Search the Community
Showing results for tags 'coolant'.
Dear all Greetings from the Isle of Wight I’m calling all the cooling experts for advice and reassurance, if I may… This is Mazda SVD with slightly modified cooling system – I tried to draw an outline here: There’s the usual mechanical belt driven pump upfront and mechanical 86*C thermostat at the back. There are two passages by-passing the stat – one going through the oil cooler and one originally designed for cabin heater, but now reduced to a straight by-pass. Expansion goes via pressurised filler cap (15 lbs) into an expansion tank (with somewhat limited capacity). Filler cap is practically the highest point in the system. Radiator is new from Coolex, I added a drain plug at the bottom. This is a new build with rebuilt engine – my first venture of such scale. The car has only been road legal for a couple of months and I’ve racked about 400 road miles. While on the move, the temperature never exceeds 90*C, and at idle the fan kicks in at 95*C with a hysteresis of 3*C. I’ve never seen anything higher than 97*C on the display. I’m somewhat obsessed with temperature monitoring (and monitoring in general) and I log and review all the pressures and temperatures (CLT, Oil T, IAT pre- and post- charger, EGTs). Now to the issue – a couple of days ago, after parking the car in the garage I heard unusual gurgling sounds and found the expansion tank overspilling; it probably takes about 100 – 150ml before it would spill. There were occasional small bubbles coming out as well. I suspect there was a big lump of air, that made it initially overspill, but I couldn’t see it as it came out. Normally getting the car in the garage sees the temperature rising and the fan goes off, but never overheating. The first thing to check yesterday was compression and leak down test – both were OK. Then I remembered that there’s a pinhole at the bottom of the rad, where I added drain plug – it only weeps the odd drop when under pressure and didn’t cause noticeable coolant level drop. Is it possible (and I hope it is) that air is being drawn through said pinhole and accumulated over time and eventually discharged through the expansion way? I’m really lost, and that would be the best possible outcome of this situation. I will of course fill the pinhole, but in the meantime any advice will be much appreciated. Here's the actual engine bay Edit - I think I should have clarified, that the filler neck has a cap, that incorporates 15psi valve and only then does the coolant expand into the expansion tank, which in turn is bottom fed - basically replicating the original MX5 concept. Here's edited version:
MattV posted a topic in Tech TalkHi All, To avoid further hi-jacking Julie's raceline water rail fitting thread further, thought I'd put this into a new thread. So my car decided to deposit all its coolant on the floor the other day, and suspecting a dodgy thermostat housing I've ordered the Raceline water rail. Whilst waiting for it to arrive, decided to strip out the existing set up This looks like the sender unit for the temp gauge in the dash and looks pretty corroded/knackered, so I think this might be the cause of my leak. Everything else looks fine. Does this thermostat look right? I figured that whilst cold it should be sealing the coolant path but there's a gap of around 1cm? Raceline recommend getting rid of the expansion tank that I'm currently running, but I note that when @Julie Hall - AO Representative, Peak District AO fitted her water rail it was kept? Image supplied by Raceline is below As you can see they're running the over flow from the 'stat housing into an overflow bottle down near the headlight. This system looks like a simpler set up and would reduce potential future failure points, so I'm throwing this to the WSCC experts - keep the expansion tank on the scuttle, or set up as per raceline? Thanks All! Mat
Hi all, picked up my “new” westy at the weekend and drove it 200 miles home with no problems. Noticed a sight coolant drip from the bottom hose when I got back and the expansion tank was a bit murky and virtually empty. In my wisdom I thought this would be a good time to refresh the coolant. However, can’t get the bottom hose off to drain all the old stuff out (did get maybe a litre out though). Filled the expansion tank which only took a litre. Ran the engine to get it warm and open the thermostat but not sure what the problem is now!! The top hose got hot enough I could cook on it, but the bottom hose which I assume comes from the water pump still felt empty. See pic attached in case I have the labels wrong. Temp gauge in the car said 50 degrees. Do I need to leave it running longer? Do I have an airlock somewhere? converned that the gauge won’t show the correct temp if it isn’t getting any water and don’t want to melt my engine! thanks