Engine Shortblock Replacement

[DaveRulz]

Cliffnotes:
My front pre-cat failed and destroyed my engine. I was able to repair my car by purchasing a used 2004 Mercury Sable engine and using just the short-block from that to replace my destroyed block and pistons.

The Whole Story
First, I've always done my own maintenance. I'm not a mechanic, but I'm also not an idiot, and I'm pretty mechanically inclined.

In May my car started making a noise. A knocking/tapping sound from what seemed like the top of the engine that wasn't there before. Very soon after the sound started, I started experiencing large amounts of blow by, smoke was pouring out the tail pipe, out the dipstick, the oil filler etc. No good. I wasn't sure what had happened, and I wanted a diagnosis from a professional so I took it to the Mazda dealer to see if they could tell me what the problem was. No help, they couldn't narrow it down, they did take my 100 dollars for the diagnostics though. There are some known things that kill v-6 6's , spun rod bearings, failed PCV valves causing oil consumption, and catalytic converter failure. I knew that my engine was most likely done. I just didn't know what to do.

So we backed the car into my parents garage and jacked up the front. Took off the front bumper and the valve covers. Of course we couldn't see anything. Ran a compression test, front cyls were at 80, rears at 130. Hmmmm...think there's something wrong with the front of the motor. Made the decision that the motor has to come out. Dropped the sub-frame and disconnected all the suspension (the lower control arms were a bitch, but with a puller not too bad), pulled all the wiring etc over the course of a week at night, then on the weekend my brother and friend came over dropped the motor down on a transmission jack and jacked the front of the car way up so we could pull it out. Once the motor was out, we got it on a stand and started disassembling. We got it down to just the short block in about an hour. Then we popped one of the front pistons out, pulled off the ring and put it back in the bore. .20 gap. .20! point two-oh!!! That explains where all the smoke is coming from. So it was clear that we needed to measure the block to make sure it was still usable. Well, long story short. It wasn't. Way out of spec for distortion and taper on the front bank. Rear bank is all in line, front bank is HOSED. So no simple re-ringing here.

At this point I started evaluating my options. New short-block was 3200 bucks, and you couldn't get it anyways. Re-manufactured short-block was 12-1300. Re-manning my existing motor was also 12-1300. Used Mazda engine was 12-1300. The last option is what I ended up taking and this is it: the Ford Taurus uses the same Duratec V-6 short-block as the Mazda. Identical part number. Used Taurus (actually Mercury Sable) motor with 34k on it was 350 from the salvage yard. That's what I got.

A little bit before that, while trying to figure out what happened, I realized that I hadn't checked the front cat to see if that was still intact. I turned the exhaust manifold down and out came crumbled pieces of catalytic converter. So there's what happened. Cat died, got sucked in and was like sandpaper in the front clys.

I picked up the salvage motor, stripped it down and verified that everything was identical. I also verified that all of the cylinders still had crosshatch and that everything rotated freely. It was all seemingly in good condition. I didn't unbolt any of the mains, or rods. The engine only had 34k and there were no signs that there were any problems with it. I bought a motor gasket set from the Mazda dealer, this will come back to bite me later, but we'll get to that. Since I had everything blown apart, there were other things that I decided to do. First was a lightweight flywheel and a new clutch. Car only had 70k on the clutch, but if I could replace it now and not have to worry about it in another 50 why wouldn't I? So I got a new Exedy OEM clutch and a Fidanzia 9lb flywheel (amazing $220 BNIB on ebay). Next, no way I was putting cats back on that close to the exhaust ports. So I got a score on a set of ebay headers for 108 shipped. These are known to be of so-so quality, but for that price I figured I'd give them a shot. They're stainless steel, and I've got a friend that welds very well, so I'm not too concerned about making them work. I also bought new AWR engine mounts on a group buy to accompany the CPE dogbone I already had.

We cleaned up a couple welds on the headers, and sanded the flanges on a big beltsander so they were perfectly flat, and the headers were ready to go. After I got the gasket set I started putting everything together. I used the old Mazda heads on the new(to me) Ford short block. I made sure to use a new oil pump as I didn’t want to risk having low oil pressure due to contamination in the old oil possibly ruining the old oil pump. Engine build up went pretty quick until we got to the timing. Logic says just put the crank in the position the manual says and then line up the dots on the gears and the chain. But the manual explained it differently and totally confused the situation. We ended up spending a lot of time doing it the wrong way as we thought the manual was telling us to. Then we were like, wait, this is dumb, lets just line up the dots. Did that and everything worked as it should. Then I went to put the timing sprocket on. Reading the manual, it told me to use the wrong keyway. Luckily we had marked it when we took it off, and I verified online that I was using the correct keyway. Lesson: the Mazda service manual is almost worthless. Buttoned the whole engine up and flipped it over to put on the oil pan. Now here's where I got bit in the ass (twice actually) the oil pan gasket was different. The Mazda parts guy assured me that despite the fact that my oil pan had a gasket that pushes into the groove and then seals against the block, the metal one with a bead of rubber on the inside that he gave me would work. So I put it on and tightened everything down. It was seemingly fine at this point. At this point we put on the intake manifold so we could bend the tube to the correct position for the EGR. We installed the clutch, which was very straight forward and then went to put the transmission on. This was bite number one from the oil pan gasket. It had pushed the pan down about 1/8 of an inch making two holes that go from the oil pan to the transmission not line up. Grabbed a drill and bored the holes out until it the bolts would thread into the transmission. There's about 45 minutes to an hour lost. So now the transmission is all bolted up, everything is ready to go. Reverse of removal to get the engine back in the engine bay. Hook everything up, over a few days. Plugging things in, attaching hoses. Putting all the parts back on the engine that make it run.

