Disco 2 FPR

I think I may be reaching the limits of my patience with my Disco. Driving back home this morning and suddenly started to lose it on the most gentle of bends. Stopped to investigate what might be going on and lo and behold, diesel all over my rear wheels. The F#*%ing Fuel Pressure Regulator pumping out my diesel in a high pressure jet!
Had to get recovery to get me home. Thing is, I thought I'd already sorted the standard leaking FPR issue when I replaced my head gasket. However, I used one of those replacement regulators to replace the one leaking; just the regulator, not the whole assembly. You can get just the regulator itself and a simple circlip removal and pop it in in place of the duff one. New gasket and then refit the now refurbed FPR assembly. Well, maybe these replacements are not quite the answer I thought. So, I've ordered an OEM FPR at great expense and will de-bone my knuckles fitting it when it arrives.
Anybody have any useful tips before I get out the spanners?

Remove and clean the strainer in the head under the o-ring before you fit the new FPR

I thought the diesel pressure regulator was under bonnet drivers side,mine was when i changed it.
So how come it was spraying all over back wheel

Mark Ormond said:

I thought the diesel pressure regulator was under bonnet drivers side,mine was when i changed it.
So how come it was spraying all over back wheel

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That's what i thought!!

How about the fuel filter mounting corroded through

discodrivercumbria said:

That's what i thought!!

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Presume he meant so much coming out it tracked along.
Heard of many people "fixing" or "refurbishing" FPR's, then having to do it "properly" (ie replace it!)

Disco DJ said:

Presume he meant so much coming out it tracked along.
Heard of many people "fixing" or "refurbishing" FPR's, then having to do it "properly" (ie replace it!)

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well i did think of that, but was wondering if he meant near the rear wheel, filter, pump etc, not a spirt near rear wheel as he said!!!

Mark Ormond said:

I thought the diesel pressure regulator was under bonnet drivers side,mine was when i changed it.
So how come it was spraying all over back wheel

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The answer to that is fairly obvious. Hacking along at 60mph with diesel jetting out the FPR, it quickly travels back under the vehicle (something to do with the airflow ). It is the same principle that causes the diesel to also deposit itself on the road!
Fortunately (for me), I'm still here to joke about it. I'm glad I did all those track days back in the day; learned how to catch that tail slide before it became a 360° and rollover.

discodrivercumbria said:

well i did think of that, but was wondering if he meant near the rear wheel, filter, pump etc, not a spirt near rear wheel as he said!!!

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To be pedantic for a moment, "he" didn't actually say that. "He" wrote two sentences, each describing a different aspect, i.e., diesel on rear wheel, and diesel squirting out of FPR. There was a full stop between the sentences which one could correlate with the length of vehicle and hence distance between the FPR and the rear wheels.

CliffordGarrett said:

So, I've ordered an OEM FPR at great expense and will de-bone my knuckles fitting it when it arrives.
Anybody have any useful tips before I get out the spanners?

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Mine was dripping so fitted a genuine replacement. Had aftermarket and "original OEM quality" things before which haven't been satisfactory and didn't want to chance it on this with high pressure fuel.
Did find the bottom bolt to be a sod to access and used a long extension 3/8" drive socket from underneath to get to it. Rest is fairly easily done from the top.

On a more serious note, my main concern here is if there is more to the problem than just a failed FPR? Since the diesel was streaming out at full force (same rate as if a fuel line had been disconnected while running), I'm concerned that there is nothing else causing this, e.g., some kind of blockage inside the head. I was hoping that if anybody here knew of a reason why the FPR should go like it has, they might let me know. Is it just a case of foreign object inside the FPR itself causing diaphragm to allow fuel past it, or is it possible for pressure inside head to be too great causing the regulator to blow? Suggestions most welcome.

Thats why sierraferry said clean out the gauze filter in the head behind the O ring.
It does appear that you get what you pay for with some parts, reminds me of running my old MG, so many aftermarket parts are just rubbish.
The FPR is not that complicated, but bad machining and cheap O ring materials will screw it up.
Mark

markomate2 said:

Thats why sierraferry said clean out the gauze filter in the head behind the O ring.
It does appear that you get what you pay for with some parts, reminds me of running my old MG, so many aftermarket parts are just rubbish.
The FPR is not that complicated, but bad machining and cheap O ring materials will screw it up.
Mark

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It has LR original part casting etc, with a replacement bosch regulator. I'll be fitting original part replacement. I'll be amazed if the failure was due to dirt in that tiny little gauze filter. I will of course be cleaning it. That's if I ever manage to get the old one off; the bolts are so tight I've not managed to crack them. Only one out so far. My hands seem far too big to get in there.

