BJ70 Cooling saga continues...HELP! (1 Viewer)

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Joined
Dec 15, 2004
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Location
Folsom, CA
The continuing saga of my BJ70 cooling problems...I'm ready to drop this thing off a 9th floor window:

Last November....truck ran fine and cooled well, even up longer grades but H20 temp would climb to about 210 (just below red on the factory gauge) if the outside temp was 90F + when running up big hills. Since I live in an area where temps often reach over 100F I wanted to make sure my cooling system was bullet proof.

SO, I all I needed was a 4 core rad...right?

Ordered a 4 core rebuild from 4 wheel auto & dropped it in. While I'm in there I also do the following:

Remove oil cooler that was located behind the rad
New hoses, belts, 82C T-stat (tested before installed), 13lb Rad cap, Modified clutch fan to solid fan

So now I should be cooling like a Mo-Fo right? NO! It's worse now!...temp climbs up on small hills w/o the AC on!

SO, I flush the rad again and bleed all the air out and I replace the stock gauge with new AutoMeter so I can get accurate temp readings.

STILL FRIGGIN HOT!!! Just tested it on a flat stretch of Freeway, AC off, 85F ambiant temp and I'm running 202F!

My head shows NO signs of a crack, no white smoke, no loss of coolant etc. My original H20 pump is not leaking and is making no noise (plus it only has 200,000kms on it). I got a laser thermometer and got the following readings at idle:

Engine - 195F
T-stat housing - 195 ish
Top of T-stat housing - 180ish
Top of rad - 175ish
Sides of rad - 140ish
Bottom of rad - 150ish
Bottom hose - 175ish

So it looks like the T-stat is opening, flowing to the rad, rad is cooling...eveything looks like it should.

So where the hell do i go from here? I've not yet tested it up any hills but if I'm at 202F on flat land at sea level when it's not all that hot out I can imagine what it'll be like up big grades.

Any ideas???? HELP!!!

Signed, pissed off in Sacramento.........
 
dieselbigot said:
The continuing saga of my BJ70 cooling problems...I'm ready to drop this thing off a 9th floor window: Signed, pissed off in Sacramento.........

Before you drop it out the window, drain the block, take out the block drain plug, and see if there is a build up of crap in water jacket...If there is stick a pressure washer in that drain and clean it out (of course making sure the rad is not connected so as to not recieve the crap).

Dunno if that is it...but perhaps worth a shot...

gb
 
Temp sender for the autometer replaced the factory sensor...me thinks that has to be accurate
 
Hi Brett,
Being the least experienced here, take my thoughts with a grain of salt.
when I got my truck it ran hot up long grades (no turbo, no AC). I changed thermostat (88C, not 82), fan clutch, the brown syrup that was supposed to be the coolant, belts and temp sensors. that helped a bit, but not significantly. the needle did not go to the red anymore, but close.
then I changed the waterpump against a n orifinal new toyota one (the old one showed no sign of leaking or malfunction), and that helped a lot. needle goes barely to half now, under any conditions.
I don't have an accurate gage, but the difference is obvious.
I then opened the pump up, and there was a lot of deposit in there-cleaned it, tested it, now it is a spare.

hope you solve the problem. are the hoses original or aftermarket? could one collapse under neg. pressure?
for what it is worth...
regards,
Jan
 
me, I would fix that fan clutch.........yeah I know it "should" cool better solid.........but maybe not, it might be block airflow

did you take the non contact thermo to the motor when moving(or RIGHT after)?

195 at idle sounds just fine to me, up to 205 or so when running is OK IMOP.

and why did you toss the oil cooler? would seem to me like that would maybe help with the engine temps.
 
me, with temp readings like you got form the tech... i would just drive it...
but it isn't my truck or my money...
cheers
 
Brett,
From what i'm reading you have the autometer in the NPT port on the Thermostat? If yes.. I don't think your readings are all that bad. 202? That's nothing. I rolled up to downieville to do some wheeling and I got her up past 210 on lookout mtn. and was upward of 215-220 in some spots and the stock guage was reading good (within what I feel is acceptable anyway) and I've already replaced a head so i'm a little on the cautious side. I was in third pushing 1200* and I had to back it down to 2nd and go 25mph to keep her cool. It was Hot in Denver today at just over 90* and TreerootCO wa having major vapor lock problems. If you ask me 202 is fine.. I'm at 210 now in the summer around town.

Now take my numbers with a grain of salt because I have my temp sensor in the rear heat coolant return at the block. I am going to put it into the thermostat here this week and run a few Hills to see the difference.

Personally I don't think you can baseline your previous readings because you were gauging with the stock gauge which is almost useless if you ask me. Heck my fuel gauge started spiking today. Great another wonky guage.

Just run that thing I think your fine.
 
west, we have GOT to get you turbo'd, my boy! Up there at altitude you'd be so much happier.
 
