3b temp fluctuations

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brisveganbj42

brisveganbj42

Joined
Jan 9, 2005
Threads
61
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1,768
Location
hobart.tas.au
Website
www.phat42.com
hey guys..

got my 40 rego'd today (YAY!) and went for a cruise to get the mail tonight and i noticed something wierd (for me anyway)..

so.. jump in the 40 and start it, 2mins later we are goin up a nearby hill.. probably 4th gear at about 2500ish rpm (guestimate as I was not paying that much attention)..

get a strong smell of hot coolant (as much as i can figure) and glance at the temp guage when we get to the top of the hill. its sitting at about 190(f).. this all in a space of about 2-4mins from first starting the car..

pull over and check it out.. radiator is hot to touch, hoses are warm. check for any possible leaks (hard to do in the dark without a torch), can't see any fluids dripping so decide to continue.. at another hill (not as long as first hill) the temp guage can be seen going up about 4-5deg in a matter of seconds.. then back down once we crest the top..

firstly im just wondering if this is normal behaviour.. this particular 3b is new to me so i'm not to familiar with its traits just yet. My previous 3b would only budge when pushed REALLY hard.. and after the thermostat housing gaskets were replaced, hardly moved at all.

anyway .. your thoughts are appreciated.. just wondering if it could be cause for concern.

thanks

andrew
 
mine never gets over 100 C it isn't normal behavior at all, but I know the EGT's on this motor would scare the s*** out of you if you had a pyro... Expecially if you run a small restrictive exhaust.

The sweet smell of rad fluid is bad too, could be a head gasket...

If it doesn't drip it uses it, or burns it off somewhere like the heater core...

others will be able to help more...
 
Is the system full of coolant? They need a few on/off cycles to get all the air out of the system.
Once you get it full and it stays full and you continue to have a problem then you need to look it over closely.
 
did you see any variations in your cooland level at next day . ? did you do a compresion test . ?
 
Eric Winkworth said:
Expecially if you run a small restrictive exhaust.

The sweet smell of rad fluid is bad too, could be a head gasket...

If it doesn't drip it uses it, or burns it off somewhere like the heater core...

others will be able to help more...
Click to expand...

the exhuast is a 2.5" straight through..

cruiser_guy said:
Is the system full of coolant? They need a few on/off cycles to get all the air out of the system.
Once you get it full and it stays full and you continue to have a problem then you need to look it over closely.
Click to expand...

Previously the radiator, fan and shroud have been replaced from my other 3b (the radiator was in good condition) so it is possible there could still be air in the cooling system.. I did attempt to bleed it though by letting it idle with the radiator cap off and the front of the vehicle raised (we have a slightly sloped driveway)..

The other thing that has me thing is that I am suspecting the fuel has been turned up. would this have a dramatic affect on water temp if it was..

also this 3b supposedly has had is top and bottom ends rebuilt so I would like to think its NOT a head gasket..

thanks for your help so far guys.. its always fun learning the behaviour of a new to me 3b..

A
 
a bit more food for thought...

When i drove it up from victoria (approx 1800kms over two days) with varying terrain (hills, flats, etc).. the hill last night was nothing out of the ordinary.. during this trip the stock temp guage hardly budged at all..

since then i have..

replaced radiator with a known good one (recored,etc)
replaced the fan shroud and what appears to a fan for a different model (its was bigger and had a viscous coupling?).. these bits were removed due to the rubbing on the a rusty bit in the shroud that had came free when going over bumps, etc. (the previous 3b fan is original and has no viscous coupling )
replaced some hoses with good ones
installed a mech temp guage with thread tape from the other 3b.
- thermostat remains the same (this was fine on the trip up)
 
Could be an air lock in the system. Try burping the air from the heater hose at the on/off valve, or the highest point. My HJ60 has temp fluctuations when the rear heater is on! Guage goes up & down like a yo yo. Turn the rear heater off and it settles right down!:rolleyes::cheers:
 
Could be your thermostat though. if you smell rad fluid it is probably boiling over and out the overflow tube.

I suspect the thermostat isn't working fully.

You say the rad is goo d- was it tested? Was it flushed? Any repairs on it?

Regards,
 
i would check the thermostate a well, i have seen good ones start to stick closed...
cheap and easy to repalce...
al;so check the viscous coupling to make sure it is actually doing its job...
fixed fans are my friend...
 
Garry said:
Could be an air lock in the system. Try burping the air from the heater hose at the on/off valve, or the highest point. My HJ60 has temp fluctuations when the rear heater is on! Guage goes up & down like a yo yo. Turn the rear heater off and it settles right down!:rolleyes::cheers:
Click to expand...

ok.. will try this again.. when i did it in the driveway the grade isnt too steep so the heater hose on/off would of been higher or the same level as the open radiator.

lshobie said:
Could be your thermostat though. if you smell rad fluid it is probably boiling over and out the overflow tube.

I suspect the thermostat isn't working fully.

You say the rad is goo d- was it tested? Was it flushed? Any repairs on it?

Regards,
Click to expand...

on the way home from work today i went up the otherside of the hill.. it was a 3rd gear hill and rpn was about 2-2.5k up it (only about 15-20secs) as soon as the temp got over 185f and rising the smell of coolant became noticable..

the radiator is good, was tested and flushed and was only 3% blocked when first given to them.

I'll check out the thermostat as well..


crushers said:
i would check the thermostate a well, i have seen good ones start to stick closed...
cheap and easy to repalce...
al;so check the viscous coupling to make sure it is actually doing its job...
fixed fans are my friend...
Click to expand...

in regards to the viscous coupling? what is it and where can i find it? the fan blades that was bolted onto the waterpump is fixed and hasn't got a metal bits in the middle.. the one that was swapped off did but it had LN105 or something similar scribbled on it, was bigger (less gap around the edges hence it rubbing on the shroud) so i figure it was from a wreckers..

thanks for your suggestions so far guys..
 
bj42turbo said:
I thought you wern't supposed to use thread tape on senders.
The problem you have is the same problem mine has STILL :crybaby:



BJ
Click to expand...

oh really?! What are you supposed to use instead?

I jacked up the front end in the drive way this morning and attempted to bleed the cooling system of air again.. there were a few little bubbles appearing. (like 4 or 5). did this for about 10mins..

then i went and did that hill again.. not being afraid to give it some.. went up to about 185f this time.. dwon the otherside and back up.. same again.. found a steeper bit and attempted to bleed it again, no bubbles this time

seemed a little better kinda hovered just under 180 (like the good 3b did), but was still moving a fair bit..

i'll do some more driving in it today to see how we go..
 
Gday
After youve checked all the obvious stuff, advancing the timing on 1 of my 1HZs had the same affect on the temp. It goes harder and is fine on long, average, trips (2780km in 29.5hrs), but travelling to work, I go up a long 11percent hill, about 200m change in elevation, and at 80 shees only just out of the red. At 60 shees fine. This was the result of advancing the timing, as she was fine temp wise before, but didnt go as hard.
Hope this helps
Matt
 
Im pretty sure its only Oxygen sensors that get messed up by some sealants. I only do diesels, tho. Some sealants dont like aluminium either, but youd probably have trouble finding one like that now.
(Getting ready to be corrected)
Sorry for getting off topic.
Matt
 
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