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The pump on my car is fitted to the underside of the wheel arch, it has started making a VERY strange noise like a bearing has gone. Do any of you gents out there know where i can buy a new pump, without having to buy the kit that normaly comes with it?

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The pump on my car is fitted to the underside of the wheel arch, it has started making a VERY strange noise like a bearing has gone. Do any of you gents out there know where i can buy a new pump, without having to buy the kit that normaly comes with it?

 

Any good motor factor or bosch dealership.

 

The part number should be stamped on it or 0580254909 will work

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I'm no expert in the world of fuel pumps but when mine (Bosch) became unreliable a few months ago it became apparent that more than one type have been fitted to sixes over the years. They don't all have the inlet/outlet connections in the same place and unless you want to mess about with the pipework I'd make sure you're replacing like with like before you order.

Edited by grmills
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Hi,

I see from your other post that you might have a PRV problem too? Does your pump make the noise if you run it on its own? I ask because I also had a wheel arch fitted pump that made the noise you describe - turned out it was because the PRV was at fault and causing the pump to work extra hard! I ended up replacing the whole lot anyway, but if you are on a tight budget, it might be better to eliminate the PRV problem before forking out on a new pump too.

P.S. (The problems with my PI also started on the way to Bournmouth - maybe the answer is to not go there? :rolleyes: ) Glad to say been fault free since changing the pump and PRV 2 years ago.

Regards,

Michael.

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Just an observation on Bosch pumps and noises..

 

I did a long journey (150 miles) in yesterday's hot weather. The pump got gradually noisier unitil I refillled with fuel - after which it went quiet again.

 

Presumably the fuel returned to the tank just gets gradually hotter as it goes round and round, and this causes the pump bearings to complain..? Adding 35 litres of cool petrol, brought the temp down to normal.

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Hi All,

 

having had the runaround chasing what appeared to be PI faults (injectors not firing, drops in fuel pressure, not starting when hot, odd pump noises) and having the frustration of thinking I'd fixed it only for a different symptom to arise (weak / no spark, not starting at all, rough idle) I would recommend you fit a relay to drive the Bosch pump with uprated wiring directly from the alternator (if you don't already have one) Originally the pump switches directly through the ignition switch, the same contact also energises the ignition coil - this worked for me for a few years with no problem at all however the Bosch pumps can draw up to 8.5 amps when set to deliver 100+ psi which will eventually damage the ignition switch and you will see a voltage drop across the switch directly impacting pump and ignition supply. Fitting the relay and changing the ignition switch for good measure has made immediate and satisfying improvement to starting and running smoothness at all RPM and also gives a rock solid fuel pressure which is much easier to adjust through the PRV. I must admit that I dismissed this as a possible cause of my problems, instead I got stuck in to pump, MU, injector rebuild etc. For what it costs and even if you don't think it's the cause of the problem, get one fitted because it will become a problem sooner or later. Hope this helps ..... Dave

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get one fitted because it will become a problem sooner or later. Hope this helps ..... Dave

 

Dave,

Concur with that that - my Bosch pump used to run off the ignition circuit (with a relay) and I was surprised how hot the wiring got under the dash. I discovered the problem by accident but glad I did as I think a fire /meltdown was only a question of time. I now run the pump directly from the battery and only power the relay from the loom.

 

Bill

 

 

 

Presumably the fuel returned to the tank just gets gradually hotter as it goes round and round, and this causes the pump bearings to complain..?

 

Bryan

 

Yes, I think you were in the early stages of cavitation - the hotter the fuel the more inclined it is to vapourise and vapour doesn't pump too well.

 

Bill

Edited by badshead
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I'm no expert in the world of fuel pumps but when mine (Bosch) became unreliable a few months ago it became apparent that more than one type have been fitted to sixes over the years. They don't all have the inlet/outlet connections in the same place and unless you want to mess about with the pipework I'd make sure you're replacing like with like before you order.