For the headers, obviously I needed to do something about the second O2 sensors. My brother pointed me towards a Subaru site that showed using spark plug defoulers to pull them out of the stream of exhaust. So I figured I'd try that first and if it doesn't work go to 02 simulators. I had to extend one 02 sensor's wires because they were too short with the new locations in the headers.

I also had to relocate the alternator. This was actually very easy. I was able to source bolts and spacers online, had to trim the heat shield slightly with an angle grinder, and got a longer belt. I think it was 3 inches longer than stock.

I also had to remove the one catalytic converter that would have been left on the rear bank so that I didn’t have an imbalance in the exhaust. I cut it out and welded in a simple piece of steel pipe as this will be temporary until I can put a proper catalytic converter on the car after it is up and running.

I installed an oil pressure gauge so that I could monitor oil pressure, I feel it's important now that I've got a rebuilt engine. Put a brass fitting into where the dummy light sender goes, extended it with a hose up and then put a T with the dummy sender and the new oil pressure sender. Ran all my wiring for the gauge.

Installed a pillar gauge pod with the oil pressure gauge, a voltmeter and an Aeroforce Interceptor scan gauge (really cool piece)

The next night I came home excited to get the engine started, and that's when I see the puddle of oil under the car. Oil pan gasket strikes again. It was not the right part, and it did not seal. No problem though, we can still start the car and make sure it works. First we decide to pump up the oil pressure. We unplug the fuel pump and hook up my dad's car via jumper cables and start turning over the engine. Pressure isn't building. We just keep turning it. After a while it kinda blips. We wonder if the gauge is working and fiddle with that a little. Then we have the idea to take out the front spark plugs so the engine will turn easier and maybe prime the pump quicker. This worked. Pressure built up fast to 100 psi. Great!

Time to fill up the coolant. Start pouring it in...what's that trickling sound. Doh! forgot a hose. Hook that up, more coolant, more trickling, Doh! Another hose I forgot. OK that's it for hoses. Filled with coolant.

Hook the fuel pump back up, turn it over and it starts on the second revolution. WHAT A RELIEF! Let it run for about 5 mins then shut it down. Time to tackle that oil pan. Thank god I didn't put the sub-frame back on yet! Drain the nice fresh synthetic into clean containers. Pull off the stupid gasket, put the old one back on, put the pan back on, tighten everything, put the oil back in. Good.

Start the car again and let it get up to temp. Everything is working. There’s some rattly noises coming from the exhaust but at this point I’m not too worried since it’s running and I can deal with that stuff later.

So now the sub-frame goes up, pretty quickly. But the lower control arms turn out to be a huge pain in the ass. They required a puller to pop apart in the first place, and they required a clamp and heat to get back into the knuckle. That part was a lot harder than I had expected. I realized that there was some collateral damage to one of the tie-rod ends during disassembly, so I replace that. Eventually everything is back together. As the last parts are getting cinched down I’m starting to get pretty excited that the car is about to move on its very own again.

I get it back on the ground, torque the lug nuts, and slowly drive it out of the garage. It’s back. And everything works! And it’s LOUD!

I park it for the night with a piece of cardboard under it to make sure there are no leaks, and in the morning, not a spot on it. So I guess I did a pretty good job.

I’ve been driving the car for about 2 weeks now with no real problems other than the exhaust leaks and an intermittent P0174 CEL, which I believe is being caused by said leaks. I have a tube of Copper RTV waiting at home for when I have 24 hours to let the car sit so it can dry and that should solve my exhaust problems.

It's been an ordeal, and it was pretty daunting, but it's really all just spinning a wrench and using common sense. It's really rewarding that it works and I saved a TON of money. But it has taken me the better part of 6 months at this point, just because I have so many other commitments to deal with too.

I’m breaking the clutch in for another 500 miles, but the nice thing about going with a used engine is there’s no break in for that. The Aeroforce Interceptor is key to keeping an eye on the sporadic CEL, and I have a full complement of gauges to monitor everything going on with my new engine.

Even though I haven’t been able to get on it, there is no doubt that it is an entirely different car now than it was before. The headers have given me noticeable increases in power, and the car revs a lot easier with the light-weight flywheel. The engine mounts make sure the engine does not move at all, and that translates to great shift feel. The one downside of most of these mods is increased NVH. It’s loud. But hey, at least it’s running.

The unfortunate part for you all is I don’t have a ton of progress pix as a lot of this work I did myself, without someone else around to help and take pictures.

