operating temperature?
Yeah, I hear mine roar everytime I start the truck, and yes all OEM parts.
02-16-2011, 12:46 PM
#42
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 195
F 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
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 195
F 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, stuck in traffic, go stop go stop sit bake a/c on, it goes 204-225-204-225 until I finally move again and back to 194-198 or so,
then down in the 180's
225 is not a problem for the engine, oil, or any engine system. it is pushing it, and if it ever went past that something would pop
but, since new in 1998 and up to today, it'll go to 225 and stop rising then go back down on the hottest days if I am stuck on the interstate going nowhere
Last edited by BigBallsMcFalls; 02-16-2011 at 12:47 PM.
02-16-2011, 02:23 PM
#43
Registered User
Join Date: Feb 2010
Location: Outer Banks, NC
Posts: 570
Likes: 0
Received 0 Likes
on
0 Posts
Log,
Then I guess you are good to go. If others are running in the 200s, I guess it is OK.
I've got to install this Autotech oil pressure gauge I have sitting next to me one day. I like how yours is set up. I wish I could read the oil pressure through the Scangauge, but I know it is not possible.
Once I install the fan clutch and bracket on my friend's 4 runner this weekend, I'll see if the coolant temps can remain under 195 while idiling and at low speeds.
Then I guess you are good to go. If others are running in the 200s, I guess it is OK.
I've got to install this Autotech oil pressure gauge I have sitting next to me one day. I like how yours is set up. I wish I could read the oil pressure through the Scangauge, but I know it is not possible.
Once I install the fan clutch and bracket on my friend's 4 runner this weekend, I'll see if the coolant temps can remain under 195 while idiling and at low speeds.
02-16-2011, 11:38 PM
#44
Registered User
Join Date: Sep 2009
Location: Sunny San Diego
Posts: 129
Likes: 0
Received 0 Likes
on
0 Posts
Log,
Then I guess you are good to go. If others are running in the 200s, I guess it is OK.
I've got to install this Autotech oil pressure gauge I have sitting next to me one day. I like how yours is set up. I wish I could read the oil pressure through the Scangauge, but I know it is not possible.
Once I install the fan clutch and bracket on my friend's 4 runner this weekend, I'll see if the coolant temps can remain under 195 while idiling and at low speeds.
Then I guess you are good to go. If others are running in the 200s, I guess it is OK.
I've got to install this Autotech oil pressure gauge I have sitting next to me one day. I like how yours is set up. I wish I could read the oil pressure through the Scangauge, but I know it is not possible.
Once I install the fan clutch and bracket on my friend's 4 runner this weekend, I'll see if the coolant temps can remain under 195 while idiling and at low speeds.
electronic pressure gauge is an easy install, you should do it.
my operating pressure when engine is cold is 60 psi, it goes to 70 when i press on gas pedal. then it goes down to 25-40 when warmed up and im cruising on the highway.
02-24-2011, 07:41 PM
#45
Registered User
Join Date: Sep 2009
Posts: 228
Likes: 0
Received 0 Likes
on
0 Posts
quicksilvr chiming in:
I'd never even seen 200 on my SGII until today. Today I drove 850 miles from MO to western CO. With O/D off, hammering it up the mountain passes, my coolant was reading a steady 215. I was kind of surprised, because the ambient temps were in the 20's. But my transmission was only 160, and nothing else seemed bad. I think I ran it at 215-218 for nearly 2 hours before it had a chance to cool down.
My fan seems to be working just fine....I just think that hitting 4000 rpm on a regular basis climbing passes makes a lot of heat!
I'd never even seen 200 on my SGII until today. Today I drove 850 miles from MO to western CO. With O/D off, hammering it up the mountain passes, my coolant was reading a steady 215. I was kind of surprised, because the ambient temps were in the 20's. But my transmission was only 160, and nothing else seemed bad. I think I ran it at 215-218 for nearly 2 hours before it had a chance to cool down.
My fan seems to be working just fine....I just think that hitting 4000 rpm on a regular basis climbing passes makes a lot of heat!
02-25-2011, 05:15 AM
#46
Contributing Member
quicksilvr chiming in:
I'd never even seen 200 on my SGII until today. Today I drove 850 miles from MO to western CO. With O/D off, hammering it up the mountain passes, my coolant was reading a steady 215. I was kind of surprised, because the ambient temps were in the 20's. But my transmission was only 160, and nothing else seemed bad. I think I ran it at 215-218 for nearly 2 hours before it had a chance to cool down.
My fan seems to be working just fine....I just think that hitting 4000 rpm on a regular basis climbing passes makes a lot of heat!
I'd never even seen 200 on my SGII until today. Today I drove 850 miles from MO to western CO. With O/D off, hammering it up the mountain passes, my coolant was reading a steady 215. I was kind of surprised, because the ambient temps were in the 20's. But my transmission was only 160, and nothing else seemed bad. I think I ran it at 215-218 for nearly 2 hours before it had a chance to cool down.
My fan seems to be working just fine....I just think that hitting 4000 rpm on a regular basis climbing passes makes a lot of heat!
