2003 BMW M5

[95naSTA]

Well, I've told multiple people throughout the years that I wasn't going to get one of these but I ended up getting one.

I've obviously always been into these (re: headlight conversions) and the recent bring-a-trailer ad with an M5 touring (wagon) swap rekindled that interest. Looking into what it would cost to do a bare bones version of that swap got me thinking.. I could actually build something that I like that would still actually be worth something for once..

First of all, I could never afford one of these but prices have dropped substantially. I've heard these have timing chain issues but the more I looked into it I found it's the the M62, not the S62 engine with the issues. Being a BMW, I would think the engine wouldn't last much over 100-125k without major overhauling, but there are plenty of examples with over 200k still kicking. That also tells me that the bearing issues some talk about aren't an absolute. And finally, I had the idea that working on one of these would be a nightmare.. But, my free E39 showed me that at least the body is very straightforward to work on. I've done complex DOHC V configuration stuff in the past too so the engine can't be that bad.

The other thing is, while the G35 is nice, low miles, reliable and isn't slow, I miss the feel of a 13.0ish stick car that doesn't feel like it's being nanny controlled.

My thought process was to find a semi-rough bodied salvage title car with around 130-140k on it and good mechanicals. That way I could drive/park it guilt free and I could get another 60-80k out of the drivetrain. I've been looking for about 4 months or so, all across the US. The other week I spotted a stupid clean, 2003 100k mile salvage title Cali car with a new clutch that was meticulously maintained for what I felt I could negotiate to a good deal. I did a carfax, asked the seller for pics of the accident and it was a joke. Only the corner of the bumper, passenger fender and steering wheel air bag were impacted. The car hasn't been modded or monkied with either. It's all stock with the exception of some OEM+ bits including an E60 short throw shifter. I'm also moving to San Diego for 1-3 years next year and I have a free place to store the car.. So, while I was out in San Diego on for work, I picked it up. CA also lets you register cars with an out of state license.. No issue there. So this is the 3rd state I have a vehicle registered in currently.

There's no way I'll do a wagon swap while I'm out in Cali and I'm not sure if I will now that I have this cherry of a car.. But, I am very happy with it. The pics show just how well the car was cared for. There are rock chips up front and some other small imperfections but other than that, looks like it maybe has half the mileage on it. Everything works, it's tight, quiet and most importantly.. it moves.

I would post sound clips but it's sooo quiet.

[Sirius]

Looks like a nice score! My GXP has a rebuilt title which resulted in me picking it up for a ridiculous low-ball price. It was rear-ended when it had about 7k on it. The owner somehow got it totaled. A shop replaced a quarter panel and some other rear body parts. The car has been flawless. I don't ever plan on selling it, so I'm not worried at all about the rebuilt title. The point is, you can get a pretty nice car for a sweet price with a rebuilt title as long as you check out the history. A flood car is probably not a good bet.

You going to drag your bikes to CA with you?

[95naSTA]

Yeah, I agree. As long as you check out the history and you don't plan on selling the car you can get a good deal.

I am definitely bringing out my Ducati. Not sure about the DRZ.. I don't think California police would be very happy with my 2 stroke bikes. So I am planning on leaving them in PA. The good thing is I'm keeping my house in PA. Anything I leave behind I will be able to keep there till I get back, like those bikes and the Bonneville.

[95naSTA]

Last month I went through the car including the suspension to see where it needed any attention. The suspension was all very tight and all the boots were in good shape. Hard to believe it's original.. Other than that there were a few bits that needed replacing. I ordered most of the parts to be ready for my current trip out to Cali and when I went to work on the car, everything took way less time than I expected.

Hit list this trip:
Spark plugs
MAFs
Cabin filters
Headlight level sensor and LCA linkage
Passenger rear license plate light
High concentration washer fluid pump
Regular washer fluid tank level sensor
Windshield trim
And I added some WeatherTech floor mats

The spark plugs took the longest out of everything but were very easy.. almost I6 or pushrod engine easy. The windshield trim was second longest only because it took a long time to clean the disintegrated original part and the channel.






Thanks 90s BMW engineer who made room in the ABS lines for an extension.












Next up are new fogs since the driver's side is cracked and the rubber trim on the top of the driver's door since it's started to separate.

[nos4blood70]

Amazing! I can't believe I missed you getting one of these. They are so amazing to drive.

[95naSTA]

Thanks. I definitely agree so far. It's a calm touring car or a very quick car for its age. It just depends on the pedal angle.

[crash93ssei]

Love it! I definitely have the E39 but after having the 03 540i. Would love to have a E39 M5 one day.

[96 SSEi]

wow, thats a whole lot of over - engineering.

a normal one will cost you at least 1000 bones a year as they age
I would hate to price parts for that one!! guess - 2000 year

[95naSTA]

Sounds like you've done more research and have more experience than me. Oh well, too late. I guess I'll just have to enjoy my loss.

