Overheating !

[tpelletier]

2002 4runner about 200k miles.

Having trouble diagnosing the cause of the overheating engine this weekend.
would love some opinions and diagnostic tips/tricks.

Current known issues/codes: catalytic converter & evap system. Slow oil leak.

Thursday 4pm:
Loaded the black beast to the brim with friends and camping gear to head to Live Oak Florida, about 6h or 450 miles.

Noticed quickly since the new roof basket and the 1,000lbs + of bodies/gear the gas mileage went down from ~22mpg to about 16/17mpg.

9:23pm
About 2 hours before arrival. Felt weird gear change, looked down, CEL, temp in the red, pulled over, coolant everywhere, let engine cool, fill radiator with water, turn engine back on, engine stutters for 5 seconds then normal, radiator liquid seems to be circulating, close the cap, back on the road.

11:15pm
Temp creeped back up into red territory, not enough for CEL though.
again, let engine cool, filled back up, back on the road.

11:35pm
Arrival at camp.
suspecting blown head gasket: lots of white smoke from exhaust.
but unsure because:

1. I know my catalytic converter is f*cked and could be letting out more smoke than normal
2. Outside temps at camp are low ~58F vs ~80F in South Florida.

NEXT 4 DAYS
started the car 1-2 times per day for 30 seconds, nothing out of the ordinary.

Monday 11am
Pack up even more people and gear into the truck and head home.
Coolant still full from Thursday (was plenty is reservoir).
Stop at an auto zone to get head gasket sealant.
Also added a quart of engine oil, it looked a bit low. (I have a small leak).

Planned to drive about 150 miles to the next gas station and empty the sealant into the radiator then since we figured the coolant would have leaked out enough by then.

~2h /150 miles later, pull over for gas, open the radiator cap and she is still completely full to the brim. Totally confused. Oh well, eat some brisket and back on the road.

About 1 or 2 hours after that, temp creeped back up into the red. This time we caught it pretty quickly and pulled over.
popped the lid and got the sealant out.
managed only about 1 cup of sealant before it was full again.

After that there were no more overheating issues.

small details:
-I had the computer plugged in to see exact temp readings. when going uphill temps would go as high as 98C, downhill down as low as 89C.

Im now starting to think my radiator / pump is just crap ?

 

[Bad Luck]

A bad catalytic converter will not cause additional smoking. It sounds like you have a bad head gasket/cracked or warped head and it is pressurizing the cooling system. The temperatures you posted at the end (192-208 degrees Fahrenheit) are above what most of us normally see but aren't that hot. Those temperatures probably wouldn't show a difference on the instrument cluster temp gauge.

 

[spartacus]

Do a compression test and a leak down test to implicate or eliminate the overhead gasket.

 

[alumarine]

Don't use any more sealant.
It's going to cause problems.

 

[19963.4lsr5]

With your milage and age it’s worth a new Rad and t-stat. If it still overheats after that I’d just roll up the sleeves and do head gaskets.

It’s been my experience that Old water pumps start leaking. Not stop circulating fluid.

Do you have any visible leaks from hoses etc? The heater control valve area is a know leak area with old rusty hose clamps. It’s easy to smell antifreeze leaks on a hot engine. Finding them is harder.


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[Romeo1]

Your coolant reservoir, isn’t a reservoir. It’s a degas bottle. Keep it full to minimum to reduce the amount of evaporation/wicking from the system.

The radiator vessel itself is the sole container for cooling outside of the engine, houses, and heater cores.

White smoke out the exhaust equals coolant getting burned. Cracked head and or leaking head gasket, are the usual suspects.

Coolant sealant that pours in is just death for engines and heater cores. Fix and replace whatever issues instead.

 

[tpelletier]

Thanks for the input everyone.
Didnt know sealant was bad, wont add anymore of that.

Btw I use the truck for my daily commute and havent seen temps above 195F since getting back from the trip, nor any signs of coolant draining.

----------------------------------

Current plan of action:

1. Combustion Leak Test Kit.
tests for exhaust gases in the radiator.
amazon.com/gp/product/B06VVBSFTF/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

2. Compression test

-----------------------------------

I have a 900 mile trip to Mississippi for thanksgiving which will be done in 2 legs ~450miles each.
Really hoping I can get this fixed before then.
Will update when I get that test kit.

 

[gamefreakgc]

Thanks for the input everyone.
Didnt know sealant was bad, wont add anymore of that.

Btw I use the truck for my daily commute and havent seen temps above 195F since getting back from the trip, nor any signs of coolant draining.

----------------------------------

Current plan of action:

1. Combustion Leak Test Kit.
tests for exhaust gases in the radiator.
amazon.com/gp/product/B06VVBSFTF/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

2. Compression test

-----------------------------------

I have a 900 mile trip to Mississippi for thanksgiving which will be done in 2 legs ~450miles each.
Really hoping I can get this fixed before then.
Will update when I get that test kit.

The head gasket sealant stuff in a bottle hardens when it comes in contact with air. Keep your coolant topped off non-stop and do not let it get low. If it does, guess what's going to start to harden all over your radiator and inside the coolant passages inside the heads? Just helped my dad's truck recover from a Blue Devil sealant disaster. It had completely closed several major coolant passages in the block and caused a massive amount of work and parts to be just thrown away, all because the coolant level dropped and the sealant hardened in the block instead of the gasket. It also gunked up all in the combustion cylinder and had begun to block the spark in cylinder 4 of his Vortec V6 engine.

