Any cooling system/ mason alrm experts online?

mp3oplecarrier · Post by **mp3oplecarrier** » Wed Oct 24, 2007 4:01 pm

I have just changed the radiator following the members area instructions and I have a problem working out what the alarm is trying to tell me...

I have bled the system the way I did 3 weeks ago when I changed a hose, then run the engine up to temp (gauge moved off rest point until it reached about 12 o'clock) I checked that there were no visible leaks and took some temp readings with my new toy (IR themometer). The metal pipe between the two top hoses read about 30 deg c and the hose from the top of the radiator was hand cool (?) at about 18 deg.

I then took the car for a very short run of about 1/4 to 1/2 mile. as soon as I got halfway the temp gauge shot up to the top line and the alarm went crazy even set to full, I slowly drove home quickly (if you know what I mean).

I opened the bonnet expecting to be met with a cloud of steam but instead got much the same readings, no leaks, no hissing sounds. I opened the pressure cap on the expansion tank and was rewarded with a cup full of warm water but no steam.

The way I am reading this is that either I have missed an airlock, so the engine is getting hot but the water is not getting around the system (most likely), or there is a problem with the alarm (I fitted it whilst waiting for the radiator so have not seen the way the gauge moves yet), or something I'm missing...

Help please?

Steve

mikeonb4c · Post by **mikeonb4c** » Wed Oct 24, 2007 4:17 pm

In this situation its hard to escape the feeling you need the type of head temp sensor that clogger fitted originally, plus you need to know what temps to expect from that sensor (clogger et al have posted the data somewhere on BF). If its not that, you have to suspect something to do wth the temp gauge wiring (was anything disturbed when the mason alarm was fitted for example?). It doesnt sound like you are going to get any good clues from coolant levels etc.

I'm not a real expert here - lets see what others have to say

Mike

PS - I suppose you could use your IR temp gauge to read head temperatures?

paul9 · Post by **paul9** » Wed Oct 24, 2007 5:13 pm

i would disconnect alarm,you can disconnect it from the unit by unscrewing the screw at back and just unplugging it,no need to remove the dash,then see what sort of reading on your gauge your getting,sounds like you may have an air lock still,so disconnect alrm for now until your temp gauge an cooling system is back to normal.

haydn callow · Post by **haydn callow** » Wed Oct 24, 2007 5:19 pm

I agree with paul9 ..I think you have a air lock ...Could be at the top of the Radiator. Remove the cap and let coolant overflow down from the header tank then replace cap.
Really sound as though it needs a "proper" bleeding session.

paul9 · Post by **paul9** » Wed Oct 24, 2007 5:27 pm

another thing i noticed the other day,i had been testing a mason alrm on another bongo,when i removed it i had forgotten to tighten screws up on back of clock so wasn't getting any temp reading,i must have overtightened them afterwards and the temp gauge went to the top,must have earthed it out the way you do to test sensor wire,when i loosened one of the screws,can't remember which one,and screwed it in and out it showed it was the gauge that was at fault,i swapped clocks with my other bongo and all was well after

mp3oplecarrier · Post by **mp3oplecarrier** » Wed Oct 24, 2007 5:56 pm

Thanks for the help guys, I let it cool down and then undid the rad cap and replaced it then bled the air out from the hose, topped up the header tank and took it for a run. This time the gauge got up to about 1 o'clock like it used to, so I set the alarm just above where it was sounding and drove off. I did about a mile and a half through traffic and up a long hill and the gauge rose to about 2 o'clock, when I got back home I sat there with the revs at about 1800 rpm and could not get it to rise any higher. The alarm is currently set at about 3.5.

Phew....

daveblueozzie · Post by **daveblueozzie** » Wed Oct 24, 2007 6:08 pm

my alarm was set to about 4 was driving up and down dale and the bloody thing kept going off with the temp needle at about 2 oclock position.reset at 5 and then no more probs. the needle does move about a lot, takes a bit to get used to , from the norm of 11 oclock before i had the alarm.

haydn callow · Post by **haydn callow** » Wed Oct 24, 2007 7:10 pm

To bleed it properly you need to use the small bleed pipe under the passenger seat. Put a funnel on the end of this and raise/lower it whilst the engine's at it's operating temp. Bubbles will come out of the coolant in the funnel and make sure you top up the header tank before the level drops below the FILL mark. This is called the SEE SAW method and works well. It should take about 30 mins to do the job properly.

mp3oplecarrier · Post by **mp3oplecarrier** » Wed Oct 24, 2007 9:50 pm

Thanks Haydn, that sounds like what I meant.

Steve