Heater not getting hot

[mayk19]

I think scooby is trying to give me sleepless nights ! Supposed to be off away for 10 days this weekend but I think I have cooling system problems, will try to list all sypmtoms here to see if Im worrying needlesly or there is something.

Basically the heaters are not geting hot. Ive got 2.5d R reg with Climate control system. If I whack it upto 32 degrees, even after driving for a an hour the temperature out of the heaters isnt really that hot. The climate control fan works fine. The A/C works fine. Could I have trapped air in the cooling system ? The cooling system will have been drained at least twice by the garage in the last few months. I've done a big trip to wales since then with no issues.

Other points. Top radiator hose is hot, bottom one cold.
Sometimes when I accellerate the temp needle will shoot to the cold end, then flicker back up to 11 o clock, doesnt happen after I've been driveing for 30 mins or so.

Ive got Haydns alarm on. When I first start up the bongo, Im usually reversing out of the drive and the alarm will beep for a second, just a few times, maybe 4 / 5 then stop. I could re-create that by starting engine from cold, sitting idle, switch off the AC system Haydns alarm beeped. Non of this could be re-created after I had been driving for 30 mins.

I;m thiking. 1, Temperature sender. OR 2, Trapped Air, or 3, Im of too nervous disposition to own a bongo !!! or 4, Thermostat ? Whats the worst that can happen if the thermostat is trapped open ? would this be the same.

THanks once again to the Bongo community for your help

[maxheadroom]

Thermostat is stuck open I would think, which is much better than stuck shut.

[westonwarrior]

Thermostat is stuck open I would think, which is much better than stuck shut.

or missing completely

not that I have a clue realy

[brorabongo]

Are the rear heaters getting hot? If so you might of dislodged the wire which controls the flap for diverting air over the heater matrix? AFAIK the wire is down by your left foot, and it seems that it's easily knocked off.

[mayk19]

thanks for tips.

No rear heaters. Its a wellhouse conversion, rear heater bits are removed.

[Simon Jones]

Whats the airflow like? Bongos have a pretty gutless fan anyway, but are prone to bearing failure due to water ingress. Could it be that its hot, but you're just not getting much air thru the vents? If you've got the mechanical controls (knobs rather than push buttons), then problems with the linkage controlling the flaps is not uncommon.

[mayk19]

Hi Simon, flow is OK, as you say its not a gale that comes through them but you can tell when its on Max. I have the climate control version, with buttons.

Cheers.

[Simon Jones]

If you're coming to the Bash next week, you're welcome to come & have feel of my fan (ooh err), so you have something to compare against. Mine has digital controls too & I've always found it was hot enough for me, but I've also got an Eberspacher diesel heater in the back for when it gets really chilly. Don't you have a summer up 't north?

[mayk19]

lol simon, nah no summer sorry not coming to the bash, heading to the south coast if we get there !

[Aethelric]

Top radiator hose is hot, bottom one cold.

This is normal

Sometimes when I accellerate the temp needle will shoot to the cold end, then flicker back up to 11 o clock, doesnt happen after I've been driveing for 30 mins or so.

This is weird. It suggests cold coolant in the heaters suddenly coming into the engine!

Ive got Haydns alarm on. When I first start up the bongo, Im usually reversing out of the drive and the alarm will beep for a second, just a few times, maybe 4 / 5 then stop.

Could happen if the level is a bit low. As the coolant heats up it expands and the level goes up

If the stat is stuck open then there will be continual unrestricted flow of cold coolant from the radiator which would tend to stop the heaters working very well. But the temperature of the coolant flowing into the heaters should be about the same as the top hose If the stat was stuck open the top hose would not get as hot as normal.

Strange one!

Dave

[mayk19]

Cheers Dave, some good stuff there.

mmmm, wonder if I'm linking random problems together.

Temp gauge / sensor is electrical ? Heater....maybe thats as well as they perform, I don't recall if they have ever been better or worse TBH..

[Aethelric]

Cheers Dave, some good stuff there.

mmmm, wonder if I'm linking random problems together.

Temp gauge / sensor is electrical ? Heater....maybe thats as well as they perform, I don't recall if they have ever been better or worse TBH..

Could be Simon, an electrical fault affecting the gauge and the A/C. An electrical fault would cause the gauge to move faster than cold water entering.
Another possibility is that something has gone wrong when the rear heaters were removed and the front ones have a restricted flow for some reason. The flow should be from the block, around the heater(s) and back into the top chamber of the stat - it is not restricted by the stat.

Dave

[mayk19]

The guage is certianly moving faster than cold water could possibly flow into the system and register on the needle, thats a very good point.

So changing the Thermostat wouldn't change how hot water gets to the front heaters ?

Worth researching what you say about how the rears were removed. The pipe that wellhouse had fitted was leaking from the clips, it was also a pretty accute angle. My local garage has re-fitted with a new pipe and clips, maybe its not a large enough diamter...or still kinked.

[haydn callow]

The only reason the alarm should "beep" is if the level of the coolant in the header tank drops below the top sensor screw. You need to top up with coolant when COLD to the FULL line. If you do this you should never get a beep unless you lose coolant. You say the temp gauge drops to zero then flickers back. Could be a poor electrical connection or faulty sensor.It could also be caused by a air bubble hitting the sensor. The sensor needs coolant to regiester.
If the tank is FULL and the alarm "beeps" it could be when you switch somthing on (could be glow plugs cycleing in the morning) you are getting a large voltage drop and the alarm is detecting it.. Is your battery good and strong?

[mikeonb4c]

My low coolant alarm had a momentary glitch a couple of weeks back and started to go off (weak sound fading to stronger). I checked coolant level and it seemed fine. I reckoned I'd been canted over at an angle on the kerbing with coolant level at 'low tide' (when engine is cold?) and the level had got just below the sensor. I put a rad more 50/50 mix in the header tank to avoid a repeat. I can remember how my heart sank when it beeped though!

Were you on an incline of any sort when it went off?