E46 318i Touring: Oil leak fixed! Rubber rocker-cover gasket was the culprit!

It's about time I got back to wrenching on some Beemers after a busy hiatus, so where better to start than with the massive oil-leak on my E46 318i Touring. The car hasn't seen much use over the winter months, but as I start to need it again for its cavernous load-lugging functions, I figured it was time to spend a bit more time getting it right.

I was going through about a cupful of oil every 100 miles or so (I think that is a pretty favourable estimate to be honest, more like half a litre!) and worse than the cost of all the topping-up, smoke continued to billow from not only the sides of the bonnet (hood) while stopped at traffic-lights, but also straight into the cabin with the blowers turned on. This meant for the last 12 months I have had the climate-control set to full recirculation mode and on low, making de-misting the windscreen a nightmare on colder days.

I could see the oil-leak was coming from the rear left side of the engine, as it so often the case with N42 engines and assumed it to be the vacuum-pump (like with my E46 318ci in this this post), but after removing the rocker-cover (cam-cover) I found it was actually the rubber gasket itself. The thick rubber gaskets tend to harden and go brittle over time and almost completely down the left side of the cam-cover there was noticeable leakage, primarily at the back corner, next to the vac-pump of course. The gap at the rear-left corner was so pronounced I feel you could have slipped a credit-card through with a little force and touched the back of the cam-shaft! This was allowing a constant drip of oil out onto the heat-shield and down onto the exhaust-manifold, as shown by the arrows in the picture and causing most, if not all of the smoke.

Luckily, I suppose, I have been working through the Covid epidemic, so I am classed as a 'key worker' and had a day off, so I managed to blag Euro Car Parts that it was essential work and instantly collect the new Elring gasket (£22, but eBay alternatives are as cheap as £9.50 if you can wait!) and some Corteco White instant gasket-sealant (£7), though they still had me waiting for an hour outside!

Knowing how prone the top-end seals of the N42 are to leaks and not wanting to take any chances of removing the rocker-cover again anytime soon, I slapped on a liberal bead of the Corteco sealant over the vacuum-pump ring and along the entire left-side (lower) surface of the cylinder-head top edge along with the new rubber-gasket. The job does not take long at all (I will post a guide soon), with removal and refitting of the cam-cover only taking around 30 minutes each and that's taking your time...

Needless to say, this has stopped the major part of my oil-leak in this area! Not only has the oily steam stopped from the sides of the bonnet while stationary, the smell/smoke from the climate vents has now ceased and the car is no longer consuming oil at a silly rate, so I would say job done! There is still a tiny weep of fresh oil coming from around this area, but nowhere near like before and, after a run where the engine is warm, there is no dripping pool on the under-tray! For the money I spent, the difference in convenience is worth vastly more! I would have spent the ~£30 I did in oil in a couple of weeks using the car daily, so if you have this problem, it's safe to say this is the culprit and get it sorted!

E60: Update + New Turbo!

Right, now the E60 is back on the road and all legit it's time I fine fettled the engine-vacuum and rattling exhaust issues left from the engine swap. The exhaust needs realigning at the back of the turbo so it doesn't contact the bracket and the vibration-dampers can be set correctly. The only way to do this is to first remove the rocker-cover and injectors and after my injector-seal problems with the new engine I haven't been able to justify doing that unless it's really essential and that time is now.
The culmination of all my messing around with the vacuum-lines [from this post] is a partly-boosting turbo that sounds like a police-siren. From the word go I was told this is the key sign of a broken turbo, but just couldn't believe it as the turbo seemed to be working ok after the initial engine rebuild (or was it?!) and the other vacuum niggles gave me false hope that it could be a cheap, easy fix. I should have learned by now that this is never the case and have now come to the conclusion of a glaringly obvious broken turbo. I guess that swirl-flap destroyed every part of the motor that it passed through, so lets hope and pray, seriously, that I don't have catalytic-converter issues in future.

So here is my replacement turbo. It's from an E65 730d and was the only used turbo I could find that fits my 'vacuum-actuated' setup, rather than the later and far more common 'electronic-actutor' type. I got it for the spiffing price of just £200, including delivery, but alas there is another catch - the front casing is dented at the outlet-port to the intercooler and the alloy has cracked, maybe during transit, but probably in the crash that wrote-off the 7-Series. This isn't a major setback though, as the front casing just bolts on and is a dry fit, so should not be much drama to swap the cleaner casing from my turbo onto this one. It also plays no part in the functionality of the blower, so if the mechanism works then it works. I'm no turbo expert but there is less play in the spindle than my current blower so if it cures the problem it will have definitely been worth the extra effort for the knock-down price.

E60: Split Vac-line, some boost, weird noises.

The turbo whine and lack of boost has persisted, so I took off the inlet-manifold again to check the vacuum-lines and found one has snapped off. Luckily, there was plenty of hose left to cut it down and push it back onto the T-piece. I re-checked every line twice against the diagrams on RealOEM.com and refitted the manifold, making sure the seals were super flush. Now when I fired up the turbo started making a ridiculous whoosh and dump-valve style hiss, as in the vid below. Some boost had returned too, though not as much as there should be and certainly nothing like the turbo sounded. Still, the vac-line repair did get a result, so it looks there could be life in the turbo yet.

There was nothing else I could do other than pore over the vac-line configuration, so I made this quick one-piece diagram to show the route of the four coming off the servo-pipe to save switching between several diagrams on RealOEM. I then started pulling vac-lines off in order to find the faulty area and, amazingly, managed to get rid of the whoosh/hiss and still have some boost. The turbo is still whistling though and there is not enough pull as you get over 2k rpm, so something is still amiss.

