kiwipetrolhead

I have never had a compression test done on my '94 540i and I don't have any urge to do so - the spark plugs tell me enough about the engine's condition. It's done about 240,000K and it doesn't use any oil and it runs sweet. But it's very common to have some variation in any car without there being any fault. With more cylinders, of course the odds are greater for variation too. If you want to test things further though, squirt some engine oil down the spark plug holes (not too much, about 3 or 4 squirts from an oil can is about right), spin engine over for a few seconds then do another compression test. If the compressions move up, then it's a sign of leakage past the rings. If the compression remains the same, burnt out (or burning out - leaking) valves are the issue. Another trick is to put new plugs in and some good upper cylinder lube in the tank and take the car for a good hot thrash (yip, somewhere where you won't get caught, and being a 540, you have to go pretty damned fast to thrash it enough) then do another test. (Holding it in third gear at 5,000revs to the redline for a few seconds each time is good.) If everything is OK then you'll find the compressions are a lot more equalised after that. The alternative to a good thrash is a nice long hot trip, but even then it might require raising the revs up to around 6,000 in third gear a few times to clean out any determined carbon deposits and/or loosen the sticky rings properly. Well, that's what I used to do to cars in my mechanic days. This method worked really well on cars owned by little old Nanas (not always a female :-) that puttered around town all the time. Sometimes I'd get massive amounts of smoke out the rear end as I got the revs up, but after a few high-rev blasts in third gear, the car went well again. So it often really didn't need the 'traditional' tune up that it was booked in for - what had the most impact on the 'tune' of these cars was the good thrashing I gave them. Sometimes I also gave the engine a good treatment of Redex (upper cylinder lube) as well (a bit in the tank, but also some down the intake while the engine was running off the idle, and was hot - lots of sweet-smelling smoke everywhere... fun!)...and that often performed miracles. My boss often used to try the car out after I completed the tune up and more than just once or twice he said to me, "That's the best that car has ever gone!" Of course, with modern engines warming up lots quicker and with better petrol (cleaner burning) and leaner running engines, bad carbon deposits and sticky rings are pretty much a thing of the past nowadays. But there can still be some issues, especially with big engines doing slow round-town running all the time. P

That is quite true, but would anyone really want a racing M3 to use on the road? I guess a handful might, but they won't get to drive it very far if they did - it'd spend most of its life sitting idol in the stable having big dosh spent on it. Real racing cars tend to be like that and that's what the true M3 is. Still, a road M3 would be lots of fun all the same. P

Agreed. Lots of people buy an M badge to put on their 'plain' car and some put on the after market body kit (and more) as well. Personally I'd only ever buy a real M or a car with no M badge if it is not an M. In other words, it's not a genuine factory M and it has a M badge, don't expect me to buy it 'cause I won't. BTW, an M635 has a different engine to a plain 635CSi. It's twin cam and all. The csi is just a single cam (and just 2-valve too I think). Well, if everything I have ever seen in real life, and everything I have ever read about 635 is accurate. The bottom end is probably very similar in both, if not identical (altho the M might be beefed up a bit perhaps), but you can't miss spotting the obvious difference in the top end when you see them. P

Yes, you're quite right Will - I was about to same the same thing (but then I saw your post first). If anyone disagrees, they are wrong and obviously don't understand exactly how diffs work. Cheers Paul

Swapping from side to side might help. If they're directional though, that means taking off the rims. P

The Toyo 235/35 17 directionals on my '94 540 are just over a year old now (bought Nov 2005) and they still look like brand new. Done about 15,000K I think. I drive the car fairly hard most of the time, but not a real thrashing. I haven't turned the traction control off and spun the wheels up or anything like that (that sure does eat rubber quick as), but I am pretty impressed with the wear rate so far. Had no alignment done either. Mind you, I have had them rotated once so far and I drive very tidily through the bends and I use the brake pedal way less than the average driver - I don't tend to brake into tight corners like most people do, instead I stay at a higher (and steady) speeds but keep it tidy too... better tyre wear, better fuel consumption and minimal brake usage means things on my car last - yet I drive faster than your average Joe - and even faster when the missus is not there telling me to slow down all the time. I'd look at your driving style, and that spinning up will sure cost you. Paul