[nos4blood70]

It's always a gamble posting anything non-GM on this forum. Haha

[95naSTA]

I've explained owning and modifying a naturally aspirated 1995 Pontiac Bonneville to 'car guys' for over 15 years. I didn't really care if people got that, so I definitely don't care if people get owning this car. Lol.

I took a road trip up to Palm Springs to stay there over Thanksgiving with the wife and some friends. We also got to check out Joshua Tree yesterday. It actually snowed a couple nights ago and many of the mountain peaks were snow capped.

[95naSTA]

Last month the car clipped 111,111 miles and to celebrate it got a check engine light. The code was for Bank 1's exhaust cam position. This could mean either it's the sensor, VANOS (variable cam timing) circuit boards/solenoids, VANOS grounds or seals in the VANOS unit it's self.



I opted to replace the cam sensor first and did all 4 because they're OE. I am and have been trying to stick with BMW parts just so long as it's not astronomical in price. So, BMW sensors went in. The problem cam was by far the easiest. The job would have be really rough if I didn't have a ratcheting 1/4" hex driver. Brackets block the intake cam sensors and the heater core lines make bank 2 a bit harder. Overall though, not terrible.

Old vs. revised exhaust and intake BMW cam sensors



Some blurry call pics of the sensors on bank 1. The first shows the exhaust and the second shows how the aforementioned bracket on the left that shrouds the intake sensor and allen bolt. You can see the round bolt to the right of the sensor plug.




Unfortunately, that didn't take care of the CEL.

Next up, I removed the VANOS solenoid boards and brought them home with me (carry on luggage) to test/clean/strengthen. Fortunately, these are right in the front of the engine and come out in about 15 mins.

I tested the solenoid boards as they came out of the car with a 2 amp 4.5v power supply. The solenoids are PWM like injectors and other VVT solenoids. I chose a low steady state voltage since the effective voltage they see is probably well below 12v. All solenoids worked testing at the solenoid, main board and the connector. I also checked the resistances at all the points. All were within spec, consistent and didn't change when the solenoids or wiring harness were moved around. The solenoids were all pretty dirty and none of the filters were intact. The filters were removed (permanently) with all the old o-rings. The solenoids were cleaned with multiple rounds of brake clean and compressed air all while activating them. After cleaning the boards up I bridged the solenoid mini-board connections for good measure. Everything was re-checked and all the solenoids sounded consistent at the end.







It took a little longer for the CEL to initially come on. Then, it was back to coming back on as it was before. So, I decided to swap boards to see if the problem followed. What's weird is, now there's no code at all. Before swapping the boards between banks, the CEL would come on after a short drive. I drove about 50 miles and keyed on-off multiple times but the code hasn't come back yet.

I was thinking that the VANOS units were a mirror image of each other where the inlet and outlet solenoids fulfill the same rolls top and bottom. That would mean the Old B2 intakes are now B1's exhaust solenoids. And I just figured the old problem B1 exhaust solenoids were living their best life now as intake solenoids.

Bank 1

Bank 2


But, the VANOS units are the same meaning inlet and exhaust solenoids are swapped top and bottom going from one bank to the other. Because of this, the old problem B1 exhaust cam outlet solenoid is now a B2 intake cam inlet and B1 exhaust inlet is now a B2 intake outlet. Basically the solenoids swap roles completely when the boards are swapped bank to bank.

The M5board brought up that last bit and the fact that it's better for the inlet solenoids to have a slight leak than the outlet which makes sense to me. So, I'm thinking that the original B1 exhaust cam outlet solenoid is leaking slightly and it doesn't matter as a B2 intake inlet solenoid.

It's been suggested that I re-clean the original inlet and outlet B1 exhaust solenoids but I don't think I'll be able to get them any cleaner. I may give it a shot anyway but have another solenoid ready to be soldered in if it doesn't work.

It's weird that there hasn't been a smoking gun when trying to diagnose this but at least it's more or less narrowed down to one solenoid. I’ll just enjoy the no CEL and normal performance for now.

Also, I have to say, there's a wealth of knowledge out there for these cars and I'm enjoying learning about it so far.

[Sirius]

Funny how something will work here, but won't work there. Occasionally we'll have some electronics drawers that don't seem to play well with each other. Maintenance teams will go out to a site and swap drawers around and in the process discover that, say, Logic Coupler #123 works fine unless Power Supply #xyz is in the rack. But #xyz works fine as long as something besides #123 is installed. Bench checks indicate both drawers are within spec, they just don't like each other for some reason. It's not worth the effort to determine why, so the team will just tag the components to not install them in the same rack. Sounds like you may have a clue why your VANOS units work when they're swapped, though.

