BMW E30 M-Tech cabrio, V8

[StefanAnghel]

Any updates buddy?

Did you sort out the exhaust prolem?

[Jonsku]

Yeah it's been a while but at last i've time for her again...

I decided i'll redo the exhaust manifolds. Hopefully I'll get the flanges from laser-cutting this week and also new chain tensioners for secondary chains (right one was "broken" so that's why the chain rattled a bit. I'll replace both of them).

So in couple of weeks i hope i get her fired up again and some test-driving done before winter. Tons of other stuff to do too, so not much time for the cabby :-/

[Jonsku]

Some update.. Got the exhaust manifolds done (quite happy with them this time, they're not perfect but good enough for now) and chain tensioners changed. Going to lift the engine in today and hopefully get her up'n'running on saturday. Maybe some testdriving on sunday
More pics here.

[ImysE30]

A vid would be nice

[JazzMan]

absolutely awesome nothing else I can say

[Jonsku]

Thanks

Did the maiden voyage yesterday! Drove it ~5km or so and damn it feels good

Some problems are still there, mainly caused by light flywheel so i have to get the engine remapped to cope with 12kg lighter rolling mass etc..

Anyways, still lots of things to do but now i've winter time to do them. Sorry no vid. clips yet but i assure you the cabrio sounds really, really cool

[eta]

How are you going to get the rev counter to read accuratley? Are you even going to bother with the econometer? Nice built, a litle bit jealous.

[OSE30]

With 6 cylinder coding plug most likely it won't work. With 4 cylinder plug readings should be accurate.

[Jonsku]

I've 4 cyl coding plug + little magic black box which makes 8cyl signal to 4cyl signal so rev counter works as it should

I don't have econometer because i've E30 M3 instrument cluster. Oil temperature gauge works (of course).

One thing i didn't mention before is the clutch, which works very very well indeed.

[ImysE30]

Awesome, looks at home in the bay

[PiLLLe]

Nice

Congrats!

[Jonsku]

Ok, here's a videoclip.

As you can hear there're still some problems. The damn rattling noise is coming from somewhere but dunno where so feel free to shoot "educated guesses"

The noise went away for a while when i changed the old timing chain tensioner back but came again when i gived it some revs. With new tensioner the rattling noise is there all the time..

[Barx325i]

I thought that read stealthometer will

that's a horrible noise, but maybe something simple like a chain guide

otherwise...it sounds amazing & need to see a huge number 11 when the rattle is sorted. superb job

[PiLLLe]

I'm afraid you'll have to take everything appart. Maby you have damaged o-rings on the hydraulic tensioner during the assembly. And if oil leaks, there is not enough pressure, and the chain is not tensioned correctly.....

my 5cents worth thought

[Jonsku]

Today i had time to check oilpump and frontmost mainbearing & connecting rod bearing. They were all fine. Also rolled the engine many times over manually and checked all the chains - they seemed fine also.

The oil that i let out of the engine had tiny metal pieces in it, not very much but some anyways. So i guess the timing chain may be stretched (the engine has done way over 200 000 km and this is the original chain) so it may be hitting something..

Tomorrow i'll do compression test to every cylinder, and after that i'll drive the cabrio to local engine shop who promised to listen to the engine once i get there.

Jonsku, just a very long shot..... remove your fanbelt and see if the noise remains. (grasping at straws here... )

Must have played your video 50 times at least trying to figure it out. Still think it has something to do with the cam chain though.

I've tried it without "auxiliary-devices belt" but the noise remains the same. Would've been too easy that way

[Jonsku]

Okay, the story goes on.

Today i drove the cabrio for about 100km and visited couple of places. The brakes are really good, definite update compared to old ones. The clutch works very well also

Local engine specialist said that the noise is definitely not coming from the engine. He thought that gearbox is more likely to make that kind of noise. Well I lifted the car up on a lift and listened from beneath, the sound comes very loudly from the gearbox. But it can't be the gearbox, because when i've gear in and clutch pressed (car on the ground) the gearbox is "locked", correct? But the noise comes also then, so only options left are clutch, flywheel and starter. Checking them means that i've to pull the gearbox off, dunno if i can do it when engine is in it's place..

I changed the gearbox oil also, old oil (driven for ~75km) was really, really nasty looking black shit so i wonder is the gearbox ok after all. Though it has been standing without oil for over 3 years now so...

[Jonsku]

If you lower the crossmember down and undo your engine mounts, you may be able to tip it enough to undo the top bolts. Is your motor hard up against the firewall? The way I am mounting mine allows me to get to the top bolts from the top as it sits away from the firewall.

The topmost bolts aren't a problem, i can reach them easily from the engine bay. The bolts causing problems are starter upper bolt, but i guess i'd unbolt them when tilting the whole package backwards.
Though it'd be bit bad to lift the gearbox off the engine when under the car, the clutch shaft gets bit too easy tilted that way..

