2003 BMW M5

[95naSTA]

Yep, generally it seems like they didn't skip thoughts about maintenance and accessibility. It wouldn't seem that way at first (especially with the badging) but there hasn't been anything really frustrating working on the car yet. Same was true on the free 528i.

Good news is I got my wideband hooked up with my logging software. Amazon sold a usb serial cable that said worked with my PLX. Technically it does, but only after you splice it and swap the wires for the tip and ring of the 3.5mm headphone jack. Receive and transmit were swapped.

I've been wanting to learn how to do properly cut/buff paint for a long time. I decided to pick up a Griot's Garage kit from Autogeek with a G9 polisher and everything needed to follow their 3 step polish/compound/wax process. Being a data junkie I also picked up a paint gauge so I have an idea of where I should go easy. On my wife's Jag the paint was on average 300um with the thickest paint being on the trunk lid. On my M5 it went from about 100um at the kidney grills to 175um on the trunk lid. I decided to test the kit out on the Jag's trunk first and even through it had visible scratches, I didn't even need to use compound. Next I tried the M5 trunk which needed quite a few passes with compound to work out the spider scratches. I measured the thickness during the process and was pleasantly surprised about how little I knocked down the clear. Eventually, I'll continue the process on the majority of the car. The trunk lid is on the left and quarter on the right in the gif below.

[Sirius]

Results with the buffer are amazing aren't they? I couldn't believe the difference in the black paint on the SSEi when I hit it with the compound. Since you're going to the trouble of paint correction, you might as well lay a ceramic coating on it. Correcting the paint is the hard part, most time consuming, of putting on a ceramic coating. You'll be practically there! Been happy with the coating I put on the SSEi and the Civic so far. Still beading water.

[95naSTA]

I can't argue with that at all. Looks Armor Shield is getting added to the list.

I actually smoked my cutting pad today polishing my headlights prior to ceramic coating them. I went to take the pad off the backing plate and it was more or less melted on there. Oh well. Learning experience. This was my second go at restoring these headlights. The hard coating areosol Meguiars sells ended up being hazy like some of the reviews mention.

[Sirius]

Whoa! The polished lens looks fantastic! I need to do that to my truck...

[95naSTA]

Thank you. That was my first time bringing lenses to a full polish then sealing. The other times required a haze for the coating to stick.

I actually got the bumper back from a respray last week. Here are some before/after.





I only snapped that one after shot. I've been focused on logging/tuning with this car and the Ducati in my spare time.

I'm primarily messing with WOT A/F on this one but I also re-wrote the hex to enable sport mode memory (to stay on with key off cycle) and to change the dash oil temp warm up lights on the tach to coincide with the oil temp in Celsius. 4k - 40* or less, 4.5k = 45*, etc. Originally it was 0 through 60*C. Now it's 45 through 60*C.

Here's the tach lights extinguished once fully up to temp.

[nos4blood70]

Are the tach lights a limiter as well or just a warning?

In the S2000, if you try to get into VTEC before you have 3 bars on the temp gauge (considered warm), you hit 6000 rpm like a brick wall lol

Repaint looks great! Between the bumper and headlights car looks like it lost a decade for sure.

[95naSTA]

Are the tach lights a limiter as well or just a warning?

In the S2000, if you try to get into VTEC before you have 3 bars on the temp gauge (considered warm), you hit 6000 rpm like a brick wall lol

Repaint looks great! Between the bumper and headlights car looks like it lost a decade for sure.

Thanks. I was impressed with the color depth on the bumper. I'm hoping to get a little of that back with the rest of the car.

The lights are just a warning. I like the idea since the engine was designed for and runs 10W-60. It'll take a little longer the get the oil up to it's operating viscosity.

[95naSTA]

I decided to start the header install Friday and wrapped it up this afternoon. The removal of the OE manifolds and install of just the primaries wasn't too bad. I did have to raise the engine up slightly to clear the steering box on the driver's side. I was only able to get to 3 of the rear nuts on the driver's side from underneath, the remaining 6 I got from above with the oil filter and p/s reservoir out of the way. All passenger side bolts I accessed from underneath. The slip fit connectors are a PITA to get seated, even with the primaries loose, a block of wood and a mini sledge. I marked them prior so I knew how far I need to go.

Now, I wanted to run stock cats back but Evolve doesn't make adapters anymore. Their current version isn't even close as it's way too long and the first bends don't even start to point at the stock cats. I've seen some solutions with the adapters that bring the 2.75" outlet of the collector down to less than 2.25" at the front of the stock cat. I opted to cut the stock cats farther back to use 2.5" flanges and adapters from the downpipes. It was a tight fit.. I cheated a little on the bends but that's about as good as I was going to get it.

I didn't take a pic of the before but here's another M5.


My collectors and install.






My MIGing could be better but it'll work. My 'work area' wasn't doing me any favors either.



