Coolant Leak - Any Ideas?

[Tiger_kpt]

My car was running fine with respect to this when I got it. It was in standard form.
 
I have since spent alot of money on performance and reliability parts. Some of which I fitted myself to keep labour costs down.
 
One of these parts was the Pettit Racing AST with pressure cap as well as their uprated 22-24lb race pressure cap. I fitted the AST tank and used the uprated race cap at first.

I then begun to experience coolant loss problems... engine fine when running and cold. No leaks.
 
But after being run and warm, when turned off - the coolant system leaks and loses alot of the coolant. And I have to keep topping it up before driving.

I first thought that maybe it was down to the race cap, being too highly rated. Excess pressurised air not able to escape from the cap and so found an easier route - and created a leak somewhere. So switched to the standard Pettit Racing cap. Same thing still happens. Once a leak, always a leak though eh?

The water seems to be coming from the front left hand corner of the vehicle. Not sure, but it seems from around the expansion tank area or one of the lines to or from this tank. But the water is dripping from that area as it can be seen down the undertray as well as dripping through the rad/oil coolers at that corner - seen through the front grille on the standard FD UK spec bumper.

Any ideas as to what this problem could be anyone? And a good way to solve it?

[teabagger]

I\'ve heard lots of things about after market AST and caps not sealing properly to the point where a few places simply won\'t stock them any more. I think your best bet is to refit the standard Mazda one and a new AST cap and see if it cures your problem.

[Tiger_kpt]

If an aftermarket AST tank and cap wasn\'t sealing correctly... what would the effects be on the coolant system? Where would the coolant leak from? And in what form - gas or liquid?

[teabagger]

AFAIK you\'d see the exact symptoms you are describing; coolant being expelled from the expansion tank because the system can\'t maintain the correct pressure. There is a small rubber grommet on the top of the tank, you should see it if you shine a torch down behind the headlight. That will be where the water is coming from I should think. I\'d be putting the standard AST back on myself with a new 0.9bar cap, I know they tend to crack but most people reckon it takes a good few years to happen and consider them a consumable. You said yourself that the problems started after fitting the after market AST so it would seem to suggest that could be the problem.

(edit)

I read on here just this morning that RotaryArt no longer stock non standard ASTs because of the amount of problems people have had with after market ones not sealing properly, hence me thinking that you\'re probably better off with a standard one.

[Kash_]

I had a similar problem and it turned out the AST cap had a hairline split in it... If the AST cap isn\'t working correctly then water will be thrown into the expansion tank

[Tiger_kpt]

By running with an aftermarket AST and cap like in my case which isn\'t functioning correctly... is there any danger that it may have caused permanent effects or damage to engine water seals, etc? Or would all issues likely be resolved when rectifying this problem?
 
I just sold my standard AST tank and cap. Was in mint condition - for £25! lol.
 
Where can I get a standard one from? And how much do they retail at?

[teabagger]

I would want to be sorting it out ASAP. Engines don\'t like excess heat, and if your cooling system isn\'t working as well as it should then there is a risk of doing more serious damage or reducing your engine life. You could well be o.k, but personally I wouldn\'t want to be driving around knowing my cooling system has a problem.

Any of the guys on the sponsored links should be able to sort you out with an AST, not sure of cost I\'m afraid.

(edit)

Crikey, Mazda AST is around £75 + VAT. A cap should be around a fiver

[Tiger_kpt]

Well car is going to WGT\'s to have the following work: -
 
Koyo Radiator
SARD Cooling Thermostat
Greddy Pulley Kit - (removal of airpump)
WGT De-cat Pipe
Greddy Turbo Elbow
Greddy Type RS BOV
ACT Steetlite flywheel & Counterweight
ACT HD-6paddle Streetlite Clutch Disc & Pressure Plate
Host Of Gauges & Pods
 
Full Major Service, Compression test & Inspection.
 
And a PFC map.
 
Have a Greddy Intercooler planned for a later stage with coilovers to make the car sit right on the 18-inch Works Emotion wheels.
 
Car already running downpipe, Apexi PFC + Commander, fresh 7\'s and 9\'s plugs with Magnecor wires, HKS Ignition Amp, ARC super induction box, Racing-Beat cat-back and the troublesome Pettit Racing AST+cap!
 
Going in tomorrow and back next Saturday. So Pip will likely sort it out as he\'s got to replace the radiator anyway.
 
My PFC Commander reads out a running water temp of 84-94 degrees. Peak of 95 has been reached. Think fans come in at 94 degrees as it is.
 
What should the optimum water temp be for these engines?

[gonzoninja]

The Pettit racing AST is one of the better fitting AST\'s apparently. Have a look at the pipes going to the AST.

I know the one I have uses COMPLETELY different sized pipes so the mazda ones have to be jubilee clipped really tight to get them to hold.