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5VZ-FE Possible Head Gasket

Stingray said:
So far none of that yet, Just a slow rise in temps the longer I drive. So far I haven't driven it long enough to see where it stops. I've blown a head gasket on one of these trusting the factory gauge. so far I haven't let it get over 220* ( Reading off the OBD2 port using the torque app)

For reference since I've owned it over the last 80K miles it sat right at 199/205* max. 20K ago it got a timing belt set and water pump/thermostat and continued right back at the 199/205 pattern.

Also it is loosing about a quart of coolant every two weeks or so driving it 3/5 miles a trip, lowering the overflow bottle no leaks in the bottle.( My son is using it to get to work until we get his cruiser finished)

Things are busy so we are nursing it along, knowing the limits, and working inside of that for now.

Thanks for the input.
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I'd suspect a clogged radiator contributing the higher temps. Get 'er good and hot and then pop the hood when you park it...have a few beers and take turns watching the overflow bottle....see if it fills up and starts to overflow as the engine heat soaks the coolant...over the course of the next hour. Also, pull the trans dipstick and check for a strawberry milkshake.

A blown headgasket should not cause any overheating until it lowers the coolant level.

Trick for finding combustion leaking into the cooling system is stick a funnel in the radiator neck (with a relatively decent seal) while hot and get a few inches of coolant standing in the funnel. Raise the RPMs and if you've got a leak, it will look like fog rising through the coolant in the funnel. The same can be accomplished with once of those blue juice block test tools, but half the time I suck green coolant up in it which turns it yellow just like combustion gasses.

I find it unlikely that there is coolant leaking into the cylinder while running...but NOT after shut off. After shutoff, cooling system pressure will be higher for a bit and there will be no cylinder pressure....optimal conditions. When running, conditions are less than optimal. Can't say I've ever seen one leak running but not after a heat soak....seen hundreds the other way around though. None of your tests point to a headgasket problem....so far.

One other thing you can do....get your pressure tester on it while it's running and hot....put 10psi or in it and rap the throttle a few times. The water pump doesn't make pressure...it's just a circulator. If you see the pressure spike more than 1 psi or so, That might point to a combustion leak.

A thermal imagine camera would be badass in this situation to help pinpoint what's going on.

I love these engines...used to do warranty work on 'em at the dealer, and have owned at least 10. I've seen a few crack heads between the valve seats, but can't say I've ever seen one blow a headgasket for no reason....they usually pop after a severe overheat event caused by something else, but even then...mostly the earlier ones with the composite headgaskets. The MLS headgasket (OEM ones at least) usually take a beating until the head warps.
 
Lbhsbz said:
I'd suspect a clogged radiator contributing the higher temps. Get 'er good and hot and then pop the hood when you park it...have a few beers and take turns watching the overflow bottle....see if it fills up and starts to overflow as the engine heat soaks the coolant...over the course of the next hour. Also, pull the trans dipstick and check for a strawberry milkshake.

A blown headgasket should not cause any overheating until it lowers the coolant level.

Trick for finding combustion leaking into the cooling system is stick a funnel in the radiator neck (with a relatively decent seal) while hot and get a few inches of coolant standing in the funnel. Raise the RPMs and if you've got a leak, it will look like fog rising through the coolant in the funnel. The same can be accomplished with once of those blue juice block test tools, but half the time I suck green coolant up in it which turns it yellow just like combustion gasses.

I find it unlikely that there is coolant leaking into the cylinder while running...but NOT after shut off. After shutoff, cooling system pressure will be higher for a bit and there will be no cylinder pressure....optimal conditions. When running, conditions are less than optimal. Can't say I've ever seen one leak running but not after a heat soak....seen hundreds the other way around though. None of your tests point to a headgasket problem....so far.

One other thing you can do....get your pressure tester on it while it's running and hot....put 10psi or in it and rap the throttle a few times. The water pump doesn't make pressure...it's just a circulator. If you see the pressure spike more than 1 psi or so, That might point to a combustion leak.

A thermal imagine camera would be badass in this situation to help pinpoint what's going on.

I love these engines...used to do warranty work on 'em at the dealer, and have owned at least 10. I've seen a few crack heads between the valve seats, but can't say I've ever seen one blow a headgasket for no reason....they usually pop after a severe overheat event caused by something else, but even then...mostly the earlier ones with the composite headgaskets. The MLS headgasket (OEM ones at least) usually take a beating until the head warps.
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Radiator is new zero miles when the waterpump was done, and I did check for pink milkshake, I also did the blue liquid to yellow block tester tool, basically looking for exhaust in the coolant.


A thermo gun is another great idea, and I do happen to have a very expensive FLIR thermal imagining gun, I never thought about that.

Sitting at idle it will stay at 190* for days, but once I drive it, the temp starts to rise.

So thinking headgasket or weak ass water pump.

But all suggestions are welcome.
 
Stingray said:
Radiator is new zero miles when the waterpump was done, and I did check for pink milkshake, I also did the blue liquid to yellow block tester tool, basically looking for exhaust in the coolant.


A thermo gun is another great idea, and I do happen to have a very expensive FLIR thermal imagining gun, I never thought about that.

