1990 535i Time for a tune up, what should I consider?

[GRVT]

Alright so here we have it, My 1990 BMW 535i 5 speed that I purchased back in March with 113K miles on it is ready for a tune up as funds are now available. It now has roughly 117K and runs strong but there's always room for improvement. For now, I am just focusing on the engine although I know I could spend plenty of time with suspension parts and bushings. Luckily I don't have to touch the cooling system, everything there was replaced by the previous owner including the radiator. Here are the main points I'm trying to hit and the parts needed for each. If you have any suggestions for what I should add to this list I am all ears as well as any part substitutes or additions. Thank you.


New Air filter
-K&N 33-2573 Air Filter


Valve adjustment (Big one for the M30)
- New valve cover gasket P/N:
-Banjo bolts P/N: 11 42 1 738 621
-Banjo bolt seal washer P/N: 11 42 1 252 343
- 0.30mm (0.012") angled feeler gauge
-32mm open end wrench


Ignition
-Ignition wire set P/N: 12121722253
- New spark plugs


Performance
-Thinking about the Turner Conforti chip P/N: 179-500
But open to suggestions.

[ross1]

Scratch the oiled filter, they muck up the air meter.
When doing your valve adjustment check to see if the banjo bolts have been updated. There is a visual clue, I'll let someone who's had eyes on them more recently fill you in on the details of that. Always check them anyway and don't over tighten. If the rocker arm eccentrics are worn(not unlikely)make your measurements from the cam side, .8mm, .9mm if memory serves me.
A tool to insert into the hole of the eccentrics too. That or a third hand. I fabricated a tool from wire rod that has served well for a long time.
NO gimmick spark plugs!
Any quality wire set is fine, Bosch, Bremi... No need to buy from BMW, just be sure the set has the "cylinder identification" wire.
Chips for this engine will bump your ignition timing so be prepared to buy premium fuel as this engine does not have knock sensor to protect it from detonation. Also the RPM limit is raised to typically 7k. While it might be fun to rev it there it was done making power a while ago so no need to spin it so high.

What is the 32mm wrench for? Planning on changing the water pump? Not a bad idea, I've never seen an M30 pump go much more than 60k.
If for turning the engine be advised that M20 & M30 cars have a starter connection at the round diagnostic port, pin #11. Apply 12v+ there from pin #14 and the starter will turn the engine for you.
These are sensitive to valve adjustment. My experience is that they "like" to be run on the wide side and idle much better that way but are somewhat noisier. Make 'em quiet and they idle rough. At least that's my experience with high mileage examples.
One last bit of advise if I may. If bumping the engine over with the starter keep your fingers out of the way of that cam. I badly crushed one once doing this, feeling for the cam lobe to come to the bottom. There isn't enough room for a finger(mine anyway) between the raised lobe of the cam and the cylinder head. Hurt like bloody hell and put me out of commission for weeks.

[OGM3]

And if you haven't already done it a fuel filter is cheap and easy.

I would stick with a stock air filter as well.

[GregT53]

All good recommendations by Ross. It's nice to have some pro mechanics on board here. Good recommendation to change the fuel filter. That's always on my list for any used vehicle because it's usually never replaced by POs.

I, too, advise against the oil impregnated air filters. They sound good in theory, but studies have been done that indicate more particulate matter makes it through to the plenum. That, plus they require routine cleaning and re-oiling, things that are easy to forget about. Good quality paper filters are the way to go.

Passing along one bit of information on plugs and not for the purpose of challenging Ross. My friend, who has been an independent BMW mechanic for nearly 40 years, believes getting OE BMW plugs is worth the additional cost. For whatever reason BMW engineers had, OE Bosch plugs do not have a top with a removable cap. The difference in use as observed by my friend over the years is that aftermarket Bosch plugs can cause electrical arching resulting in poor performance and other unwanted problems. When I changed my M5 plugs last spring I forked over the additional bucks (about $5/plug) to get OE BMW.

Good time to refurbish your vacuum lines. At this age there is bound to be some deterioration and the cost is so low it's a no brainer. It's just a pain to get to some of them.