The car definitely picked up some power and it's not very lean, watching the wideband. I only took it out for a quick cruise though. I've noticed half a point variance on the same tune when logging. So, I'll have to spend the time and get some good logs.

[Sirius]

Those headers just look cool. Too bad they're hidden under the car and passers-by can't enjoy the visual orgasm.

[95naSTA]

Lol. Very true.

I can't say the car is a sleeper since it's a bight red M5 but I think it's kind of cool you wouldn't know this thing has headers, gears and somewhat of a tune. It was actually breaking traction with summer 275s on the 2-3 before the header install.

[95naSTA]

On my last oil change I noticed the area around the oil level sensor was soaked. It was too late at that point to order a new seal or sensor so I came back around to it just now. I decided to go with a new sensor since the price with seal was reasonable. It turns out my front crank seal is also seeping a bit which may have contributed to the oil above/around the sensor but I guess I'll see just how much.




Since the weather has been cooler the last few months, my coolant temp takes a while to get up to 79*C (T-stat opening temp) as displayed on a hidden diagnostic dash menu and will even drop if I get on the highway before it hits 79*. That tells me it was definitely leaking. I had a member of M5board notice it a while back in one of my pics but it wouldn't fight to get up to temp until recently. I think the warmer temps masked the problem until now. This might not seem like a big deal but it can result in the DME going into an enrichment mode which will make the engine run rough. Getting up to temp is also critical for the race car oil to be in it's operating range.

In order to avoid any immediate or long term issues I replaced the thermostat along with the inner housing seal. The inner seal goes around the T-stat body once it's inside the housing and really needs some special tools to R&R. I was able to get it done without damaging anything using tools I had on-hand and some trickery. The nice part about the inner seal is there's just enough room to see past the rubber seal to make sure the metal OD is fully seated. It turns out the coolant o-rings on the assembly's 3 pipes were seeping as indicated by some crusty oxidized coolant under the connections. New o-rings fixed that in the process. The housing assembly went back in without issue. A fair amount of people pinch o-rings upon reassembly. I feel like as long as the o-rings are lubed and it's square (which is easy to see) you're good to go. The air pump shut off valve vacuum line was noticeably dried out, which I was able to replace with the same vacuum hose I had from the replacing the FPR hose. The overflow tank and fan clutch also got replaced while I was in there.


Old thermostat assembly with housing and coolant pipes


New inner seal installed


New thermostat installed


Old and new air pump valve vac line



Fan clutch swap



Thermostat housing out and back in



Power barn before/after with the new overflow tank

[Sirius]

I was really impressed with all the work you did, but after I saw the new surge tank I had to smoke a cigarette.

[95naSTA]

Haha. That thing was an eye sore. People try and clean them but they never turn out like new.

Some other things I found messing around after the fact was that a metal collar on the ID of the expansion tank had started to back out which would have been fur for the coolant system, fan clutch was original to the car according to the date code and the coolant from the thermostat that bathed my idler pulleys and belts reminded me that they should probably be replaced at some point. The intermittent pulley squeaks are less intermittent and I found a couple ribs MIA from one of the belts. The belts don't have any cracks or terrible wear patterns so they have a little life yet.

I also have an appointment next week to have my newly painted front bumper clear filmed. I haven't even touched it with a microfiber towel yet.

[95naSTA]

Not much of an update but I got the decaying plastic cowl swapped out. It required a gear puller for the wiper arms but other than that it's pretty straight forward.

[Sirius]

Nice you can still get parts for it. Is parts availability a problem at all for this car?

[95naSTA]

Surprisingly, most parts are still available. I think the 8 year production range of the chassis and volume of cars over the world helps. When supply gets low on a part, BMW shoots the price through the roof. I'm guessing it's to maintain stock of longer while profiting. Some wear items like underbody plastics and M5 specific mirrors fall into that category. I haven't had to buy anything like that yet thankfully.

[95naSTA]

Mini update.

I got the front bumper Xpel wrapped along with the headlights. I also replaced the fog light covers due to some discoloration and a couple broken tabs. There are pre-cut wrap kits for the bumper from the manufacturer but they don't completely cover the edges and there are a lot of seams. I told the installer I was after the least amount of seams as possible and I would disassemble the front end as much as he wanted. He was able to do almost the entire bumper in one piece, tucked everywhere, with only 2 seams inside the lower air dam on either side. The seams are really tough to see depending on the lighting. Light basically has to be at a 90* angle with the seam to see it, which will pretty much never happen. I'm definitely happy with the work. I'm also happy that my freshly painted bumper and refurb'd headlights will stay fresh for much longer.

[Sirius]

So you had them cover the headlights in Xpel too?

[95naSTA]

Yep. I ceramic coaded them but figured the wrap would keep them nice longer.

[Sirius]

Cool. sounds like a great idea!