Sitting at idle it will stay at 190* for days, but once I drive it, the temp starts to rise.

So thinking headgasket or weak ass water pump.

But all suggestions are welcome.
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Ok, not gonna read through the whole thread again.

What was done to this thing just prior to your noticing an issue?

Also, does the overflow bottle ever go empty, or just lower than you put it…and how low in relation to the “low” line?
 
Lbhsbz said:
Ok, not gonna read through the whole thread again.

What was done to this thing just prior to your noticing an issue?

Also, does the overflow bottle ever go empty, or just lower than you put it…and how low in relation to the “low” line?
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No worries on doing a whole read,

No work has been done prior to this starting, Kid drove it home said the truck is running hot (220), and parked it. i go out the next morning and find a bad radiator cap, replace it and started an ongoing list of trial and error parts changing and troubleshooting to solve it.

Just about everything in the cooling system has been replaced.
lower radiator shroud section ( small lower section was missing)
thermostat ( removed a non Toyota and replaced with a Toyota I had on the shelf Installed per FSM)
fan clutch ( Asian)
lower rad hose (not bad, but worn so did it with the thermostat)
Ran compression test (180 across 6 cyl)
exhaust gas tester/block tester

Things on the list:
water pump (sitting on the bench)
Cyl Leakdown test
replace coolant temp sensors (2)

Trans runs near 200*
and all reads are being read off of the OBD2 port per Torque app, and have been being monitored continuously since I bought the truck about 80K ago.

Thanks for the input.
 
IDK shit about Toyota water pumps, but my experience with two of these motors is they last awhile, I don't have a leak, and I don't know if they have a flow issue, I read your comments about a blockage, and that my very well be what I am dealing with. it's gone 20k without an issue. but that does not mean anything.

My son has needed it for a 3 mile commute so I haven't torn into it, When we get his Land Cruiser running I'll be able to take it out of service. for now this is where we sit.
 
Update***

Took a radiator pressure tester and let it sit about 2 hrs at 20 psi, it lost less than a pound cold. (That could have been lost in the tool) no visible leaks.

So next test was start it cold, no pressure but with the tester on it to read. All looked good at idle, it got up to operating temps (185*) and pressure in the radiator was 5-8 PSI.

Once at operating temps I held the throttle at about 2k for about a min. while doing that pressures in the radiator slowly creeped up into the yellow zone on the pressure tester. 20-25 PSI.

Water temps. stayed steady at 186* Seems like that much pressure would overpower the 15Lb cap and vent, But also does not seem normal.
I have an identical second truck so I'll run the same test on that one to see what's up.

Again, It will idle in the driveway at 185-190* for days, once out driving it pushes up over 200, And I haven't let it get above 220. Probably 5 miles or so.

I also know the tester has no way to vent so this all may be normal.

I have not done a leak down test. No tester.
 
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Your issue does sound odd, didn't read the whole thread but had a similar issue on a friends vehicle that never reached operating temperature due to the short commute. If they used the vehicle for longer than 5 miles, it would overheat. IIRC, they replaced the radiator and all the cooling parts as you have, but in the end it was determined the heads were trashed. I'm no expert, so I am not sure what damage is done from not reaching operating temperature regularly.
On a slightly separate note, I had a 3VZ that had major issues due to some PO ghetto fabbing. When i removed the heads to the engine it appeared the coolant was eating away the metal on the heads, nothing leaked yet, but it wasn't going to be long be long. I also noticed my engine had a few grounds missing from it and it had green coolant, that I'm not so sure was even diluted.
Good luck
 
Ok,

Just ran a radiator temp/pressure test on a fresh rebuilt motor, from cold with no pressure in the radiator to operating temps (190) the pressure settled in right around 14 psi, also bringing the motor up to 2000 rpm caused the temps to drop down around 186, and the pressure to drop a pound or so.

Both trucks are running green coolant, the one with an issue has been about 20K miles, but well maintained, and my daily has since my rebuild about 10k ago. again well maintained. I highly doubt coolant is the issue here, betting 300k on the clock.

The truck in question pushed radiator pressures above 20 psi on the pressure testing gauge.

I really didn't want to open that can of worms.
 
Alright, I just got my results back from Blackstone, I did a sample at 1000 miles to decide If I was doing a motor or head gaskets or what.
Results are in, and sounds like the motor is sound, so this weekend will be a solid radiator flush on a 20K mi. radiator and a water pump.

Both were replaced when the timing belt was done 20K ago, but those are the last two pieces that have not been touched.


Below is Blackstones reply, I can post results also. NOTE, I pulled an oil sample at 1000 miles.


Blackstone:

Coolant/antifreeze shows in testing as high potassium and sodium. Both of those elements are low enough to rule out coolant contamination in this first sample. Given your concern, we'll keep a sharp eye on them as trends develop. There is fuel dilution to note, but 1.3% is often situational and (aside from thinning the oil a little below spec) harmless. Wear metals are low, which we'd expect after just 1,000 miles. The averages for the 3.4L are based on about 5,800 miles. Looks good on our end. If you wanted to run longer, add 2,000 more miles.
 
ok, latest update,

New water pump, and radiator flush. I gutted a thermostat to make flushing the system easier, ran a Prestone flush for about an Hr and cycled about 10 gallons of fresh water. Water was clean and clear, looked like fresh antifreeze

Right now running the cut out thermostat and distilled water, It takes longer to get to temperature but ultimately still pushes up over 215, I've told the wife it's good to go around town for her errands, she never travels more than 10 miles.

