Beiträge von Peter West

Had that happen twice. New distributor and rebuilt altenator fixed it.

You say some lights come back on if you leave the car for a while?
I have posted elsewhere about my altenator problem...fixed altenator fixed all problems.

The reason I comment is that if I left the car for a few days, then everything seemed to work ok for a while then systems began shutting down.

Try recharging the batteries and see if they all come back on. If not then either a battery or the altenator is the problem.

I seem to be recommending to everyone with an electrical probelm to check the altenator these days, but I had so many minor problems and they all got fixed with an altenator rebuild.

I know it won't cure all problems, but if it cures some it's worth the posts.

I have a mechanic near me who specialises in performance cars (West Cornwall). So far he's fixed everything I've thrown at him. Sometimes it's been time consuming diagnosing problems, but always finds it in the end. Charge 37.50 per hour. Doen's always charge for all the hours if it's a particular challenge, he seems to enjoy it too much. maybe it's because I spent a lot of money on head gasket replacement and various other pricey stuff.

I thought it was fixed, but I was having more problems like the ones Jon 850 originally posted here. Turns out the altenator was not producing enough power. had the altenator rebuilt and so far ALL electrical problems seem to be fixed.

back to the mpg question:

I've just done some tests in my 1991 850i, original 16 in wheels, original factory exhaust, no modifications:

Around town, including cold starts, heavy traffic, basically whatever comes up, running for 100 miles, always within speed limits
Economy mode 15.7 mpg
Sport mode 16.5 mpg

Long distance, on a run from Exeter to Stansted airport, using cruise control wherever possible, staying in speed limits, not including cold starts or heavy traffic
Economy mode 25.6mpg
Sport 23.7mpg

These figures are strictly according to the OBC. I'm now going to do a 1000 mile all driving test to check the OBC against petrol purchased.

If theses figures are correct within 10%, then that's a good result for an older 850 I think.

I also recently did a run from Camborne to Exeter, set to 0 at the start, included cold start, some contraflows, not strictly sticking to the speed limits perhaps (!), and a bit of heavy traffic around Exeter (96 miles), economy mode throughout and averaged 22.6mpg

Did you get your general electrical problems sorted? If not, get the output of the altenator checked. (see my recent post on the subject).

Hi Steve
I look forward to it. I'm plannign sometime next year to get de-cat exhaust and both Dynan conversions. That should get me up to about 360-370bhp.

Wouldn't it be nice to put the guts of an M6 in a e31 body?

mail me when you're around.

And anyone else in the South West who's coming this way
Pete

I have the original stock wheels for 1991 850, can confirm standard 16 inch

yeah, mike has a clent who likes old Maseratis, but I've seen many Porsches in there and occasionally a Ferrari. He drives a fairly new Audi A8 right now which is a beut. There have been Astons and Rollers in there too when I've been in.

In the scheme of things I don't know just how good he is, but he seems to be able to find the oddest things, a lot of people with good cars trust him and as he's so close (about 200 yards from me) it seems as good as anywhere.

Why don't you drop in for coffee when you come past some time?

I had the transmission failsafe on 2 occassions too, so I can confirm that.

Steve, I use Mike Remnants garage in Troon (Camborne) for most of my service and repairs. He has a couple of clients with 8s, and although it is still often hit and miss, educated guesswork, generally we get close to the mark quite quickly.

Mike arranged for the altenator to be rebuilt by a subcontractor in Camborne. I can find out who if you like, but the diagnosis was done by Mike Remnant. In this case though, by the time I got to him it had become pretty obvious, not much diagnosis needed.

The actual re-build cost £85 and works like new now. Took some labour to get it out and in though due to power steering in the way.

I have same model same year.
Generally I leave it about 20 2econds or so on very cold mornings as sometimes when vey cold a couiple of cylinders don't fire up, then when they cut in I get a power surge.

Apart from that I'm informed that cold oil in a cold engine doesn't circulate properly at idle speed so some parts are not being adequately lubricated. I don't know if this is
1. true
2. false
3. applies to some cars and not others.

If it is true then revving the engine a bit (or driving it) should solve the problem

Like many people on the forum I'd been having minor electrical problems.
One day my passenger window wouldn't close another day it would
Light bulb failures and other electrical systems failure lights when the hardware itself was working fine.
More recently 6 cylinders had randomly dropped out and left me in get home safely mode. (A previous problem where the enhine heat had melted solder on contacts causing wrong readings from the Lamda sensors had been fixed and the Lamda sensors replaced), but still occasionally and randomly 6 cylinders still dropped out.
A couple of days ago my ABS warning light came on. After re-starting the engine everything seemed fine.

Eventually we found the problem. The altenator was not supplying enough power. Everything fine in daytime, but with headlights on it wasn't coping. I've had the altenator renovated (have you seen the price of those things!), and now all is well.

