Builds Finally got my own...Meet BeBe (2 Viewers)

[gregnash]

See that is the thing though, t-stat was replaced with a Toyota OEM unit shortly after I first bought BeBe so I would have a hard time believing it would be gone in less than 3yrs. At what point does burping the system only begin to fill the overflow tank? Or does it and if it does start doing that does that mean something bad.

I know that the radiator is not OEM as the PO told me that it had been replaced, cant remember if he said it was when he bought it or the PO he bought it from told him he replaced.

 

[Output Shaft]

Technically...
As the coolant heats up, it expands and builds pressure. Excess pressure is bled out of the radiator pressure cap. Only fluid (coolant) should be flowing into the overflow tank. The fluid level normally should be between the cold and hot mark on the overflow tank when the engine is cold, and at the Hot mark when at operating temperature.
(That was an overview.. I know you already know this).

So what would cause the overflow tank to actually overflow coolant on to the ground?

Air.

One way or another, air is displacing the volume of coolant inside the engine.

So the million dollar question is:
Where is this air coming from?

Either the coolant is boiling (overheating)
Or
The engine is blowing air into the coolant.

 

[Output Shaft]

The last time I had my cooling system apart and the block drained.. Bone dry, I replaced every cooling component. New radiator, all new hoses, thermostat, WP, ...and head gasket. All new.
The cooling system was as good as it could possibly be.

When I refilled it and fired up the engine, I burped it (or tried to) using every method known on MUD. I drove the car up on a very steep angle with the passenger front side up (fill neck), and let the engine cool there for a few hours, then turn it back on and heat it up at that angle... to try to purge air.
I did the burping funnel thing forever. I drove the cruiser up on a very steep flat incline while warming it up to try to purge bubbles.

Still with all that work, the temp gauge sat at the 3/4 mark.

Over a few weeks the engine slowly purged out the air on its own, and the coolant level slowly would drop in the reservoir as it did. . And EVENTUALLY the temp needle dropped down to its normal spot. It took about a week and a half of cold starts to get it back to normal.

My engine has always been like that... That's why I dread changing coolant.

 

[cruisermatt]

^ When I rebuilt my engine it did this too. Except I didn't replace my radiator

 

[gregnash]

Thanks @Output Shaft ..... So here is another additional symptom that I noticed as well with this which leads me to one possible (nasty) conclusion.... The oil pressure has gone up as well... normally it hovers right at the midway line, since this has been going on it has been higher, like the 3/4 mark. It is time for an oil change so I may wait and see if that affects the oil pressure level.

What I am afraid of is something that I suspect.... I believe I have a leak in my headgasket between #5 and #6... wondering if it is finally getting worse.

 

[gregnash]

So yeah this is where she has been running for the last week or so. This is after having driven around for a bit with the heater on full blast. Wife even complained that it was TOO hot inside with the heater going.

 

[Output Shaft]

That's where mine sits until it burps all the air.

Did you check the engine temps w a IR temp gun?

Just a FYI,
The Toyota manual (one of them) states that if the temperature needle is within the white marking on the gauge, the engine is operating within its normal range... Or something to that effect.

So white is still safe.

 

[RodrigzCrzr]

Did you also turn on the rear heater? To completely get the water flowing to burp it completely!

 

[gregnash]

So borrowed a friends set of ramps and got the truck up on those and letting the system go now after changing oil... Bunch of air bubbles have already come out to the point where I have actually pushed a bunch of coolant out. Thinking there was just a massive bubble stuck somewhere.

 

[gregnash]

And that would be a negative.... *sigh* ok on to the next thing, next weekend going to completely flush the system and see if something is caught in there, will order new gasket, o-ring and t-stat just in case.

 

[Output Shaft]

Yeah, seeing that you just drained your cooling system to change that oil cooler hose... then the gauge now reads hot after you've refilled (at the classic 3/4 mark), my bet is just good old fashion 2F air-bubbles-still-stuck-in-the-head-somewhere syndrome.


I'd drive it for two weeks first, starting it up from cold at least twice a day, before coming to any overheating conclusion.

 

[gregnash]

Haven't done the oil cooler hoses yet. So yeah think it is something else.

 

[gregnash]

So going to be grabbing an IR Temp gun from HF on the way home tonight to verify temps..
Question is where should I be pointing for accurate temps? Thinking; Top radiator hose, Head, Heater control valve and maybe water pump?

