MOT failure

Manifold is off as another tech had a go but still couldn't shift the bolt. The crack on the bottom of the manifold is about 2 inches long. I have some really good plastic glue so on Monday I'm going to clean it up, a little scratch with sandpaper then I'llopen the crack slightly and apply the glue. I'llleave it overnight then I might run a very thin bead of silicon sealant along the glued crack just to be safe. Gaskets are due on Tuesday so hopefully back together by Wednesday. That moment I turn the key will be a nervous one!

Mike

Hello Mike,

Very sorry to hear of your troubles! That's tragic :(  Last time I was on here your car was running well apart from a slight misfire!

That's sod's law all that should happen at once - I saw an intake manifold on ebay only a few months back going for £60 (instead of £1500 for new one?!) that I was going to buy for an LPG project!

My car has no CATs on at all and the MOTer managed to get it through - apparently is was not far off at all so he just tweaked the machine and it went through. That misfire is no doubt something (maybe all) to do with the emissions problem. If you've had gaskets leaking and oil going through, the spark plugs will be caked in oil by now anyway so after refitting the manifold and new PCV cover they might be worth replacing, as mentioned. I can't remember what the state of your coils were, but I'm surprised it's misfiring that noticeably with just leaking PCV - it could even be a faulty injector or something silly like a loose connector or damaged earth lead...??

As already mentioned, the headlights should adjust easily enough. If it helps, here's a link to a site I normally use for small jobs that should explain it for you:  http://www.bmwtechinfo.com/repair/main/741en/index.htm

The coil is unfortunately just a typical item prone to wear that will have to be replaced. For the price of an OEM one you COULD if you wanted as a temporary solution get two aftermarket ones for the same price.

I took a binding caliper apart in my old Volvo S90 and it was easy as pie - just greased up the pistons and job's a goodun!

And as said previously, save the advisories for another time when you're feeling rich ;)

 

Once again, really sorry to hear that it's all gone pear-shaped for you. I keep my MOTs till October, I find that's when I have the most amount of money :)

Take care and best of luck with it all.

Crispin

Edited by Crispy-d

Mike,
I had MOT failure on emmissions, with similar value to you.
I see from the story so far you are quite a way down the road, but I have a couple of comments anyway:

Check that the rubber cap on the PCV plate is not cracked, though I think you may be getting a new plate so probably not an issue.
It was cracked on mine and letting in enough air to cause engine stall just off idle unless you gave it a bit of a tickle on the accelerator pedal. This same leak caused the engine management to enrich the mixture so much a lambda sensor gave up, and emissions were way out.

A new lambda sensor brought emissions back from 1.something to about 1.65 then I found the airleak and it came back into the correct zone, though I think the cats have suffered some damage.

I fitted new plugs and cleaned all the coil packs with solvent, and the engine was definitely sharper for a few miles, but the effect is not long lasting.
If you return to a misfire, I would check the coils- I can't remember if you can get an engine code for coils on our engines??

Certainly mixture way off and lambda errors will be read easily by generic code readers, so you can avoid dealer expense there.

Hmm, enough waffle- PM me if you want to see about trying some bits, as I have a scrap 540i with various bits lurking....

   Well done. Keep up the good work. Sounds like a good job so far. I hope that it works for you.

                ERIC.

 Hi Mike It will be nice to hear the sound of that engine when you have fixed it. I have got my fingers crossed for you.  ERIC

Jetset...I am curious about what you mean by "a bit rough"
When mine had the air leak the ECU had raised the mixture up to the rich limit, but it still ran smoothly.
The only clue was the stalling at low revs. I can now engage first gear (on the level) and the car will pull away with no need to touch the throttle.
Every now and then I notice a little hiccup when the engine is idling, and my mums 530iT is the same, but neither is properly lumpy/rough running (as in door top wobbling when open). so I am assuming it is not too bad.
Lambda sensors do slow down in their response, but on our cars they are only really there to tweak the mixture for the benefit of the CATs and are not used as a fast-response feedback to the ECU, so it might be worth checking other areas first. I replaced both of mine, though only one was flagged as faulty, so I have an OEM one you could try if you fancy, though they are not too pricey off the web.
The purge valve, and associated plumbing on the evaporative emissions cannister, and the fuel pressure regulator are items that could be sources of stray air, or low-speed roughness.
We're in the same area, so a comparision might be of interest/benefit.

Don't panic.
Highly unlikely to be Nikasil now. More likely problem on the V8 is PCV (but I think we all know that on this thread....)
Sounds very similar to how mine runs now and then, and the 530iT my mum has also does it, but slightly more pronounced.
The 530i has a slight engine lumpiness at 1800rpm too, which makes me wonder if a coilpack is iffy, though it did pass MOt without a hitch recently.
I think I have a compression gauge somewhere if you wish to test, though I think you have nothing major to worry about.

If it's any help, I did a compression test on mine a couple of years ago and it read ~200psi for each cylinder apart from a couple that were ~190psi. If the lining hasn't been eaten away by crap petrol then they were designed to be super hard and wear resistant and so the bores should go on and on. I'll stick my neck out here and say that if it's still running well then it's got a long way to go yet :)

As for running well, I've come to realise that at such an age they are not ever going run supersmooth and will never by like a straight six just because of their nature (cams and general configuration) but sure there are things to help get it back to factory spec.

From what I've read over the years, the things that make the most difference on these engines are Coil Packs (brand new ones...) and Injectors (again, brand new ones as reconditioned are still not quite the same due irreversible corrosion...?) At 180k miles you can bet your boots your injectors are pretty fouled up and the coil packs... Well I know the state mine are in and the boots have had it. On another forum someone replaced all of their injectors (think it was on a 525i, with only 80-90k miles) and they said the difference was huge.

As soon as I can afford it, that's what I'll be doing :) because I've tried everything else! Apart from engine mounts (and gearbox mount) - that's next.

I've already done that and they came out cheaper at the dealer than Eurocarparts!! Still, they weren't exactly cheap at £125 each!!!

And the coil packs are a good £90 each I think - but I reckon it's the insulation that's more important for those to work, i.e. the rubber boots!

Hope all's going well with you, Mike...

Crispin

Forgive me for not searching back through your old threads, but have you actually checked all your injectors? As in unplug one, then the next, then the next and so on until you find one that makes little to no difference? If it's not ignition then it's hard to think what else it can be other than the fuelling! If it was just a vacuum leak then surely the car would just run rough in general. Unless any excess oil being sucked into the intake has fouled up one of the valves or if you drive really gently everywhere one of the followers has got sticky (but I don't believe THAT!)

You have obviously seen the spark plugs when you replaced them and if one was noticeably different from the rest then you probably would have said... Just wondering whether it's worth checking out your injectors while the manifold's off??

Hope it starts up ok on Friday morning - best of luck!