Bought, Not Built: M70 E34 6-Speed

[TGreene]

I was looking at this car when Pat posted the craigslist ad for this car a long time ago. A few months later I saw it on the BringATrailer auction list, and decided to bid. I ended up winning and am very happy that I did. I flew out to Cincinnati on Tuesday night and got there at midnight. The seller picked me up, talked to me about the car for about 30 minutes and then I was on my way. I made a stop in Milwaukee to grab some leather M5 pieces, stopped in Illinois that night with a friend, stayed with our own Greg 93FIM5 the next night and then finished the drive back to Oxnard, CA.

I will edit this post a bit more when I have some time, but here are some pictures.

Right now it is running rich and needs some small things addressed. I'm excited to give it some attention, but first thing to do is obviously lose the Beyerns.

Picking it up:

Untitled by Trevor, on Flickr

Breakfast in Vail:

Untitled by Trevor, on Flickr

Utah:

Untitled by Trevor, on Flickr

At the shop today getting a look underneath:

Untitled by Trevor, on Flickr

Untitled by Trevor, on Flickr

[moroza]

Wow. How's it drive compared to your old 540?

What transmission is that? Any other upgrades worth mentioning?

[zubbie]

I'm guessing the trans is a getrag 560G. The only compatible 6 speed for the M70/73

[ShapeShifter]

Wow, well done!

[S61Dan]

Awesome, saw this car a while ago glad that someone here picked it up.

[Leonator134]

Dammit. You really do love buying scrap.

/imjealous

[Sam Son]

Wow I remember seeing this thing in performance BMW or something ages ago. Very cool that it's going to be well taken care of by an enthusiast

[zubbie]

Now to tune those twin ECU's and VAF's!

[Sir Montalbon]

I noticed that you had won the auction on BaT and was hoping you'd start a thread. Cool car!

[stilljester]

Glad to see the car went to a good home. Looking forward to seeing what happens next...Congrats!

[funfunfer]

Thanks for posting. It will be interesting to watch how this car changes as you make it truly "yours."

[BleedsBlue]

I am forever shamed for not making it down to Greggy Poo's to meet up. This looks cool!*

*needs new wheels stat

Hope you're planning on coming back out sometime soon, maybe for our un-planned meet.

[TGreene]

Wow. How's it drive compared to your old 540?

What transmission is that? Any other upgrades worth mentioning?

It reminds me a lot of the M60. It is very smooth, though after some attention it will be even smoother. It has kind of a turbine whine to it that I love. It has more torque, but also runs out of steam pretty quickly around 6K RPM if not sooner so I am getting used to shifter earlier rather than bouncing off of the limiter like I do with the M5.

Dinan springs and HR springs, Dinan adjustable sways, N-ring brake calipers and floating rotors, feels like there is a quality short shifter kit in there, Koni adjustables with Moosehead rear shock mounts. '95 Sport seats. It was well taken care of. Very clean chassis, no rust, clean rockers, good paint, interior is clean enough that you know it has always been garage kept.

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Wow I remember seeing this thing in performance BMW or something ages ago. Very cool that it's going to be well taken care of by an enthusiast

It came with the magazine, and the man I bought it from was a friend to the guy who bought it for the 6.0 Hartge engine. Lots of history with the car, so I am excited to find it all, and then put my own twist on what is already a very well done car.

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Now to tune those twin ECU's and VAF's!

Yeah, and replace some $600 intake gaskets.

- - - Updated - - -

I am forever shamed for not making it down to Greggy Poo's to meet up. This looks cool!*

*needs new wheels stat

Hope you're planning on coming back out sometime soon, maybe for our un-planned meet.

Would have been cool to have another E34 there. It was really cool to see Greg again and hang out with him for a bit. I did not have much time but we were able to have a few beers and bleed the clutch. He also showed me some of his plans for his car and it is very impressive what he has done and what he plans to do. I wonder what his car would look like if he were able to spend more than 1% of his time on it.

[BleedsBlue]

Would have been cool to have another E34 there. It was really cool to see Greg again and hang out with him for a bit. I did not have much time but we were able to have a few beers and bleed the clutch. He also showed me some of his plans for his car and it is very impressive what he has done and what he plans to do. I wonder what his car would look like if he were able to spend more than 1% of his time on it.

And man, did you leave right on time--I was clearing snow all Sunday at a family member's house along your route. A solid three feet up there. That powerband sounds just like the R129 V12 powerband. Epic for high-speed cruising.

[shogun]

Yeah, and replace some $600 intake gaskets.

No need, save the $600. We never use new intake gaskets, and I have done a lot of M70 intakes, liquid seal will solve the problem. See my website under fixes>>>engine-general>>>Top end overhaul

it is all in there for the M70 engine. Large file with many pics.