Correct - Mike Walker. Do you know him well? Nice 5. An ee? My wife's parents have a 525ee. P

Hey, if I recall correctly, the fan put a cut on the top radiator hose on this car when they did the Targa stint around Manfeild. Afterwards, the guy came into my mate's muffler shop in Feilding to get a bit of pipe to join the two halves back together again. I was there helping out, since it was me who advertised my mate's muffler shop to the Targa lot - free use of hoists, etc..., and I helped this guy out finding a suitable piece of pipe and things. I was at Manfeild watching the cars too, and saw the steam coming out as he drove back into pit lane. Quite a few other drivers took advantage of the offer to use the shop too! P

Nice wheels. I almost bought a set like that for my 540, but then I bought a different style in the end. P

P.S. In that photo I just posted where the rubber intake thing is on the throttle assembly, you can just make out a couple of ss dome nuts - one of the throttle assembly and one on the injection lines mounting bracket. P

Thanks for the compliments guys. I'm pretty pleased with how it's turned out. In the three pics posted at the beginning, note that there's no master cylinder or brake booster. I had them reconditioned and only put them back in after taking these photos. Note one other new pic in this post below - look over the top of the engine and you can just make out that the brake booster and master cylinder reservoir is back in - and I used that 'racing' elf brake fluid, $40 for a 500ml bottle. I'll take some more pics of the completed project ASAP and post here. blackbma, I had the rocker cover polished professionally by a local metal polishing outfit. It cost $50 cash. Gus, Yes, that's the head I bought from you. It turned out the 6mm thread was stuffed where the small long bolt that holds the cam belt cover on. I have a heli-coli being put in today to solve that. No big drama really, easy enough to get at. I got the stainless cap screws and things (washers and dome nuts too) from a local place (in P.Nth) called "EDL Fastening Ltd". I don't know if the same exists in Auckland, but there's bound to be a supplier of ss stuff somewhere up there - look under "Bolts & Nuts" in the Yellow pages and then ring around. I went back twice to get more - I think I spent around about $10-$15 in total - a pretty cheap way to make things look a bit tidier. I also bought some 6mm ss dome nuts (them sort with the round ends that hide the stud) to bolt the rocker cover down and so on - they're not yet fitted in the pics here though - so all you can see is the rocker cover studs. One of the pics in this post shows the throttle assembly with plain nuts, but I changed them to ss dome nuts later on. Also, a few close ups of the cap screws for you Gus. These photos don't do them justice though. Cheers Paul     Stainless Steel cap screws...    Â

At least he's in the shadows!

One of many pics I took during the 2006 NZ Dunlop Targa Rally. Nice eh! [if this upload worked]

Here's three pics on my e21 with the engine not far away from starting up after a rebuild. Note the polished rocker cover and stainless steel cap screws used to spruce it up a bit. Looks pretty good for a standard 23-year old car don't you think? The car is going now, so I'll take a few more pics when I get a chance. We're taking it to Art Deco weekend in Napier (from Palmerston North) to run in this weekend [topic="http://www.artdeconapier.com"]http://www.artdeconapier.com[/topic]. Paul

OK. Sounds to me like it might just be the seal. That's easy and cheap to fix - they take the tank off, put a new seal in and then put the tank back on, pressure test and then you're back in business. It'd make sense to have the whole thing cleaned out while they're at it too - remove both tanks and physically clean any crap out and put new seals in at both ends). No big drama. Paul

