The condition and pressure of the tyres can make quite a difference to the steering. Has it suddenly gone heavy or gradually?

Pardon my ignorance of modern cars but does it have electric steering or an engine driven pump?

Roughly how much would it cost for these sort of things to be checked, and if they had a problem, repaired/replaced?

I'm really only looking to keep the car until the end of the year if something suitable comes along to replace it, however, I may need to hang onto it for long if nothing does (nothing as yet really has caught my eye).

At present, the heavier steering is a minor annoyance rather than a major issue - given I now (since May) have been commuting to work by car again (175 miles pw), I'm wondering if and when it'll get worse/undriveable (hopefully at least after I return from holiday - which could include from 700 to 1000 miles worth of driving). I almost certain don't have time (4 days) to get anything diagnosed/fixed before I go away. I'll just have to keep my fingers crossed until I return.

Sometimes its easier (as with the clutch going recently) when a problem has only one or two causes, rather than many!

No problem - thanks for your help. I did try looking on the Mazda3 forum, sadly no similar issues reported as far as I could see.

My local dealership had a look at it (though how detailed is unknown as I was at work at the time) when I had my clutch changed, and said it was ok - just that the heavier steering was attributable to the car 'getting old'. Hmm - I still suspect they were trying to get me to buy a new car, at least in a small way.

How us your alternator? I had a Volvo s40 which is a focus clone like Mazda 3. My alternator failed and steering was periodically very heavy as the battery power fell. Can you check battery voltage easily?

Only by taking it to the dealership. Not sure if it makes any difference, but of late, after I putit the Wynns stuff, the steering is lighter for a few seconds after starting up when I move off. It doesn't change other than then. My battery is only 1 year old as well - until recently I did go through them every 4 years or so as I was doing low mileage (not short journeys but just not used often).

Unless it gets any worse, I'll probably wait until it's serviced in Dec/Jan before taking things further, especially if it means replacing more parts just as I'm thinking of buying a new car anyway. The problem is that there appears to be many possible causes but which are difficult to diagnose without replacing the part in question - I could replace several and still find its wasn't the cause.

I managed to source some of the 'Trans Tune' stuff from (what appears to be) a reputable online UK retailer for £16.50 - its being delivered next week, so I'll give it a go next weekend and let you know how I get on.

I'd rather pay this now, even if the problem still persists and the car needs a far more expensive fix after a 'full' diagnosis (as said before, no nasty noises or sudden changes in steering feel or it not trying to centre itself - just heavier than it used to be), well, I've only spent £16 extra (not a lot if you're spending £800+ for a new PS pump to be fitted). If the Trans Tune does the job, then I'll get the system properly flushed and PS fluid completely replaced at the forthcoming service in lat Dec/early Jan, just to remove any residual gunk.

Watch this space - if it works, it may be worth using as a first resort (before shelling out £££ for expensive new parts) on many an older car with such a problem (assuming someone hasn't correctly diagnosed the problem at a reasonable cost). What's strange is that UK garages don't seem to have heard of this stuff, or to try and use it (or anything similar) to remove gunk, other than to flush the PS system with ordinary fluid, which presumably doesn't work.