Azmontana

BMW E34 M5 S38B36 Restoration

106 posts in this topic

Well I posted some info on the sills thread but I thought it's best to start my own thread to keep a log of work that I'll be doing to the M5.

f0bbe3c5d25d853a5a3047be26e641da.jpg

This is how I bought her 4 years ago. Since then she's been in storage while I was living abroad. Since moving back I spent a year and I've nearly completed my Hartge H26 restoration which now is just waiting for paint so I decided to start cracking on with this M5.

I have removed the sills to find the following.

f2a90c8293a8c291996ad97e2b5904ec.jpg

76f9d7c2a54a1d58adbde966d9dd9bcd.jpg

So that will need sorting.

I've also started on the mechanical side of things with a compression test. The results were ok on all cylinders apart from 1 and 4 which was down on compression around 15psi below the other. I'm thinking it's been sat for so long and not had a good run in over 4 years hence my plan is to give it a full mechanical service including new ignition components, EV6 injectors, shims, TB sync and some other works part of normally servicing. I'm hoping this combined with a good blast on the road will help remove some of the carbon deposits and hopefully restore compression back within tolerance.

I removed the plenum today to find this

4f4947de536bd4b2d061253243675e24.jpg

6cbe3fc89168eaa3699acbbfd7fcdeb0.jpg

The usual mayo signs haven't appeared in other parts of the engine so again my theory is that due to sitting for so long condensation has led to this build up. So I'm going to clean it up and after the service see if I get any further build up.

With M cars the M stands for Money so as a last resort I will pull the motor and do a full rebuild. Until then I'm being optimistic and hoping for the best.

If you like what you've read I'll keep on updating this thread with my progress.

Carl-e34 likes this

Share this post


Link to post
Share on other sites

Always keen on someone's else having M5 fun and games, typical rust plus probably find some more when further into the project.

3.6 engine is just a touch easier than the more stressed 3.8

please keep posting and we have quite a lot of expertise and frustrations on M5 work, money is a prime requirement plus patience as well.

nice car to bring back to life.

Carl-e34 likes this

Share this post


Link to post
Share on other sites
Always keen on someone's else having M5 fun and games, typical rust plus probably find some more when further into the project.

3.6 engine is just a touch easier than the more stressed 3.8

please keep posting and we have quite a lot of expertise and frustrations on M5 work, money is a prime requirement plus patience as well.

nice car to bring back to life.

Thanks. Do you still have all 4 of yours? I remember reading about them in one of the mags.

Share this post


Link to post
Share on other sites

Looks a nice car. What's the mileage? Jacking points are standard E34 repairs now, I doubt many cars have got away without rot there. Did the car run well before storage? Check all the vacuum lines under the plenum and the main hose from MAF to plenum for splits, you'll probably need a new rotor arm, cap & leads if they're original and check the cooling system carefully before you nail it. Also make sure you have the correct plugs fitted, I know of two cars that holed pistons after high speed runs with the wrong plugs in. 

Share this post


Link to post
Share on other sites
Looks a nice car. What's the mileage? Jacking points are standard E34 repairs now, I doubt many cars have got away without rot there. Did the car run well before storage? Check all the vacuum lines under the plenum and the main hose from MAF to plenum for splits, you'll probably need a new rotor arm, cap & leads if they're original and check the cooling system carefully before you nail it. Also make sure you have the correct plugs fitted, I know of two cars that holed pistons after high speed runs with the wrong plugs in. 

I've never driven the car I bought it while abroad but the previous owner did use it regularly and seemed genuine enough. Mileage is around 150k.

Interesting about the plugs can you elaborate?

Share this post


Link to post
Share on other sites
2 hours ago, Azmontana said:

I've never driven the car I bought it while abroad but the previous owner did use it regularly and seemed genuine enough. Mileage is around 150k.

Interesting about the plugs can you elaborate?

The correct plug is Bosch Y6DC. I think there is a champion equivalent that is the one that caused the problem in the two cars I know of. Both engines blew within a few hundred miles of changing plugs. Could be coincidence I suppose but I wouldn't risk it personally. 

urquattro likes this

Share this post


Link to post
Share on other sites

Thats pretty strange. I would only use what was recommended by BMW which as you state in the Y6DC. I decided for the Hartge build i'd try the Bosch Super 4 - WR78. Haven't run it enough to make a decision but I can't really tell any difference, bearing in mind I rebuilt the engine so can't way if the plugs improved drivability as i'm still breaking the motor in.

Share this post


Link to post
Share on other sites

M20s run smoother on NGK plugs, BPR6ES are the kiddies for your H26

 

Good luck, my M5 sills looked like that at the front! 

Share this post


Link to post
Share on other sites

9dca8e1be03f6bf1055b5232d532b47d.jpg

Removed the fuel rail as I'll be upgrading the injectors.

What's strange is the fuel rail wiring harness leads into part of the main wiring harness. I.e. There's no connector so that you can remove the complete fuel rail? I didn't have time to investigate further but seems strange.

Also I noticed this

05fbef9e8bee88efef7d1799ff83efa4.jpg

Next to the big breather pipe on the right there's a smaller breather pipe which has been plugged with a screw. Anyone know what's actually supposed to be there? Doesn't seem right.

Share this post


Link to post
Share on other sites

Hola Az , great to see you back onto the M5 .

 

As you know , I know this particular car very well and it's a good one .

