Dont know how much more of this I can take

[Adammcf]

Finished the rebuild and got the car started up today for the first time in 7 months. It was smokey for a while but thats to be expected seeing the exhaust etc has been sitting over the winter in the garage.

Anyway I took it for a nice 10 mile drive and the car was running really nice and smoother than ever.
Got home and checked everything and look what I found. Completely gutted. Looks like Im gonna have to strip it all down again!

[Gouki]

that must be gutting mate, dont know what else to say

[bigdek]

what is wrong m8 as i dont see anything obvious in the pic

[Adammcf]

The car is running really nice but the head gasket is leaking oil. Im just praying its the gasket and not yet another dodgy head.

[Jimbob]

If you just built it then it may weep a little, don't panic for the next few hundred miles man. Try to chill

[Adammcf]

Are you sure? It never weaped the last time I built it. I'll take it for a few more runs and see.

[buster]

Its a common problem with m20's.
It happened to me before,sometimes they just dont seal up properly,and that was with a genuine BMW gasket.Or maybe it wasn't clean enough when you put it back together.
You could try and tweek the head bolts up a bit more.

It sucks but £75 for a new set of head bolts and head gasket and half a day and it can be put right.It should come appart with no hassle as its only just been rebuilt.Not the end of the world.

cheers
andy

[Adammcf]

Yeah I know it should hopefully just be the gasket but its just another kick in the teeth just when I thought it was finally sorted.
I knew I should have used a genuine BMW gasket instead of the one Linwar sent me with the second head.

[buster]

Yeah i never use non gen engine parts for that reason.

[Adammcf]

Yeah same here. Everything else was genuine but Id thought Id chance it with the gasket they sent. That'll teach me.

[Grantley]

Give it time mate, am I rite in thinking the head will have to be re-torqued after so many miles if so it mite all work out for the best. Chin up dude !

[StuBeeDoo]

Adam.......
Have you traced where the oil is coming from??
Have you had the front top exhaust stud drilled out and the hole "helicoiled"?? If so is the oil coming from that area? Is there a dark stain developing on the front runner of the exhaust manifold?

[E30Adam]

I had the same trouble when I built my engine. Head gaskets, even genuine ones are notorious for not sealing properly on the M20.

I ended up taking it all apart again and swapping the gasket. You have to get the surfaces of the block and cylinder head clinically clean. I mean not the tiniest speck of grease, dust or anything on either. U got through about 2 tins of carb cleaner when I did mine, you could eat off the thing.

Make sure there's no fluid in the head bolt holes in the block too as this can compress when you're doing the head bolts up and can actually crack the block. Some people think that the fluid will squeeze out when you do the bolts up but it doesn't. If it doesn't crack the block then it cna cause incorrect torque reading when tightening and can also lead to leaks.

I feel for you dude, I really do. It's such a kick in the bollox. Just as you thought it was all finished!

[Adammcf]

I hate M20 engines! lol The money Ive spent on this one could have put a friggin M50 in there.

Is it worth doing as JimBob says and drive it for a while to see if it stops or could I risk damaging anything?
This would also explain the smoke out the back as well if the oil is getting into the chambers.

[StuBeeDoo]

Dude. I've been exactly where you are now!
DON'T get despondant.
Can you see exactly where the oil is coming from? Is it tracking down the side of the head?

[Adammcf]

Nah from what I can see its seeping out between the head and the gasket.

[Widge]

Drive it, retorque it, clean the clock and drive it some more to see if it solves the problem. This is why every M20 is covered in oil, nearly everyone I have had has leaked from the same area too, not that that helps, but you won't damage the car. Chances if it's running well the chambers are sealed and it's just the edge of the gasket thats leaking.

[Adammcf]

The tightening sequence was 30nm I think then 90degrees then 90 again so who knows what torque that ends up with.
I'll take it for a wee spin tonight and see if it gets better or worse.

[Widge]

Just a rebuilt 2.5 is it mate?

