Don't like the adverts?  Click here to remove them

Overheating

S

SiCarrie

New Member
Joined
Aug 8, 2010
Messages
22
Here's the deal - after a bit of fun at Kirton, it's overheating - but only once you crack 42mph it seems! At idle, or trundling round the off road site, it's rock steady in the usual position. Will seemingly idle for ages with no concerns. I jetted the rad in case it was blocked but that didn't help and had to resort to calling the AA. According to his combustion gas test, it's fine. Pressure does build in the cooling system however.

Any thoughts? Try no to mention cracked heads if you can at all help it...
 
SiCarrie said:
Here's the deal - after a bit of fun at Kirton, it's overheating - but only once you crack 42mph it seems! At idle, or trundling round the off road site, it's rock steady in the usual position. Will seemingly idle for ages with no concerns. I jetted the rad in case it was blocked but that didn't help and had to resort to calling the AA. According to his combustion gas test, it's fine. Pressure does build in the cooling system however. Any thoughts? Try no to mention cracked heads if you can at all help it...
Click to expand...
I had this problem on my 80, in my case I could do up to 60mph all day long with no problem but over that as the speedo needle rose so did the temp, in my case it was mud clogging the outside of the rad and in front of that the aircon rad and in front of that the intercooler rad so it was impossible to clean the mud out from the front and because of the cowl on the back of the rad that couldn't be jetted over the whole rad.
They all had to be stripped out to do it properly, jetting them all took about an hour, there was so much mud you could have planted potatoes there! :shock:
 
you will get pressure in the cooling system as it warms up, that's normal. It's often a lot harder to clean the mud out than you think, especially what's trapped between the radiator and what's in front of it like the aircon radiator. We've seen a few pics on here now where people have removed their radiator on a 90 to discover a huge mess trapped so that's probably what your problem is.
 
Jon Wildsmith said:
you will get pressure in the cooling system as it warms up, that's normal. It's often a lot harder to clean the mud out than you think, especially what's trapped between the radiator and what's in front of it like the aircon radiator. We've seen a few pics on here now where people have removed their radiator on a 90 to discover a huge mess trapped so that's probably what your problem is.
Click to expand...

For future: Is there a way of increasing the gap between the rads to make it either easier to clean in future or reduce likelihood of it recurring?
 
Just for your information, Toyota make their temp gauges with a dead spot purposely to stop people freaking out about the needle moving during normal useage and the consequent flood of telephone calls.
The needle will only start to move when the coolant is over 90 deg C which is getting uncomfortably warm.
My point is you can't rely on the factory temp gauge as a reliable indicator.
I bet the Rad needs to be replaced mine did the exact same thing and a new rad cured it.
 
Don't like the adverts?  Click here to remove them
My money is on mud caked rad. You cannot clean it easily in situ. The AC condenser gets in the way from the front as Jon said and you simply cannot get to it well enough from behind. The 90 rad is so easy peasy to take out it's worth doing. You do not want to heat up a 90 too much.

My 80 rad was blocked after wading recently. Temp off the scale. Oil boiling, block making hideous noises. In the end I had to take it out. It ran muddy water for ages. Doing it in place can lead to damage to the fins if you are too hard with it. Worth a flush inside too.

Chris
 
adrianr said:
For future: Is there a way of increasing the gap between the rads to make it either easier to clean in future or reduce likelihood of it recurring?
Click to expand...
You'd need a pretty big gap to make it so you could get between for cleaning to the point where I doubt that's the answer. If removing the rad is not an option I would look more towards making the fan shroud more easily moved out of the way or the fan more easily removed so that you can wash the fins through properly from the engine side. Mods to my shroud for other reasons mean removing the fan is easy and then moving the shroud out the way is also fairly easy, easier than removing the radiator. Using hot water works much better than cold so if that's an option use it. For the time in between getting it muddy and cleaning it, fit some extra cooling fans and put the heater controls on hot ;)
 
Fan shroud on a 90 just unclips Jon. Top and bottom are easy to remove. I have had a 90 rad out in 15 mins from a standing start. It's no way near as big a pain as an 80.

Chris
 
Yeah it took me less than a hour to remove clean and refit the rad, much quicker than trying to move the rad etc. Unfortunately a caked rad is one of the down sides of mud plugging :roll:
 
On dirt bikes we used to use nylon stocking type material to stop mud from building up on rads.
The material allows good airflow but is fine enough to stop mud from penetrating between the rad fins.
Maybe this could work on a 4x4 radiator?
Clean up is simples just move the material and the mud falls off.
 
Bounder said:
On dirt bikes we used to use nylon stocking type material to stop mud from building up on rads. The material allows good airflow but is fine enough to stop mud from penetrating between the rad fins. Maybe this could work on a 4x4 radiator? Clean up is simples just move the material and the mud falls off.
Click to expand...
That's just given me a thought, maybe a thin frame with that stretched over it could be made to drop between the rads and so be easily removable when not mud-plugging :confusion-confused:
 
I just pull the heater blind down now when it gets really deep and wet. The 90 doesn't have one fitted.

Chris
 
Chris said:
I just pull the heater blind down now when it gets really deep and wet. The 90 doesn't have one fitted.
:doh: Chris
Click to expand...
My heater blind has gone AWOL
 
Wow - thanks for all the comments. A clogged rad was my first thought, but I thought the jetwash would have cured that. Glad to know I'm wrong! I'll whip the rad out and let you know how I get on. Good time to change the coolant too I guess.
 
Where's that spare can of worms I had lying around... :p
 
Don't laugh but I need to get some for our Colorado having dropped the rad out in summer for sluice down... :lol:
 
You must log in or register to reply here.

Similar threads

L
Radiator overheating
Replies
14
Views
652
Tractionman
T
W
Engine idle not increasing or decreasing with AC...
Replies
3
Views
150
Dave
D
chapel303
Power steering?
2
Replies
22
Views
918
Soutie
S
B
Handbrake balance.
Replies
2
Views
382
Barrys4x4
B
T
Getting back into the 90 series scene!
2
Replies
25
Views
1K
Mick W
Mick W
Back
Top