys for play, locking up and alignment. I used to work for this really junky equipment rental place and even the wore out stuff they had with a serpentine belt would go for years and years as long as pulleys were aligned and everything was tight.

 

You should be fine. I recommend taking it to a reputable shop or dealer to perform a compression test and coolant pressure test. If it passes those two, odds are the motor is in good shape with minimal to no damage. If you are mechanically inclined you could run over to your local parts store and borrow the equipment needed to perform these tests your self and record the results. Then call up to a shop or dealer and ask what the specifications are. Also take what some guys say of they should/shouldn't break with a grain of salt. It's basically a reenforced rubber band. They can, and do, break. There are MANY factors that's go into the longevity of a drive belt.

 

I'm a "probably no damage" vote. But this is a tricky thing to determine from the end of the internet.

Definitely change the oil. Engine oil removes a lot of heat -- I've heard over the years probably as much heat as the coolant, although that's apocryphal as far as I'm concerned -- and it's cheap enough, assuming it got cooked. Worrying about running down the battery was a mental error, you know. Less than two miles driving means nothing to a car battery, and heat removal is *everything*.

 

Had something similar happen on an 02 Trooper. Put a new belt on and found that the pump's bearing was toasted and seized juuust enough to cause drag, and eventually killed the belt. Never had any squealing or anything, I only figured it out because I had another belt die quickly after and looked into it deeper. Both times engine overheated doing the same scenario as you, and both times the engine was fine but had toasted oil. Did 2x oil change each time and she still ran like new till I sold it and bought my Tacoma. Is your engine fine? That 1GRFE is definitely just fine. Id focus more on WHY, and even if it is just a faulty belt, you'll know not to buy those belts anymore.

To add - the only way to be sure the engine isn't alright is to just run it like normal unless you're gonna have a shop tear into it. If it is indeed screwed, you'll only know after running it and either way you'll still need a new engine. Cheaper to run it than to have a shop rip into it for potentially no issue - or to find out you need a new engine anyways.

 

Do not panic, just go slow and steady. In 1958 my cousins 1950 Buick blew a heater hose, it way over heated. Died dead as we pulled into driveway about 2 miles from the incident. That Buick was hot. Next day checked that the engine had not siezed, changed the hose, filled it with water, drained what was left of the oil, (here is what might help you), filled the crank case with a mixture of 50 50 auto trans fluid and Wynns Friction Proofing. Started and drove a couple days, and changed the oil. Everything was fine.....you will probably be too.