11th Sep 2005, 07:17

Spark plugs going in pieces is not really the engines fault. Yes it's unfortunate, but these things may happen due to poor quality plugs or some manufacturing process fault. Ultra-rare occasions though.

15th Dec 2005, 03:43

I wonder whether anybody has experienced high oil consumption with Miller engine fitted to Mazda Xedos 9?

10th Apr 2006, 19:18

I have a 1997 Mazda Xedos 9. Four years ago, at the mileage of 75.000 km, the transmission box (gear) broke. I had to repair it for a huge amount of money. Now it has happened again, after another 70.000 km. Is there anyone who have experienced a similar accident? Is there an explanation why this can happen, and even twice?

19th Feb 2007, 20:33

For the person that commented that his Mazda "shutters and clanks" my wife and I (each) own Millennia's (identical year color, in fact can't tell them apart). They are 1999's with the Miller Cycle engines. They each have a miss generated by a defective coil. They both start missing when condensation is present in the coil. This is usually during warm up. Her's knocks so bad that you think that the supercharger is going to self-destruct. Being in electronics, and after finding that Mazda Canada wants $600 CDN for each coil I decided to take a chance at repairing it myself. First buy some "no arc" a high voltage liquid dielectric used in T.V. repair shops to stop arcing in or around the flyback transformer. Next remove the defective coil (use a code checker to determine which coil). 1,3,5, are across the back of the engine from passenger to driver side. 2,4,6, is across the front side (towards radiator). Pray that it is the front side you need... they take 1/5 the time to get at. Sand the coil and metal parts so the "no arc" will attach when coating. Bake the coil in a small counter top oven at 175 F for 1.5 hours with the door left open 1/4 inch. This will allow trapped moisture to escape. Coat with "no arc" and bake again (same time) let dry additional 24 hours... reinstall. Good Luck...

16th Jun 2007, 15:41

I must express my deepest disappointment with what is happening constantly to my MAZDA XEDOS 9 MILLER CYCLE ENGINE. Now at 134,000km it has happened that my transmission box broke. I bought a Mazda believing in Japanese quality, and wishing never to see car service any more. However, to my deepest disappointment, the opposite has happened and I am constantly in for service and I have spent huge amounts of money repairing things that normally do not require service. I was told I had to pay 2,200.00 Euro for transmission box repairs. As soon as it is repaired I am going to sell it immediately.

I do not have any further comment.

15th Aug 2007, 01:48

I have a xedos 9 with miller cycle engine, 250,000km engine and gearbox working normally.

12th May 2008, 04:16

Apologies if this is in the wrong place. I have a 1998 Xedos 9 2.3 Miller (Millenia S for US readers) on 83k miles. There are some problems with the car, but the main one is that when accelerating at speed or when the engine is under load, the acceleration is very jerky. It is most noticeable when travelling on a motorway (highway) from a flat onto a gentle incline. So far the only solution I have is to use the hold button to downshift to get up the hill. I have had the throttle body out twice and cleaned up but no joy from that. Any clues/advice? Thanks.

26th Jun 2008, 09:38

One of the above postings relates to using a code checker to determine which coil is faulty, could anyone please enlighten me as to what this is. My Xedos 9 is shuddering like a tractor. I bought it last year it had only done 21k miles and I had it serviced at a non Mazda garage in October. They changed the plugs (apparently a no no until 50k miles), but it's shuddered since. I took it back, they switched the plugs around and said it was OK, but if I had any more probs to return it and they'd get a new coil. It happens when stationary and after driving somewhere parking for a short time then restarting. Thanks!

5th Aug 2008, 06:24

Hello All.

Just to add my comment on the above.

I have a 1999 Xedos 9 Miller.

I have experienced the shuddering and spark plug problem - The spark plug in the center back head exploded due to them not being changed - which they SHOULD have been on the full MAZDA service history the car has. All the spark plugs were pulled out and have never been changed (car has 50k miles)

Anyway, the spark plug broke one of the exhaust valves, which is why there is no compression and slightly marked the piston top.

Mazda quoted 2k (GBP) min to fix, so I did it myself - it takes many hours to get to the back bank, and you have to take the cylinder head off to get to them, but it does fix the problem.

At the same time I changed the timing, A/C and alternator belts.


200 for head gasket set (does both sides of V).

50 for timing belts.

50-ish for other belts.

Oil, antifreeze, etc.

On the smoke and high oil consumption problem.

It probably is the supercharger (Lysholm compressor) - mine smokes badly on start up; a white smoke though.

Better to get a new supercharger than try and fix - if you want to try, you need new seals and bearings, and a press break, and getting hold of the seals seems to be a problem - I am trying at the minute (I have a spare supercharger, which is no better, but at least the car runs). If anyone wants to know if I succeed or fail reply on this board.

Also know that a smoking supercharger will eventually ruin the cats.

Anyway, despite all the problems - I got the car at 42k, it now has 50k, and I have had no other issues with the car, and think it is fantastic - on a par with the Lexus GS300.

I have posted my own experiences here - I take no responsibility if I am wrong :)

17th Sep 2008, 08:58

Hello all, I have a Xedos with a miller engine (2.3) year 2000. The car is stunning - it has done nearly 100,000, and it drives like a sports car with the refinement of a Jag.

I have in the past had white smoke from the exhaust, but only when not started for a week or so, and it clears after about 5 minutes.

My problem is with the tickover; it idles fine sometimes, but at times I have to knock it into neutral to stop it rocking so badly.

I think it's related to the supercharger, as at tickover it sounds a bit rough around the bearings. Any comments would be welcomed.

6th Mar 2010, 21:43

Hi I have a 1999 Xedos 9 2.3 Miller S and am having the erratic idle problem - engine rocks car badly when stationary and in drive + clanging noise; not so smooth acceleration and the fuel consumption seems to be on the high side. There's also a problem on starting when it has been left overnight or not used for a while - if it does not start on the first attempt, it takes a few more tries to fire it up, but once it starts once it's fine and starts even if you turn it off immediately after that 1st difficult start. I have recently changed the plugs and this has made no difference to any of these issues. There has been mention of a faulty coil - can this be the cause of these issues? Any comment, suggestions or advice would be much appreciated.

19th Nov 2010, 05:37

Previous comment said:

"engine rocks car badly when stationary and in drive + clanging noise; not so smooth acceleration and the fuel consumption seems to be on the high side."

It sounds like issue with the alternator and/or ignition coil.

21st Oct 2015, 15:09

I am experiencing high oil consumption with my Mazda Xedos 9, 1999 model. I also need advice on this.

14th Dec 2017, 14:22

My Xedos 9 1997 model is giving me heartaches; high fuel consumption and puffing black smoke. Anyone who can help?