CliffordGarrett said:

To be pedantic for a moment, "he" didn't actually say that. "He" wrote two sentences, each describing a different aspect, i.e., diesel on rear wheel, and diesel squirting out of FPR. There was a full stop between the sentences which one could correlate with the length of vehicle and hence distance between the FPR and the rear wheels.

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not used to looking for full stops........... you should of said lifted the bonnet then, or got a complete new unit and stop being a tight arse!

Hahaha!

Here's a thought, since it is the genuine LR part that leaks diesel on all Td5s, why is it that the general consensus is a Genuine LR part is better than an OEM part? As far as I can tell, the FPR in LR version is stamped Bosch 4 bar and so is the OEM version (which you would expect). The FPR that is available on its own, ie without the casting, is also Bosch. In theory, there should be no advantage in replacing the entire assembly as it is the same manufacturer's part that is failing everytime.

The genuine parts are made by the manufacturer(in this case Bosch) to meet very strict requirements and high standards imposed by the customer(in this case L.R.) which have to pass restrictive bench tests(the most expensives), those parts which failed the high standard tests but still within generaly accepted limitst or the same parts made by the same manufaturer but without taking so much care for the details or without using high spec materials are named OEM(as they are made by the original equipment's manufacturer), so a kinda aftermarket parts made by a reliable manufacturer(cheaper),... then there are "OEM quality" aftermarkets made by manufacturers with good reputation and known brand approx at the same price as OEMs ,,, and the last option are aftermarkets made by chinese or no-name builders which are the cheapest and a lottery, my father used to work for Lucas Automotive before he retired many years ago and that's how i know.... sellers are often naming "genuine" some OEM parts especially on ebay but that's not always true. The best example which is visible with naked eye is to buy a Genuine drive belt and a OEM one and compare

CliffordGarrett said:

The FPR that is available on its own, ie without the casting, is also Bosch. In theory, there should be no advantage in replacing the entire assembly as it is the same manufacturer's part that is failing everytime.

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The complete OEM assembly has been subjected to stringent test conditions as sierrafery explains. Give a DIY mechanic two OEM parts to assemble and he may make an error, such as nipping an O ring, and immediately negating the benefits of the OEM testing.
Or you may have just been unlucky with the replacement part, it does happen but from my experience it is less likely with genuine bits.
Good luck with the rest of the bolts.

Having finally managed to get the FPR body unbolted, I was at last able to inspect the FPR. It seems I'm able to blow and suck air through it unhindered. Clearly, not doing its job as a pressure regulator. I would concur with others' comments regarding quality of spare parts. These ebay versions may not be up to the job. Although seemingly OEM parts, they could be counterfeit copies, quality control rejects, or just rubbish to start with. Whatever the case, having one in your vehicle that rather than "leak", opens like a safety release valve, is not a very safe or sensible money saver. It could lead to your ultimate demise!

CliffordGarrett said:

Having finally managed to get the FPR body unbolted, I was at last able to inspect the FPR. It seems I'm able to blow and suck air through it unhindered. Clearly, not doing its job as a pressure regulator. I would concur with others' comments regarding quality of spare parts. These ebay versions may not be up to the job. Although seemingly OEM parts, they could be counterfeit copies, quality control rejects, or just rubbish to start with. Whatever the case, having one in your vehicle that rather than "leak", opens like a safety release valve, is not a very safe or sensible money saver. It could lead to your ultimate demise!

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i see where you are coming from, i tend to use top quality or genuine for critical jobs and oem where they are not as important, FPR is a ****ty job, just like the thermostat,

CliffordGarrett said:

Whatever the case, having one in your vehicle that rather than "leak", opens like a safety release valve, is not a very safe or sensible money saver. It could lead to your ultimate demise!

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And when it leaks the starter motor is below and getting it. Have read it can lead to the starter's early demise so that's another potential cost.