1992 BMW 7 Series 730i 3.0L petrol

Summary:

I love my Big BM

Faults:

Pollen filters (Micro filters) were blocked when I bought the car. I still haven't found an independent garage in my area who can locate them, never mind replace them. Ergo, I'm not sure if the Air Conditioning actually works.

Front suspension vibrates at about 60 mph and when the road is rutted.

Rear brake light has intermittent fault, probably due to condensation in the boot.

General Comments:

I bought this car on e-bay for £1000. Probably the best £1000 I've ever spent. It is an ex-wedding car and is absolutely immaculate inside and out. Looks and drives like new.

It is very thirsty, probably getting less than 20 mpg. I am getting it converted to LPG in June.

Ride comfort is unsurpassable and it drives superbly. Could perhaps have a bit more grunt, but it's fast enough for me. It doesn't naturally cruise at very high speed, motorway driving can be quite tiring. Wish the original owner had gone for the Cruise Control option.

Would you buy another car from this manufacturer? Yes

Review Date: 28th April, 2008

1992 BMW 7 Series 730i SE 3.0

Summary:

Very affordable luxury; find a trusting mechanic to advise you on maintenance. Watch those fluids!

Faults:

I recently bought this car with a known defect: it had an auto gearbox fault. It would not drive forward, but would drive backwards. I am a DIY mechanic and have a lot of experience with big cars.

As I have previously repaired a BMW gearbox, (a ZF 4HP22 4-speed) common to Range Rovers, Jaguars and Volvos of the 1990's, I decided to have a go at repairing the 730i. The car was in near mint condition with 120k on it, and had full dealer service history too. Imagine my suprise when I found that only the selector cable had broken! It sounds unbelievable, but somehow it was pushing the selector arm out enought to engage the reverse and then neutral, but not the forward gears. How it got out of reverse is just weird, but I'm not complaining! Hell knows who diagnosed it in the first place, but if it was via a telephone call to a gearbox shop they would have suspected the box I'm sure.

I replaced the cable for £15. The car is a dream to drive: tight and quiet, as it should be. Everything is in tip top order except the aircon is 'empty'. It has two tappets that require adjustment, but these are straight forward to adjust in an hour, with just an allen key and feeler gauges when the rocker cover is off. This is the M30 3.0 six engine: a bullet proof engine, IF you change the oil and more importantly check the water level. If these cars lose a pint of water, they get too hot at the thermostat housing, and will not operate the temp sender (as it's no longer touching coolant). This overheats the engine, but doesn't necessarily tell you until a hose bursts. It gives symptoms of head gasket failure, but since the head cracks before the gasket goes, you're in for a wallet busting repair.

If your gearbox has 'slipped away' from forward drive and still goes backwards, then don't buy a new gearbox. Take out the old (a rotten job, but so is withdrawing £1000 from your account) and then unbolt the bellhousing. Pull it off, remove the front pump, and out comes a shaft that has a pair of small piston ring seal on it. You must change the seal, and the small 70mm set of six clutches held in by a clip on the gearbox end of this shaft. One or more of these six clutches will have failed: these control 1st gear. Also, the shims will need a change too, since they may have welded themselves to the clutches. These cost around £35 for the 1st gear clutchpack, and a new filter, for around £15 too. That's IT! £50! Take care with the front gasket, and reassemble. It will drive fine. Your slipping box will be OK in the other gars, so don't get cocky and try to change the rest, as you will regret going any further. These ZF 4HP24 boxes were good gearboxes, but a poor design; those shaft rings when worn will allow the front clutch pack to be 'in gear' ie at full contact pressure when in neutral. Did your car tend to creep a tiny bit before it went all 'slippy' when put back to neutral? Search the web for '4HP24' and read about it.

General Comments:

This car drives like a dream. It corners so well, like it should be smaller. I have had BMW 7's in the past and they were good too. And such value from a stupid showroom new price. I got this one for just £200! Not a mark on it, apart from a few stone chips. Has anyone any comments on driving with an LPG kit on this exact model? I intend to keep it for a couple of years. Avoid cars that still have metric tyre sizes: they cost too much, around £190 a tyre! Many will have replaced the alloys for 16 inch ones; however, mine were nearly new.

Would you buy another car from this manufacturer? Yes

Review Date: 27th August, 2005

12th Apr 2007, 06:35

I have just bought a 1992 730i with the 3 litre V8 engine. I would like information where to find an English engine manual and also on converting this engine to run on LPG. I am a Canadian air force officer presently serving in Germany, but I will return to Canada this summer.

23rd Apr 2007, 11:17

I have 1994 V8 3L. Converted to gas 20,000 miles ago. Very pleased, no change in performance. Get 190 - 230mls per £25 of gas. Car now "dead" with auto gearbox failure. Started with occasional noise & vibration through select lever over last 6 months when decelerating, but often went away. Thought it was prop shaft so didn't panic. Noise suddenly became permanent & sounds like a hammer drill, even when coasting in neutral & sometimes slips in "park". Any ideas please or is it terminal?

Have done only 129,000 miles.

14th Jun 2011, 08:12

Your review is one of the best I've read. Kudos man.

I'm about to buy a 730 year 94. I tested the car and it drove great, just that it doesn't engage when put into reverse. The gearbox fails to respond, not sure whether it's the same problem as yours (difference is reverse gear).

Another thing, my foreman told me that the engine requires a top-overhaul, head gaskets damaged or something along the line. The car is being sold at below market price, so do you think it's wise to get it?

Thanks for your time.