05 4.7 2uzfe overheat

Is it possible for coolant to burn threw exhaust from intake gasket leak? Truck will idle all day, soon as put it in drive it gets hot. Oil is fine, no combustion gas in radiator. I already have head gasket kit. Really just hoping not to have to go that deep into it

 

Yes - you can usually smell it and it will smoke a little - especially on startup. Most likely a head gasket leak.

 

I disagree with “most likely a head gasket” given the minuscule bit of info we received, and thinking about the other ways coolant could hit hot stuff on the 2UZ specifically.

Can you give us some history on the truck? Like, any recent major overheat events? Any recent changes like water pump, thermostat, radiator, heater core, anything that touches fluid, or replacement of fluid, since overheats can be caused by not properly burping?

I ask this because there’s the coolant crossover tube that could potentially land coolant on something that would burn. There’s a whole section for “coolant leaks” that discusses the crossover in the thread-everyone-should-read: https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

 

Yessir, I bought the truck 2 years ago for 1k because engine was not running (I dislike the term "blown up" because if there isn't parts laying across the yard it can be fixed). When I started dismantling it I found both intake valves setting on top of #1 piston. Now this could be from previous owner or from the fact that all I had ever torn into was a vortex Chevy and didn't know what Interference engine even meant. Very possible I turned crank with timing belt off.....that being said the intake was melted on bottom so it had ran pretty hot before I got it. I found a engine in Buffalo new York, 210k miles for 3k$.....cheapest I could find. When it arrived to Flatwoods TX (my residence) everything metal on it was covered in scale. Salt from iced over bridges i assume. I stripped; sanded, and coated it. After install it crank right up but wouldn't move. I soon realized I had jammed flex plate against torque converter and busted pump (I presume, haven't had chance to break down transmission yet and see). I found a transmission in Oklahoma and drove there next day to buy. After install it I had to replace computer or I did at least because I kept getting pcm processor codes. Also the original radiator had swollen on top and was leaking so I replaced it and thermostat with oem. After a few minor things like grounds and plugs needing cleaned up it fired up and I went around block ( live 15 miles from a red-light or gas station so "block" is about 3 miles. Noticed temp gage had quit working around 1.5 miles but figured my luck can't b so bad its hot.......I was in correct. When pulled up to house steam was ROLLING!! Next day I fired it up and it seemed ok. Only used water on first test drive so went and bought new temp sensor and red coolant. Now when crank at idle it is fine but smell coolant burning from exhaust and steam from passenger side between firewall and block. Will idle at least 20 min with no issue other than the loss of coolant and heater not blowing hot. Put in drive and u might get .5 miles before it spikes and have to shut it down. No oil in coolant, no bubbles or combustion gas in radiator. That is all I can think of. Sorry for lack of info before but my La 1A public education mixed with fact that sunlight and cell service has to b shipped down in the woods.........

 

I have since answered my question finding that there aren't any water passengers in plastic intake....du. so now other than pin in tensioner and service bolt in left head is there anything else I need to do? Gonna go ahead and take it down the valve covers tonight and lay it down. Not going any farther until someone with more experience (wouldn't take much) gives me a head nod. Thank u whomever is there and God Bless ALL.

 

Uh...wow! Lot's of variables here. Assuming the new engine wasn't toast when you got it:
1. Have you filled and "burped" the coolant correctly so that there's no air in the system?
2. Have you checked the ATF level (you have the "no dipstick model)?
3. Find a way to pressure test the cooling system.
4. If you're not using a new OEM radiator cap, then go get one.
5. Is the fan clutch behaving properly (search this site or google).

Edit: I just re-read your synopsis and found the "smoking gun"...no heat! Definitely air in the system. Search the site (or google) how to burp the cooling system.

Another Edit: Steam from the passenger side/firewall suggests a leak in the coolant bypass and/or heater hoses.

 

Headgaskets can fail in many ways, I've had more than my share.

