Puff of white smoke after steep down hill

[911nFJ60]

Hi all, seeking help on diagnosing cause of white smoke from left headlight on FJ62.

I live on top of a hill which is about 2 miles from the golf course at the bottom. There is a fairly steep 0.7 mile stretch of road before it flattens out at the course. As I approached the stop sign at the bottom of the hill, there was a sizable puff of smoke from the left headlight area and a faint smell of hot coolant. Temp gauge was barely registering anything, which was not unusual as I’d driven less than 2 miles mostly downhill. I eased it about 500 feet into the parking lot, played 18 and drove it back up the hill, no problem at all. Checked it out after cool down, the radiator was full, but the overflow reservoir was empty. I added coolant/water and drove the truck on some errands that took me down less steep streets again no problems and temp barely above lower line.

A couple of days later, drove to the course again and same puff of smoke at the bottom of the hill. Played 18 and drove it back up home. After cool down, there appears to be the same amount of coolant in the reservoir.

Any ideas on the cause? Thermostat starting to fail? Radiator hose leaking? Should I jack up the rear end and run it to try to reproduce in the garage?

Thank you in advance!

Cheers,

Ron

 

[ToyotaMatt]

Hi all, seeking help on diagnosing cause of white smoke from left headlight on FJ62.

I live on top of a hill which is about 2 miles from the golf course at the bottom. There is a fairly steep 0.7 mile stretch of road before it flattens out at the course. As I approached the stop sign at the bottom of the hill, there was a sizable puff of smoke from the left headlight area and a faint smell of hot coolant. Temp gauge was barely registering anything, which was not unusual as I’d driven less than 2 miles mostly downhill. I eased it about 500 feet into the parking lot, played 18 and drove it back up the hill, no problem at all. Checked it out after cool down, the radiator was full, but the overflow reservoir was empty. I added coolant/water and drove the truck on some errands that took me down less steep streets again no problems and temp barely above lower line.

A couple of days later, drove to the course again and same puff of smoke at the bottom of the hill. Played 18 and drove it back up home. After cool down, there appears to be the same amount of coolant in the reservoir.

Any ideas on the cause? Thermostat starting to fail? Radiator hose leaking? Should I jack up the rear end and run it to try to reproduce in the garage?

Thank you in advance!

Cheers,

Ron

if you have to add more coolant to the overflow bottle on a routine / regular basis ..............?


- then , you have one of 3 possibilities :

- Internal Engine leak , bad head gasket and or a crack or corrosion allowing coolant to enter one or more of the 6 combustion chambers

- external leak , metal pipes or rubber hoses or both

- if you suspect a internal coolant leak PULL a 6 plugs and # each 1-6 with black sharpie as you pull each one in order ,. lay out look for variations in color and deposits on each end , post photos if un sure ?

- this 3rd possible cause i have seen only 4 or so times in my experience : the throttle boy . upper air intake plenum / chamber id - some how in-taking coolant and sucking it into the engine with your air fuel mixture , a 3F-E has a ISC valve / IAC valve , ANYWHERE the little 10MM mini coolant hoses go to under the intake and beyond , this is sorta a remote possibility but after 30+ years , Nothing should be left to chance

- also WATER PUMP weep hole , inspect it and all the 360' degrees around the perimeter


this is how you start this process , Confirm , Verify and then the correct diagnoses most often shows you what the issue is , and you don't have to actually go looking for it ..... if finds you first

use the TOYOTA paper print media FSM step by steps , THEY WORK !