2001 3.4 liter with Radiator Leak Overheated and stopped running

Help.

My check engine light went on at 70 mph and I was 4 minutes from an exit. Before the exit the engine stopped. I coasted onto a frontage road and let the engine cool. I saw a 3 inch crack at the top of the radiator. It was HOT.

I put some water into the radiator and had the truck towed home. Some steam came out. I think I should have waited to add the water (can't undo it)

The next day, I replaced the radiator and hoses and filled it with coolant and it started right up.

Ran okay for 2 minutes.

I thought I dodged a bullet.
Next day I started it and it ran for a minute and started running rough on idle and okay at 1200 rpm and up. I saw vapor coming from the exhaust and shut it off.

It seems clear the heads or head gaskets are leaking so obvious choice is to rebuild the heads and install new gaskets.

Questions.
Does this truck have a high temperature shut off?
If it got so hot it stopped running, will that damage the crank bearings?
Would too much heat damage the pistons or rings?
Will too much heat warp the intake manifold.

The truck has 210,000 miles and it's in great shape. Still clean inside and out.

My concern is that it's going to be a job and expense to replace the heads and gaskets, and I wonder if the crank or pistons will just go bad later. There are used motors but you never know what you're getting or if it will fit easily, and a rebuilt motor is $5500 plus labor to install.

Rebuilt heads are $750 plus $500 for full gasket set and $100 for fluids.

I want to keep the truck, but I don't want to put $7,000 into it.

I can pull the oil pan and check the bottom end visually, and I can check the pistons when I get the heads off. Is there a way I can get a sense of how much damage was done. Should I rebuild or replace, or sell it for scrap and find something else

What do you know about overheating?
What would you would do?

 

if it shut off, your better off putting a used engine in. These engines will not turn them selves off because of heat, you likely got the pistons too hot and probably warped the heads.. at least

 

when looking for a used engine, find one from a US built vehicle, with proof of it running and compression numbers.. JDM engines are a big gamble. and engines that sat on a shelf in a yard for 4 years can also be a gamble

 

Well there a few simple tests that you can do before you throw the towel in on the first original engine. Leak down, compression and exhaust vapors present in the cooling system tests.

If they fail, I’d be looking at a used engine. The 3.4L are a lot more common than the 4.7L’s.

 

Thank you, I was hoping it had a thermal shut off. I'm game to do the work but don't want to do it and have the engine fail later.

 

I cracked the radiator on my 4runner with the 3.4 and didn't realize it since all the coolant drained out and it ran until it couldn't anymore. Surfaced some heads and put them back on (in a college apartment parking lot in a blizzard under a tarp too ) and she fired up and ran for a long time after that. I would check everything, but in my experience case of one person, just the heads are fucked. And your engine was in a better scenario since most of the block was full of water since you said the leak was near the top of the radiator, in my case I cracked the bottom of the radiator so the entire engine was totally dry.

 

Thanks for your help. Did you have the heads rebuilt or just milled? Did you replace all the gaskets, water pump, thermostat, and timing chain?

 

Look at www.car-part.com, it looks like a used engine can be had for well under $1000. Granite, these are the local ones to me but might be worth looking into.

 

How many miles did you get from your four Runner after you milled the heads and replaced the gaskets, please? When it stopped running, what was the cause?

 

Snivilous: How many miles did you have on your four Runner when it over heated, and how many more did you get after you milled the heads and replaced the gaskets, please? When it finally stopped running, what was the cause?

 

When I did it I found a used set of heads that were super nasty, and got them surfaced and cleaned and checked for cracks and everything. I would've used the heads on the engine, but that got rid of some down time since I could get the "new" heads rebuild while I pulled the fucked heads. I did all the top end stuff, valve seals, checked valve lash, gaskets, etc. As I recall that was it, I didn't replace the thermostat or timing belt or water pump, but I was also hardcore on a budget and bought the cheapest top end rebuild kit for like $150.

 

I had like 180k on it when it overheated, probably got another 10-20k on it over a couple years. I had a bunch of issues and stuff that was just janky that I didn't fix/do correctly and it eventually caught up to it. I parked it, and eventually scrapped it since I had moved on. When I parked it it was having issues with the idle air control valve, and a coolant issue. I don't think it was the heads since it wasn't blowing white smoke and it was running and driving, but it was losing a lot of coolant (I think it was from the oil cooler, but never confirmed that). I don't think it was from rebuilding the top end since it was a lot of miles and hard driving later, but I can't say for sure. Once that happened (it was driving back to Colorado from Utah for the summer) I ended up getting a different vehicle, and kept the 4Runner for a few more years until I decided it wasn't the project I wanted to work on.

So your call. Being transparent, I did have engine issues a few years down the line which may or may not have been from the overheating, but I also had about the most intense form of overheating possible and rebuilt the top end in a parking lot and on my apartment kitchen table and it fired right up after that and I drove all around the western US and many stints of 3500-4000rpm for long bouts of time climbing mountains pushing 35s. So take it with a grain of salt. But my $.02, if I was in your position and had the time/know how/want, I would rebuild the engine and have no issue trusting it. I'm also a lot wiser and more experienced now, so I'd be a bit more thorough about inspecting stuff though.

 

Where are you? Want to make it a 4x4 v8? I have a complete 2001 Access Cab 4x4 parts truck that runs and drives. Its smashed up front so "runs and drives" is more like it could help get itself onto a trailer rather than it could co around the block a few times. The radiator is busted for sure.