Temp gauge

[pollyden]

I bought a Bongo a couple of months ago & have only used it a few times.
I noticed that the temp guage didn't seem to be moving when i collected it & the buyer said that is does move, but only registers at the bottom of the scale & because of the overheating that these vehicles are known for, he was happy that it didn't get too hot.

Now having driven it for a few hundred miles, it starts & goes perfectly. The engine is great & performs beautifully (it was replaced with a recon unit 27000 miles ago).
However, the temp guage still hardly moves. If i go up a long slogging hill in a lower gear, it may rise to about a qurater the way up the guage, but as soon as the load is taken from the engine, it drops back to "zero" within a mile or two.
The heater belts out lots of nice hot air even though the gauge is on zero.

Now, does all this sound as though the engine has had the thermostat removed?
As said, i cannot fault the performance. It starts, runs & performs beautifully.
But, what i want to know is, am i doing any harm by using the vehicle if the engine never seems to get up to the correct temp, or am i best to leave alone, seeing that i have no cooling, heating, or mechanical issues & just drive the thing?

BTW, its a 1997 2.5 diesel.

[stefan442]

If the stat is open or been removed the bottom.pipe going into the radiator will get warm straight away as it will be circulating coolant as soon as you turn the engine on.

[pollyden]

Ok, will check that this eve. . . but any thoughts on my other question?

[Driver+Passengers]

The dashboard temperature gauge (in its factory condition) will sit at around "11 o'clock" until the thing has already overheated and then you'll see it move towards "12 o'clock".

There is an over-temperature alarm called a Mason alarm that some vans have installed which will "change the range" of the needle, and there is also a DIY modification that many people perform (which involves solder a resistor to the back of the temperature gauge) which is an alternative method of "changing the range" of the needle. By doing this, the active range of the needle can pretty much be set to whatever the modifier wants. If you see it "off the stop" when you're working the van a bit harder, that's ok. Granted, it would be nice to see it off the stop under normal driving conditions and then you get to know it's "expected" range of motion.

Doesn't sound too bad to me. If you're worried about the stat, as stefan said, from cold run the van a mile or two. Under the driver's seat is a fat hose out of the head, this should be warm. Under the van on the passy side are two sections of rubber hose, one dropping from the engine down to the bottom, and one under the bonnet connected to the bottom of the radiator. These should not get hot until you're well up to temperature, and even then, a clean, well operating cooling system may not get hot enough to open the stat until you're parked idle in traffic, or beasting uphill.

Hope some of this helps.
Matt.

[Northern Bongolow]

starting from cold.
does the temp of the heater hoses match the temp of the bottom hose.
if its running cool you may not get proper warm up so the motor will use more fuel, and wont engage top gear as easy, if its an auto.

[pollyden]

Thanks Matt. Good info. That puts my mind at rest to a certain extent.

Have not checked the warm up of the hoses. As said, all is fine with the engine, so have had no need to play as yet.
I will check at the weekend.

As for warm up, yes, all seems fine. The heater starts to belt out heat after a couple of miles & as i said before, i cant fault the starting or performance of the engine & have also been pleasantly surprised by the excellent fuel consumption. The auto box changes perfectly up & down & no problems slipping into top gear at any time.

Its useful to know that it is just probably the temp guage under reading. If Bongo temp guages do that, thats fine. I can live with that.
Will just keep an eye open to see when the needle goes above cold!

Thanks for your answers.

[Driver+Passengers]

Thanks Matt. Good info. That puts my mind at rest to a certain extent.

Happy to help.

Given your description of the gauge behaviour, it is likely that your gauge has been modified. Either that or the temperature sensor itself may be faulty. I'm not backtracking, but covering my a** - worth whatever additional checks you can muster rather than taking my advice! If in doubt, I'm sure someone local to you could help you confirm.

[teenmal]

Hi pollyden,

I would get the thermostat investigated as soon as possible,it might be butchered to mask a serious fault.Did you get a guarantee with the vehicle.

PS What is the excellent fuel consumption.
Cheers.

[pollyden]

When i bought it (privately) it came with a full service history & a 2" thick file of past service & repair invoices - including one for over £2500 for the recon exchange engine.

The rest of the vehicle seems pretty honest with no issues.
It hasn't missed a beat, or given a hint of any problems in all the time ive had it, so im not suspecting any faults or issues with the engine.
If it was playing up & overheating & running cold etc, i would suspect something. . . but it runs perfectly & is a delight to drive.

I recently did a 200 mile round trip to Mid Devon on M5, A & B roads.
I filled it to the brim when i left & filled it to the brim when i got back & it took 28.5 litres.
Thats 6.26 gallons. 200 miles devided by 6.26 gallons = 31.948mpg. Im well pleased with that.
Obviously, running around is a lot less, but i thought that was pretty good in all sorts of driving conditions.

My Saab turbo only manages 28mpg on a good day. . .

[Velocette]

I have an Enginesaver digital temperature guage/ alarm and you know what your engine temperature is doing at all times. under a steady load you should see a steady temperature mine hardly waivers unless I get lead boot syndrome or climb some huge hills. Even then it is a gradual change and will settle at say 90 instead of 87 if I am driving hard. Stat starts to open at about 75 I think and is fully open about 105/110 is it? Then the fan takes over control. Only ever seen 101 on mine and that was climbing up a mountain range in Spain.

I would reccomend the enginesaver for piece of mind and you can get it with a combined low coolant alarm.

[pollyden]

I have an Enginesaver digital temperature guage/ alarm and you know what your engine temperature is doing at all times. under a steady load you should see a steady temperature mine hardly waivers unless I get lead boot syndrome or climb some huge hills. Even then it is a gradual change and will settle at say 90 instead of 87 if I am driving hard. Stat starts to open at about 75 I think and is fully open about 105/110 is it? Then the fan takes over control. Only ever seen 101 on mine and that was climbing up a mountain range in Spain.

I would reccomend the enginesaver for piece of mind and you can get it with a combined low coolant alarm.

Theres an "enginesaver" alarm already fitted, but that has no bearing on the temp gauge reading which was my original question.

i dont have an engine issue. I dont have an overheating issue. I dont have any faults or problems at all with the cooling system.

I simply wondered if because the temp guage always reads so low, there was perhaps no thermostat in there.

But, as i have found out that the Bongo temp gauge seems to read low anyway, i wouldn't appear to have an issue.

Velocette. . . are you a motorcyclist perchance?

[Driver+Passengers]

I think the dash gauge not getting 'off the stop' during typical running temperatures and only moving with an increased load is "not normal" when you consider what most other gauges in their various states of modification do, but nor do I see it as being anything much of an issue.

You can maybe learn a bit more about the variant behaviours from this thread...
viewtopic.php?f=3&t=46855

[haydn callow]

Do you have a EngineSaver Digital temp gauge fitted or a Low Coolant alarm.
If you have the temp gauge ...what readings are you getting ???
Should be between 85/95 running under average normal conditions.....if not then you do have a issue if the gauge sensor is fitted as per instructions (back of cylinder head).