Coolant to exhaust failures for me have ALWAYS resulted in exhaust in the coolant, never coolant in the exhaust.....which is logical, as the cylinder pressure is far higher than coolant system pressure. I would examine EVERY possible option before doing a HG with your symptoms.

 

^^^ +1

Don't even think about pulling the head!

Try this: https://www.motortrend.com/how-to/impp-1108-blown-head-gasket-diagnostic/

Then find a way to do a compression test.

 

At the moment I have the intake off. Against my better judgment I'm going to clean up and install new gaskets on bypass, put back together and if problems persist i will make video. Only running on 7 hrs sleep in 3 days because I need this thing going before I start a remodel Wednesday. Hope yall r correct and I have done a block test. NO COMBUSTION IN COOLANT. 1 other thing....every vehicle i have ever seen has the thermostat in upper hose. This 1 goes to bottom of radiator and I promise a cap isn't causing this issue. Have burped this fella (if not family safe i have a better word!) Until it thinks its a newborn, heater core not blocked but 1 thing i forgot. If I crank with cap off it blows a stuff everywhere for 1 second. Like a big bubble but all fluid?? Doesn't matter how long i burped it. On incline or decline. Maybe I got thermostat in wrong hole? Right side of engine. Left if looking at it

 

And you clocked the t-stat with the jiggle valve between 11 - 1 o’clock during install?

It’s the only other thing I don’t see mentioned above.

Not saying it’s not the head gasket, it very well could be, but the guys aren’t wrong about the other things to check before digging in.

Also there are two coolant temp gauges on these trucks. One goes to the ECU, the other goes to the gauge in the dash. For newer models like yours and mine they’re in different places up top.

 

Thanks for reply. I was wondering abut the 2 temp sensors. I only find 1. It is before thermostat, where is other? I did clock thermostat to noon. Think i might have explanation. I used the crossover from original engine for no other reason than it was prettier. I believe the original issue was the same 1 I'm having now. Believe crossover was communicating with secondary air. Other than a check engine light what would it hurt to block it off. Like egr on vortex. I've never owned a vehicle that check engine light wasn't on and windshield wasn't cracked. I'm gonna install other crossover but why can't I block it between valve and exhaust?

 

That’d be a question I’d throw @empty_lord if he was able to answer publicly (don’t PM the guy, best to keep any answer public so others can benefit). I personally don’t like messing with coolant flow across a block. There’s at least one place I wouldn’t hesitate because I’m in the south - and that’s the pass thru at the throttle body - but that’s about all.

 

Block what exactly?

 

Actually just remembered @BubbaW posted info on ECT senders, and I stumbled the details prior. Things changed for '05-'06. More info on that here: https://www.tundras.com/threads/hot-no-crank-no-start.130875/#post-3331586

FSM for our year of truck is here if it'll help.

Coolant crossover tube.

 

And to that point, I'm only seeing one sensor in the exploded parts diagrams, and it's in the EFI diagram for whatever reason. My part# (2006 access cab v8) is showing as 89422-06010, and it's located where you see it in these pics from the FSM:

​

 

Blocking the crossover will lead to uneven distribution of the cooling. You’ll likely end up warping a head

 

No sir. Blocking the 2ndary air pump. I think my issue is communication between 2ndary air and crossover on back of engine. That how coolant is burning out of exhaust. Think back crossover must b cracking inside. Block both downstream of valves on each side. Do I really need 2ndary air? Like I said I will take bulb out of check engine...hahaha. I keep a code reader plugged up n every vehicle always. Honestly think its BS.....naw its BULLSHIT that they don't come mandatory built in. Cost another 1k at most for best made to just build I to media screen. Should b law.....or to a backwoods river rat at least. I mean. I have another crossover I'm about to install. Guess its just more of a incase question. I like knowing how things operate when possible and not very often do I get to ask someone who knows. Thx for all help. I will let yall know how it's goes. God Bless u all

 

Don't be the guy who lets your truck run intentionally with the money light on. There are inexpensive bypass kits for the SAI pump that trick the truck into believing the temperature outside is low enough SAI pump doesn't need to dun. Essentially an SAI delete. Hewitt Tech's 1st gen version is easy enough for the average person to install, I can link you up with a video. But I and at least two others on here have posted instructions on how to build your own bypass kit (bypass kit info here, build your own kit instructions here). The SAI system is pretty well documented on here, both the pump, the valves, and their functions (at least I feel like they are).