• Split vac-line to swirl-flaps - Low boost, quiet turbo-whistle higher up.
• Repaired vac-line - Some boost low down, cuts out higher up. Loud whoosh and hiss noise, turbo-whistle constantly.
• Vac-hose removed from wastegate - Low boost, quiet turbo-whistle higher up.
• Swirl-flaps and engine-mount vac-lines switched round - Some boost, no whoosh/hiss, constant turbo whistle, less engine vibration.

The diagrams do not make clear the route of the red/black striped hose on the right of mine. This turned out to be the N/S engine-mount and another scan of RealOEM.com revealed how they work in the pic below. I had wondered about a problem with the engine-mounts anyway, as there seems to be a lot more engine vibration than before, especially on tickover, so my next job will be to find the pipes that link the mounts together and check their condition. They all run through the subframe next to the steering-rack. M57N is a complicated vacuum arrangement.

E46: New secondary air-pump - one last bash...

Thought I would have one ultimate stab at the E46 as it is such a nice car to drive and only let down by shabby bodywork, which I can do something about, and the super low idling problem, which apparently I can't.

I refitted the Vanos-actuator and checked for anything I'd disturbed under the inlet manifold, finding a loose wire connector which I clicked back in, though the CCV was all plumbed up fine. A replacement secondary air-pump and its hose / filter was £30 and the only thing now missing from the inlet arrangement. It took no time to fit, just two 13mm bolts holding it on and swapping the hoses over, but has still, alas, made no difference.

I've spent nearly £300 on parts to cure this engine of its fault, but nothing has done the trick so I guess I will have to call it a day and scrap her after all. Again a shame, as it has 9 months MOT and 4 months tax left on it. The running gear is sound, I sorted the brakes and the engine runs fine when underway, pulling well in all gears over 1500rpm. Handling is as sweet as any E46. The interior and exterior are in terrible nick, but thats nothing that couldn't be sorted with a day or two spent on it. That's only worth doing if the car is useable however, and it sadly isn't.

On top of the impossible low-idling, the handbrake-shoes have collapsed in some way and stick on completely in reverse with the handbrake off. This is probably from being used so much to stop the car while my right foot was still keeping the revs up, but is extra work regardless. A large M12 bolt holding one of the front shock-absorber struts broke while I was attempting to fit the coilovers months ago. I've been driving on it and the strut hasn't moved at all, but it too will need replacing at some point and removing the stud will be interesting. Inside the car, the fan for the heater/blower doesn't work and the driver's door card is missing, meaning no speaker or door handle. Exiting the car with dignity can only be done by lowering the window and reaching out for the other handle, but all these foibles I rather liked. Using it every day was a nightmare though and, with the 5-Series engine swap underway I just won't have the time and money to restore it, so I'm hoping I can get the £200 I paid for it back from a breaker. That means I'm down about £300 on the whole deal. I could make the £500 back and probably more by breaking the car, but I could really do with it out of the way quickly now so a loss it may have to be.

E46: Brakes + oil leak sorted - still running rough!

Wednesday 16/7/14:

Replaced vacuum-pump.

Replaced both camshaft-sensors.

Replaced MAF sensor.

Well, I'm certainly glad to report that the oil gushing onto the exhaust / cat has stopped with the replacement of the blown up vac-pump and I now have good pedal feel and stoppage. Sadly, even the return of some vacuum isn't enough to cure the low-idle and rough running. I replaced the obvious things, both cam sensors and the mass-airflow meter, but this hasn't sorted it either. I'm guessing there is either a severe vacuum / vent problem, or it's going to be to g related... Oh joy!

The diagnosis will go as follows:

Remove and fully check out inlet manifold.
Thoroughly check all CCV lines and the valve.
Clean and check all electrical connections.
Test for compression.
Move on to timing.

Other jobs:

Adjust handbrake and refit discs.

Fibreglass fill n/s/r wheel arch.

Check squeaky ABS sensor.

E46: Vacuum-pump severe failure...

With a new servo and master-cylinder, but still no brake assistance, I decided the vacuum-pump must be leaking air. I whipped it off, only 3 bolts and no need to remove rocker-cover etc., and opened it up. This is what I found...

This chamber should be full of air, not oil. The pump bolts on to the back end of one camshaft, which turns a spinning-boss. A plastic-bar slides up and down in the spinning-boss and creates a constant vacuum into the servo to help 'suck' the brake-pedal down when you brake. My plastic bar is missing. Where is it? Well, it's smashed into pieces lying in the oil.

After a clean up it was a decent pump-body and would work fine with a new O-ring and plastic-bar. They sell O-ring kits for the N42 vac-pump separately, but plastic-bars they do not, so I bought the pump from the same donor car as the servo + M/C. All pieces seem to have sheared off with a clean break, the bar was literally blown apart, except for one of the round end-caps (the tiny piece in the middle of the pile in the photo). That had been spread into thin strips as it broke off, so it looks like that end contacted the side of the case, spread into fronds and jammed the plastic-bar, which promptly blew up. How though? Did the timing slip unbalance the camshaft enough to wreck the pump? Or did the plastic-bar break apart and jam the pump, causing the camshaft to stop briefly and the timing to slip in the first place? Hmm...

Another side effect of the vac-pump failing was a terrific oil leak. The O-ring seal had gone completely and the spinning-boss was acting like a mini oil-pump, sending a constant stream down the back of the head onto the hot exhaust [bottom of the pic]. The pressure also made the vacuum-hose connector, normally only filled with air, to leak at the jubilee clip and pour oil onto the gearbox-housing [middle of pic]. After removing the pump a huge third pool of oil arrived. This was what had run out of the vacuum-hose to the brake-servo after disconnecting.