Hello,

I have a 2002 Protégé. It has recently had the head replaced with a new one and a new head gasket installed, have receipts. New plugs, air filter and valve cover gasket that I installed myself. I do not know a lot of history on this car as the previous owner had the head done about 1000 miles ago.

The vehicle starts right up, no ticks or knocks, no overheating and it doesn't run rough, but it smokes like a chimney. It has a check engine light code for a catalytic converter below threshold, but no other codes are pending or stored.

I did a compression test on all four cylinders and cold they are ranging between 185-200 psi per cylinder. The oil is old and dirty, but there is no anti freeze or funky discoloration in it. I also looked at the outside of the engine and was unable to see any visible leaks or anything. The amount of smoke on initial startup is quite thick and it is white/blue in color and smells horrid.

Whether you rev the engine up or let it idle, whether it's warm or cold it will blow out stinky exhaust - more clouds on revs though and I'm talking so much smoke that in an unvented area you would asphyxiate yourself in like two minutes or less guaranteed. Anybody have any idea what could be causing all of this? I am not sure how long the car was driven with a blown head before it was actually replaced.

 

Head was done, compression is good.
Changing, fixing head makes me worry. Coolant and or oil may have been mixing causing your O2 sensors to foul and your catalytic converter to clog (hence your code).
Especially with your car being that old, i would change at least the front O2 sensors.
Heres what to do:
1) put 1 gal of lacquer thinner in a half tank of gas - drive it for at least 1 hour on highway between 2,000 rpm and 3,000 rpm, no more as we don't know how clogged your catalytic is.
2) change your front O2 sensors (before the cat on each side if V6 - this one tells computer the air/fuel mixture (re-set computer). Check your sensor wiring for shorts.
3) change your PCV valve - Mazda never did! Change your oil
4) change the rear O2 sensors & inspect your catalytic converter if code still present

How can I tell if my catalytic converter is... — Yahoo! Autos

http://www.lambdasensor.com/main/mfaults.htm

 

I agree with UseYourNoggin.
adding 2 thoughts:
1.Replace the bad oil and oil filter immediately. You could use inexpensive oil of the proper grade, add 1/3rd of a can of "Seafoam" to the oil. Don't treat the intake and the fuel with Seafoam since you have new head on the engine. Then replace this oil and filter after about 500 miles or so, going to a better quality oil. The thinking here is that maybe the oil control rings are stuck and the naphtha (Seafoam) may get them unstuck.
2. Do your lacquer thinner ride, then fuel up with mid or high octane gas and clear the codes. Don't immediately jump to replacing the O2 sensors. They have received a lacquer thinner cleaning as well. If the code returns, then repeat the lacquer thinner ride and replace the O2 sensors.

Good luck.

 

I would just change the front ones.
O2 sensors don't have a long life span.
Search: O2 sensor life and decide for yourself.
But i'm a freak and I have already changed my sensors! (not totally my fault - way too early).

 

Thanks for the input guys. I did forget to mention one tiny little detail lol my bad. I purchased the vehicle from an insurance auction so it was deemed totaled with a junk bill of sale. It will drive down the road, but not legally - no plates and no headlight (just got one stripping out the interior as well.) Long story short - I have an ES Protégé that I picked up from a friend for $200, it threw a rod out the side of the block. I purchased this car for the engine and some interior parts etc. I hate being difficult, but is there another way to make a somewhat definitive conclusion? I figure worst case scenario - I do the engine swap, start it up and it still smokes like a chimney then I get to have the honors of removing it again, and rebuilding it agghhh! I just don't know if I feel like taking that risk lol.

~ Frannie

 

BTW, Seafoam rocks! My husband swears by that stuff lol.

 

Take the spark plugs out and have a look : are they oiled up and black?

Do a compression test. Obviously the new head should hold fine, so a loss of compression would indicate a worn bottom end of the engine. If the cylinder bores are scratched up and the piston rings are worn out it will allow oil to go up into the combustion chamber and cause smoke.

 

LOL, Noggin! You are a freak!

So I did a little research on O2 sensor life span and found that: a) the manufacturer is legally required to guarantee emission system parts, including O2 sensors, for 8 years/80 000 miles. So they will likely beat the minimum requirements.
Some reported that they had the original O2 sensors, working properly approaching 200K miles.
and then this:

Cryptokid on some forum: "A little something to note, take out your O2 sensor and burn the crap out of it with a propane torch. This cleans off the carbon. O2 sensors don't actually go "bad" they just get clogged up with carbon. After a good burning with a torch, most O2 sensors can be made to work good again, and if it doesn't, so what, you were gonna replace it anyways."

I replaced the upstream O2 sensor in my 98 Protege, but that was before I learned all these things, like using lacquer thinner and the blowtorch to clean the catalytic converter and the sensor. I still feel I wasted $70 bucks and an hour of my life.

 

Looks like this Freak made you work! Ha Ha!
Ever try to remove an O2 sensor with lots of mileage and think you can clean it and replace it without damaging it when removing? I would just put a new one. I could live with 80,000 + mileage before changing anyway!
So how's your car now after treatment?
Mine is running good with new plugs and a bit of lacquer thinner. Just did 180km/hr on a back road with snow tires on!

 

180 km/h on back roads? Don't they have private air strips in Ontario?

An apology to JustTheSix for riding on your thread.