[Adammcf]

Yeah the first engine had a cracked head so got another head and then two months later the valve seat broke up in the engine where it was welded in the recon process. They gave me another head and some valves and a full gasket set and I got this bottom end from Dips off here.
Ive changed every gasket, seal, nut and bolt there is.

Just went out and drove around for 50 miles and it was driving lovely and it has plenty of power there even though I never used any of it or went over 3500rpm.
The leak is still there though. I'll do another 50-100 miles and see if it stops then its another head gasket by the look of things.

[buster]

I had the same trouble when I built my engine. Head gaskets, even genuine ones are notorious for not sealing properly on the M20.

Yep,exactly what i was talking about.

In that corner is the oil return hole,and thats where its leaking from and thats exactly where it leaked on mine.

[Adammcf]

What do you reckon the chances are that it will stop? lol
Fingers crossed everything else is ok as on my drive tonight it was running really nice. Its still a bit tappety as Im using the same Alpina cam and rockers that were in the old head but apart from that its sweet.

[buster]

Nope,i dont think it will stop,mine didn't.
I found also the harder i drove it the more it leaked ! which i suppose is to be expected as the oil pressure is a lot higher.
You could try and nip the head bolts a bit more.

[Brianmoooore]

The leak in the pic looks to far forward to me to be the oil feed leaking.
Sure it's not coming from the cam seal/retainer plate/ "D"seals?

[buster]

not the feed,the return in the corner

[GDBN]

Hi Adam .... mine also does the same. Never did before the head was changed but after there is a tiny leak in the same place. I have always thought it was the cam shaft oil seal that was leaking ( as per Brian) but have not got around to further investigation - But I have already bought a new one.
The engine seems fine though and it is not something that worries me. There is no sign of oil on the no.1 spark plug and the amount of oil that is lost is tiny.

Giles

[zaust]

If you just built it then it may weep a little, don't panic for the next few hundred miles man. Try to chill

i agree, when i rebuilt mine it threw a bit out for the front seal for a copule of days then it was fine..
so dont panic yet..

[StuBeeDoo]

Got an update for us on this one Adam?

[Stealth]

Just for your info...

I have re-torqued my head bolts and it seems to have stopped the flow.. i will keep you posted..

[bigun]

i know how you feel adam i just rebuilt my m20 2.5 i had to take the head off 4 times as gsf supplied me with the wrong headset when we torqued it down the engine would lock up =4 times on the 4th time we put engineers blue ink on all the valves put it back and just nipped a few head bolts turned it over again it locked so we took it off again and the marks off the ink were on the edge of the gasket they had given me a 2.0 gasket set marked up as 2.5 did you get your head skimmed

[Stealth]

Nope....

It's still leaking, I have done the first 90 degrees re-tighten.. but i'm a bit concerned that a SECOND 90 will do some damage as the first 90 was really really hard work

Any suggestions or just leave it... at least the under tray is catching the drops..!!

[StuBeeDoo]

Nope....

It's still leaking, I have done the first 90 degrees re-tighten.. but i'm a bit concerned that a SECOND 90 will do some damage as the first 90 was really really hard work

Any suggestions or just leave it... at least the under tray is catching the drops..!!

Dude, am I reading this right?.......
You torqued the 'head bolts to the setting and then you ran the engine before doing the two subsequent 90deg's??........

[Stealth]

Yep, The head work was done some months ago and the engine has been given a run every now and then..

[StuBeeDoo]

That could be why you have a leak then.
It's 30Nm, then 90deg, another 90deg all in one hit going 'round in the bolt sequence each time. It's not like "The Good Old Days" when you did the bolts up to, say, 60 ft lb then ran the engine for, say, 500 miles and then check the bolts are still at 60 ft lb.
When I did mine, the final 90deg was hard work, even with a 2ft bar.
HTH
Stuart.

[Stealth]

What's the best thing to do..

I have 1 more 90 degress to do, or whole new head gasket, or live with it..??