A round moulded bit near the top of the left-side tank (it's plastic too) is leaking on my 540. A very slow and intermittent leak though. I first noticed it while on holiday in Christchurch about 4 weeks ago and made it back to Palmerston North no problem, and I drove it up to Taupo and back for A1GP after that as well. Been ok, just kept an eye on it and topped it up when required - it even made it over the Arthur's Pass no problem without having to stop to top up on the way. I keep some water in the boot just in case, until I get time to have it fixed. Anyway, I'm not sure what the fix is, but DON'T use Stop Leak stuff! Get it fixed properly. Stop Leak is for emergencies only. In fact, I'm not sure if it actually works on plastic, but it might. I'm going to take mine into a radiator shop when I get time to show them and see what they say, then I'll take it out myself and have them repair it (or replace the tank if that is the only satisfactory solution). These sorts of repairs don't tend to cost very much. Paul

Going on what your saying (asking) here, sounds to me like you should leave your servicing to the experts! Seriously. But to answer some of your questions... If only one wheel bearing is worn out, just do that one. That's what I'd do. Some people might do both though, or clean and repack the other side with new grease. To clean, thoroughly wash in petrol or white spirits, then rinse in fresh cleaning of the same type then thoroughly dry. Best to dry with compressed air. Then thoroughly repack the bearings with grease and reassemble, ideally with a new seal. Tighten nut correctly - do NOT OVER TIGHTEN or you'll have your new (and/or cleaned) bearing wear out in no time. Buy new bearing kits from any bearing suppliers - SKF, etc (check your Yellow Pages). Once I bought one from SKF and the cost was about a 5th of the price for the same SKF brand bearing from the dealership. That was for a Citroen though - I did a stint working on them in my motor trade days. The thing in the middle, yes you could call it a "dust shield" or "dust cap" or "bearing cap", or whatever. And yes, you pry it off, or use a coal chisel and hammer. But since you ask "blonde questions" and you are "a magnet for destroying things", leave this sort of work to work to the experts. It's too dangerous for you to tamper with things like this. P

Very interesting, thanks for that. An extra 9kW, quite a difference really. If you run on 98 all the time then a bit more spark advance should be the thing to do for a bit more power as well. P

Yip, I hadn't stopped to think how much it actually was in real terms. My tank it about 70 litres too, so like you say, that equates to just the cost of a latte. But still, I just go to whichever petrol station is convenient at the time. P

In Palmerston North? Must be, "Challenge on College St"! Paul

You can get your discs machined on the car, or take them off to have machined. If you're removing them to machine, or to replace, all you do to remove them is undo the two brake calliper bolts and slide the calliper out of the way, then remove one small disc-to-hub locating screw. Then the discs will slide straight off the hub. Easy as! Same procedure front and rear. When you put the discs back on, make sure the mating surfaces are nice and clean to prevent any risk of misalignment. Front discs for my e21 are about $70 each, and a new rear discs for my e34 540 are $98 each (that's trade price I think - even though I'm not in the motor trade... anymore - so always ask for trade price and you might just get it) - that's a current price, I'm buying ONE new rear disc for my 540 this week because the left-hand handbrake drum is warped. Normally I'd buy a pair of discs, but the other disc is in perfect condition and being the back ones, I'll get away with just one disc. The drum is warped due to the previous owner leaving the handbrake on I suspect. I've had the car 2 years and known about it since the beginning, but now the shoes are being destroyed so I thought I better do something about it! Whether to machine or replace is a matter of how much thickness there is on your existing discs, there is a specified minimum thickness. Some discs have it written on the edge, but otherwise and brake shop should be able to advise. If in doubt, take one off and get the brake shop to measure it for you. Of course, it needs to have enough thickness left to allow for the machining and then still be within the minimum thickens afterwards. And something to realise is that the thinner your discs are, the more prone they are to warping, so new are the best option (especially if you brake a lot or drive fast and brake hard) and they're not that expensive to replace anyway. But DO put new pads in too, regardless of whether it's a machine job or new discs - that's a MUST! As for your other questions about bearings and seals, that's a separate issue unrelated to the discs themselves. If everything else looks okay (no sign of grease leaking out, etc) then forget the rest. Paul

