New to forum, unsure what to do with m42 before swap

[Jaredmac11]

I purchased an e36 m42 local.  After 3 months of searching, I found one and picked it up.  Had 2 areas of concern.. one, he parted out the radiator and starter so I never saw it running. Two, it has a bad valve cover gasket so oil is everywhere.  Found oil at the tops of the plugs, possibly lower so now I'm afraid it has a cracked head.

I wish I found y'all earlier.  I can't even look at the for sale section without feeling sick.  People are selling m42 plus trans for the price I paid for the m42. Yeesh..  but that's ok, lesson learned-- I'll find m42club first in the next life.

This is my first rebuild and the goal is to know the ins and outs of the m42 after I'm done.  Problem is I honestly don't know what to look for.

What I know: 
Timing case rebuild is smart at 250k but I'm 100k before that. I'll crack it open and look.
Cracked heads are suspect, perhaps common from improper care by PO.

What I don't know..
How this thing runs.  I don't have a trans and I don't have a starter. Would hand turning the camshaft pulley bolt give good compression? I don't want to do a rebuild before knowing if I have a mess or not. 

Hindsight being 20/20, would have waited for a better example but I got too excited to start a new project.  Need to get a good scope of this one.  Any help is greatly appreciated.

I'll come back with pictures as I start the tear down.  It should be on a mount soon

[Jaredmac11]

Trying to get more details on my engine.  Primarily the month and year it was made.. but also to make 100% certain it is not an M44.  I read that the serial number is under the intake manifold, right above the oil sump pan.

I keep trying to use these numbers in realoem but Im having no luck.  This is right behind the oil dipstick tubing (removed).
http://imgur.com/a/xLRRD

[Darky]

Hi and welcome very easy to determine if it's a m44 that's maf(hot wire) where m42 is vaf(flappy door) just after the air filter.
There are other differences but that's the easiest way to tell the difference.

What is the aim of the rebuild?

Are you planing bigger Pistons, crank or valves?

Rohan

[Jaredmac11]

I'd like to keep everything stock, just to keep costs low.  I have considered overhauling the M42 but I dont want to put more than $1000 in to this.  Honestly, since it has 155k miles I plan to open the timing case and see how everything looks.  A full timing case rebuild is almost $500-600 and may be unecessary at this point..  May end up doing it regardless.

As for rebuilding the engine, I will determine what comes up when I start tearing it down.  I plan to have the head checked for cracks at a machine shop, otherwise everything else is addressed as necessary.

Since this is going in an e21, I think I will be quite happy with a stock M42.

[vee030]

Almost every unopened m42 will need the timing case guides, tensioner and new idler sprocket. Cam sprockets and crank sprocket can be reused if they are still flat on top of the gears.

Would be worth taking apart the bottom end. I just stripped down my m42 and another m42 that I bought for the head. Both had destroyed bearings. Crankshaft and pistons appear to the within spec fortunately.

These engines were both running and at 210000kms/145000kms to give perspective.

[Jaredmac11]

The more I read, the more I wish I read before getting this M42.  This isnt going to be a simple prep and swap.  I'm going to need a more robust rebuild.  I definitely wasnt anticipating new bearings and potentially needing machine work beyond resurfacing the engine head surface.  Definitely a bummer.  I wonder how many of these bad bearings need machine work.. I'm going to dive in and find out.

Found a  useful post from someone in another forum that is level-setting me pretty well:
http://www.r3vlimited.com/board/showpost.php?p=1166639&postcount=3

[downforce22]

why not diagnose the engine first before jumping to conclusions on what needs to be replaced?

Mine had 220k miles last documented in like 09. I've put over 7000 miles on it since I bought it late in '15 and it still runs great. 30 mpg on my last trip this weekend and thats after a track day and a 1000 mile road trip. She hasn't let me down yet and I haven't opened it up beyond the upgraded timing chain tensioner.

[Jay-Vee]

Hi Jared

Very strangely, my name is also Jared, and I'm in almost the same situation as you right now.

E30 M42s arent very common here in Australia so I snapped one up for a swap project which was also only briefly seen running. Yet to open it up, so I get your anxiety.
The unknown can be a scary thing haha, but I suppose its always going to be somewhat of a gamble.

I'd be interested to hear your progress as to what you found and had to fix. Good luck.

[normboudreault]

I had my 265000km M42 rebuilt. Cost around 4000 Cdn, 1000 of which was for new stock Pistons. Nothing else needed replacing though I refurbed the injectors and put in all new sensors. Ive just finished breaking it in over the summer. It runs like new. Engine is absolutely awesome - so much fun to drive (I also have an 1990 e30 M3 so I know about fun e30s!)

Jared (the Aussie) saw the car about 70% complete.. Hopefully when he comes back we'll be able to go for a spin..

My point is, if you can afford it, a rebuilt engine will pay off in spades and will reward you over and over again.

[Jay-Vee]

Hi Norm

Good to hear your advice as I've been starting to work out exactly what I wanna do with the M42 and have been thinking more lately to just get the thing rebuilt.
I think its a case of 'while I'm there'... and before you know it the plan becomes close to a rebuild anyway.

Would be great to go for spin mate. We'll sort something out.

[normboudreault]

Do it - you will have no regrets! A newly rebuilt m42 is a sweet thing!

You're always welcome Jared - look forward to seeing you!