Or from Max Lumens US-made hi-temp 3-ply fiberglass re-inforced silicone rubber http://www.bimmerforums.com/forum/sh...lve-covers-off

[HE53]

Glad someone that will care for the car ended up with it. Also nice to see it on the forums.

[93FIM5]

After seeing and being in this car I have to say it has lots of potential and is very cool. Trevor put me at the top of the list if you ever want to part with it, good seeing you man!

-Greg

[Chivava]

God Im jealous.. That must be a beast to drive.

[TGreene]

The biggest problem the car has is that it runs very, very rich. It has been that way since I bought it, though no mention was made of it in the ad. It feels like it is running on 11 or even 10 cylinders until about 3k RPM.

The car really has not seen much love. I tried to figure it out when I first got the car and ran through the gamut of troubleshooting that I could find online. I ran the engine on each bank alone by disconnecting one of the EMLs at a time. Both banks were able to run independently of the other. I disconnected the injector harnesses one by one while the engine ran on one bank to see if I could find a dead cylinder and had no luck. I switched 02 sensors and it only got worse. I checked the MAFs and they don't seem to be the problem. The previous owner had replaced the spark plug wires and caps and rotors, but I replaced the coil packs. No change. With the help of a local friend, we replaced the spark plugs and that did make a big difference but the car was still far from happy.

Untitled by Trevor, on Flickr

Untitled by Trevor, on Flickr

Untitled by Trevor, on Flickr

Untitled by Trevor, on Flickr

After spark plugs, swapped in some M50 injectors that were tested and refurbished by a local injector nut.

Untitled by Trevor, on Flickr

Untitled by Trevor, on Flickr

Untitled by Trevor, on Flickr

Untitled by Trevor, on Flickr

A few weeks ago the car died on the way to work. My two mile commute started fine but without a few hundred yards of the parking lot the dash lit up and the car started to struggle. I replaced the battery with a good used one and the car worked for a few more miles before starting to die again.

With all of these problems adding up, it is finally time to get into the very neglected engine.

The plan:

- Intake Manifold Gaskets
- Valve Cover Gaskets
- Lead from Alternator to Terminal on Passenger's side firewall
- Research and determine if it makes sense to swap from the 530i's vacuum brake assist to the E32 hydro brake assist so I can run factory air boxes.
- Coolant Temp Sensors
- Check things out while I am in there

Relevant links I am using:

http://bmwe32.masscom.net/sean750/V1...eFix_part2.htm

[shogun]

For the M70: go to my website, there is a 60 page write up under fixes>>>engine>>>top end overhaul, all there what you need.
Alternator cable is on left side = driver side, not on passenger side. Also for that I have a write up with pics under fixes>>>electrical power>>>Replace charging cable between alternator and distribution post

If the car dies while driving that means the alternator could be bad, or the cable to the B+ post area.
Did you check both fusible links?
Did you check both fuel pumps?
Are the fuel pressure regulator vacuum hoses connected correct? Must be crosswise like this http://2.bp.blogspot.com/-swlVIV5RYo...0/P1160580.jpg

Is the EML light working when you switch ignition on and then it disappears? If not, M70 runs in limpmode.
Test the throttle valves, clean them inside http://www.mwrench.com/Whitepapers/DKMotorcleanup.pdf test data are on my website too

The M70 has 3 coolant temperature sensors http://www.realoem.com/bmw/enUS/show...diagId=11_0785

[Layne]

- Research and determine if it makes sense to swap from the 530i's vacuum brake assist to the E32 hydro brake assist so I can run factory air boxes.

It's a good system. RHD 540i's had it (see pic. It's still mounted on the left side, there's a linkage under the dash) which I would assume is identical to the E32 system, and pretty much functionally identical to an E28 system with slightly different parts. I assume if it fits with the V8 (90 degree vee) it'll fit with the V12 (60 degree vee). But space will be tight.

[AHenry014]

Did you check both fuel pumps?

Here to x2 this.

[TGreene]

For the M70: go to my website, there is a 60 page write up under fixes>>>engine>>>top end overhaul, all there what you need.
Alternator cable is on left side = driver side, not on passenger side. Also for that I have a write up with pics under fixes>>>electrical power>>>Replace charging cable between alternator and distribution post

If the car dies while driving that means the alternator could be bad, or the cable to the B+ post area.
Did you check both fusible links?
Did you check both fuel pumps?
Are the fuel pressure regulator vacuum hoses connected correct? Must be crosswise like this http://2.bp.blogspot.com/-swlVIV5RYo...0/P1160580.jpg

Is the EML light working when you switch ignition on and then it disappears? If not, M70 runs in limpmode.
Test the throttle valves, clean them inside http://www.mwrench.com/Whitepapers/DKMotorcleanup.pdf test data are on my website too

The M70 has 3 coolant temperature sensors http://www.realoem.com/bmw/enUS/show...diagId=11_0785

Shogun,

I have been on your website a good bit. I found out about the charging cable being prone to failure that way. It was always on my to do list, but now with the alternator suspect I will also be changing the voltage regulator to see if that does the trick.