Well, next weekend i've to do it anyways so then we'll see what's the problem and how it goes..

[Jonsku]

Just a thought, have you used the dual mass flywheel? Those things come apart after a while and may be your problem.

As said before i've one-mass 8kg flywheel, which causes it's own problems (idle, engine braking tends to shut engine down) but those are fixable by programming..

Flywheel is custom made, it might be the problem so i've to take it apart and see how it looks like..

Btw, yesterday i checked the compression of the cylinders also:

Cyl 1 - 16,1 bar
Cyl 2-7 15,0-15,1bar
Cyl 8 14,0 bar

So no major differences, though some.

Tried also to press and rotate hydraulic lifters on righthand side, they were just fine (rotated freely, didn't go down when pressed).

[Frenchguy]

Good luck, the fi(n)nish line is near!

[Jonsku]

Hehe, thanks guys. I think i've to buy stethoscope and listen to my engine heart beat very carefully to find out where it's making the noise. It might be one or two hydraulic lifters sticking or then it might be starter gear touching something. Dunno, but sure as hell i'm gonna find it out!

Ok, grasping at straws again.... you did fit a pilot bearing into the crank for the spigot shaft??

Oh yes i did.

[Jonsku]

So, back in business. I've been doing some minor things to cabrio; changed the front lamps to yellow ones (some hate them, i love them ) and differential to brand new one with 3.07 ratio. Theoretical top speed dropped from 347km/h to 300km/h but i think it's fast enough

Tomorrow when the exhaust has dried (i painted it) i'll listen to the engine with stethoscope so i can hopefully find out where the problem is..

Here're more pictures

[ImysE30]

One of the best on the Zone for sure, thing of beauty

[Jonsku]

Here's one picture of the new look:




Couple more new pictures on aforementioned website. I think the rattling noise comes from hydraulic lifters on righthandside. "New" engine costs half of the cost of new lifters so i think i'll source new heart for my cabrio..

[suzie650]

You're running the 6 speed gearbox, aren't you?
What oil did you use? I read from a few gearboxes destroying (badly swelling) some plastic bushes when run with good but non MTF-LT2 gear oil, creating similar if not anywhere as loud symptoms as yours...
And I know from experience that the S6S is not as strong a box as the 5 speed units. (motorsport use on S50)

It's a highly unlikely possibility, but do not forget to listen to your box as well as the engine. - And it would be bad if it were the box, as I expect you paid more for it as for the engine...

[Jonsku]

You're running the 6 speed gearbox, aren't you?
What oil did you use? I read from a few gearboxes destroying (badly swelling) some plastic bushes when run with good but non MTF-LT2 gear oil, creating similar if not anywhere as loud symptoms as yours...
And I know from experience that the S6S is not as strong a box as the 5 speed units. (motorsport use on S50)

It's a highly unlikely possibility, but do not forget to listen to your box as well as the engine. - And it would be bad if it were the box, as I expect you paid more for it as for the engine...

Yes my gearbox is 6 speed, from E39 M5 and damn expensive

Anyways, the rattling noise can't come from the gearbox because there isn't anything turning when the clutch is engaged and gear is in when the car is sitting on the ground.. I'm using BMW MTF LT2 oil.

I'm 95% sure that the rattling noise comes from right hand side intake valves hydraulic lifters..

[suzie650]

IIRC it was to do with amplified vibration onto these bushes, not rotation. But it is only a highly unlikely possibility thrown in with the others.

[kerrie]

Hi, just a thought, I had a lighter flywheel made for my M42 some years back and it had the same noise and a vibration as well, I eventually found that the crank bolts were too long and were bottoming in the threads before actually tightening the flywheel correctly, same noise,was catching on the starter and engine casting when revd, Did you use the original crank bolts?
Cheers

[Jonsku]

Hi, just a thought, I had a lighter flywheel made for my M42 some years back and it had the same noise and a vibration as well, I eventually found that the crank bolts were too long and were bottoming in the threads before actually tightening the flywheel correctly, same noise,was catching on the starter and engine casting when revd, Did you use the original crank bolts?
Cheers

Hmmm... that sounds interesting. The flywheel is made so that the original bolts are long enough but that's one thing i have to measure when taking the whole thing apart again.

Anyways, now i've "new" 190 000km driven engine from E38 with some kind of warranty. Got it for good price so had to buy it. Someday when i've time i'll take the engine out and start swapping parts to this newer one.

[Jonsku]

Ok, at last i had some time to build the cabrio again. Today we lifted the old engine out so i can swap all the new parts from it to "new" engine. I hope the new engine will go in around next weekend.




Btw, could moderators move this thread to "M60" section, thanks.