Highly doubt that it is the t-stat or the fan clutch as I hear the fan engage and disengage regularly (it was replaced at same time as the t-stat) and the t-stat is pretty new, maybe only a year and a half old?

So that leaves me with the following (based on my logic)....
- bad temp sending unit in head
- bad gauge in dash
- clogged radiator
- clogged heater core
- water pump going out
- crack in head/headgasket issue
- ????
- profit

So without throwing a bunch of money at this I am going to try the temp gun first.. next will be to flush the radiator and see what comes out (at which point I will replace the oil cooler hoses).
From there check the temp sender and see if it is corroded or partially pulled off (some sort of issue). But from there how should I go about this without just throwing money at it???

 

[gregnash]

Ok so I measured at different points around the engine compartment and got various readings....
Top of radiator ~175*
Top radiator hose ~165*
Lower engine block where EGR cooler should be ~149*
Valve cover ~183*
Top of thermostat housing ~198*

These numbers sound right? This is with the temp needle sitting right about 3/4 of the way up.

 

[gregnash]

Something else I noticed last night when I was taking temps was that I could hear a very slight hissing/popping coming from my radiator cap. Buddy is convinced that the cap is not holding pressure properly and thus the main issue. Put in an order with Onur for new t-stat, oring/gasket and rad cap. Will plan to flush the system once those items get here, replace oil cooler hoses that I bought last week and try the new rad cap and see if that fixes it...

If not then thinking that narrows it down to water pump or radiator issue. Have the extra t-stat for good measure.

 

[micruz60]

Radiator cap is easy peasy, it's what allows the system to 'self-burp' although I would still try to park inclined.
Those temps are fine. Since you are going with tstat service, you may want to also pull the housing off the head, see if there's buildup in the water passage, new gaskets and (hoses, if they haven't been done / look suspect). Be gentle with that housing, bolts can be pretty cinched in.

 

[Output Shaft]

I'm using the same. HF. IR temp gun.

Those temps you got are good.
Where I've found are good places to shoot the gun is at the top drivers side front of the radiator, the mid top of radiator, the bottom of the radiator, the bottom hose of the radiator, the top of the head near the front but away from a head bolt, the back of the head near the water outlet pipe, the spot on the head mid point between spark plugs 1 & 2 on the head.

For some reason shooting the gun at my new shiny upper T-stay housing always gives a cool reading compared to the front top inlet side of the radiator. Also the big radiator inlet hose doesn't seem to give me a good reading.

If I were to choose two spots to shoot the gun, it would be the front top drivers side of the radiator and the top front of the head. Those two locations consistently gives me the hottest and most reliable readings.

 

[gregnash]

@Output Shaft I ended up finding an old thread with a list of locations you came up with so I plan on taking a stab at those tonight/this afternoon. When I got to the office this morning it was just about into the red, but of course I forgot the gun at home.
Normal morning routine is to warm the truck up for about 10-15 minutes. Heater is going entire time while it is warming up and then drive to work which is about 2.5 miles away. When I left the house temp gauge was just about dead smack in the middle but when I got to work it was on the edge of the red.

Really hate just throwing parts at things to try and fix something. But would find it hard to believe that the t-stat would be bad after maybe 2yrs.

 

[Output Shaft]

Yeah, your IR temp gun will now let you verify.

I wouldn't come to any overheating conclusions (or repairs) until you've verified it's getting too hot with the gun.

I'd say, with a 190° thermostat, if the temps are 205° or lower when you're just cruising around town, there is no overheating going on.
210° really isn't overheating either, depending on what the engine has been doing and the ambient temp.

225° would get me a bit concerned (in the winter). But the coolant won't boil till 260° or so with a good cap.

If you drive on the freeway and then pull over and start shooting the gun at the radiator, while idling, the temp will start to rise due to heat soak. Bit that's not overheating.

 

[gregnash]

Yeah I have been trying to take the temps after a few minutes of stopping. Last night I let the truck cool for like 30 minutes before I started it back up again and let it get to temp then checked around. Don't really ever get on the freeway and don't hit more than 45mph in one short section of road (maybe 1/2 mile).

Regardless the radiator cap will be replaced with the OEM unit once I get it and then will retest.