I know you are focusing on the engine for now, but since you are a relatively new owner, there are some other things to keep in mind for future maintenance.

A filter that is commonly overlooked is for cabin air. I'm willing to wager it is pretty clogged by now. This is another low cost but pain in the ass job, but well worth it to take the stress off your blower motor. While you're at it, do yourself a favor and change the blower motor fuse (#19) from 30A to 25A. I run a 20A fuse with no problem. This will prevent overheating of wires potentially causing a fire.

You should change brake and cooling fluids every two years. It wouldn't hurt to change transmission and differential fluids just to get a solid baseline from the beginning of your ownership.

[ross1]

To clarify my statement about "gimmick" spark plugs. Just standard electrode plugs, don't need four of them, not even two. No whiz bang 21st century miracle plugs.
M30 & M20 wire sets require the cap to be removed from the spark plugs to properly connect. Sometimes folks don't know this and install plugs with out a removable cap or forget to do so and arcing occurs in the wrong place as a result. Greg, I think you meant to say that OE plugs DO have the removable tip.

Cabin filter is a good idea but early cars didn't have one. Not sure the date for the change to them but suspect OPs '90 is without.

[GregT53]

Ross, well I bought a set of Bosch from Autohauz and they had the removable top. The ones from BMW did not. They installed just fine on the M5 and it's been running smooth.

[GRVT]

Thank you all for great suggestions, so oiled oil filter, stay clear. I will look for paper filter or I know aFe has a non-oiled filter. I have a slight feeling it never had a valve adjustment so I'm assuming banjo bolts are outdated because the P/O was an older gentleman who had the general maintenance done for it but not too in depth. And does anyone know why the Turner ignition wire set is almost $100 cheaper than the Bosch? If it is a lower quality I will stay away, just curious. Thanks for the insight Ross on chips, now is there an M30 community preference on chips other than the Conforti? And that starter trick is genius! and fuel filter and vacuum lines, good suggestion I'm on it. As for the blower motor and cabin air filter, My blower motor went out due to a rodent, so I ordered the blower motor and cabin air filter off pelican, come to find out my car doesn't have one! so anyone in need of a cabin air filter let me know. And it's probably due for some fluid changes you're right, any chance there's some stainless steel brake lines on the market? I haven't heard of any.

[ross1]

Ross, well I bought a set of Bosch from Autohauz and they had the removable top. The ones from BMW did not. They installed just fine on the M5 and it's been running smooth.

That's interesting. OE wires on pedestrian M20/30 attach to the threaded stud. You'd think the BMW counterman would know that, or perhaps not as the M30 is likely older.
Maybe newer replacements have gone to the traditional way of fitting. Does the ///M use different wires?

[GregT53]

That's interesting. OE wires on pedestrian M20/30 attach to the threaded stud. You'd think the BMW counterman would know that, or perhaps not as the M30 is likely older.
Maybe newer replacements have gone to the traditional way of fitting. Does the ///M use different wires?

The S38 may very well have a different setup. About two years ago I did a complete overhaul of the ignition system, all OE including a plug wire set. The plugs seat very snugly into the boots.

[E38740iMD]

New fuel injectors. New tps, cps, while your at it

[Neel]

+1 on injectors.. i just did them and WOW what a diff.. i went with the redesigned 19lb from bosch. I also recently did wires from kingsborne, they are definitely worth it in my opinion, 159 for 8mm wires, couldnt be happier.

I would suggest buying a spare water pump, and fuel pump to have around just in case they go to save you "down" time. My water pump just went so thats why im harping on that. Check your fuel lines at the rail, make sure they are pliable still. It also wouldnt hurt to check and adjust your valves.

- - - Updated - - -

My pump hasnt grenaded so to speak, its leaking from the weep hole so its time.

[E38740iMD]

^ah should have put two and two together. Your Neel from on stage we have been chatting a while about stuff.

[Neel]

^ah should have put two and two together. Your Neel from on stage we have been chatting a while about stuff.

Yessir... Threw injectors in and then saw the leaky pump, i was like GTFO..

[Tre0Tre34]

Probably a bit overwhelmed right now, but really all good suggestions from experienced owners/enthusiasts...

