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hey everyone, I replaced the valve seals in my 16valve DOHC 1.6l mx3 engine, and it SHOULD have stopped the smoking at high rpm's and at cold engine startup.. but it didn't.. anyone else have anymore suggestions?

If you replaced the valve seals, and its still smoking,, you might want to look into your rings, On your pistons.... If your running a straight pipe, or no catalytic converter , then they are usually what goes first

Compression test the engine.. Then do it again with a capful of oil down each cyl. If the psi increases by more than 30 psi with oil added, your rings are mostlikely gone.

A leakdown test is another good method. Try that too.

Smoke at high RPM is mainly the rings. a compression test will tell you, but also preform a leak-down test
Dean

any way to let me know how this is done? I'm a newb to pistons/compression and leak down tests
thanks alot!

SnoSurferr wrote:If you replaced the valve seals, and its still smoking,, you might want to look into your rings, On your pistons.... If your running a straight pipe, or no catalytic converter , then they are usually what goes first

Why do u say that running no catalytic converter causes the rings or pistons to go first?

thanks

If it was rings it would smoke ALL the time... not just at cold start and high RPM's.. I don't have a clue what else it would be other than the valve seals.. I'm going to try to switch to 10w-30 for a little, see how much that changes things, it'll be a little thicker so it should cut down on consumption quite abit. I am also going to put in some STP oil treatment.. supposed to swell up the seals as well as thicken the remaining oil. If anyone has any suggestions, let me know ASAP.. I haven't been able to drive my car in MONTHS.. big downer!!
Thanks,
Craig

I did the same routine as you on a '78 Honda Accord back in the eighties. It smoked heavily (giant cloud) on startup but cleared up after 5 minutes or so. Tried the valve seals, different oil, and additives all to no effect. It was the rings.

if you have a broken piston ring it will smoke at start up and high RPM's. its not just the valve seals that will cause it. general rule of thumb, is Valve guid seals, piston rings, maybe a hole in a piston (I have seen it), and quite possably a burnt valve.

on this little POS civic i was given, it smoked like hell at start up, but after 20 to 30 minutes of running, it quit. so i drove it home, 40 miles with no problem. after i took it all apart i found that one of tha valves had a hole in it the size of my thumb. aint that some crap, it should have been smoking the entire time but it wasent. same kinda thing with my 55 ford. the car didnt smoke at all but i wanted to rebuild it. after i took it down i found that almost every ring in it was broken in several places, never smoked ever. cars sometimes do wierd things so you need to look everywhere. its not always a text book answer.

well hopefully after this afternoon she won't smoke.. i've pretty much replaced everything cept for the piston rings.. and obviously im hopeing to find no holes haha

MX3driver wrote:any way to let me know how this is done? I'm a newb to pistons/compression and leak down tests
thanks alot!

You get a guage for the compression test. I think you can get them at autozone or if all else fails, buy one online.

Easy way to see if your leaking water, pull off your oil filler cap and look for white/yellow goo build up. This will be water in your oil. If none there, unlikely your leaking water/coolant. Another way to check also is pull your dip stick and look for the same, if none- same as above.

Just a note to you fellas.. A compression test is a good thing.. however.. a compression test WILL NOT tell you if your oil control rings are shot. It will only tell you if your Compression rings are shot (or good). By way of example.. Recently I put an engine in my B2000.. great compression numbers so I figured it was good.. EHHH wrong! It smoked like a freaking hippie van at a grateful dead concert. Tore the engine down.. found that 3 sets (out of 4) of the oil control rings were badly worn.. no spring left to them at all.. also found that the 4th set was actually seized to the groove of the piston.. apparently the japanese (or where-ever this engine came from) Dont believe in changing their oil.

A compression test is only good for checking your compression rings and how tightly your valves seal when they close. Hope this helps

Tunes67

in terms of oil control rings.. what are they worth to replace.. any ideas?
thanks man.. good help!!

Well I dont know how much a set of Rings for a MX-3 costs specifically. But they wont be too expensive really. But the first step is to determine the cylinder wear of the block. If its not excessive.. You can just get a new set of stock replacement rings.. I would recommend Chrome Moly (spelling is prolly off) set.. these are generally the rings that will last the longest. Keep in mind that these rings take longer to seat and break in properly than others. Next would be Cast Iron Rings.. these are usually equivalent to most stock rings.. these rings also seat fairly quickly. I used Cast Iron RIngs for my truck engine and they worked out just fine. For my truck (a 87 B2000) a full set of rings was $26. The engine block in my truck also showed very little wear at only .002 off stock specs. By way of comparison.. the Chrome moly ring set was $54 for my truck. Also.. please keep in mind that while I am referring to these ring sets as "Chrome Moly" and "Cast Iron" There are other types and this is in reference to the compression ring material. If you have a lot of wear in your cylinders you will need to get a oversized set of rings.. If you have to go more than one size larger due to wear in the cylinders.. I would recommend rebuilding the engine and using oversized pistons at that point. Hope this helps.

Tunes67

yeah that's great advice.. feel like doing the labour haha
im actually in the process of oil control rings because I've replaced the valve sleals and guides, as well as checked the bore of the cylendars.. and they are fine..so really.. the only thing left that it would be is either a cracked block or the oil control rings.. can you guess which one im hopeing for? haha
thanks alot though man.. i'm gonna keep this topic up to date with progress ect, so anyone with the same symptoms as me can find out what it is cheaper than what I have.. thanks a lot guys,
craig