New buyer of 1995 840Ci

[d205497]

I’m thinking about buying a 1995 840Ci but after test driving it I was disappointed in the power. Could cleaning the MAF sensor and throttle body make a significant difference? What are some other options for improving performance?

[olinjohnston]

Sorry, but these are slow cars nowadays.

I swapped mine to a 6-speed, changed the differential to 3.15 limited-slip, and chipped the motor to make more power, but a current 3-Series would still destroy it (and probably an 850CSi) 0 to 60...

[d205497]

Thanks for the info. What’s the cost for a 6 speed swap and a chip? I don’t expect modern day performance from a less than 300hp motor but I think with this investment any improvements are worth exploring.

[olinjohnston]

What’s the cost for a 6 speed swap and a chip?

If you can find all the parts and a shop willing to do the labor, it's about the cost of a second 95 840Ci.

I did it 7+ years ago myself with the help of a friend and I was working at a BMW dealer at the time, so I was able to get most things rather cheap. The transmission was only $500 out of a junked 540i, the driveshaft is now NLA, but you can have yours custom-lengthened for 500 bucks or so. The hardest part is the pedals/clutch hydraulics. The electronic hurdles of getting the car to start without being in "Park," wiring of the reverse lights, and elimination of the "Trans Failsafe" warning are not too hard, and the earlier (pre-1/1995 production) cars are a bit easier to work with. The shifter support arm and linkage is 840-specific and no longer sold by BMW, so that will have to be fabricated now too.

More here:
https://www.bimmerforums.com/forum/showthread.php?2089505-So-it-begins-US-840Ci-6-speed-swap



I will say that all the engines in the E31 with the factory rear-end ratios feel "lazy" as they are geared more for top-speed cruising than acceleration. Also these are HEAVY cars that no amount of "mods" will overcome.

[Original 8]

I’m thinking about buying a 1995 840Ci but after test driving it I was disappointed in the power. Could cleaning the MAF sensor and throttle body make a significant difference? What are some other options for improving performance?

E31 is far from being a sporty car. Its a slow, heavy, and old now. Its proper GT from 30 years ago, and its anything but quick.

[R Shaffner]

Visit Timm Meek's website at https://www.meeknet.co.uk/e31/Index.htm

He says the #1 thing to boost acceleration is a shorter (higher number) differential.

[Hyper]

... What are some other options for improving performance?

You can find a rare 4.6L vanos engine swap teaser at Up Before Six.
The fantastic fantasy is to try out a common 4.4L vanos, especially into an early 840.
Maybe next year. (Yeh. Right. Sure.)

[d205497]

[chicosito]

Some dealers did add the optional e31 spoiler. Looks similar to an e36 m3 spoiler, but they are different if I remember correctly. If this is your first time buying an e31, I'd drive them all before making your purchase (depending where you live). I know some areas across the USA might not have many available for sale, and might make it difficult for you to experience the driving experience each model has to offer.

I've driven them all, except the Alpina versions, and they all have their pros and cons. Each variant drives & feels different, but they all look great. My best advice is to purchase the most well maintained and complete car. The reason I say this is because parts are now scarce and you will not have to worry about replacing missing pieces or fixing things that cost a lot of $$$$. There are some people in this group that have bought an e31 for little $$$$, but turns out they have spent the same or more for a well maintained example at market value.

Also scroll through Bring a Trailer at past sold examples to see photos and videos of how things should look. There are some great examples and some that need attention.

Good Luck & hope this helps!

[m6bigdog]

E31 is far from being a sporty car. Its a slow, heavy, and old now. Its proper GT from 30 years ago, and its anything but quick.

Humm,
Yep,
A Tesla Model S Plaid and most EV's are faster.
New BMW ICE cars are mostly smaller boosted engines.
The E31 was BMW's best effort at a Luxury Performance GT with the best engineering technology of the day and it still is not an obsolete car, aging but not obsolete..
30 years of neglect can certainly take a lot of the performance out of a $100k MSRP car, I know 30 years has taken a lot of performance out of me.
AND, Not all E31's were created equal!!
However, a chassis is just the part that holds the engine, wheels and seats!!

The modern BMW is better tuned and often times lighter than the E31 but in 30 years the story will be different; as age takes its toll on the cheaper car.
There is a lot that can be done to remedy and update the E31's suspension and drivetrain tune to make it much better than it was when it was new!!

In my 850-M73, I've been on long drives with many M3's, including the E90-M3-V8 and I don't see that they have much if any real performance advantage.
However, my 850-M73 has the suspension tuned so it is on rails, upgraded Euro ///M brakes, the 3.23:1 LSD and upgraded Sport Drive transmission control module certainly puts the V12 torque to the Max Performance summer rear tires.

If you going to buy an E31, V8 or V12, make it a Garage Queen..
I say, don't skimp on the initial purchase price, don't be in a hurry, get the best one you've seen, well cared for inside/out with the lowest mileage; then carefully refurbish and upgrade it to improve and renew what 30 years has done to it.
It will not be cheap or easy, but you should end up with more car and with less expensive than a current model BMW...

If that doesn't make sense, then pass on the E31; as it is not the car for everyone

[Timm]

The M60 840ci needs to be wound up to 4000 RPM before you get much power out of it, at least it has a 2.93 diff

[m6bigdog]

Thanks for the info. What’s the cost for a 6 speed swap and a chip? I don’t expect modern day performance from a less than 300hp motor but I think with this investment any improvements are worth exploring.