I also suspect a blown head gasket. The word "blown" isn't an accurate word to use as it may be just a very tiny leak. When you loaded down the vehicle with lots of extra weight the engine had to work harder and hotter and made the issue much more noticeable. My guess it'd already been there before the trip.

Last note, when the coolant temperature gauge hits the top it's near 250 degrees. The engine starts to incur heat damage over 230 degrees. There's a chance that the heads are warped even if the gaskets haven't failed. Doesn't mean you have to tear it down but even if the overheating issue is fixed the heads and gaskets may become a separate issue down the road.

 

[phattyduck]

I'd also suspect a bad radiator cap. Get a new OEM one while you are at it. A bad radiator cap can let out steam or leak under pressure and cause all the overheating issues you are seeing.

White 'smoke' out the exhaust can also just be cool/cold temps and high humidity, so it isn't a 100% sign unless it also has that sickly-sweet coolant smell.

-Charlie

 

[tpelletier]

The head gasket sealant stuff in a bottle hardens when it comes in contact with air. Keep your coolant topped off non-stop and do not let it get low. If it does, guess what's going to start to harden all over your radiator and inside the coolant passages inside the heads? Just helped my dad's truck recover from a Blue Devil sealant disaster. It had completely closed several major coolant passages in the block and caused a massive amount of work and parts to be just thrown away, all because the coolant level dropped and the sealant hardened in the block instead of the gasket. It also gunked up all in the combustion cylinder and had begun to block the spark in cylinder 4 of his Vortec V6 engine.

I also suspect a blown head gasket. The word "blown" isn't an accurate word to use as it may be just a very tiny leak. When you loaded down the vehicle with lots of extra weight the engine had to work harder and hotter and made the issue much more noticeable. My guess it'd already been there before the trip.

Last note, when the coolant temperature gauge hits the top it's near 250 degrees. The engine starts to incur heat damage over 230 degrees. There's a chance that the heads are warped even if the gaskets haven't failed. Doesn't mean you have to tear it down but even if the overheating issue is fixed the heads and gaskets may become a separate issue down the road.

Holy hell.. is it a good idea to drain all the coolant to get rid of the bit of sealant there is in there ?
this sounds like a nightmare.

 

[gamefreakgc]

Holy hell.. is it a good idea to drain all the coolant to get rid of the bit of sealant there is in there ?
this sounds like a nightmare.

I realized that money might be part of the equation, hence the stop leak in the first place. If you are able to keep it topped up until you can get it tested that should be ok. The more you drive it the more the risk increases. You'll have to change the coolant again if you do have to replace the head gasket and there's no sense in paying for twice the coolant.

 

[Devbot]

FYI, starting your car and not letting it get up to temp is not helping your cat. In fact that's how you hurt them :flame:

 

[19963.4lsr5]

FYI, starting your car and not letting it get up to temp is not helping your cat. In fact that's how you hurt them :flame:

As soon as my vehicles go closed loop I start driving. And that’s sooner than you think. It warms up faster driving than idling.

On our 3.4l you know it goes closed loop when the idle starts dropping after a cold start.


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[DenverAirport]

9:23pm
About 2 hours before arrival. Felt weird gear change, looked down, CEL, temp in the red, pulled over, coolant everywhere, let engine cool, fill radiator with water, turn engine back on, engine stutters for 5 seconds then normal, radiator liquid seems to be circulating, close the cap, back on the road.

Did you notice coolant leaking near the top of the engine compartment / near windshield? I had this happen to me when my heater control valve exploded.

 

[tpelletier]

Thanks for the input everyone.

----------------------------------

Current plan of action:

1. Combustion Leak Test Kit.
tests for exhaust gases in the radiator.
amazon.com/gp/product/B06VVBSFTF/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

2. Compression test

-----------------------------------

I have a 900 mile trip to Mississippi for thanksgiving which will be done in 2 legs ~450miles each.
Really hoping I can get this fixed before then.
Will update when I get that test kit.

Did a combustion leak test kit for a good 30 minutes with no signs of exhaust gases leaking into the radiator.

Sealant might've done its job but I am still getting 16mpg. Tires were at 29psi, bumped it up to 33.

Just ordered a compression test kit to test out all the cylinders.

 

[tpelletier]

FYI, starting your car and not letting it get up to temp is not helping your cat. In fact that's how you hurt them :flame:

I plan on putting in a straight pipe through. that cat is only impeding airflow at this point

 

[tpelletier]

Did you notice coolant leaking near the top of the engine compartment / near windshield? I had this happen to me when my heater control valve exploded.

It was dark and raining at the time. + by the time we stopped there was coolant everywhere since it had boiled/popped out the coolant capture reservoir thing so hard to say.

but my heat does not work... I dont know how long its not been working.

 

[19963.4lsr5]

It was dark and raining at the time. + by the time we stopped there was coolant everywhere since it had boiled/popped out the coolant capture reservoir thing so hard to say.

but my heat does not work... I dont know how long its not been working.

When ones heater stops blowing hot air, that is a great indicator you’re low on coolant.


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[tpelletier]

When ones heater stops blowing hot air, that is a great indicator you’re low on coolant.
Sent from my iPhone using Tapatalk

Coolant has been topped and no signs of leak since the incident.
Heater has never worked since I bought it 3k miles ago.

 

[Cree]

Have you checked your cooling fan?