OH yeah.. I know. BELIEVE me I know :) I don't have any issues keeping up with the 40's and I've resigned myself to just enjoying the cruiser. Slow doesnt' bother me. Now I can do 80 down the hills here pretty well.

Shot from today's run. 7x16's stuffed :D
110_1099.JPG
 
Last edited:
Brett,

Something to consider with the aftermarket gauge is the thermocouple going in to far and touching the housing, if that was the case then the reading would be off, just a thought.

I was running 195 and up to 205 on big hills with my silver 70 series (pismo last year) and then I changed to 82c thermostat and it runs 185 pretty steady and maybe up ot just under 200 on big hills.

One thing I did recently was to turn down my fuel (not much temp difference) but then I turned up my boost to 11psi and it seemed to help statilize my temp 180 to 185 on flats and up to 190-195 on hills.

I am running solid fan, no air on this one and I have thermocouple on passenger side of block up front where water line for rear heater came from, still have stock gauge mounted in thermo housing. Also running AXT turbo on that cruiser.

Michael
 
west, it's worth it to turbo even if you don't turn up the fuel. In your situation (high altitude), it's just incredibly useful in holding down EGT's. Pump more of that rare air in there. I haven't done my BJ-73 yet; however, it's on my TO DO list--right after I swap the 1KZ-TE into my 45.
 
Guys,

Thx for all the great feed-back. I guess I'm partially venting here, I'm just so frustrated after doing all this work and getting negative results.

Greg

When the flush was done yesterday there was nothing in the block, this thing has had 3 flushes in the last 4 yrs...block is very clean

Wes

If your temp readings were correct, would anything over 212 not make your rad boil over? I'd be interested to see what kind of readings you get once you move your sensor to the factory gauge location

I think my plan for now should be to do the following:

Turn my boost back down to 7 lbs (currently at 13-14)
Turn my fuel back down to stock
Chemical test my coolant to make sure I'm not getting exhauast gas in coolant
Swap my clutch fan back in

If that does not work then I guess I head in for a H20 pump. Any other thoughts?

Thx guys :cheers:
 
dieselbigot said:
If your temp readings were correct, would anything over 212 not make your rad boil over?

Only at sea level pressure, 212 irrelevant in a pressurized system.

Turn my boost back down to 7 lbs (currently at 13-14)
Turn my fuel back down to stock

14lbs boost on your turbo? That could warm things up.
 
Brett,

This may be a long shot but a few year ago I had a pump go out on my 3B in my BJ42. I got a new one from SOR and it was an aftermarket one, and after installing that pump my temps were always running higher. If you get a new H20 pump stick with Toyota (probably best price from Cruiserdan).

If you go back to stock clutch fan and want to get your money back for the solid fan just let me know, I have plenty of orders for solid fans..No worries.

Good luck, and keep us posted I am very intrested in you outcome because I have the same setup on a few of my 70 series.

Michael
 
ok, so now I am really confused. Lets talk maximum acceptable temps. My VW TDI's factory temp gauge has two temps indicated on it. Half way is 190F...it always stays there nomatter what. The "red" temp is 260F. So if water boils at 212F, I was always under the assumption that 212 is as hot as you ever want to get. Am I wrong? (lets assume that my autometer is giving me accurate readings)
 
sure water boils at 212, but that is if its in the open(like a pot on the stove), not in a closed system(like a rad) the rad cap will increase the boiling point a good deal. Also distilled water(ONLY) does not boil.........it needs some impurities to boil

most stock temp guages don't move once they get to operating temps............but in reality the temps are changing.......just the stock guage does not indicate it.

on a SBC I think up to 230 is OK(many of the newer SBC's run 210+ when normal). On a cruiser 205-210 is ok, now this is for a gas engine, I dont know crap about dsl cooling systems

dieselbigot said:
ok, so now I am really confused. Lets talk maximum acceptable temps. My VW TDI's factory temp gauge has two temps indicated on it. Half way is 190F...it always stays there nomatter what. The "red" temp is 260F. So if water boils at 212F, I was always under the assumption that 212 is as hot as you ever want to get. Am I wrong? (lets assume that my autometer is giving me accurate readings)
 
Landpimp said:
sure water boils at 212, but that is if its in the open(like a pot on the stove), not in a closed system(like a rad) the rad cap will increase the boiling point a good deal. Also distilled water(ONLY) does not boil.........it needs some impurities to boil

I am sorry to chime in, but as a scientist I can't let that go.
distilled water boils just fine, at precisely 100 celsius at sea level. no impurities needed.
J
 
As far as temps go. I start to watch carefully at 230 and start to worry at 240. At 250 I actually actively do something.

Funny, we recored Charla's BJ73 to four row and it seems to be hotter now too.

Are you sure you have all the air out?
 

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