Bongo Fury

My transmission safe mode episode started me thinking about driving style and keeping the bongo engine cool: in safe mode I was forced into 3rd gear, doing high rpm on a flat road. According to my Mason gauge, the engine ran just slightly cooler in safe mode than normal motorway driving in overdrive. My understanding of how to keep your engine cool in difficult conditions (i.e., driving in mountains or on a very hot day) is that you should lock an automatic out of overdrive and slow down. A few years ago I drove a rented Chevrolet up the Rocky mountains, near Pike’s Peak in Colorado. It was very steep, and a hot day, and the temp gauge started shooting up. Locked out of overdrive at 35-40 mph the temp gauge came back down. Another time, I was approaching Las Vegas from the West in record-breaking heat, even for Nevada. The road was a very long, not especially steep grade. I was driving a lightly loaded overpowered van. In this case, the engine ran coolest with me keeping my speed at about 80mph. Other traffic was slowing down, and I was belting past everything. I suppose I was doing the right thing, as the grade was not taxing for the van, and keeping my speed up kept a good flow of air over the radiator.

Am I correct in my thinking about driving style to maximise engine cooling? The fact that the coolant temp was lower (although not by much) on my bongo in safe mode than it was tootling down the (very flat) A11 in overdrive may suggest that my cooling system is not working as efficiently as it probably should be. It could be time for a flush.

Hi,uncomfortable as it sounds and is,turn your heater to HOT, fan on max,and windows open.This will disperse a lot of heat from the engine,not nice for the occupants but it does work.

The Bongo scavenger fan should come to the rescue in extreme heat. Rather than trust to the 12yr old sensor working and activating the fan, I've fitted an over-ride switch and circuit. The Bongo engine covers a a bit of a radiator anyway - great in winter, unwelcome in summer. So I plan to switch my scavenger on for passenger comfort as much as engine protection. Its an easy mod. though not been done widely so we'll have to wait and see if there is any downside (I don't think there will be though)

Ours always runs cooler in town, the opposite of what you
would expect, only by a few deg but definitely cooler,
Some Diesels don't burn enough fuel at low revs to
get hot and this may be whats going on but it never
over heated even after 2 hours in stop start traffic
the fans never came on. Putting the air con on
could help as even thought it puts more load on the
engine it also turns on the fans at low power.

The over-heating could be attributed to the engine labouring. The equivelent of using 5th up a long slight slope, as opposed to fourth. The revs may increase by "dropping a cog" But wil be in a more efficient rev range,so the engine isn't relying solely on very low down torque.

before I changed hoses and coolant....

when it was pushed up a big hill, or a long overtake with acceleration the gauge would creep up and the masons alarm would beep

as soon as you eased off the revs, ytou could watch the temp on the gauge fall.....

this was not a huge movement by the way.... just a few mm

I've only done a couple of runs since, so to early to say......

but I did wonder if the coolant was mixed (jap and uk don't mix too well and this can affect the ability of the coolant, allegedly ), I ran coolant flush through and flushed the rad....

the needle does seem a little bit lower most of the time... but not sure could just be me hoping for a difference


John