Trying to figure out engine type.

[JutHolman]

Hi everyone,
I purchased a 97 318ti with a blown head gasket a little while ago for $500, i picked up a motor at a pullapart out of a 96 318i. The motors look identical, except the wiring harness plug. The 96 318i engine has a main plug for the wires running under the header and above the block. While the 318ti harness runs through the motor and has no main plug.(will take pics if needed) The only number i could find were on the block itself. The 318ti has HG3 1739675 stamped on it, While the 318i has HG1 1739675. Can you guys tell me what i have? Id really appreciate it so i know if i could stuff that motor in and make it work.

Thanks a lot.

[familytruckster]

I think you mean intake.

Depending on the actual build date, you might have grabbed an M42.

As long as the motors are both identical, use the ti harness. There are a few things the 96 wont have because it's a mid year model. The timing covers are different (the later one has mounts on it for smog stuff) and a few other minor things.

[dave45056]

One quick way you can tell the difference between a late build M42 and an M44 is by looking at the cam position sensor. On the M42 the sensor is on the exhaust cam. On the M44 it's on the intake cam.
Since you have the engine out of the car, another tell-tale is the plastic y-coolant fitting on the back (firewall side) of the head. M44's have this fitting, M42's don't.

The way you described the wiring harness doesn't make sense to me. Post some pics and we can really help out. There are many poeople on here quite knowledgable about swapping engines, transmissions, etc.

[JutHolman]

Hey guys. As far as i can tell the motors are identical. Other then the plug. The only thing i recently noticed was this hole in the motor out of the 318i... I call it the scary hole, as it is a oval shaped circle in the side of the block, right above the dipstick. Hope these img's work. Decided id try flickr.


Here is the motor out of the 318i, and that plug you see is the one i was referring too.

Here is where it was on the 318i at pullapart, and you see the 318ti does not have a plug.

The hole that really scares me in the block of the 318i. It almost looks to clean to be a blow out, but not clean enough to have anything cover it.

The rest of the 318ti motor i pulled out of the car this afternoon. No hole as you can tell, but was full of muddy water (not sure if its rebuildable)

[JutHolman]

hmm pics are not showing for me, you can right click and open in new tab then they show. Sorry for the pain, any suggestions on future pic posting?

[cooljess76]

You need to have 5 posts before you can post pics. That "scary hole" looks like a rod shot out of the side of the block. I'd take it back to whoever sold it to you, drop it on his front lawn and punch him square in the face.

Edit; just realized you pulled it from a junkyard. Live and learn. Some junkyards offer warranties, find out if they'll give you credit and look for another one.

[dahamler]

why not just swap the head?

[JutHolman]

I bought the 30 day warranty from the junkyard(which i'm within). The only problem is that was the only bmw there in the 96-98 bracket. They have 2 others, one a 92 and one a 94. Not sure if motors are intact. I was also thinking myself of just swapping heads. There is no difference in the head off a m42 and m44? Assuming i did pull a m42 out of the 318i. Still not 100% on type of motor. About to go see if it has the y fitting on the back of the head.

Edit- The 318ti had some muddy, water like, nasty oil come out when i drained it. Do you guys think the block is save able? Should i pull it apart and try to clean it? Also, since it had a blown head gasket should i get the pistons checked? Or slap it back together and hope for the best.

[dahamler]

I'm willing to bet that it won't even turn over. Have you tried to turn the crank?

[cooljess76]

It's a crapshoot. Your 318ti has a blown head gasket and depending on the severity, it may have a warped or cracked head. If water has been sitting in the cylinders long enough, they may have corrosion damage and or scoring. If this is the case, at the very least, you'd want to replace the piston rings and have the cylinder walls resurfaced as well as have the head checked for flatness and cracks and replace the headgasket. Again, depending how long the car has sat with water in the cylinders, you may or may not be able to get away with just doing the top end.

The motor you pulled out of the 318i has a blown block. This means the lower end is junk. The crankshaft, pistons, rods, bearings, you don't want to reuse any of this stuff. Not when "known good" used parts can be sourced for so cheap. If you reuse those parts and find out one of the rods was slightly bent or one of the crankshaft journals spins a rod bearing, you'll be right back in the same boat you're in now.

You might be able to use the head off of the 318i's motor on your old 318ti block like Dahamler said, but here's the deal, you're looking at a new headgasket and everything associated with that(expect to spend 300-500 there). Once you pull the head off and expose the cylinders, if you notice the rust/scoring, you're looking at more $$$ to get that stuff sorted out, plus since you'll have to take apart the bottom end, you'll probably want all new bearings, seals, rings, and gaskets $$$.

THEN... Once you remove the head off of the 318i motor, the warranty is voided. There's no turning back. So if you lift that head and find out it's warped, cracked or valves are bent, you're SOL. At the very least, you'd want to take it to an automotive machine shop and have it checked for flatness and cracks.

Chances are, the junkyard won't give you your money back anyway. They usually only give you credit or a replacement. So if you do decide to return it, I'd take the credit and pull as many E30 LSD's as you can find and if there's any e36 convertibles, pull the x-braces. Those things are easy to remove and will sell fast on the forums and you'll recoupe most of your money.

BTW, the 318i motor has a plastic oil filter housing cap. This is a good indication that it's an M44, however some later model M42's came with plastic caps. The easiest way to tell is look at the thermostat housing, if it's plastic, it's an M44. If it's aluminum, it's an M42. The other ways to tell are a little more difficult. If it has 2 oxygen sensors, it's an M44. If it only has one, it's an M42, BUT... since it's illegal for junkyards to sell catalytic converters, they usually chop them off, so you wouldn't be able to tell if it has a post cat o2 sensor besides a dangling wire where it used to be. Then, as stated before, M44's have a plastic "Y" fitting on the back of the engine between the head and the firewall. You won't be able to see it unless the engine is removed though.

[dahamler]

Yea I've rebuilt a few M42/M44 I have yet to see one that DIDN'T have a cracked head after overheating. Also this engine unlike the M50 series with nickel and dime you to death. The last rebuilt I did was almost $1000 in parts alone and I didn't even touch the bearing/pistons etc. I say go the M5X route and never look back.

I may be able to help you depending on where you are located.

Do you have any pics of the car?

[JutHolman]

Ok, pretty sure both engines are m44's. They both have the Y piece at the back of the head. The motor did crank at the junkyard, only reason why i did rip it out. I should of inspected it more but after 3 hours of hassles i was ready to gtfo. Like you said, live and learn. I spent $180 on the motor with warranty at the junkyard. I'm about to go put the 318ti motor on an engine stand and rip off the oil pan to see what it looks like underneath. The car has been sitting in a garage since iv bought it. Any suggestions on cleaning the inside of the block? I do have a pressure washer, but not sure if that's safe.

Dahamler i'm up in Bethune, SC 29009. I google mapped you and it said you are 3 hours away.

Thanks guys, appreciate the help.

Here is a pic of the car, def a work in progress.


This is the top of the 318ti engine, under the head. The walls feel smooth, but as you can tell that rust isn't helping.

[familytruckster]

Oh no, another boston green....Good luck!