rworegon

When you changed the radiator, did you fill the block with coolant through the upper radiator hose before filling the radiator? I can generally get about a gallon in through the top hose, a gallon in the radiator, and then another 1/2 gallon in after the thermostat opens with the heater runiing on high and in the hot postion.

The air pocket could certainly account for localized heating that caused the head to warp. The coolant temp sensor for the dash is on the lower manifold and would need to be submerged in coolant to give an accurate reading to the gauge. I don't think it gives any reading if its dry.....hmmm, I may have this backwards though.

-MUDSLINGER-

I will, and thank you for links and other info you provided. Im sure this was caused by myself, not filling up the coolant all the way or getting the air bubbles out of the cooling system or something of that nature. take your time ppl and it never hurts to double check, even if it something you have done multiple times, complaicent kills! so does misspelling, lol!

-MUDSLINGER-

nope, i just filled the radiator! I was in a hurry, Like i said in the last post, all this was caused by my negligence. I have sence put in another motor and made sure to do it right and it runs good, no problems! I just want my old motor back together for when this one gives up.

vital22re

iTrader: (2)

You severely overheated the motor. The temp gauge cannot read air temp, your block was empty and the thermostat did not open. You ALLWAYS fill the block first then the radiator or put the front end up on ramps so the coolant once it fills the radiator can flow down the upper hose.

-MUDSLINGER-

wierd thing is, I put two and a half jugs of coolant in after I put the new radiator in. it was reading fine on the temp gauge while i was driving down the drive way only on the way back up the hill it started over heating ( gauge went to the red). i think it had an airlock cause i put a different upper flex-hose that would not kink like the stock 3.0 hose. (cause i linked it and moved radiator 1/2 away from the pulleys and put an electric fan on the outside of the radiator) I solved the radiator hoses issue by swapping the bottom 3.4 water outlet to the 3.0 one that is shorter and has no bend, now the hose is like an (L) instead of an (S) witch can kink suck flat at high rpm. The top hose I changed back to stock 3.4 Hose just had to trim a few inches off of it to keep from kinking, the flex hose that was on there went so high up, i think the combination was creating an air lock and not flowing, therfor overheating. Problem solved! Just wanted input on warped/ cracked/ heads and block, and if i should have block checked before putting it back to getter cause it thought aluminum heads would crack and warp prior to the cast block, but its obvious with all the money being trown at it to have it checked regardless. thank for the imput and I will let you know what i find on the block.

Texas_Ace

You already have the heads ready to reinstall? If so install them since you won't be out anything. See what happens.

If you have more problems, fine a junkyard motor and swap it out. After the motor overheats like that getting a junkyard motor seems to be the best option besides a complete rebuild, which costs more then a replacement motor.

-MUDSLINGER-

I just picked up the heads today, And dropped the block off at the same time. I will know the damage on block by end of next week. And for you to say i wont be out anything is pretty stupid, Have you priced head gaskets for a 3.4? 60 bucks each and my labor, also the head bolts can only be used once. I dont think your advise is very wise, cause i could go through this all over again. I paid $360 for the full gasket set, head studs were another 100$ and a good timing kit was 140$ total for the heads done and all parts to put the top end back together was 600$. I dropped the block off w/ the crank and rods pistons etc. still in it, to get it hot tanked, inspected for cracks, warpage, etc. the bottom end is getting rebuilt with a minium of hone, rings, and bearings regardless while its apart. Then I have a fresh motor for when this unknown motor gives up.

rworegon

Fingers are crossed for good news on the block.

Texas_Ace

Actually the advise is about as good as it gets since you have already spent too much money. You could have got a whole engine for $750 and come out far ahead of this rought but you were past that so the best idea is to just use what you got and hope it holds up.

Fact is I have seen a LOT of these deals where a rebuild after overheating ends up with another blown motor a few months later. Not worth messing with at all when a used motor can be had for less then half the cost of a rebuild.

If it were mine, I would sell the heads to get back whatever I can out of them and then go get a used motor to drop in.

I didn't want to just say you messed up, so I tried to put it in nicer terms.

I hope it works out well and holds together long term, I really do.

-MUDSLINGER-

750$? Were ill buy a couple right now, I paid $1200 for a 70,000 mile 2002, and just paid $2000 for a rolled taco extrcab with 18x,xxx miles. My machinist is only charging me another 600 for a fresh bottom end regardless if he has to get another block. Helps to have good friends! Im now going to be in this motor $2400 total, witch is the price of a new remaned! and it is going to be fresh again, just like that remaned. two for the price of one! lol. Its in my wheeler, i rod the piss out of it every time i drive it. If it were my Daily driver i would care alittle more.

Texas_Ace

I have seen them go locally for $750-$1000 on a regular basis. Higher mileage motors can be had for $500-$650. I know, I was looking earlier this year when I was thinking about getting a motor to build.

I just look at things from a $ to results perspective. In this case even at $1200 for a used motor that would be the better deal. lol

I would actually prefer an OEM toyota motor over a rebuild of an overheated motor. I have seen it happen more then once that a full rebuild doesn't last very long after an overheat. I really wish you luck though, hope it lasts for you, it is really luck of the draw.

-MUDSLINGER-

Thanks for the luck, lol! Ill keep you guys updated on the outcome.

-MUDSLINGER-

Got the tacoma motor pulled from the rolled tacoma and put it in my mobber to take out on new years! got my block back from the machine shop, tanked mag'd (NO CRACKS OR DECK WARPAGE) and new bearings rings hone freeze plugs and bottom conversion gasket set assembled for around $480, the heads was the only problem Warped .0015 out from being over heated, resurfaced and put the motor back together and stuffed it in another 91 extrcab I traded for few days ago. And I got another project underway, Fml! Another 3.4 swapped 90s build, thinking of long travel, something for the dunes and tuff trucks, my wheeler sucks for jumping and speed.

bruced_500

curious how this ended. My 3.4L engine just took a and lost all it's coolant out the tail pipe. I'm in the market for a new engine now . I'm wondering if all years/models of the 3.4L are interchangeable . Mine is a 4x4 Auto. Some dismantlers are trying to tell me a 2x4 engine will not work in my 4x4?? Any truth to that ?

Texas_Ace

Pretty sure that a 5vz is a 5vz. I would try to get one from a 98 and up as they are stronger.

You may have to swap over all the external stuff from your block to the new block but the base blocks should be the same.

Man4God

Never heard that the 98+ motors are better. Can you explain or show a post?

Carry on!

Texas_Ace

The pre-98 engines had head gasket issues that they fixed in the 98+ years.

Man4God

I had always thought it was limited to 96 models. My 97 has just about 200K on it and never had an issue. I should look for a TSB or something.

Texas_Ace

I had heard it was both years, or maybe that was just the ECU that doesn't play nice with a supercharger is in both years.

Man4God

I forget you are boosted. I too recall that the early ones have ECU issues with the supercharger. And when you add boost, one small thing can make a motor go bang!

I think if you are staying N/A and just using the long block, a higher mileage 96+ should do the trick. Just crack a valve cover and see what it looks like. Gold colored? Run it.

Thanks for the info TA.