95 4runner 6cyl overheats when stopped

1995 4Runner 6cyl 4WD, wife is 2nd owner; she got it at 30,000 miles.
Oil changed every 3,000-3,500 miles, other maintenance to schedule.
By oil change, it's used almost a quart (self-refilled at 1/2 qt down).
140,000 miles - 50/50 city/highway mileage.
Normal hwy trip 2 hrs up Mt Hood, 1.5 hrs back down; reverse trip 2
days later.
Normal city trip is 12 miles in 30 minutes of stop-and-go, reverse 9
hrs later.
Never used for heavy towing, light towing is <500 miles total.
No significant prior problems, no collisions.
BlueBook low-to-avg is $5,150-$5,895.
NADA low-to-average is $5,500-$6,825.

Last week, first temps > 80F of the season, noted a problem.
It overheats after appx. 5 minutes of running at idle in park.
Also overheats after 5 min of <5mph traffic jam on I-205.
Fan runs, radiator properly filled w/ coolant/water mix as prescribed.

What should the mechanics look for first?

What's a reasonable charge for a good (not cheap) shop (e.g., Master
ASE) to do that?

Are there typical failure mode(s)? Approximate costs?

What's the worst case repair and its approximate cost?



Thank you kindly,all, for your on-topic responses.

"John Bartley" <john.bartley@gmail.com> wrote in message
news:1118969543.791943.93450@o13g2000cwo.googlegroups.com...[color=blue]
> 1995 4Runner 6cyl 4WD, wife is 2nd owner; she got it at 30,000 miles.
> Oil changed every 3,000-3,500 miles, other maintenance to schedule.
> By oil change, it's used almost a quart (self-refilled at 1/2 qt down).
> 140,000 miles - 50/50 city/highway mileage.
> Normal hwy trip 2 hrs up Mt Hood, 1.5 hrs back down; reverse trip 2
> days later.
> Normal city trip is 12 miles in 30 minutes of stop-and-go, reverse 9
> hrs later.
> Never used for heavy towing, light towing is <500 miles total.
> No significant prior problems, no collisions.
> BlueBook low-to-avg is $5,150-$5,895.
> NADA low-to-average is $5,500-$6,825.
>
> Last week, first temps > 80F of the season, noted a problem.
> It overheats after appx. 5 minutes of running at idle in park.
> Also overheats after 5 min of <5mph traffic jam on I-205.
> Fan runs, radiator properly filled w/ coolant/water mix as prescribed.
>
> What should the mechanics look for first?
>[/color]

The fan. The fan clutch, actually.

The fan is driven by a clutch -- a viscous coupling realy -- and it sounds
like yours is toast. A fan clutch is a part that the normal shade tree
mechanic can install in an hour or two, and a real mechanic can do much
faster. I don't know what labor rates are, but I'd guess that they will get
an hour or hour and a half, and the clutch will run around $100. This is one
of those jobs that you can do your self, if you have the inclination to do
this sort fo thing.



[color=blue]
> What's a reasonable charge for a good (not cheap) shop (e.g., Master
> ASE) to do that?
>
> Are there typical failure mode(s)? Approximate costs?
>
> What's the worst case repair and its approximate cost?
>
>
>
> Thank you kindly,all, for your on-topic responses.
>[/color]

John Bartley wrote:[color=blue]
> 1995 4Runner 6cyl 4WD, wife is 2nd owner; she got it at 30,000 miles.
> Oil changed every 3,000-3,500 miles, other maintenance to schedule.
> By oil change, it's used almost a quart (self-refilled at 1/2 qt down).
> 140,000 miles - 50/50 city/highway mileage.
> Normal hwy trip 2 hrs up Mt Hood, 1.5 hrs back down; reverse trip 2
> days later.
> Normal city trip is 12 miles in 30 minutes of stop-and-go, reverse 9
> hrs later.
> Never used for heavy towing, light towing is <500 miles total.
> No significant prior problems, no collisions.
> BlueBook low-to-avg is $5,150-$5,895.
> NADA low-to-average is $5,500-$6,825.
>
> Last week, first temps > 80F of the season, noted a problem.
> It overheats after appx. 5 minutes of running at idle in park.
> Also overheats after 5 min of <5mph traffic jam on I-205.
> Fan runs, radiator properly filled w/ coolant/water mix as prescribed.
>[/color]

