wiggis

Any thoughts on the merits or otherwise of replacing :

1) Oil Pump
2) Water Pump
3) Main Crankshaft Bearing Shells
4) Anything else whose failure would mean engine destruction .. ?

on an otherwise healthy but high mileage engine ?

Just a question to think about for now, but as many of us are over 100,000 miles, these questions may be worth asking. What do you reckon ?

eljockvis

hi
who would you get to change the crankshaft bearings??
that would be really expensive at the dealer no? anything you can do to
protect the 2x vanos units?

DavidS

Wiggis,

I am all for dealing with potential problems before it turns into a costly repair, but the golden rule of M5 maintenance is : if it ain´t broken don´t fix it.

If BMW mechanics were generally known not to screw things up, and BMW spare parts were known to have high consistent quality when those parts arrive at the mechanics´it might make sense to do scheduled replacments.

Things are a far cry from that.

I would suggest to do frequent oil analysis of the engine oil. If the oil shows signs of metal wear, then think about locating the problem area and deal with it accordingly.

David

__________________
2000 M5 LeMans blue/Silverstone sport interior, double glass windows, all options except alcantara ceiling and trailer. Michelin PS2 tyres.

How to test the MAFs yourself:
http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/54788-how-test-mafs-yourself-how-mafs-work.html

Some further useful threads and info:
http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/88323-davids-som-useful-threads-info.html

wiggis

Good advice. I found a UK based company that does this for £20, and I'll give it a try in a couple of thousand miles (my oil only has about 2000 on it since last change).

My whole train of thought is because, simply put, I wish BMW hadn't royally screwed up the situation with the warranty in the UK. At £700 per year, I would have renewed forever, but at £1,800 and not available above 100,000 miles, they've taken all options away from me. All the 3rd party warranties I've seen have weasel words which would essentially make every sizeable claim an issue of goodwill. Most don't even mention the words VANOS, and most are limited to £5,000 if you're over 100,000 miles. Not much good if you're staring at a spun bearing requiring a new block.

As a result, I am saving up for the day when I either have to spend £££'s repairing my M5 or worst case write it off in the event of catastrophic engine failure. My thinking is that if I can use some of that rainy day money to prevent a catastrophic failure, then it is probably money well spent. I do agree with the general statement that the fewer people with spanners who have been near the engine, the better, but there has to be a risk/reward balance, no?

The warranty situation is making me seriously think about ditching BMW when I buy my next car - not because of quality issues with their cars, but because of the disgraceful way they have treated owners of high mileage M cars over this issue, and the effect it's had on residual values.

I'll give you an update when I do the oil analysis - thanks for the good advice.

verhagke

Excellent advice. Also, in addition to the water pump, you may want to look over the rest of your cooling system (replacing your thermostat, cooling hoses, and perhaps radiator/expansion tank). As the car ages, the entire cooling system becomes increasingly more susceptible to failing, and aluminum heads tend to warp/crack easily when overheated. As you can imagine, this becomes very costly to repair.

PJK M5

Thermostat is on the water pump, so that one is easy enough!

Paul

DavidS

There is a serious design flaw in all BMW cooling systems: in the event of a fast coolant leak, the coolant temperature sensor will get dry and keep showing a nice low temperature while the valve-seats are melting from lack of coolant. There is no sensor for the cylinder head temperature! Insanely stupid!

I have seen a few cylinder heads being replaced for this type of damage, and it is not a pretty sight.

The sign something is wrong is that the engine is suddenly starts loosing power over a few seconds. It supposedly feels like there was an uphill even if the ground is flat. If you ever encounter this you need to stop and switch the engine off within seconds. Pressing the accelerator to "help" the engine will destroy the heads immediately.

I have no idea what happens if this occurs with the cruise control engaged, but I think it is not smart enough to know the difference between a genuine uphill and this condition.

David

PJK M5

Is there an alternative mounting point for an auxilliary sensor then? Any hose we could splice into to measure a more pertinent temperature?

Paul