M20 game over...

Thu Jun 10, 2010 1:22 pm

Right, more mapping work was attempted today and a number of worrying signs have started to crop up: a consistent misfire on one cylinder, mayo forming on the oil filler cap and oil droplets in the coolant, which was receding at quite a rate.

Let it idle for a bit while I had a poke/listen and suddenly a 'crunch' and a very loud tap before the engine dies. The exhaust is billowing white smoke...

Rocker cover off, the head has coolant sitting inside it and the cyl5 exhaust tappet is very loose (dropped a valve?). I can also hear dripping inside the engine and can only surmise that cyl5 has filled with coolant which is now dripping into the sump...

Long story short, the car is dead. Which annoys me because I've just spent a lot of time fixing up the suspension bushings etc. and undersealing the thing....

Now my options are:

Get a new car, frag the touring and replace the whole suspension... that gives me the option to get a 'lesser engined' 2 door and have the bigger struts, discs etc. Is also the quickest method to getting a car on the road that I can use!

Pull out the M20 and replace like for like, finish the MSII project.

Sell MSII stuff, buy engine project (will probably be M50/2)and get a rubbishy car as a daily driver for a while.

Thu Jun 10, 2010 1:29 pm

M50 on MSII

Thu Jun 10, 2010 1:45 pm

So just because you suspect the cylinder head is cracked,the car is scrap?
Cheap fix is a replacement s/h head,surely?
More time consuming fix is a replacement M20.
Even more time consuming is a replacement M50,but may just be cheaper overall,depending on your fabrication skills!

Thu Jun 10, 2010 1:54 pm

Just pull the head off and see what the damage is

Thu Jun 10, 2010 2:20 pm

Head off first, then weigh up your options. Surely whatever happens you'll be better off using a "known good" shell/suspension?

Thu Jun 10, 2010 2:23 pm

Yep, head will be coming off today/tomorrow to see what's going on. Been looking at switching to a 2 door for a while so this might be an opportunity for a reshell...

Thu Jun 10, 2010 6:02 pm

Just as expected... this is cyl5, but intake... the valve has snapped and turned in the port, gouging nice holes into the piston...

so the engine is scrap unless I rebuild the whole thing...

I'm really tempted by the reshell idea, but it is a shame to let go of such a rust free shell...I'm just not feeling the tourings any more....plus the paintwork is pretty bad...

So...ideas? It would be nice not to have to buy a cheap runabout ...

Thu Jun 10, 2010 6:34 pm

Drop a S/H engine, you have a good solid shell that is rust free. There is an increasing following for Tourings so get it running good and sell it on to someone who will bring it back up to it's former glory. Put the cash towards a 2 door.

Fri Jun 11, 2010 12:28 pm

Good shout mate, been thinking it over and really that's the only sensible option...I'll probably be thankful I kept the touring when it next comes to moving house!

So anyone know a good base M20b25?, my wanted ad is below:

http://www.e30zone.net/modules.php?name ... c&t=171904

How hard is the job of swapping engines anyways? I've got time on my side (just finished my final year *woop!*) but never done anything like this before... even worse, the car is on gravel and asides from parking it in the middle of the road, there isn't anywhere flat to do the swap...

I assume it's a case of undoing all of the loom, exhaust, intake, prop, coolant and AC/PAS lines then strapping it to a hoist, undoing the mounts and pulling the thing out? Is it easier to undo the gearbox or take it out with the engine?

Thanks!

Fri Jun 11, 2010 1:21 pm

it's easier to take the gearbox with the engine
not very hard to do,don't forget to take the slave cylinder
of the gearbox too
Indy

Fri Jun 11, 2010 1:45 pm

you may be able to get away with just some new pistons in there. and a new head or that valve replaced and the seat redone.

have you got better pictures of the damage? as it may be a lot lighter than you think.

Fri Jun 11, 2010 2:12 pm

Are the liners ok? If so why not just leave the piston as it is?

Fri Jun 11, 2010 2:15 pm

cool stuff, will give it a try and see what happens, hopefully it won't be that hard

not got the downpipe off the exhaust manifold yet, surprise surprise one of the nuts has rounded and I can't work out how to get the accursed thing off...will give it a try tomorrow anyways, or filing that take off the manifold and work it out when the engine is off. But even if the damage isn't huge, I'd still need to take the engine out and if so I might as well swap in another and use the remains of this one to do a full refresh/rebuild/2.8 depending on funds.

Fri Jun 11, 2010 8:07 pm

is this the engine which snapped 3 rockers a few weeks ago and you wouldn't remove the head to fix it?!

Fri Jun 11, 2010 9:22 pm

has anyone worked out why valves break like this? is it purly fatigue?

Fri Jun 11, 2010 9:33 pm

iirc this guy posted pictures of the timing clearly out, hence 3 broken rockers. My guess is its been bodged back together and been made into a time bomb

Fri Jun 11, 2010 11:07 pm

Yep, you're right - this is the same engine and it snapped 3 rockers a while back with a timing belt slip. I know it was the bodge thing to do putting it back together but was hoping that I'd have a little more run time than this...

I wasn't happy with the way I did it, but unfortunately time was the limiting factor when the timing slipped and I needed something running quickly to get as much mapping material as possible for the MSII project.

Good news is I may have scraped enough back to get a decent mark on the project, bad news is I've wrecked the engine...not ideal, but I can fix that...