Thread: 7 day challenge

Had to watch exhaust temp on the steeper ascents (36c outside) but just dropping the speed eg 95 not the 110 I could have done, engine temp reached about 88 then dropped to 80 as soon I crested, after that for the rest of that day engine temp never exceeded 70c (38c ambient) so need to look at this I think last few days never reached 70c.

That to me suggests that something is wrong and the temp sensor is not working correctly at the very least.

There is no way that after driving on the highway the engine temp will remain below 80c on a 38c day.

The design operating temp on the 4BD1 is 85-90c and the thermostat is designed to open at 82c.
Good thing is that it's a wax thermostat so even if the temp gauge/sensor is wrong it will still open, but you probably should get that checked.

Originally Posted by Chris078

Had to watch exhaust temp on the steeper ascents (36c outside) but just dropping the speed eg 95 not the 110 I could have done, engine temp reached about 88 then dropped to 80 as soon I crested, after that for the rest of that day engine temp never exceeded 70c (38c ambient) so need to look at this I think last few days never reached 70c.

That to me suggests that something is wrong and the temp sensor is not working correctly at the very least.

There is no way that after driving on the highway the engine temp will remain below 80c on a 38c day.

The design operating temp on the 4BD1 is 85-90c and the thermostat is designed to open at 82c.
Good thing is that it's a wax thermostat so even if the temp gauge/sensor is wrong it will still open, but you probably should get that checked.

Both the themostat & the temp gauge (VDO mechanical) were brand new, will check temp gauge in near boiling water tonight.


The right hand side of the radiator was reasonably cool to touch when ever I stopped.

Originally Posted by Chris J

Both the themostat & the temp gauge (VDO mechanical) were brand new, will check temp gauge in near boiling water tonight.


The right hand side of the radiator was reasonably cool to touch when ever I stopped.

If you haven't overheated by now, the thermostat is good.
I didn't realize the temp gauge was a mechanical one and doesn't have a sender unit. makes testing a little easier I guess.

My understanding of the cross-flow radiator type as fitted to the Perentie is that it should heat up from bottom to top and right to left (when you are looking at the front) . As per your thermostat, I'd say your radiator is also good, and focus on that temp gauge.

82c is where the thermostat opens, and a normal operating temperature is 85-90c.

After reading your post Chris I realised we had a calibration thermometer in the lab draw at work, filled a cup from the kettle & both stabilised & dropped within 1/2 a degree of each other.

The only other thing with the cooling system is I just looped the heater pipes rather than reconnected the heater core & fitted a new fan belt.

Will check part No. on thermostat when I sort out gearbox seal & reconnect heater when I put engine back in, also might chuck fan in car & try & find a clutch fan at a wreckers (thinking nissan).

ps: took forever getting engine to temp prior to all the works.

Originally Posted by Chris J

Have you worked out a cause?

KLR will take another look for me but I think the input shaft (?) has been replaced by the army with a newer unit with square edges that is suspected to have split the seal. Someone who actually knows these gearboxes may be able to translate this for you lol.

Is anybody else not surprised by Chris Js temps?

From what I understand, factory gauges don't show the true fluctuations on engine temperature, and he has a new aftermarket mechanical gauge. And I can certainly understand temps as low as 70c, as my engine struggles to warm up in winter (I have since replaced the thermostat but am yet to test it).

What are other peoples thoughts?

Originally Posted by Chris J

Extremely bad news just drained 1.5L of gear oil from bell housing, it appears something went wrong with the new seals & gaskets I installed to the front of the gearbox.

Most probable cause is the oil pump cover plate. Did you check it for straightness. They usually need to be linished and then finished off on glass to guarantee a straight edge. The new type are a lot thicker and less prone to warping. Also you have to apply ample sealant to all the front cover plate bolts especially the input bearing retainer bolts to stop oil migration through the threads.

Originally Posted by Bearman

Most probable cause is the oil pump cover plate. Did you check it for straightness. They usually need to be linished and then finished off on glass to guarantee a straight edge. The new type are a lot thicker and less prone to warping. Also you have to apply ample sealant to all the front cover plate bolts especially the input bearing retainer bolts to stop oil migration through the threads.

Spent a fair bit of time on the glass as was warped, I think you maybe on to something with the bolts, but I think like Dingsy my gearbox input shaft has a square edge, I must have damaged a seal to get that much oil in the bell housing.

The reason I changed the seal was some oil in bellhousing & my log book shows changed rear main seal & changed clutch at 10,123, my thoughts are gearbox seal from Tenix rebuild leaked slightly, then I damaged due to square edge - find out soon