The moral of the story, if you are having persistent minor electrical failures, get the altenator checked. If it is slightly under par it might not be coping.

Thanks everyone for your help and suggestions. The problem turned out to be hard to find but simple to fix:
First, the lamda sensors were not working properly. These we replaced for surprisingly little cost (£48 each compared to my friends jag where they were over £250).
The engine now ran more smoothly generally, drove more responsively, but still dropped into get home safe mode when the engine temperature reached normal.
Eventually we found that long term heating of part of the wiring loom that passes over the engine block (made worse by 3 faults that had caused overheating in the last few months) had caused some solder joints to come loose, breaking contact at a cretain temperature, which interrupted data from the lamda sensors to the Engine management system and caused the limp home mode. Limp home mode switches off 6 cylinders, but doesn't stop that half of the engine continuing to turn, so unburnt fuel in the exhaust caused the damage to the sensors.

All seems to be ok now.

The mechanic re-soldered the joints while the engine was running, and says that as soon as the solder melted more cylinders fired up.

Hopefully this is the end of the last year of troubles.

Thanks Terry, tried that, but no difference.
It seems as though one bank of cylinders cuts out when it gets to operating temperature.

My mechanic tried moving various coils and sensors from one side of the engine to the other to see if he could get the fault to follow a component, but no luck. hence I ASSUME I'm in limp home mode and not some other problem.

Peter

Having spent thousands on my 850 in the last 6 months, mine is off the road for a while. The final straw was after a fairly thorough engine re-build, I now get a limp home mode, but with slightly different symptoms. Mine's Automatic by the way.

The car runs fine until the temperature reaches normal, then I loose most of the power. It moves, but accelleration is non-existent.

terry, is there a similar proceedure for automatics? I don't fancy the idea of running up to 5000revs in drive, I don't think the hand brake will hold it!

Peter

Sounds to me like they think you are making a warranty claim. Maybe they think an 850 is a new model!

Having said that I've taken my car to the local dealer on occasion (it's a 1993 model) and they've fixed things and not charged: once an electrical fault that took them 4 hours to hunt down, and a couple of smaller things. Maybe they'll just send you one. How good would that be??!!

Hi Mike
To take your questions in turn, I can only answer how things are on mine for you to compare, so here goes.
When you are in drive there should be a readout on the dash that says ED (That is Economy mode, drive selected). Next to the transmission select lever there should by a sliding switch that has S towards the front of the car and M towards the rear. This slider (push it and release) changes the transmission to Sports or Manual mode. The readout on the dash will change to SD or MD depending which you choose. Put the selecter to 3 and you will see E3, S3 or M3 on the readout. To return to the economy mode press the switch down (ie towards the floor) and release. The readout should return to ED.

Choice of tyres will make a huge difference. Be careful though pushing the car hard, it will burn through soft-compound high performace tyres faster than a Ferrari. I can get about 8000miles out of the front pair and 16000 out of the rear pair.

No idea what the drain is, but the fan should not stay on more than a few minutes after you stop. I find the fan cuts out more quickly if I do a few miles at low speed at the end of a journey, but then I had a heating problem that blew the head gasket. It may be better now.

I'm not sure what your seller meant by radar detection, and certainly not on the front. If you have it on the back it will look like 4 or 5 colour co-ordinated circles in the face of the rear bumper. If it's working it will cause a beep inside the car as you reverse and get close to an object. It will get quicker as you get closer and become a continuous tone when you really don't want to get any closer.

Hope that helps

all the best
Peter

Glad to hear it's getting sorted. I should get mine back in a few days.

How much did you pay by the way. Mine £ 7,500 GBP and in reasonably good condition. A few things went wrong, but most of my recent troubles have been due to the knock on effects of a minor accident, things which didn't get noticed for the insurance claim. Generally the car is good.

The sliding roof, all of it is electrically driven in mine (1993) and I think is in all models. The roof panel inside slides independently and differently to the outer panel, but both controlled by the same button.

Peter

I have mixed feelings about the M6. The new 6 series is so ugly! But then you can put up with a lot of ugliness when you have 500BHP. The new M5 seems a better deal to me. Same engine and transmission as far as I can make out, same extras, lighter weight car and not so ugly.

Now if you could get that engine in an 8 body, then you'd be talking!

I parked next to a new 6 recently. Despite all its high tech features the driver was raving about my car. He'd just bought an ex demo and saved £9,000, more than I paid for mine!

Hi Mike. That Scirrocco sounds fast. But you can't beat the sound and feel of a V12 engine powering a big machine. It may or may not be as fast as the Scirrocco, I don't know. I expect on good form the 850 will be faster because the transmission is so efficient. But even if it's not got quite the accelleration, the feel is so different, I know you'll love it.

Peter