[95naSTA]

And that is why I'm a mechanical engineer and not an EE. lol.

I tried hard to convince myself to just leave it alone but I ended up ordering another solenoid.. Looks like my soldering stuff and power supply are going in my suitcase next time I go to Cali.

[95naSTA]

This is due for a large update.

I decided to replace the suspect VANOS solenoid a few months back after all. They're not available separate from BMW. You have to buy the whole board, which is astronomically priced. There are folks who sell cleaned and tested solenoids and I picked one up from ebay for ~$180. A couple days too late I actually figured out a potentially much cheaper solution. I saw mention on M5 board of possibly being able to use ABS solenoids but could not find one post confirming that they will work. This rabbit hole eventually lead me to find out S50B30/32 M3 guys have the same solenoids as my S62 and they have successfully swapped in these ABS solenoids into their VANOS units. A few people had issues but it seemed to come from not cleaning and testing the noids prior to installation. No part numbers were listed but I was able to narrow it down. A used ABS unit with 3 usable solenoids cost ~$60 on ebay. So theoretically I ended up with 4 usable noids for $250ish. Not bad considering some vendors sell a single solenoid for $300. The funny thing is.. I actually figured out by comparison is that ebay vendor mentioned above is actually selling ABS solenoids. But, if you read the item description carefully, they aren't false advertising. Good hustle on their part.





The only noticeable difference was the additional filter screen and indents for it at the top. Everything else dimensionally and resistance wise measured out the same.

Overall height: S62 ~ 36.53, ABS ~ 36.55mm
Large side to small end base: S62 ~ 28.7, ABS ~ 28.75mm (from grub screw to bottoming out)
Board o-ring ID: S62 ~ 23.94, ABS ~ 24mm
Large o-ring ID: S62 ~ 24.74, ABS ~ 24.74mm
Small o-ring ID: S62 ~ 14.51, ABS ~ 14.51mm
Resistance: S62 ~ 3.5, ABS ~ 3.5 Ohms

I cleaned my ABS solenoids and ended up trying one of those while putting the boards back to their original locations. (how it was originally throwing a code) After about 25 miles or so, there were no codes. So, a success.

All that was all about 4 months ago. I haven't put very many miles on the car since then since I haven't really had time when working in Cali.

Fast forward to now and I recently got factory/dealership BMW software DIS and INPA working. This gave me access to special tests, idle sync, and a bunch of other interesting features. I was able to test VANOS functionality and the good news is that my average B1 VANOS test results seem to be within an acceptable range. My understanding is that anything under 3* cr on the leak test is ok. I ran the test several times after driving the car for about a half hour to ensure everything was heat soaked and stabilized. The results varied a but were overall in a common ballpark.

Bank 1:





Bank 2 seems a bit tighter:




My fuel trims seem to be in good shape from what I can tell with INPA but it only displays data real-time. I'm planning on getting a reverse engineering version of this software that creates usable logs. What's cool is it can be integrated with an aftermarket WBO2.

About a month or 2 ago I saw a mention in a thread that the hydraulic tensioner should be replaced as a maintenance item so I got that checked off the list. I also replaced the FPR vac hose. The hose actually looked fine until I tried to manipulate it.






And finally, some upgrades. My plan was to pick up Evlove 'medusa' long tube headers first then eventually a 3.45 diff (3.15 stock) but a week or so after I ordered the headers, a good deal on a DINAN (3.45) diff came up.. It came off a 'S2' car with paperwork proving it was replaced about 30k miles ago and was going for what stock diffs are sold for in ebay. So, I now have header and a diff waiting to be installed. The diff will likely go in first until I have time to have the car apart to figure out a header to stock cat solution for the headers. Since there are less E39 M5 owners modding and will smaller bank accounts, Evolve doesn't have that as option anymore.





Eventually I would like to dabble with some tuning as I've done on most of my other platforms. That's part of the reason I'm looking to get the reverse engineered software mentioned above up and running with a wideband. I still have a long way, and many threads to go till I start messing with that though.

[Sirius]

Those headers look cool.

[95naSTA]

I definitely agree.

I got the pinion shaft seal replaced on the diff and it's all sealed up, ready to go for whenever I have time the next trip out there.

[Sirius]

It will be interesting to see how the new differential changes the performance according to the seat-of-the-pants dyno.

[95naSTA]

Yeah, I can't wait. On my i30, the gears were too short for the power and the DBW TB that was converted to cable had no resistance. That all combined made the car feel very raw. I loved it. I wouldn't want that level of twitchyness with this car but a 0.30 difference in ratio should make things a bit more fun.

I also got a few datalogging sessions in before I left to familiarize myself with the weirdo BMW fuel trims, cam timing vs. load and a few other things. I can't wait to get a wideband integrated to log that as well.

[nos4blood70]

Those headers look like art.