A bit more on this topic, more sutff I just received from Race Brakes (they are very helpful guys)... "If you care, I’ll give you the long answer. All the serious race rotor manufacturers (Brembo, Alcon, AP Racing) go “B†for increased bite. Although most have gone away from straight slots and now use a variety of patterns that can look like fish hooks or spaghetti. If you are using curved vane rotors, you are obliged to fit them one way only and the slot pattern ends up where it will (always B that I have seen). DBA in Australia are the only company that recommends A. When I questioned them as to why they thought they knew better than F1 manufacturers, their (feasible) reply was that since most of their rotors go onto road cars, having the slots the “wrong way around†helped to decrease noise and didn’t throw brake dust onto the wheels as badly. I do notice however that any curved vane rotors that they make, such as the 355mm FPV GTP fronts, have the slots going the normal motorsport "B" way when fitted with the curved vanes going in the right direction i.e. discharging the hot air like a water pump impellor, not scooping it in as a lot of people (race car owners) seem to think. Cheers, Steve Race Brakes 0800 Brakes 351 New North Road Eden Terrace Auckland New Zealand Ph: ++64 9 377 2000 or 0800 Brakes (272537) Fax: ++64 9 377 2100 Web: www.racebrakes.co.nz E-mail: info@racebrakes.co.nz"

Price might be the same in Auckland, but in Palmerston North (and a few other areas too I think) I have paid up to 5 cents per litre more for 98 then 95/96. So it pays to take note of the prices. If they were both the same price though, I'd put in BP 98 all the time. Paul

BP have 98 octane and you pay more for it. All other companies higher octane is 95 octane (cheaper than 98). In fact, I have paid 10 cents more for 98 than what 91 costs, whereas 95 is usually 5 cents more then 91 (in Manawatu at least). I haven't really noticed any obvious difference in performance (or economy) between 95 and 98, but I haven't really tried to 'feel' a difference (performance-wise). A bloke I know likes using BP 98 in his WRX - he claims his car runs better on 98 and because it produces more power (supposedly), it is actually more economical too, so it costs less to use 98 despite the higher price. I must say that I am not totally convinced about that though, but I'm not disputing such claims either - I just haven't 'tested' them all to see for myself. Aside from all that, my old e21 ('83 323i) as well as my '94 540 are both run on the higher octane as recommenced. Although I do admit to having put 91 in my 540 on two occasions in the last 2 years with no obvious difference in power. I can't see that it'd do any real damage running on 91 in the long term though, but I'd recommend you use 95 or 98. If you are really into this sort of thing though, run a series of tests with each of the three fuels. I'd be interested to hear the results if you can be bothered (given that I am too lazy to do it myself! Paul

Excellent, thanks Yuen, I have checked and the vanes in my discs are straight, so the correct answer to my question, based on what you said already as well as this new info is indeed "B" (although there is some debate in the industry...). I put them on over the weekend, but as per "A". Still, according to Race Brakes (Auckland) who I emailed late on Friday, it does not matter too much which way slotted discs rotate (so long as the internal vanes are straight). So while it does not really matter, I will switch them over as per "B" sometime soon anyway. FYI, here's a 'Copy And Paste' from Race Brakes' reply... Steve Currie of Race Brakes 0800 Brakes said... "Assuming they are not curved vane rotors, and I don’t see why they would be, I would normally advise that B is forward i.e. right hand rotor in photo. This is the short answer. DBA’s website will contradict this, but that now becomes the long answer. Truth is, it doesn’t really matter unless you are an F1 team looking for 100ths of a second. Then you wouldn’t be using cast iron rotors anyway." (I don't know who DBA are exactly, but I assume they are some other brake manufacturer.) So, "B" it is, but really it does not matter too much. Thanks for everyone's comments, much appreciated and I think we all learned something new out of this thread. Paul