02-25-2011, 06:26 AM
#47
Registered User
Join Date: Nov 2009
Posts: 127
Likes: 0
Received 0 Likes
on
0 Posts
Mine seems warm too. 205 is not uncommon, even when it's near zero air temp....just cruising down the road at 55 or 60. This spring I'm changing everything. Hoses, T-stat, radiator, coolant. This has only started happening in the last year or 18 months. Before that, it would rarely go above 193.
02-25-2011, 05:19 PM
#48
Registered User
Join Date: Sep 2009
Posts: 228
Likes: 0
Received 0 Likes
on
0 Posts
Hmmm....I think I'd be a little concerned with that, mainly because the ambient temps were so low. Yeah the higher RPMs and mt passes make lots of heat but at those ambient temps the cooling system shouldn't have much trouble dumping it. I'd check out the whole system if it were me starting with the t-stat. I've run non-stop from Kansas to Vail in mid-summer and the only time I got that hot was while doing about 75mph up to the Eisenhower tunnel (11,000 ft) fully loaded down with gear. While passing through Denver ambient temps were 95 F.
It might just be time for a new t-stat. The radiator is fairly new (within 5 years) the coolant is fresh (although it is Prestone...not OEM). I wouldn't think that the coolant itself could make that much difference...but maybe?
02-25-2011, 05:51 PM
#49
Contributing Member
Join Date: Nov 2010
Location: Columbia River Gorge, Oregon...east side
Posts: 5,125
Likes: 0
Received 2 Likes
on
2 Posts
According to SGII, mine runs 191-193 in normal driving around town or on the freeway, jumps to 195 when climbing the mountain to go skiing in 20deg air temp, and drops to 188 when I'm taking it easy coasting in drive coming down the mountain.
However, a year ago I was seeing temps of 203-207 in normal driving...changed the radiator, thermostat, and flushed the system and filled with Toyota Red: Result...201-203 in normal driving.
Then it was time to change the TB and Waterpump at 180k miles. The WP showed only a tiny leak and the bearing seemed fine, but the WP pulley and the Lower Tensioner Idler pulley (it seemed fine too) both had a layer of cooked rubber from the belt on them.
It appeared that the tensioner was shot allowing the belt to have a bit of slack and to 'slap' the pulleys (hence, the rubber transfer) yielding insuffucient coolant flow.
After this work, my temps dropped to what I have been seeing for the past year.
However, a year ago I was seeing temps of 203-207 in normal driving...changed the radiator, thermostat, and flushed the system and filled with Toyota Red: Result...201-203 in normal driving.
Then it was time to change the TB and Waterpump at 180k miles. The WP showed only a tiny leak and the bearing seemed fine, but the WP pulley and the Lower Tensioner Idler pulley (it seemed fine too) both had a layer of cooked rubber from the belt on them.
It appeared that the tensioner was shot allowing the belt to have a bit of slack and to 'slap' the pulleys (hence, the rubber transfer) yielding insuffucient coolant flow.
After this work, my temps dropped to what I have been seeing for the past year.
Last edited by rworegon; 02-25-2011 at 06:13 PM.
02-25-2011, 07:56 PM
#50
Registered User
Join Date: Sep 2009
Location: Sunny San Diego
Posts: 129
Likes: 0
Received 0 Likes
on
0 Posts
According to SGII, mine runs 191-193 in normal driving around town or on the freeway, jumps to 195 when climbing the mountain to go skiing in 20deg air temp, and drops to 188 when I'm taking it easy coasting in drive coming down the mountain.
However, a year ago I was seeing temps of 203-207 in normal driving...changed the radiator, thermostat, and flushed the system and filled with Toyota Red: Result...201-203 in normal driving.
Then it was time to change the TB and Waterpump at 180k miles. The WP showed only a tiny leak and the bearing seemed fine, but the WP pulley and the Lower Tensioner Idler pulley (it seemed fine too) both had a layer of cooked rubber from the belt on them.
It appeared that the tensioner was shot allowing the belt to have a bit of slack and to 'slap' the pulleys (hence, the rubber transfer) yielding insuffucient coolant flow.
After this work, my temps dropped to what I have been seeing for the past year.
However, a year ago I was seeing temps of 203-207 in normal driving...changed the radiator, thermostat, and flushed the system and filled with Toyota Red: Result...201-203 in normal driving.
Then it was time to change the TB and Waterpump at 180k miles. The WP showed only a tiny leak and the bearing seemed fine, but the WP pulley and the Lower Tensioner Idler pulley (it seemed fine too) both had a layer of cooked rubber from the belt on them.
It appeared that the tensioner was shot allowing the belt to have a bit of slack and to 'slap' the pulleys (hence, the rubber transfer) yielding insuffucient coolant flow.
After this work, my temps dropped to what I have been seeing for the past year.
Good info right here... I know my water pump is leaking, maybe that's why im seeing slightly higher temps. not sure if a leak in the water pump can cause it.
