Valve Seals

[Gippo]

I have a 94 MX3 RS 4 cyl 1.6L does anybody have an idea on how much it costs to change the valve seals. I assume that's what it is it smokes quite bad when you start it up but the smoke goes away after a couple of minutes of run time. I live in Nova Scotia but I don't want to get ripped off when I have them changed because there aren't that many mechanics around here that work on MXs. Post reply or PM me.
Thanks for your help in advance.

[Freq2002]

It's not doing it all the time, just for a couple minutes at startup? What color is the smoke? White is oil, black is fuel.<p>I'm assuming you're talking about the valve seats, and having them done involves taking the head off the engine & tearing it down & grinding the valves & seats. Easy enuf, IF you have the equipment. Bad valve seats wont cause smoke, not for a couple minutes anyway, it would run crappy all the time.
Otherwise there are the valve guides, if they are loose oil can seep down from the top of the head into the chamber behind the valve & cause some smoke until it burns off. Same deal, requires removing the head & stripping it, BUT should ONLY be done by a professional!!<p>If you're getting black smoke only when the engine is cold you may have dirty injectors.
I say "could be" because I never looked at the flow maps for my MX-3. On another car I built up with EFI, the ECU would pour more fuel into the engine while it was cold like a choke system on a carberated engine. If the injectors aren't fogging the fuel well enuf, there is alot of unburned fuel & hence the black smoke. One of these expert guys may be able to shed more light on it.

[Gippo]

Thanks it's white smoke, car runs great, nice and smooth even when it's smoking, just that initial white/blue smoke. I did an oil change and added some LUCUS additive and the smoking seems to go away quicker. Anybody have any other comments???
Thanks

[mx3man83]

No, hes not talking about the valve seats. It is the valve seals. I have the same issue with my GS. I priced them at mazda and they are 14 bucks a piece. I priced them with an aftermarket company and they are 9 bucks a piece. My friend showed me a site online that has them, but i forgot what it is. Im sure you can search online and find one, if not ill ask him. One more thing, does the engine take a little longer than usualy to start up?

[mx3man83]

There sure is, check out the online manual.

[Freq2002]

Of all the wierd crap,... Leave it to the japanese to add yet MORE silly a$$ parts that can fail in the engine,... Have worked on lots of DOHC engines, none of wich had seals on the valves,... Wierd.<p>ANYway,... Lookin at the manual & what all is involved in changeing these things, doesn't look real complicated at all. Could possibly do it with the head in the car. Providing you have the proper tools anyway. If it has to be pulled, may as well spring the $$ & have it blue printed & get a valve job too.
Better to do it now than have to do it later when it takes a big hairy dump.

[Ogimoj]

Valve seals can be done with the head in. They are just little rubber oil seals with a loop spring in them that sit on top of the valve guides with the stem of the valve passing up through the center. To get to them, you'll have to remove cam shafts and valve springs, so it's a time consuming job. Careful to put each part back in the same spot that it came from.

[92RedMX3]

Ogimoj has it correct. one note to add. When leaving the head on(i would) the valves can drop into the engine. To prevent this you put a lot of rope through the spark plug hole(redneck way) or hook up a compression tester connecter and hook it to a compresser. the pressure keeps it there and if it got bumped and was to start falling the pressure pushes it back up.

[92RedMX3]

Oh, personally i dont see it being too hard except one thing. I always have a fear of getting the camshaft in the correct position so that it will still be in time and such when you go to start it. I mean who want to turn the key only to hear the sound of crunching metal as the valves are deformed by the piston.

[Ogimoj]

Fortunately, it's a non-interference engine, so worst case is you have to open it up again to re-position the timing belt. No bent valves to worry about.

[boostedmx]

if you are working on it at tdc all you have to do is put the cam in at tdc. very simple job. one thing though, a regulator has to be used in order to use air pressure to keep the valves up. this prevents the piston from shooting down from excessive air pressure. and i would recomend getting a ohc valve spring tool. it makes it soooo much easier.

[Gippo]

Thanks for all of the input MX3ers, I checked it out with a mechanic about 100 kms from me and he said parts and labor about $1,000 Canadian. Might just do a swap.
Thanks again, I will still take all comments I can learn alot.