LS6 Swap 2nd Gen Build + New Tundra

I’m pretty sure that’s how I have it. The only thing I could guess is that there’s big enough air pockets for the pump to start cavitation and overheat. I’m gonna try sucking the air out with a vacuum pump from the steam vent. Can’t think of anything else.

 

yeah with being rear mounted that seems like the most probably thing if you’ve checked everything else. What I like to do to power fill an empty system is to use one of those 12v water pumps and use a flush kit that has a hose tap at the heater hose and push coolant into the lines until it overflows out of the radiator.

 

That’s a ducking brilliant idea. Has to be the heater hose? I have a place on the top of the water pump, but I imagine the pressure is just going to take the path of least resistance and not fill. What’s your suggestion on what to buy to make this work?

 

doesn’t have to be but any of the smaller hoses. Maybe one that taps off to go to a temp sensor or the like, just not the larger main inlet/outlet hoses. The heater hose is nice because it’s at the top of the block so it forces water in most of the places it needs to go and easy to access. Not sure on the LS engines but on the taco and my old ford there are block drains you could also crack to check they flow without air as well.
I used something like this kit
https://www.autozone.com/cooling-heating-and-climate-control/radiator-flush-tools/p/peak-flush-and-fill-kit/525931_0_0

on my 7.3 the heater outlet is super easy to access

 

My apologies and I really don’t know but on my vehicle’s the hot water exiting the engine comes out and goes in the top of the radiator on one side than exits on the opposite side and low.

Could be the radiator in the front of the bed down low not getting enough air flow?

Dear old dad built a mid engine rail with a Ford 289 with a 914 transmission. The radiator was custom made to fit between the top rails that went down and to the rear of the rail. He then found a small high speed motor and mounted a fan blade that would blow a ball cap off your head and the engine would over heat if idling for a long time. He then made some air scopes that were about 2.5 to 3” tall and 10 to 11” wide on each side. Temperature would drop like a rock as soon as you started moving. Sorry i wish i had some pictures for you.

 

Per @6 gearT444E I got one of those flusher kits and got the T installed. No coolant came out when I cut the line :/


Gonna flush fill it tomorrow and see how it comes out. Gonna take the overflow line off the reservoir and stick it in the 6 gallon jug of coolant I have right now, that way eventually it should circulate in there.

 

Maybe the hot goes in the top, not the bottom I could have been mixed up...I don't think it would cause to overheat nonetheless. I think the theory since heat rises if the hot outlet goes into the top of the radiator it will spend more time in the radiator due to heat rising...I could be wrong though.

 

This should help.

 

LS6 is a tad different, both heater hoses come off of the water pump on the thermostat housing.

 

Some other good news, the transmission isn’t a 4L60E like I was told, it’s a built 4L75E!

still not an 80e, but definitely better than a 60e. It’s good for like 650HP/600TQ, 2800-3200 stall with lockup converter. Definitely more than what I need, thank goodness.

 

Good thing that I said "should". I tried doing g some brief search, with no luck finding a similar illustration. Regardless, one port will go to the top of the radiator, just the same as before. That is an easy test to find out. Simply knowing which one pumps out. I am.sure you know that already. If the heater hoses are in opposition to the radiator flow, it could create a problem.

Just a guess though, but it kind of seems like you may be experiencing vapor lock.

I have heard of some setups similar to yours that required a pump to aid the flow across the distance. Just s thought

 

I believe the illustration is of a SBC (for illustration purposes only). My 5.3 L33 cammed truck engine now has the same water pump as you (I believe). As I switched to Vette accessories that are 1.5” closer to the block making the engine more compact. I.e. more room for the custom fan shroud I had fabricated to fit & cover every fin in the radiator. The shroud sets within 1/16” of the fins and holds two 12” SPAL fans combined pull 4400 CFM. The shroud slides and bolts in just like the factory composite plastic one does. The shroud also has six 3” holes in the aluminum shroud with thin rubber flaps that will allow for more flow at highway speeds. All this behind the drop in Mishimoto radiator in the OE location to get maximum air flow to keep the baby all aluminum 5.3 cool. I want the installation to look as factory looking as possible!!

The drop in radiator below;
https://www.mishimoto.com/aluminum-radiator-toyota-tacoma-2005-2015.html

*edit*
The gentleman I’m having do the install is working with a motor mount manufacturer to make mounts that are 100% bolt in. I asked for this to help perspective owners who may want to also drop in an LS in the future into a 2nd. or 3rd. Gen. being no one makes a kit as of yet. Just trying to get more to jump aboard hopefully….
Oh, being my Taco is a 4x2 I’m going to have Andy take photos of the engine and oil pan using a tape measure to take pictures of the clearance above the cross member/s. As I don’t know how far up the front differential sets above the cross member/s… Again just trying to help others.

 

Well that idea didn’t work. With the pump running, the coolant is being heated up evenly, but without the electric pump running, the radiator isn’t getting hot. Idk what to do.

 

No room in the front for it.

 

Sounds like an auxiliary pump may be required.

 

Im going to back the car into the driveway on some big wheel ramps and try the previous steps ive done again. Hoping that will make the difference!

 

Man, the holley gets really upset if the battery voltage drops too low. Dropped to 11.9 and it wouldn't start anymore, despite the starter spinning the motor at like 270RPM.

I backed the truck onto ramps to try and bleed, and it wouldn't restart. after jumpstarting, it started, but I couldn't bleed the system. I think I need a fill port on the engine side. One will be here tomorrow, it's my last shot before the truck goes to 454 next week for the front end to be put on.

He's going to do full aluminum skids, front bumper, fiberglass, core support, engine crossover, resi mounts, just the "small stuff" to get this thing finished and looking like a tacoma again.

 

On todays post of “shit I bought that I don’t need to get the truck working” @Baja Designs Brandon hooked it up and got me a linkable light bar for the Tacoma. Can’t wait to get it on.

 

That's cool

 

Hallelujah!


Fill port on the top of the water pump is all it took. The system sucked down another gallon with this. After that, the cooling system stabilized at 205. Took her on her first real drive, went around the neighborhood a few times, about 10 mins. No issues! I want to have someone remake my power steering lines, the an fittings I have are leaking. Need that, an exhaust, and AC lines made, but man is this thing fun to drive! It’s freaking quick.



got the linkable light bar from Baja designs installed tonight too. Real trophy truck shit! As if the suspension wasn’t, lol. Anyways, gonna take the truck to the gas station tomorrow and give her a fill up.

the truck had an issue with hot starts. Whenever it got up to temp, if you shut it off, it wouldn’t want to restart. It would just crank and crank and crank. Lowered the fuel regulator pressure from 85 to 60, and now it hasn’t happened since. I think I was vapor locking the fuel system. The truck got to learn its tune a little bit so it’s not running quite so rich, but it needs an exhaust to really clean the AFR up. T- 1 week to 454 motorsports to make this thing look like a truck again!