2002 Protege LX oil eater at 338k

TDiLisio

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2002 Protege LX
Hi Folks,

I have the subject car and it emits blue smoke for a couple minutes after starting. It seems to go away, or diminish while driving. She's been on a Mobil 1 diet since she was born and now drinks it at the rate of 1qt every 700 or so miles. Getting a little xspensive to keep her full.

I've read that the valve seals are probably at fault and would like to change them out w/o removing the head.

It's got the 2.0L DOHC 16 valve motor.

My question is: Do I have to remove the timing cover, Lock the DOHC's in place, remove the cams and then replace the seals? or is there another way? (short of having someone else do it)

Are there procedures anyplace to do this? Mostly Lock and remove/replace the cams and timing belt.

I've been told that this is an interference type engine and that if I don't get the cams re-assembled just right... it'll be an expensive repair to replace the bent valves.

Has anyone done this on a DOHC engine?
 
My LX has 325,000 clicks and burns a bit of oil, not that much though.

First, might be valve seals, might be bottom end, might be PCV. Remove intake and exhaust manifolds to find out which it is. Second, yes, you need to remove the timing cover. How are you going to "lock the DOHC's in place" and then remove the cams? You know what DOHC stands for, right? The timing belt is a b**** to change in the car, but you'll need to do it. Third, you need to remove the head to change the valve seals, there is no way to do it in the car. Well, there is, but it's a hack DSM way and risky.

Finally, the engine is not an interference design, however time it wrong after you're done and you'll have a super bad running engine.

Sounds to me like you're in over your head. Take it to a shop, please.
 
By removing the intake and Exhaust manifold.... What would one look for to determine if the problem was with the top or bottom end? The way the valves look? Clean(ish)=bottom end, gunked up=top end?
 
Yup. Pull both manifolds and see if any valves are getting pissed on from above. I bet you'll find one or two, not nearly enough for concern. It's the rings I bet.
 
She made it to 364500 miles... and dumped on me. The check engine light started flashing on the way home.
Severe miss at idle... like only running on 2 cylinders... till about 1500-2000rpm then the others seemed to kick in... but still a slight miss.
Got it home... tried to start... nogo.
Compression check revealed #1-55lb, #2-90lb, #3-0lb, #4-0lb.
Valves stuck open or head gasket?
Gonna pull the head this weekend and see how she looks.

Contemplating sending it (head or engine) in for a rebuild, or just throw a used one in there. Anyone have any experience with doing either (rebuild or replace)? like which is easier/cheaper?

I have the basic tools... but no Mazda specific Special Service Tools.
 
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I think it would be best/cheapest/easiest to just get a low mileage long block off ebay with less than 100k miles and swap out the whole engine. rebuild will get expensive because the head and block would both need a parts and machining. LKQ has good engines with warranty. The degree of precision required to rebuild an engine is high and a lot of special tools are needed. Just start over with a new engine... Good Luck.
 
Finally got the head off... 1 exhaust valve on #3 and one exhaust valve on #4 have a chunk missing. I think it blew the chunks out the exhaust because it's not on the piston... and I cannot feel a ridge at the top of the cylinder sleeve. Can still see the factory hone marks... so I guess being religious about using one brand of synthetic oil might have been a good thing.

Taking it apart, of course I found multiple things that need to be fixed... new upper timing cover, manifold heat shield, upper and lower hoses are a little brittle, the pre cat O2 sensor is bulging in the middle of the holy part, and the front lower engine mount.

The cat looks like it has a bunch of calcium deposits... and I can only see sunlight thru about half of the "veins"... so I hope I can clean it up enough. Anyone know if these can be resurrected? If it can't... this one item will blow the budget to crap.

So... I'll replace the head, Belts, water hoses, upper O2 sensor, motor mount, heat shield, clean up things a little... put her back together, and hope I did it all right.

If I get another 100k out of her I'll be happy. Carquest wanted $2600 for a long block... not getting it from me.

I'm hoping to get her up and running for under $1k. Gonna be close.....



P.S... I now see that it's impossible to replace the valve seals w/o removing the cams on this engine.
 