You should know: We've had cases of dudes on here who had a leak all the way up at the front of the block making its way back to the rear of the block. Water finds a way.

 

PS - taken from the megathread, the "leak beyind the t-stat housing" is the one that was draining all the way to the rear of the engine IIRC... but you'll also find links to videos of other leaks, like the crossover tube etc. that will leak at rear.

• Coolant leaks: Three common causes: One is the is the gasket behind the thermostat housing, another is the coolant crossover at the rear of the block, and last but not least, old radiators is another source. Here's a list of things to check if you're losing coolant. For repairing the leak behind the t-stat housing, check this out. For the coolant crossover tube issue, you'll likely find coolant at back of the block, near where the trans and engine meet, check this reply for video/fix. This reply contains links to three other off-brand/odbball leak cases. For radiator leaks, this is one example of a tiny one - always replace with Denso brand radiator, and know different cab types use different sizes, careful where you order, scAmazon especially tends to deliver damaged products often (RockAuto has a spotless record with forum members). Proactive radiator replacement is wise. The transmission line routes through the bottom of the radiator ... go look up "pink milkshake", it happens in these trucks.

 

My man I'm the guy that puts a holley dp on this machine before I'm done. I will go HEI and not points tho. So (theoretically) if I take pump, switch, and both valves and thro in tall bushes. Cut wires and cap will it affect ANYTHING except a code? I do my own coding. Surely u don't think I got exhaust dampeners (catalytic converters) on here do u? And no delete kit just 2' pipe straight welded to exhaust flange to a super 40 and kicked out at 45 on each side. Vehicle inspection around here just glad u got insurance.......a fresh $20 and that can be worked out 2 if needed

 

Oh the SAIS. You need the Hewitt delete kit. Just blocking it with nothing else will make the truck pretty much un useable. ECU will set in to a safe mode


The ecu will not let you drive past 30mph if I remembered right.

 

10-4 ima just go like it is but use other crossover and c if that fixes it. B silly to buy something when I actually not even sure head gasket not blown. 90% sure crossover was cracked and communication between coolant and secondary air was happening. Just looked at passenger side rear of exhaust manifold and I didn't tighten good I don't guess because its loose. That explains steam from firewall and what made it thru came out exhaust

 

I have no idea how the Secondary Air, and coolant would be at all related. Secondary Air is triggered off the Mass Air Flow Sensor, at least that’s what the Hewitt intersects.

I may have missed it, but have we done a Compression test? I’ve pulled the radiator on multiple 2UZs many times and have never had issues with air pockets in the system.

 

So you can kill the 2uz

 

I mean, "kill" is a relative term. There a few things that'd require surgery taking things down to the head gasket, none of them are common, though.

The worst damage we've seen is from people who fail to take the timing belt as seriously as it should be. But we've also seen people replace their entire engine because a valve was stuck. They took a compression test literally and pulled a perfectly good engine.

I'll take anything that'll run 300k-400k miles or more without anything more than basic maintenance.

 

I've seen pics of a few that have had windows poked through the side of the block.

 

I mean, we had one here recently. But if I think about how many times I've seen it here versus what I'd typically see it on a GM, Ford, or Dodge forum, it's maybe 1/5 or 1/4 as much.

 

Quick question @KueCo, what color is your truck? Do you have a pic of it by chance?

 

The rear coolant crossover tube and the valves on the exhaust for the SAIS are right next to each other. But you are correct, there is no way for them leak from one the other like the OP is saying. They are 2 completely different systems that just happen to be near each other.