Next week I'll have a new Toyota thermostat, and two new hoses, but betting this won't really help the problem.

I do have two new temp sending units, one for the water temp gauge, and one for EFI, again, not sure these will help.
 
At this point I've told the wife to drive it into the ground, it will solve itself.
my money is still on a head gasket.
 
Still reading off of ODB? Sending units are all that’s left?
 
May be with throwing a mechanical gauge and sender on it as sanity check before pulling heads?
 
If anyone needs to pull there harmonic balancer, I bought a tool that works pretty well
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LATEST UPDATE

I've had a problem with high water pressure, over 15 psi. and over heating if driven more than 10 miles.

Well last night it pushed the upper radiator hose off and dumped the coolant, also ran the temps up to 230*'. My son drove it about 3 miles and it happened during that drive, suspecting as he reached the house. Thats when I saw temps start climbing.

went out this morning and reinstalled the hose, refilled the radiator and took it for a drive. drives like it never happened. still high water pressure, and overheats, So I'm over it, Junk yard motor going in, I'll hunt one down this weekend and swap it out.

I thought I could solve this but I'm over it.
 
Stingray said:
LATEST UPDATE

I've had a problem with high water pressure, over 15 psi. and over heating if driven more than 10 miles.

Well last night it pushed the upper radiator hose off and dumped the coolant, also ran the temps up to 230*'. My son drove it about 3 miles and it happened during that drive, suspecting as he reached the house. Thats when I saw temps start climbing.

went out this morning and reinstalled the hose, refilled the radiator and took it for a drive. drives like it never happened. still high water pressure, and overheats, So I'm over it, Junk yard motor going in, I'll hunt one down this weekend and swap it out.

I thought I could solve this but I'm over it.
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weird....

you going to yank the heads on this one to check after? Just curious.
 
Well never did solve it, and didn't like the the JDM/Junkyard options, So started the process of pulling the heads this morning, I'm down to needing a slide hammer to knock the intake loose, my back said I was done so quit for the day.
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What did you find when looking for an engine? Mine blew head gasket a couple weeks back. My local JDM place is ridiculous price, $3400. I can order from out of area (CA) about $2700, but then don't get to look at it and not sure i trust it without being able to look it over. Been watching the classifieds for any wrecked ones. Not sure I just want to do headgasket with 295k on my engine.
 
dukkhnter said:
What did you find when looking for an engine? Mine blew head gasket a couple weeks back. My local JDM place is ridiculous price, $3400. I can order from out of area (CA) about $2700, but then don't get to look at it and not sure i trust it without being able to look it over. Been watching the classifieds for any wrecked ones. Not sure I just want to do headgasket with 295k on my engine.
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Local So Cal are $2400-$2900 from a list of "JDM" suppliers, no one can confirm any real mileage, All say low- around 60K.

I've asked where are you finding 60k mile motors when this motor went out of production more than 20 years ago. I did a bunch or research and could not get a solid answer, basically because I said so.

found a couple local guys stripping trucks, $900 -$1500, and your on your own.
 
Stingray said:
Local So Cal are $2400-$2900 from a list of "JDM" suppliers, no one can confirm any real mileage, All say low- around 60K.

I've asked where are you finding 60k mile motors when this motor went out of production more than 20 years ago. I did a bunch or research and could not get a solid answer, basically because I said so.

found a couple local guys stripping trucks, $900 -$1500, and your on your own.
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Thanks, that is my feeling too. I kept getting told to expect them to be very sludged up because, "they only got driven short distances"...im guessing it is higher miles and no oil changes. I'm going to hunt for a little longer for something wrecked with confirmable mileage, if I cant find one i guess ill just do top end of mine.
 
dukkhnter said:
Thanks, that is my feeling too. I kept getting told to expect them to be very sludged up because, "they only got driven short distances"...im guessing it is higher miles and no oil changes. I'm going to hunt for a little longer for something wrecked with confirmable mileage, if I cant find one i guess ill just do top end of mine.
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I'm pulling the heads on mine, and if I need a motor I'll source one local that i can verify
 
Stingray said:
I'm pulling the heads on mine, and if I need a motor I'll source one local that i can verify
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Ill probably end up doing the same, mine never got hot, just started stuttering one day and threw P304 and I stuck one of those cheap borescopes you hook to your phone in cyl 4 and could tell it was head gasket.
20230321184912915.jpg
 
So I'm pulling the heads and the dots to line up the cams seem to be on the backside of the gears Is that right?

Towards the back of the motor,
 
Stingray said:
makes it super easy to reinstall in the truck:homer:
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yea, I thought that was an odd design choice.

I am sure I'll get the displeasure of finding that out oneday. Since I now have the desire to have a supercharged 3.4L.
 
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