Are you sure the fan is actually working properly? I had this problem
with a 1986 Honda, where it would run great at highway speeds then
overheat at a stopping position. It turned out that the fan had
somehow gotten stripped -- the motor cut on but the fan didn't spin. I
blew a radiator... turned into an expensive problem.
[color=blue]
> What should the mechanics look for first?
>
> What's a reasonable charge for a good (not cheap) shop (e.g., Master
> ASE) to do that?
>
> Are there typical failure mode(s)? Approximate costs?
>
> What's the worst case repair and its approximate cost?
>
>
>
> Thank you kindly,all, for your on-topic responses.[/color]

"Jeff Strickland" <spamcatcher@yahoo.net> wrote in message
news:UfGdnU-0vvPvvy_fRVn-uA@ez2.net...[color=blue]
>
> "John Bartley" <john.bartley@gmail.com> wrote in message
> news:1118969543.791943.93450@o13g2000cwo.googlegroups.com...[color=green]
>> 1995 4Runner 6cyl 4WD, wife is 2nd owner; she got it at 30,000 miles.
>> Oil changed every 3,000-3,500 miles, other maintenance to schedule.
>> By oil change, it's used almost a quart (self-refilled at 1/2 qt down).
>> 140,000 miles - 50/50 city/highway mileage.
>> Normal hwy trip 2 hrs up Mt Hood, 1.5 hrs back down; reverse trip 2
>> days later.
>> Normal city trip is 12 miles in 30 minutes of stop-and-go, reverse 9
>> hrs later.
>> Never used for heavy towing, light towing is <500 miles total.
>> No significant prior problems, no collisions.
>> BlueBook low-to-avg is $5,150-$5,895.
>> NADA low-to-average is $5,500-$6,825.
>>
>> Last week, first temps > 80F of the season, noted a problem.
>> It overheats after appx. 5 minutes of running at idle in park.
>> Also overheats after 5 min of <5mph traffic jam on I-205.
>> Fan runs, radiator properly filled w/ coolant/water mix as prescribed.
>>
>> What should the mechanics look for first?
>>[/color]
>
> The fan. The fan clutch, actually.
>
> The fan is driven by a clutch -- a viscous coupling realy -- and it sounds
> like yours is toast. A fan clutch is a part that the normal shade tree
> mechanic can install in an hour or two, and a real mechanic can do much
> faster. I don't know what labor rates are, but I'd guess that they will
> get
> an hour or hour and a half, and the clutch will run around $100. This is
> one
> of those jobs that you can do your self, if you have the inclination to do
> this sort fo thing.
>[/color]

To check the fan clutch, run the engine until it is good and hot, turn the
engine off, and grasp the fan and see if it spins - it should spin freely
when cold and be locked or harder to spin when hot.

Other possibilities you can check yourself:

Check the radiator and AC condenser to make sure that you can see through
the fins and they are not clogged or bent over to restrict air flow.

Coolant should be a 50/50 mix of coolant and water and should be
translucent. If it is murky, it needs replacement and if it is transparent
like water, then it will boil more easily. Coolant should be replaced every
2 years. You can invest in an inexpensive (under $10) anti-freeze tester to
check the mix.

If the radiator cap is original, replace it.

This requires disassembly, but the opening temperature of the thermostat
should be checked. If it was replaced recently, it may have been installed
upside down.

Make sure the exhaust is not clogged and ignition timing is correct.

Make sure none of the accessory drive belts are slipping.
[color=blue]
>
>[color=green]
>> What's a reasonable charge for a good (not cheap) shop (e.g., Master
>> ASE) to do that?
>>
>> Are there typical failure mode(s)? Approximate costs?[/color][/color]

Typical failures at 140,00 miles are clogged cooling system (usually flush
and replace radiator) - in the $300+ range

Bad thermostat - in the $150 range

Bad radiator cap - in the $15 range
[color=blue][color=green]
>>
>> What's the worst case repair and its approximate cost?
>>
>>[/color][/color]

A radiator replacement is probably the worst case repair.[color=blue][color=green]
>>
>> Thank you kindly,all, for your on-topic responses.
>>[/color]
>[/color]

--
Ray O
correct the return address punctuation to reply