 

I am back in the UK for a few weeks as of tomorrow should you need any assistance and my uk mobile will be back on .

 

The oil residue under the plenum is standard and can be easily cleaned up for better breathing .

 

A new distributor cap and rotor arm is a good shout by Kobyashi and 3.6 's are regularly a tad spluttery after being sat for a while , particularly on cold damp mornings , until the ignition system dries out a bit with a decent run .

 

That rust on the sills is actually pretty good compared to many that are on their original 27 year old sills ..... Ask Keith / Urquattro !!!!

 

Bet you are glad you bought her when you did , as a lot has changed since then !!!!!!!

 

D

Share this post


Link to post
Share on other sites

Hola Az , great to see you back onto the M5 .

 

As you know , I know this particular car very well and it's a good one .

 

I am back in the UK for a few weeks as of tomorrow should you need any assistance and my uk mobile will be back on .

 

The oil residue under the plenum is standard and can be easily cleaned up for better breathing .

 

A new distributor cap and rotor arm is a good shout by Kobyashi and 3.6 's are regularly a tad spluttery after being sat for a while , particularly on cold damp mornings , until the ignition system dries out a bit with a decent run .

 

That rust on the sills is actually pretty good compared to many that are on their original 27 year old sills ..... Ask Keith / Urquattro !!!!

 

Bet you are glad you bought her when you did , as a lot has changed since then !!!!!!!

 

D

Hi David

Yes very happy to be finally cracking on with her. I'll be replacing the complete ignition system. Original ignition leads from BMW gave me a shock but I'll be replacing them also.

I didn't realise you were no longer in the country? Are you living abroad now?

One thing I will say is whoever owned this car previously did a right botch job on the wiring. I removed the driver wing yesterday to see a wire coming from the drivers door to the indicator wiring same on the otherwise too. I'm guessing it's part of the aftermarket alarm. They way it had been routed and connected was terrible.

Thanks for the well wishes. Hope you are keeping well too.

classic-md-autos likes this

Share this post


Link to post
Share on other sites

Yep , alarms are the blight of the M5 with battery drain being a particular downside .

The Engine Wiring loom with injector loom spliced in is standard though , so don't worry about that .

 

I've been spending a bit of time in Spain after buying a place over here and flit between the two for now .

 

I still have the workshop and numerous NLA spares , so keep that mobile number ( 07762 214118 ) in your phone .

 

D

 

arfan786 and Azmontana like this

Share this post


Link to post
Share on other sites

Thanks Dave.

To provide some background on myself. I did my degree in mechanical and electrical engineering. I've been working on cars since I was 12 years old with my uncle who was a Mercedes specialist. I do all my own work including engine rebuilds and fabrication work.

Always loved the older bmws not too keen on the newer ones. So I know them pretty well this being the first m5 I'm working on it's interesting to see the differences but also commonalities between the range from these years.

Having worked as a mechanic while putting myself through university I used to revel at the chance of working on the German and jap cars. So well put together with clear thought as to how technicians will repair the cars in the future years. Same can't be said with French cars that I worked on

urquattro and arfan786 like this

Share this post


Link to post
Share on other sites

I drained the coolant and removed the thermostat housing. Doesn't look like it's been changed for a while so good job to do.

ca4c9c983cbc42b9981cd6bbc6078951.jpg

043c487c6616eb28b310cf5dc117e3ab.jpg

I'll be checking the valve clearances next. Is it worth me doing a write up on this to help other out?

Carl-e34 likes this

Share this post


Link to post
Share on other sites
27 minutes ago, Azmontana said:

I drained the coolant and removed the thermostat housing. Doesn't look like it's been changed for a while so good job to do.

ca4c9c983cbc42b9981cd6bbc6078951.jpg

043c487c6616eb28b310cf5dc117e3ab.jpg

I'll be checking the valve clearances next. Is it worth me doing a write up on this to help other out?

 

All the experience, tips and advice helps with the M5, I certainly asked, got and posted as much as I thought helpful on my jobs.

hth

Carl-e34 likes this

Share this post


Link to post
Share on other sites

020a6b98deb336eecf6bad01e5f018aa.jpg

There's something very cool about looking at a bare head especially one with DOHC.

Didn't get a chance to do the valve check only just got head off. Hopefully have some more time later today to do it.

Carl-e34 likes this

Share this post


Link to post
Share on other sites

 

Looks to my eyes like the cars in good hands and you don't need any help! 3.6 engine is a very strong tough engine if looked after and can take a good canning and cover big milege 

arfan786 likes this

Share this post


Link to post
Share on other sites

Been very busy at work travelling etc so not had much time to work on the M5 slowly getting back into it last week and this week.

 

I finished off the valve clearance. Rebuilt the headlights with new parts etc. The passenger lock didn't match the rest of the car so I managed to source a full lock set and have been replacing all the locks on the car. Door locks are a bit of a pain to do (don't enjoy doing interior jobs) but have just the passenger door to finish off.

 

The driver door still bounces up unless you to a complete full lock anti clock wise and it does the same thing if you try and lock from the boot? I'm guessing both actuators are faulty?

 

Anyway sent some parts off to the blasters

 

46cabad64f1c1c4acaf5a0f738add401.jpg

 

After getting them back

 

02d895b419755dc118cece738af8d91d.jpg

 

Looking forward to prepping and spraying the m5 cover going for a wrinkle finish anyone ever tried it before with the vht wrinkle plus?

urquattro likes this

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now