Here is the skinny.
HP is a calculated value for an engine, HP = (torque X RPM)/5252.
There are plenty of modern smaller displacement higher than 300 HP engines with either a higher RPM Limit or boosted or both that don't have the torque to even get the E31's +2 tons to move, let alone be faster than the current drivetrain offerings in the 840.

To have a lot of torque the engine must have a lot of displacement!! Boosting helps, but boosting doesn't happen at the lower RPM's.
It is the 295-310 lb-ft of torque from the 4.0 & 4.4L V8 that is important with naturally asperated lower RPM limit engines.
The M70@5.0L with 332 lb-ft and the M73@5.4L with 361 lb-ft of torque is better, however the 850 is more rare and comes at a premium.

The big issue is, the E31 is geared to cruise at +100 MPH so if you don't need that, then I suggest a lower final-drive ratio to quicken up the usable speed acceleration.

[Hyper]

... to quicken up the usable speed acceleration.

You left out my favorite word: fastly.
As in...to fastly quicken up the usable speed acceleration.

[m6bigdog]

You left out my favorite word: fastly.
As in...to fastly quicken up the usable speed acceleration.

Now, Now, quicken is good...
Is fastly a word? I like fastly...
Any E31 owner can discover "quicken".
As in.. to tabulate your upgrade costs with quicken.
Now, will the tabulated upgrades in quicken, quicken up the E31 may be debated, but quicken fastly tabulates?
Yes,

[olinjohnston]

Any E31 owner can discover "quicken".
As in.. to tabulate your upgrade costs using quicken.

Did it once - do not recommend...

(especially in the presence of significant others)

[TedBobo]

Did it once - do not recommend...

(especially in the presence of significant others)

True that!

[LappingLuke]

But can quicken tabulate the smiles accumulated and compounded on gearshifts as you fastly quicken acceleration of speed past 150mph?

[d205497]

Thanks for the input, but my original question still goes unanswered. I’ve seen significant improvements from older engines by cleaning the MAF sensors and throttle bodies. I’m assuming we’d see similar improvements in the 4.4 V8. Has anyone confirmed this?

[d205497]

Thanks! I prefer the more traditional look so my next question is can I remove this spoiler without any body work?

[m6bigdog]

Thanks! I prefer the more traditional look so my next question is can I remove this spoiler without any body work?

No!

[m6bigdog]

Thanks for the input, but my original question still goes unanswered. I’ve seen significant improvements from older engines by cleaning the MAF sensors and throttle bodies. I’m assuming we’d see similar improvements in the 4.4 V8. Has anyone confirmed this?

No, cleaning the MAF and throttle bodies is not needed and will not significantly or otherwise increase engine performance.

As I indicated the lack of power is the way the transmission gear shift control works.
Comments like yours is typical of individuals that don't understand how to drive the BMW automatic transmission to get the best performance out.
If you want a sport shift program you select 4th and then the transmission will start off in 1st gear, shift at higher RPMs and not use OD to keep the power up.
Using D Position (D = Dog) is for economy minded performance and the transmission will start off in 2nd gear and shift at a much lower RPM all the way into OD in an effort to increases the MPG.

I had a 740 with a M62 engine for 17 years and 175k mi. I changed the final drive from 2.93:1 to a 3.38:1 and it performs very well.
I did loads of maintenance but I never cleaned the MAF or throttle body.
I replaced the MAF, intake manifold gaskets and CCV when they failed.
If the CEL is not lit, I doubt anything in the MAF, throttle body or intake needs maintenance.
Given there is nothing but air that goes through the MAF and throttle bodies they are typically very clean even after 100k miles and more.
One exception is, an owner that has installed a K&N oiled air cleaner and with that the MAF should be replace and a paper air filter installed.
Also, the DME uses long and short term fuel trims and monitors misfires at each cylinder.
So typically before the driver even notices a engine run/power problem the DME will display CEL to alert that maintenance in needed, set fault codes to direct the maintenance needs of the engine.

[Timm]

[olinjohnston]

Thanks for the input, but my original question still goes unanswered. I’ve seen significant improvements from older engines by cleaning the MAF sensors and throttle bodies. I’m assuming we’d see similar improvements in the 4.4 V8. Has anyone confirmed this?

Not really noticeable on these. I cleaned mine because it was fairly gummed up and did not really see a difference in power. I have done this "service" to my 840Ci, as well as my M60 740i and M62 740i. It seemed to help my E28 533i, but that has the M30 dinosaur 6-cylinder with the air meter.

[d205497]

Thank you all for the advice! I’m about 90% convinced to buy this ‘95 840ci in the next couple of weeks. I want some rational feedback with the following input: I was stationed in Germany from 1999 to 2003 and saw an e31 for sale and I’ve regretted not buying it ever since! It is my dream car, I can afford it and I enjoy working on cars. It won’t be my daily driver, I saw it and test drove it, it’s only 10 miles from where I live, so no travel across the country to look at a car I don’t want. It looks great with a couple of paint defects. I test drove it and it drove well, although as previously mentioned I was disappointed in the power. It has 113,000 miles on it. Thanks Tim for the videos and I’m willing to invest in another differential and I don’t need to cruise at 150mph. The only problem I’ve seen is the computer is flagging washer fluid as low when it’s not, and I think this is a relatively inexpensive fix. The seller is asking “mid $ 20k’s” and I haven’t made an offer yet. I’m thinking this is a little high but given the convenience it may not be a bad deal. Please fire your guns and tell me if this is worth investing in!

[Timm]