02-26-2011, 05:36 AM
#51
Registered User
Join Date: Nov 2009
Posts: 127
Likes: 0
Received 0 Likes
on
0 Posts
Hmmm, yes I can see a failing water pump do this as well. According to the sticker on my belt cover, the job was done about 38K ago (at 113K). I can only assume that they also changed the water pump, pulleys and tensioner.
So, how big a job is the TB change? :-)
So, how big a job is the TB change? :-)
02-26-2011, 05:38 AM
#52
Contributing Member
According to SGII, mine runs 191-193 in normal driving around town or on the freeway, jumps to 195 when climbing the mountain to go skiing in 20deg air temp, and drops to 188 when I'm taking it easy coasting in drive coming down the mountain.
However, a year ago I was seeing temps of 203-207 in normal driving...changed the radiator, thermostat, and flushed the system and filled with Toyota Red: Result...201-203 in normal driving.
Then it was time to change the TB and Waterpump at 180k miles. The WP showed only a tiny leak and the bearing seemed fine, but the WP pulley and the Lower Tensioner Idler pulley (it seemed fine too) both had a layer of cooked rubber from the belt on them.
It appeared that the tensioner was shot allowing the belt to have a bit of slack and to 'slap' the pulleys (hence, the rubber transfer) yielding insuffucient coolant flow.
After this work, my temps dropped to what I have been seeing for the past year.
However, a year ago I was seeing temps of 203-207 in normal driving...changed the radiator, thermostat, and flushed the system and filled with Toyota Red: Result...201-203 in normal driving.
Then it was time to change the TB and Waterpump at 180k miles. The WP showed only a tiny leak and the bearing seemed fine, but the WP pulley and the Lower Tensioner Idler pulley (it seemed fine too) both had a layer of cooked rubber from the belt on them.
It appeared that the tensioner was shot allowing the belt to have a bit of slack and to 'slap' the pulleys (hence, the rubber transfer) yielding insuffucient coolant flow.
After this work, my temps dropped to what I have been seeing for the past year.
02-26-2011, 05:39 AM
#53
Contributing Member
02-26-2011, 10:01 AM
#54
Registered User
Join Date: Feb 2010
Location: Outer Banks, NC
Posts: 570
Likes: 0
Received 0 Likes
on
0 Posts
I think rworegon has it right. If there is not enough tension on the belt, then the impeller won't turn at the right speed to move enough coolant in order to maintain the proper temps. When changing out the tensioner, all one has to due is remove the old one, compress the new one and lock with the pin until installed correct? I guess I'll be replacing mine this summer along with the TB/H20 pump.
I was wondering how folks could be riding constantly in the 200s like log when the t-stat is 82C and the coolant temp should never really see more than 195F, with all other coolant parts doing their job well. JMHO...
I was wondering how folks could be riding constantly in the 200s like log when the t-stat is 82C and the coolant temp should never really see more than 195F, with all other coolant parts doing their job well. JMHO...
02-26-2011, 10:46 AM
#56
Registered User
Join Date: Nov 2009
Posts: 127
Likes: 0
Received 0 Likes
on
0 Posts
Oh, so maybe I could replace just the tensioner? I mean, the WP isn't leaking, and it makes no funny sounds, so it's hard to suspect it isn't working right. I guess either way I'll have to remove the cover to inspect.
02-26-2011, 11:09 AM
#57
Contributing Member
Some more links that may be helpful in water pump/timing belt replacement:
http://www.ncttora.com/fsm/1996/SIL/...imbel/remo.pdf
http://www.ncttora.com/fsm/1996/SIL/...imbel/insp.pdf
http://www.ncttora.com/fsm/1996/SIL/...imbel/inst.pdf
http://www.ttora.com/forum/showthread.php?t=171677
http://www.ncttora.com/fsm/1996/SIL/...imbel/remo.pdf
http://www.ncttora.com/fsm/1996/SIL/...imbel/insp.pdf
http://www.ncttora.com/fsm/1996/SIL/...imbel/inst.pdf
http://www.ttora.com/forum/showthread.php?t=171677
Last edited by mt_goat; 02-26-2011 at 11:22 AM.
02-26-2011, 11:13 AM
#58
Contributing Member
02-26-2011, 11:26 AM
#59
Contributing Member
Join Date: Nov 2010
Location: Columbia River Gorge, Oregon...east side
Posts: 5,125
Likes: 0
Received 2 Likes
on
2 Posts
Here is what I would try if I was going to attempt a tensioner replace w/o removing the belt. Before removing the tensioner, I'd use a soft jaw clamp on each pulley to clamp the belt in place and then mark the belt and crank timing gear with white fingernail polish in a convenient spot. Once the tensioner is back in and the tensioner release, just be sure the mark on the belt and crank line up. It just might work.....
Last edited by rworegon; 02-26-2011 at 02:48 PM.
02-26-2011, 02:22 PM
#60
Registered User
Join Date: Sep 2009
Location: Sunny San Diego
Posts: 129
Likes: 0
Received 0 Likes
on
0 Posts
This makes me want to change my tb comp, & the wp.
I'm running 5-10 degrees warmer than you guys.
