allenc408

Hey Guys,

Got me an 04 Mazda3 2 weeks ago that burns oil bad, in the process of rebuilding the engine. Been looking around searching for sources for OEM or close to OE quality parts, but not finding much out there.

Pulled the engine and looks like I will need piston, piston rings, valve seals, and all the gaskets for the rebuild. 2 of the piston have small nick on them, but cylinder walls look smooth, but will have to send that to the machine shop for them to look over.

Anyone know any vendors that sell good quality parts that won't hurt too bad in the wallet? I'm building this car more for more of an daily driver, so not looking to do any performance mods on it.

Thanks,
Allen C.

Thrizzl3

would it not be cheaper to get a used motor from a junk yard? unless you're going to be slapping a turbo or turning it into a high revving race car..i don't think it's worth putting money into building a motor. is it a 2.0 or 2.3?

allenc408

It a 2.3L, if it was a 2.0L I would of probably found a used engine. And this is a learning experience for me as this is my first full rebuild, previously I only rebuilt the head of my previous car.

Well everything is apart now, the cylinder walls look clean and smooth somehow, no deep scratches even thou there like 20 something small nicks around the edge of piston 3/4 above the intake/exhaust valves. I'll probably just get new piston and press them on the OE rods after everything is checked out.

bmpskier

After endless online research and pouring over the Lemonaid Guide about 3 months ago I bought a 2005 M3 GT with 110,000km on it. It was in immaculate used condition with regular factory maintenance having been performed since new with all records. Although the most recent dealer routine maintenance had been performed at 108K I had it completely checked over again before I purchased it and there were absolutely no problems with it. The oil still came up clear on the dipstick. After driving it about 500km I went over it thoroughly again checking the engine and all fluids and was totally pleased with my purchase.

At about 112,500km I noticed a minor engine noise. I wasn't sure if it was new or that I just hadn't noticed it previously. Regardless the noise led me to believe I it could be a sticky valve or lifter so my first thought was to check the oil. It was off the dipstick. I ended up having to put in 3 litres to bring it back to full.... meaning that it burned through those 3 litres of oil in less than 2000km. I thought I was missing something but there was not a drop showing under the car or on the driveway and no signs that the engine was burning oil through the exhaust.

I immediately took it in to the Mazda dealership to get it checked over again only to get the news that it had thrown a bearing in the crankshaft, a direct result of having run it so low on oil. The only apparent option was to either scrap it or replace the engine. So 3 months after buying what I thought was an excellent car coming with high recommendations from many different review sources I now contemplated having a $9000 bucket of bolts parked in my driveway.

The shop manager at the dealership was sympathetic and went on to tell me that the 2005-2007 era Mazda 2.3 litre engines were getting a reputation for suddenly blowing an oil seal and subsequently burning through barrels of oil in a very short time. The most disconcerting part to what he told me was that dealers have been bringing this forward as an issue to Mazda Canada for some time now but they are failing to recognize that there is a problem.

What he did say (which is to late to benefit me me but might help others) is that if you notice the oil loss early enough (i.e.... every fill up and before you run it dry as I did) you can switch to a heavier oil which will slow the burning somewhat (but not actually stop it). I confirmed the information he provided me bysearching on-line forums where I soon found that other people were having the exact same problem as I experienced... cars in seemingly good condition with no apparent problems suddenly beginning to burn oil at a rate in excess of 1.5L/100km.

After weighing numerous options, and against the recommendation of the dealer mechanic who suggested I just scrap it, I elected to replace the engine. I was looking at the following costs (including about 16hrs shop labour at about $120/hr).

$4800 - recycled engine from wrecking yard - hard to come by but if found 30 day warranty (no guarantee that this engine didn't burn oil already or would develop the same problem within weeks).

$6000 - completely rebuilt engine from reputable builder - 2 year or 80,000K warranty. (This was the option I went with with even though the warranty only covered a shop labour rate of $80/hr)

$7500 - Mazda OEM factory rebuilt engine - 1 year or 20,000K warranty (but get this.... apparently Mazda will warranty other factory rebuilt engines they sell for 3 years or 100,000K yet they will only warranty the 2.3L for 1 year/20k... go figure)

Anyhow what I am trying to say is that if your car is already burning oil at a high rate or you have found a Mazda 3 with a blown engine the cause was likely a problem similar to mine. If you intend to rebuild your engine be sure that you strip it entirely down to the core and build it back up with new everything otherwise it may be all for naught (I found another forum where a guy did not take it entirely down or re-bore the heads and when it was running again it was still going through the same amount of oil.)

AND... given Mazda's own factory warranty offering on their rebuilt 2.3L engine with OEM parts I don't think using factory parts will make your rebuild any better as it is becoming more apparent to me that this is a problem with the engine design.

Good luck with it though.... I now have a 7 year old car sitting in my driveway that cost me almost as much as it would have to drive a spanking new one off the lot.

allenc408

Everything is striped down, taking the head/block to machine shop tomorrow for them to inspect and if i'm lucky it just a deck and hone job. But I'm looking at like ~1.5K rebuild not including my labor of course.

trooperguy90

So i just finished completely rebuilding a 2004 Mazda 3 2.3L. New Crank, Pistons, Rods, Etc. First off, you will need an AlldataDIY subscription. I have not found another place that has all of the correct specs. Ford discontinued their new crankshafts & piston/rod kits, they no longer make them. You can buy Piston/Rod combos from Mazda in individual sets (4 per car). See if you can buy a Ranger Style crank on e-bay. I found one on a forum site. I also bought Eagle Rods and FSWerks Forged Pistons. However I still have 3 good pistons and rods out of my old motor i would be willing to sell. They have less than 10k miles on them. If you are interested, pm me! Also, I can tell you everything you need to know about rebuilding this motor!

Matt