Overheating... still

[320Touring]

My car and kerbs dont mix... But I'm sure I can come up with something along those lines.

I assumed it was an airlock, though why its shown its face now after weeks of normal heater operation is a bit concerning.

Its still not loosing any coolant or anything.

could be the airlock finally got to the heater? air is a bitch to move in a pressureised liquid system

[munky30]

Aye... well I'll give it a bit of a massage after dinner and take it for a spin, see if its settled back down to normal operation.

[munky30]

Hmm.... Normal-ish...

The heaters work again. There were lots of bubbles in the system, by the time I got to it anyway.

Because it had dropped half the cooling system's contents on the floor over the course of today.

The source... Water pump, or somewhere very near it.

I have a funny feeling its not because of the pump being faulty, more the rubber hose having corroded away a bit and not sealing. The top hose had done this on the thermostat housing which was fixed a few weeks ago.

More to play with this weekend, woo.

[munky30]

New dials are in courtesy of March109.

And... Temperature gauge is working as normal!!!

Well... I havent run it or driven it yet, but on turn of the key it flicks up to the bottom line of the gauge instead of halfway.

So at least I'll be able to tell if it is actually overheating now.

What's normal for a 325?

Does it run at 1/4 then creep up to halfway in traffic etc? Or go to half then creep up to 3/4?

At what point do I panic and turn the engine off cos its too hot? 3/4 or when it hits the red?

[Simon13]

all of my facelift 325's have run between 1/4 and 1/2, they get up to half when it's really hot weather or sat in traffic for hours

anything out of the red is ok. You can feel on the rocker cover when its getting too hot, if you are mincing about at home with it

[munky30]

Cool... the engine is pre facelift but I cant see that making much difference to the running temp.

I'm taking it for a test run tonight to see how it reads then replacing the rad and having a closer look at the water pump to see where its leaking from tomorrow.

Cheers.

[munky30]

right...

The new dials are in, but only one side lights up. Easily fixed with a bulb from my old ones.

The temp gauge works fine. But now the fuel gauge doesnt

I'm hoping thats a loose nut so will check that out when i replace the bulbs.

Now to the juicy bits.

The temperature worked its way up to halfway. Stayed like that for a while, then crept up to 3/4 during a bit of slow stop/start driving. Back on the open road it went down to halfway again.

I stopped at this point and upon hearing a nice hissing sound coming from the engine bay, opened it to see most of my coolant p*ssing out of the water pump somewhere, under pressure.

I think its a hose, as once it had cooled down a bit, when I wiggled the hose on the pump you could hear the hissing changing pitch as it were.

So... tomorrow I will have a look and see if it is just a hose when I do the rad. I have a spare that I can try to make sure.

I'm getting a bit fed up of cars with cooling issues... so am considering replacing every part of the cooling system.

Water pump, thermostat, thermostat housing, temp sensors, expansion tank cap, rad and all the hoses.

Have I missed anything? Is it worth doing this?

[spook]

munky, that matt black is soaking up too many rays, you need some shine on that baby to keep things cool
sorry, ive just got back from the pub after a skim full, and maybe i can enlighten you with a belly full of the blackstuff

[munky30]

right... todays update.

Fitted the new rad, and had a butchers at the water pump to find the source of last nights hissy fit.

Turns out the hose from the thermostat to the pump had a small split in it from someone overtightening the jubilee.

Last night it turned into a bigger split!

I replaced it with the one off the old engine which seems to be in good nick, topped up, did the 'pikey bleed method' and took it for a spin.

Heaters work fine, nice and hot, at speed it runs at just over 1/4 temp. In traffic just over 1/2.

Could a slightly blocked rad and a split hose have been the cause of my problems?

[Brianmoooore]

Could a slightly blocked rad and a split hose have been the cause of my problems?

Was there actually a problem?

[munky30]

Good point.... last night it was running hotter than it was today.....

I'm just wondering if the air being let into the system and the pressure loss from the small split that was getting larger would have caused the 'overheating'....

[HenryM3]

Hi,
Thought I'd put in my 5p's worth, had the same problem your describing on my M3 when it had the S14 engine, did all the things you have done or are going to do. In fact I wasted a shit load of money. In the end it was a cracked cylinder head, which in hindsight ( which is a wonderfull thing ) I should have known as now and again it would dump a very small amount of coolant out the overflow pipe. (hardly noticable ) As I'm not very familiar with your engine, if you have a small pipe going from your rad to the header tank make sure it is'nt blocked, otherwise your system won't self bleed. You now probably have enough information to dissapear up your own arse. Keep your chin up, you'll sort it in the end.
Cheers

[Morat]

My God - is it fixed?

[munky30]

yup

Running like a charm. Just been out giving it some abuse up on the moors and it never went further than a mm or so over half way on the temp gauge.

I wont count my chickens though, will be keeping an eye on the coolant levels and watching the pipes etc for any more splits, but it appears to be fixed.

Now I just need to work out why its reluctant to start (new plugs and I think the injectors aren't seated right), adjust the valve clearances, replace the loom which has my dodgy bodged wiring for the new one, replace the thrust release bearing, replace the top mounts, fix the heater, get a new brake pad wear sensor, fix the fuel gauge, fix the central locking, replace the interior, driver side wing, engine mounts (its on 316 ones atm )radiator mounts (cable tied in place atm), smoke the headlights and have the arches rolled so my soon to be new wheels will fit...

I think thats about it... but I dont want any info on that little lot in this topic... I'll start a few new ones over the coming weeks

[e30bmlover]

i got shown how to bleed the cooling system, just undo a coolant pipe, wait till its all out. undo the bleed nipple at the top, poor coolant in keep going until it comes out at the top!

[munky30]

My nipple's been rounded off and wont budge.

The heaters work though so there's no major airlock afaik, I massaged the pipes a bit, with the drivers side front wheel up on a kerb so the tank was the highest point. lots of bubbles came out, then stopped.

I'll keep an eye on it though.

[oze30]

check the orientation of the thermostat. it sposed to open with the flow of water so, spring inside the engine side of the housing, and non springy bit on the rad side.

[munky30]

Its running fine now so I think its in the right way. Cheers though.

Cant remember which way it was put in when I tested it though and now you've made me think it might be the wrong way.... Will have a quick check before I put the coolant in.

Any chance one of you helpful folks could answer my other topic? (coolant amount)

[munky30]

Thanks for all the advice on the coolant level chaps.

I opted to empty the header tank and fill it with coolant (approx 2.5 litres) and hope for the best.