Here’s the lessons I learned.
1. Don’t trust the FSM, it’s wrong in many cases. You’re almost better off going with advice on the internet!
2. Make sure you get the same gasket you had for the oilpan, no matter what the parts guy says
3. Take notes when you disassemble the engine, it will really help when you re-assemble, especially for things like that timing cog
4. Take your time. Yes I could do this faster now, but I’m glad I took my time and made sure things were right
5. Try not to get carried away! There was a lot of “while I’m in there” thoughts going through my head, and if I had followed through on all of them I would have spent considerably more money. I tried to only do the essential parts, or the parts that I could get stupid good deals on.
6. The short-block from a Taurus Sable of the same vintage works as a direct replacement.

Oh yeah, and that awful sound coming from the top of my engine? That is gone. Consensus is that it was piston slap caused by the worn rings in front.

Sorry about the long read, Sorry about the lack of pix, but hopefully this can help the more mechanically inclined fix their engines for a little bit less coin.

[Front 1ine]

Holy crap...glad everything works!

[DaveRulz]

So am I!

I thought I'd throw it out there as it's another way to get your car back up and running that is slightly more budget friendly. I know another member has done this before me.

[The Great NY]

good stuff. glad you have everything worked out.

Generally the only difference in out Duratec than the Sable/Taurus, and etc. is that our motors have VVT but the bottom ends are identical

good find on the salvage motor. i'll be looking to pick one up close to home soon.

another way to get the motor out wouldbe to take the radiator and ac condensor out with the radiator support. it would have taken an extra hour to get it all off.


great job nonetheless.

[DaveRulz]

QUOTE (The Great NY @ Oct 23 2009, 03:05 PM)

good stuff. glad you have everything worked out.

Generally the only difference in out Duratec than the Sable/Taurus, and etc. is that our motors have VVT but the bottom ends are identical

good find on the salvage motor. i'll be looking to pick one up close to home soon.

another way to get the motor out would be to take the radiator and ac condenser out with the radiator support. it would have taken an extra hour to get it all off.


great job nonetheless.[/b]

Thanks!

I wanted to leave the power steering and AC intact so that I did not have to deal with opening those systems up, so I just followed what canyonrider had done. It don't think it was any more difficult that way.

The short block is the same part number and everything, I scoured both the old and new block just to make sure they were identical, and other than one being destroyed and the other still good, they were identical. In this case the Mazda/Ford parts sharing pays off. Obviously the difference in heads is what makes a used Mazda engine 12-1300 and a used Taurus engine 350 (most likely due to the volume of Taurus/Sable engines out there)

The oil pan, the front cover, intake manifold, oil pickup, oil pump, windage tray, and the heads were all different. I even noticed a small difference in the head gaskets, but the short-block itself was identical. All I had to do was swap on everything from the Mazda motor with fresh RTV and gaskets and torque them all to spec and it was good to go.

I got my engine from LKQ which has a pretty big parts network and locations all over the place. I often see engines from them on ebay. They were good to deal with, and I'd recommend them.

It's a real confidence booster to take on a project like this and succeed. I feel like If I can have an engine down to the bare block, figure out what was wrong with it, and then get a new one and put the whole thing back together, I can probably do anything.

[jrsy91gmc]

Having pulled my own motor out the top, I'm really starting the think the best way is to go through the bottom.

It was really easy getting the shortblock OUT (I pulled the heads off with the motor still bolted in), but getting the motor back IN the car with both heads and a clutch/flywheel on it was a real challenge. There's barely enough room to squeeze the clutch past the bellhousing and get the rear-bank head past the strut tower at the same time. I was starting to think it just wasn't going to go, but we managed to "persuade" it. One of my metal A/C lines got gouged up (didn't hurt anything, but it's kinda ugly) and some of the foam insulation on the strut tower and firewall took a beating. If I had it to do over again, I'd go out the bottom...

[DaveRulz]

QUOTE (jrsy91gmc @ Oct 23 2009, 04:30 PM)

Having pulled my own motor out the top, I'm really starting the think the best way is to go through the bottom.

It was really easy getting the shortblock OUT (I pulled the heads off with the motor still bolted in), but getting the motor back IN the car with both heads and a clutch/flywheel on it was a real challenge. There's barely enough room to squeeze the clutch past the bellhousing and get the rear-bank head past the strut tower at the same time. I was starting to think it just wasn't going to go, but we managed to "persuade" it. One of my metal A/C lines got gouged up (didn't hurt anything, but it's kinda ugly) and some of the foam insulation on the strut tower and firewall took a beating. If I had it to do over again, I'd go out the bottom...[/b]

Yeah, I think it's 6 of one half dozen of the other. While taking the subframe off is a bit of a pain, I think it makes getting the engine in and out easiest.

[Shane23]

Yep dave's the freaking man add to the laundry list of crap he already knows how to do, one day im cut his head open and steal his powers like sylar..

[DaveRulz]

Oh noes! not my head! Maybe I'll be lucky and Peter Petrelli will save me! or Claire...