don't know about him, but I think zero peeps monitor ODBII

maybe they monitor OBDII ?

I know that I monitor all my vehicles with OBDII plugged in from the day
I get it from the dealer new, until I let it go or whatever. so it is not that rare, not in my neck of the woods. I always know rpm, tps, temp, injector duration, advance, all the time and every time on all my cars and trucks

 

Good job Balls, but you are not the one saying that running 200+ on a 190F thermostat is perfectly fine

 

Actually, these 5VZFEs came stock with a 180 F t-stat, but as Fog described so well in post #9, the t-stat on our trucks is in the return line side of the cooling system. It sees the coolant after it goes thought the radiator, unlike many vehicles that have the t-stat in the upper hose going to the radiator where the t-stat sees the hottest coolant. Also the temp sensor for the ECU is up in the hottest part of the system, naturally there is going to be a difference between the t-stat opening temp and the upper hose temp.

Also keep in mind that the t-stat opening temp is just the point which it starts to crack open, it doesn't open for complete flow until quite a bit hotter. For example here you can see a 180 F t-stat (right) next to a 160 F t-stat in 180+ water. The 180 F t-stat is just barely opened.

 

199yota-pickup...WTF does twin weber carb's have to do with a dang cooling issue.....lmao seriously!?!?

 

no I am the one saying if it gets to >220 that can still be normal


in other words, there is not a problem when the temp goes to 224. mine does
on hot days stuck on pavement

a thermostat doesn't really control the max water temp. it ensures the engine gets hot enough to run efficiently before dumping most of the coolant to the radiator. but it can break and cause overheating by blocking flow, but when that happens u really know it...temp will rocket past 224.

how hot your box gets ? if is never hits 224 then there is no problem AFAIK

it should run at 188-192 most days, 184 at zero deg F, 212-224 at 100 deg F outside

 

I'm glad to see you say that, because that's very close to what I see too. I had been holding back on my numbers since I'm running 10 psi of boost and have a 5VZFE in a 93 truck with a radiator designed for a 150 HP engine.

 

http://www.toysport.com/technical%20...tech_notes.htm



just go to this website.. maybe you might learn some knowledge..

 

Running 225 F on hot days stuck on pavement is about 20 degrees too hot.

When I worked extra jobs off duty, me and another officer would sit in my 4Runner with the A/C on for 24-48 hours. This was during the hottest summer months (100+ F) here in Houston and my temp never got above 205 F with the engine at idle or 195F with the high idle switch on (1300 RPM).

If I'm going to be sitting for more than 3-4 minutes in the summer time I engage the high idle which brings the engine up to 1300RPM for better cooling, better oil pressure ( 20 lbs instead of 8-9 lbs), and ALLOT better A/C performance. With the high idle on I can sit there all day and it stays right at 195F all day long.

The hottest I've ever seen was 215 F and that was going through hill country in the summer heat towing a 5000LB trailer. Even at that it would only climb up to that briefly on hill climbs.

I've got my temp gauge installed in line feeding the rear seat heater right off the back on the heads for the hottest reading. I've checked it against the OBD-II and it consistently reads with in 1 degree +/- of it.

A vehicle's cooling system is designed to keep the engine temp at 10 degrees or less than the thermostat temp on a hot summer day idling with the A/C on. If you cooling system cannot keep the engine 10 degrees above thermostat or less then there is a problem.

The 10 degree standard is for vehicles with a belt driven cooling fan. Vehicles with electric fans are subject to operation at the computer's discretion and often with GM and Ford vehicles the electric fans cycle at 215-220F for emissions which I think is totally asinine and harmful to the engine in the long run.




FOG

 

well posted

 

sorry to butt in, but I am having the exact issue you were talking about fog...my gauge is going up and down with hard acceleration or heavy loading, and on top of it it is shifting wierd. then when i come to a stop sign, the whole truck does this vibrating thing, like its recieving a phone call or something. i checked all the usual suspects: plugs/wires/pcv/air filter/trans fluid&filter/coolant/tstat/fan clutch/belts....everything appears fine. so, i am leaning towards some kind of sensor issue.

 

This might be helpful if we were talking about a carbed engine and it happened to be a 22r engine and he was having trouble with fuel and not coolant.

These two engines are light years apart and I have no idea what you are getting at.

 

i have a 94 runner with the 3slow liter. i put in some aftermarket guages to read water temp and oil pressure. when i shut off the engine the temp rises to about 230. is this normal? it concerns me because the last time the head gasket blew,was after i shut it off and parked it for an hour or so

 

Where is that temp reading at? It is normal for the head coolant temp to rise after shutdown (heat soak). Make sure you have at least a 50/50 mix of antifreeze/water and a good radiator cap (pressure) so you don't boil your coolant. That's a little hot, but still probably wouldn't move the stock temp gauge off the middle.

 

because my radiator is 14 yrs old, i always watch my water temp via scangauge.
202 normal driving no matter what the temp is outside. highest i've seen it is 212 on stop and go traffic during a very hot summer day.

transmission operating temp on sender line, 125-165.
125 freeway driving
150-180 stop and go traffic.

noticed a big improvement on my temps when I moved the tranny cooler closer to the condenser.

 

Mine reads from 190-193, and maybe 195 at rare times. My GF's friend has a 2000 and the fan clutch is on its way out; Her normal temps used to be 190-193, they now have spiked to 201 on rare occurances while idiling. So once the fan bracket gets to her house, I'm going to change out the fan clutch and bracket to see if that will bring the temp back to the operating temperature range beforehand. If not, I am chalking it up to her dying original H20 pump, which was not changed out with the first T-belt change. She has 154,000 miles.

Due to heat soak on 80F+ days, I've seen mine rise to 202 degrees after filling up with gas and the like but return to 190-193 quickly.

Log, have you replaced the thermostat, fan clutch, H20 pump or anything other cooling system parts?

 

noticed a big improvement on my temps when I moved the tranny cooler closer to the condenser.[/quote]

IMHO, probably the most important step to take in order to keep the transmission running smoothly when mounting an external tranny cooler!

 

i've replaced the t-stat, water pump @ 87k but not the radiator, its now at 130k

fan clutch? mine's an automatic.

 

http://en.wikipedia.org/wiki/Fan_clutch

 

Do you hear the fan "roar" when you first start your 4 runner? If not, the fan clutch may be dead and needs replacing to help bring your temps down. The Durk did a great write up on replacing his.

OEM t-stat?

I don't think I have heard anyone having a radiator that failed internally, only at the ATF exchanger causing the milkshake, so I would guess yours is working just fine.

 

I remember my Techstream shows my 3rzFE 4cyl is around 185-190 while driving. outdoor temp is around 80degF