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The Cat. cleaned up fairly well... some CLR, purple power, fine wire brush and 120 PSI air hose worked good enuf to see thru 95%+ of the holes/vanes. Good enuf to put back in... IMO.

Ordered about $900 worth of parts to put it back together. Now if I can get it all back together correctly and have it work.... that'll be most excellent.

I have a PDF service manual... but if you have any tips on reinstalling the head, cams and timing belts that the manual doesn't have... I'd appreciate it.

And now... for the picture everyone's been waiting for....

... The head.

IMG00174-20120310-1623.jpg
 
The manual has all the steps you need. If you just have the main shop manual, pick yourself up the FS engine supplement manual as well. You'll need it.
 
Is there a best way to clean/de-carbon the piston tops? (without removing them) I don't want to get gunk between the piston and cylinder. Like a wire brush and vacuum cleaner, maybe?
 
It's going to be difficult without getting s*** in between. Use a rag and some brake cleaner, wire brush might make too much of a mess. Make sure the pistons are at the top of their cylinder when u do it.
 
The pistons cleaned up nicely with some carb cleaner, rag, and a pointed oak dowel rod to scrape the tough stuff.
Before cleaning the tops, I ran the piston to the bottom of it's stroke, oiled the piston walls then moved them to the top of their stroke and cleaned. Then moved them to the bottom of their stroke and wiped up the gunk that stuck to the cylinder walls. I used a shop vac frequently just for good measure.

Well... shes all back together now, rebuilt head and many new parts. Started right up after she was all back together (that was a relief). Has a slight acceleration problem I need to figure out... checked the obvious, vacuum leaks, replaced air filter, plugs... but she runs fairly decent for having 365k.

Also had to figure out how to make a crankshaft SST... pretty simple after the fact. Had to buy a couple (m10x1.5 or 1.25?) bolts and slightly grind the thread down to get em to fit the bolt holes in the crank pulley.

Home made Crank SST and block... Lots of room in there w/o 2/3rds of the engine... and completed.

I'll post next week to let you know how the oil consumption is.
 

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Well.... The oil consumption is still about the same. I should of listened to that little voice telling me to check the bore measurements while it was apart. Learned from that mistake.

When the car is running a constant speed... I can set the cruise control and she sounds and runs like an almost new engine.

The problem is getting up to speed she seems to be sluggish at times (kinda sounds like the old 4 barrel kicking in w/o the boost in speed) and then there are spurts of power. It was doing this before the head replacement, too.

It came up with a P0421 and a P0455 code this past week. P0421 tells you to check and fix other codes first... so I started on P0455.
Checked the gas cap... seems to be on OK.

Checking the Purge solenoid valve, I can't blow thru it with the battery disconnected, or connected with the key on.

Does anyone know what the resistance of the purge solenoid is supposed to be?

I measured all the other solenoids under the hood and all were in the 40-55ohm range. The Purge solenoid measures like 2100K ohms and fluctuates. There is 12v on the harness side.

I'm not sure that this is contributing to the inconsistent acceleration, but I think I need to fix it to chase the problem.
 
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I just went out and tested the solenoid by connecting the solenoid directly to the battery momentarily.

No clicking from the solenoid and no air passed through when I was blowing on the hose from the catch tank with power and ground applied.

Bad?
 
I replaced the solenoid. The new one measured the same as the other ones. No telling how long it was bad. Never threw a code or anything.

So now I'm back to it after taking a break for a couple months. The possibility of an upcoming trip to Florida has motivated me to get her back on the road. My backup car has become my daily driver... which isn't as economical (but a whole lot more fun).

My wife wanted me to get rid of the car when this problem first happened... Being hardheaded and not wanting another car payment I decided to bring her back to life.... or at least try.

As of now I have the engine almost ready to remove... trying to figure out if I can just remove the engine only or if I must remove the engine and trans together, then separate.

I'm thinking go ahead and remove both because I should probably have the trans serviced (new seals/whatever they do) while it's accessible. I really don't want to tear this thing apart... again.

(I think I just talked myself into taking both out)

Will keep you posted.
 
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