I will check the fusible link. The car only has one fuel pump so far as I know, but I have not replaced it or changed the fuel filter which is also on my list of things to do after this round.

The EML vacuum hoses were not installed as you say. They went straight to the nearest FPR, not the opposite one. I wonder how much of an effect that had.

I did make sure that the EML light is working when switching on the car. It comes on then goes away.

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It's a good system. RHD 540i's had it (see pic. It's still mounted on the left side, there's a linkage under the dash) which I would assume is identical to the E32 system, and pretty much functionally identical to an E28 system with slightly different parts. I assume if it fits with the V8 (90 degree vee) it'll fit with the V12 (60 degree vee). But space will be tight.

I really wish the car had this system. Having the vacuum booster up front takes away so much space, and I had the aftermarket cone filters being routed all the way down to the fog light. It is such a sloppy swap. I will have to see if I have the original power steering pump on the car, and where the bomb normally goes on E32/E34s, and where I might be able to put it on mine if it doesn't look like I can replicate the factory setup. Time is a factor but it would be nice to get it done now while I have a lot apart.


Started be removing the hood insulation since it was deteriorating and had residue left from what looks like a cooling system failure splashing onto it.

Untitled by Trevor, on Flickr

Injectors were replaced with a set of 12 from the M50 engine that were flow tested and installed a few months ago. The fuel rails will have to be refurbished or replaced.

Untitled by Trevor, on Flickr

Injector wiring moved to the side, injectors and fuel rails removed:

Untitled by Trevor, on Flickr

Untitled by Trevor, on Flickr

Passenger's side side EML:

Untitled by Trevor, on Flickr

Driver's side intake manifold after EML is removed:

Untitled by Trevor, on Flickr

Getting at the intake manifold bolts with a long 1/4" extension. It was really not bad at all getting them off once I loosened the sound insulation strip and slid it out of the way.

Untitled by Trevor, on Flickr

Untitled by Trevor, on Flickr

Intake manifolds removed:

Untitled by Trevor, on Flickr

Finding things while I am in there: disconnected breather hose and very perished grommet on the valve cover.

Untitled by Trevor, on Flickr

This is on the back corner of the driver's side bank. I am not happy with how they did the wiring for the harnesses. Lots of room for improvement but I am not sure if I am ready or willing to tackle it yet.

Untitled by Trevor, on Flickr

[shogun]

If the one pump supplies enough fuel to both rails, that will also do. also the E38 750 has 1 fuel pump only. On the E32 750 some use for emergency cases when 1 pump failed a Y-piece from the working pump to both fuel lines/banks.
Standard capacity PER M70 fuel pump is
operating pressure is 3 bar
conveying capacity at 12 V 1.7 liter/minute
capacity against counterpressure 875 cc/30 seconds
power consumption 5.5A

from an old microfiche I have these data: 0 580 453 011 BMW 750i "M70" 87-150 L/H 780-1650 cc3/30s 3.0 bar.

Wiring problems will be your biggest problems, example http://www.bimmerboard.com/forums/posts/644209/
I had also wiring problems, besides the cable from alternator to B+ both cable looms to the 2 MAF's were cut inside of the outer sheath, the outer protection plastic was too old and brittle, broke and cut into the single wires inside the loom, that usually happens in the bend just before the MAF. We found that on several 750. Also the plug going onto the MAF breaks and then engine could run in limpmode. That plug is difficult to find, as not listed under E32, here I posted some info
http://www.bimmerboard.com/forums/posts/697579/
Have some new plugs on stock if you cannot find locally, also new Hella voltage regulators for the Bosch alternator with 28mm slipring. http://www.bimmernut.com/forum/showt...804#post348804 ,also new ignition wire set for the M70 I have on stock https://www.bimmerforums.com/forum/s...and-M73-engine
Just in case you cannot find these parts locally.

[DKJimmy]

No need, save the $600. We never use new intake gaskets, and I have done a lot of M70 intakes, liquid seal will solve the problem. See my website under fixes>>>engine-general>>>Top end overhaul

it is all in there for the M70 engine. Large file with many pics.

Or from Max Lumens US-made hi-temp 3-ply fiberglass re-inforced silicone rubber http://www.bimmerforums.com/forum/sh...lve-covers-off

would you really suggest not spending the $600 to replace items that wear every 20 years and take 6 hours to get to? I'm sure youve got the operation down pat but does liquid seal fix them all? if so, could you link what specific type of sealant you use?