Bubble bubble toil and trouble?

[378S2]

Hello, I’m very new to M100 ownership, it’s been 48 hours or so. When I got back from a spin a little while ago there was a bubbling noise, I think coming from the thermostat area. It sounded almost like a drinking straw sucking the last few drops.

When I looked underneath there was a drop of fluid and a small puddle - but when I collected some in a glass it was crystal clear and I concluded it was condensate from the AC (it’s a little humid tonight).

So ignoring the drips, hopefully sensibly, is the bubbling noise anything to worry about?

Thank you!

[alan e]

'There is a pump that will run on after you switch the engine off when it's hot, it's mounted at the front of the car above the rad on the n/s next to the light pod see if the noise is coming from there.

[378S2]

Thank you, no I don’t think it was the electric coolant pump, the car wasn’t particularly hot and neither the pump nor the fans were running. I think I’m just paranoid, most likely just something percolating through the pipes. The coolant was all still in the engine and not on the floor this morning!

[HJ2]

A little bubbeling is quite normal at cooling down, at least in my car that is.
Clear fluid appears to be water from AC indeed.

[Kipperozzy]

If it tastes and smells sweet it’s antifreeze, if not and you have air con, it’s condensate

[Simon_P]

Slight bubbling and clicking is normal - But for peace of mind it is worth giving it a few checks.

The coolant/inhibitor should be changed every 2 years
The system is bled from a screw under the N/S headlamp pod.
Run the car up to temperature = 1/4 on the gauge standard thermostat opens
Keep going until the fan comes on at 3/4 on the gauge
when the fans come on switch the engine off - you should hear the recirculating pump (N/S front)
restart engine and run until the fans switch off.

[Rambo]

If it tastes and smells sweet it’s antifreeze, if not and you have air con, it’s condensate

Just a word of warning. Do not taste it as anti freeze is poisonous, even small amounts

[david924s]

If it tastes and smells sweet it’s antifreeze, if not and you have air con, it’s condensate

Just a word of warning. Do not taste it as anti freeze is poisonous, even small amounts

As many an unfortunate cat has found out, the hard way!

[Rambo]

I may be wrong, but I think some anti freeze contains Bitrex to put off children drinking it.

And cats

[378S2]

Thanks, I managed to resist a glass of coolant!

[378S2]

Thanks for all the good advice. Have had a bit of fun with the cooling system since I asked this - I must have overtightened the (yellow) cap because it jumped a thread cooling down in the garage and spat coolant all over the floor. The electric recirculating pump wasn’t working either (which will have contributed to the above) - I found that it had been replaced and they’d made a loom to mate with the existing connector but got the positive and negative round the wrong way.

With that sorted, and the cap not too tight, seems to be ok although I’m still being ultra cautious. The pump sounds like a dying cat so I’ll need to source a decent one.

I can see that my temperature sensor has been changed, there’s some bodged wiring I will fix another time but a remaining question - the pump comes on more frequently than other posts would indicate, usually every time I stop. I’m in a hot climate so am I right that there can be no harm in a lower set point on the temp sensor? The only downside I can see would be the fans operating more often than they should?

Thanks again for the help.

[Rambo]

I' m sure that running an overcool engine can also have its inherent problems ?? Mainly economy and performance issues I think ??? I'm sure someone will come along and correct me ......

[378S2]

I don’t think it gets over cool, still sits on 1/4 but from what I’ve read the fans (engine running) and retic pump (engine off) only run when it is closer to 3/4 where as mine seems to be just a tad over 1/4 when they kick in. Summers here are 45C so my theory is that it’s been set low to cope with that.

[Rambo]

You might have a Rodney Dickman thermostat installed ? I do in my NMY and the fans kick in much earlier than my black one with an OM equivalent

[378S2]

Thanks Rambo I’ll take a look.

Ok so the coolant gremlins are back - now a slow drip from the driver’s side radiator somewhere. Very hard to see where from - is radweld ok on these cars? Is it worth a shot or does it have unwanted consequences?

[GeoffSmith]

I had occasional random drips for a number of years which turned out to be caused by the rad cap not venting. The excess pressure caused the leaks and I'm sure that I have had less rumbling since I replaced it.

[dapinky]

Random drips are a frequent thing with me too....

.... perhaps its an age thing

[Rambo]

I have an occasional drip on the Black Beastie but I just need to nip up the Jubilee clips near the radiator after putting on the Samco hoses (Jonathan's group buy)

PS I don't think an occasional coolant or oil leak is necessarily a bad thing. As long as you keep things topped up

[378S2]

Ok thanks folks. So I’ll do the following - I’ll take off the front undertray and see if I can pinpoint the leak at the hose, and if that doesn’t work I’m ok to throw in a can of RadWeld (or Aussie equivalent)?

This is my first foray in to classic car ownership having only previously tinkered with other people’s, just finding my way without hopefully making too many expensive mistakes.

[david924s]

Ok thanks folks. So I’ll do the following - I’ll take off the front undertray and see if I can pinpoint the leak at the hose, and if that doesn’t work I’m ok to throw in a can of RadWeld (or Aussie equivalent)?

This is my first foray in to classic car ownership having only previously tinkered with other people’s, just finding my way without hopefully making too many expensive mistakes.

I would think twice about "throwing in a can of RadWeld" heard some nasty tales about what else that stuff will block up as well as the leak.