You know you have to toss on a new distributor cap and rotor while you are replacing all the other ignition related items (plugs, wires, n-such). Get the bosch or bremi as they both seem of high quality. Had an issue with a part store brand i needed in a pinch.

You'll have this m30 whipped into shape and feeling responsive in no time!!

[GregT53]

Thank you all for great suggestions, so oiled oil filter, stay clear. I will look for paper filter or I know aFe has a non-oiled filter. I have a slight feeling it never had a valve adjustment so I'm assuming banjo bolts are outdated because the P/O was an older gentleman who had the general maintenance done for it but not too in depth. And does anyone know why the Turner ignition wire set is almost $100 cheaper than the Bosch? If it is a lower quality I will stay away, just curious. Thanks for the insight Ross on chips, now is there an M30 community preference on chips other than the Conforti? And that starter trick is genius! and fuel filter and vacuum lines, good suggestion I'm on it. As for the blower motor and cabin air filter, My blower motor went out due to a rodent, so I ordered the blower motor and cabin air filter off pelican, come to find out my car doesn't have one! so anyone in need of a cabin air filter let me know. And it's probably due for some fluid changes you're right, any chance there's some stainless steel brake lines on the market? I haven't heard of any.

Definitely a good idea to replace 20+ year old brake hoses. Stainless steel brake lines are more eye candy than added functionality. They are rubber hoses with braided stainless sheaths. Some install them for better pedal feel, but I would say that it's not a significant difference. I think Turner Motorsport has some that are DOT approved. One downside of stainless covered hoses is that any deterioration of the rubber is hidden.

[johnnylud3]

I bought one 2 years ago with 210k and I can tell you what made the biggest difference for me.

-clean/replace fuel injectors - all gummed up and one was leaking

-clean icv- loads of carbon in there

-replace all coolant hoses and vacuum lines - many began leaking

-new cap/rotor and plug wires- tested with multimeter and all were garbage

-valve adjustment

-complete suspension overhaul- fluid was in the front strut housing and rears swere dry. Many bushings ball joints were shot.


I thought I would be satisfied just cruising in this car but I couldn't help myself and changed to single mass flywheel, M5 clutch and tossed a holset hx35 turbo on that bitty. She's a blast now!

[Smoky540i]

Nice thread PO, also I just sent you a PM concerning the spare cabin filter. Thanks for starting this discussion...I"m stealing some of this advice as I just picked up a sorely (very) neglected 1991 535i/5 that probably needs all this and more.

- - - Updated - - -

I bought one 2 years ago with 210k and I can tell you what made the biggest difference for me.

-clean/replace fuel injectors - all gummed up and one was leaking

-clean icv- loads of carbon in there

-replace all coolant hoses and vacuum lines - many began leaking

-new cap/rotor and plug wires- tested with multimeter and all were garbage

-valve adjustment

-complete suspension overhaul- fluid was in the front strut housing and rears swere dry. Many bushings ball joints were shot.


I thought I would be satisfied just cruising in this car but I couldn't help myself and changed to single mass flywheel, M5 clutch and tossed a holset hx35 turbo on that bitty. She's a blast now!

What LWFW did you go with? Any advice on where to source good quality clutch and FW stuff without breaking the wallet?

[Neel]

I just took my 5 out for a quick run/test. After the 8mm wires, plugs, bosch type 3 injectors, and electric fan this is what I ended up getting for mileage; Avg mph 54.6 Avg mpg 23.3. I reset both factors on the obd system and drove 75 miles. Speed varied from 35mph to 90mph - I hovered around 60 to 80mph most of the time. I also have a miller maf kit and im on 17's. Overall Im pretty happy with 23.3 considering I was going well above the speed limits of 55 and 65 most of the time with some slow driving.

[Tre0Tre34]

That mileage is in line with what i usually see cruising the highways through the mountains at about 80mph.

If i keep it between 70 and 75mph, i have calculated as high as 26mpg!!! Yes, i AM excited to see fuel economy like that with this M30. Dont even look at city economy (or lack there of)

[Neel]

I was getting close to 30's if I was a super miser in my e28, but similar mileage when i was ripping it. While I lived in Colorado.