 

Bosch revised their range a year or 2 ago so many of the older part numbers may not exist - however here's the Bosch data which lists the inlet & outlet dimensions & thread sizes.

 

Incidentally picked up a brand new -909 on ebay for £49 (Item number: 4651372603) the vendor appears to be a dealer and can get other pumps too although he/she emailed to say that they were away for 2 weeks. Pump arrived quickly too. I'm not sure if I just got lucky but I suspect that price was sustainable as they were selling other pumps at a similar price.

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Guest caine62

My bosch pump has just started making a very strong humming noise. I hadn't noticed this previously but the tank is just under 1/4 full, the emptiest I've ever had it. Also, this was the first time I'd driven with the soft top up and that could be accentuating the noise. I'll fill the 6 up tonight and see if that helps. My main concern is that I can't afford to change the pump until next payday (end of the month) and the car needs to make it to France and back before then.

 

It runs smoothly once warm (jerky when cold around town though!). Having looked through the forum, it could be due to any of a number of causes!

 

Is it harmful for the engine, even if it isn't affecting cruising speed and smoothness?

 

Eli

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Guest caine62
My bosch pump has just started making a very strong humming noise.

 

Just got down to business with the fuel pump. I left the engine ticking over and started taking the boot liner off to access the pump. The whining stopped immediately: it was the boot liner pressing against the pump and it was amplifying the vibrations! My toolbox had been sliding down the boot and was pushing the panel onto the pump.

 

I need to cushion it somehow now but at least it means no costly replacement parts yet (touch wood!).

 

Eli

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Just an observation on Bosch pumps and noises..

 

I did a long journey (150 miles) in yesterday's hot weather. The pump got gradually noisier unitil I refillled with fuel - after which it went quiet again.

 

Presumably the fuel returned to the tank just gets gradually hotter as it goes round and round, and this causes the pump bearings to complain..? Adding 35 litres of cool petrol, brought the temp down to normal.

 

 

I think you'll find that whilst what you are saying is part of the reason, the major difference is that with a full tank, you have around 12 - 16 inches of fuel pressure creating a nice healthy inlet pressure at the pump. When the tank is nearly empty, you lose most of this and the pump starts to struggle to suck the fuel in. You'll also notice a similar problem if you take the car up in altitude. Back in the 80's we took our 6 to Switzerland and we were stopping regularly for small intakes of fuel just to keep the pump happy. Rather than lacking the 12 or so inches of fuel pressure, we were of course missing around 4000 feet of air pressure. On the return home, as soon as we were back out of the mountains, the pump was happy again. The pump was a Bosch one by the way.

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Sounds plausible to me.

 

Presumably this means that to get the best head of pressure, the best mountings for the Bosch pump are either in the spare wheel well or the wheel arch rather than alongside (and slightly below) the tank where the Lucas one was.

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Bosch revised their range a year or 2 ago so many of the older part numbers may not exist - however here's the Bosch data which lists the inlet & outlet dimensions & thread sizes.

 

I'm not referring to inlet and outlet dimensions, but to the fact that they are positioned differently on some pumps. Mine is a 996 and to fit a 909 to my car would involve a certain amount of modification to the pipework, hence check before you buy...

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I'm not referring to inlet and outlet dimensions, but to the fact that they are positioned differently on some pumps. Mine is a 996 and to fit a 909 to my car would involve a certain amount of modification to the pipework, hence check before you buy...

 

It also shows the shape, dimensions, inlet and outlet sizes of the universal range of Bosch pumps.

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Presumably this means that to get the best head of pressure, the best mountings for the Bosch pump are either in the spare wheel well or the wheel arch rather than alongside (and slightly below) the tank where the Lucas one was.

 

Yes, I'd just installed the Bosch pump in the same position as the original Lucas one shortly before going to Switzerland. On my return, I mounted it in the wheel arch to gain a little more pressure at the inlet. Some people have spoken about putting a small electric pump in series to pressurise the inlet, but I never got around to doing that. Never had the car back at altitude to check it out properly - but I guess plenty of others have managed OK.

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