Thread: D2 Td5 fuel pressure regulator leaking from one of the retaining bolts

1999 D2 Td5.

Had issues when purchased, including leaking fuel pressure regulator. Taken to Darwin's preferred independent for the repairs - regulator pod and its housing block replaced.

Now well out of warranty there seems to be a fuel leak coming from under the head of one of the bolts holding the pods housing block to the engine. Used bore scope to view and confirm. Finger run above the bolt comes up dry, so it does not seem to be coming from higher up and then over bolt. With engine running, about one drop every two seconds drops directly off the bolt, with more running down the bell housing and off. Otherwise engine starts straight up and runs fine.

Finger run around the pressure regulator pod and the recess it sits in comes up dry, no sign of anything coming from bleed hole or past the circlip holding the regulator to the mounting block.

Nothing seems to be coming from under the metal gasket.

Nothing from the fuel line flanges.

I've tried tightening the offending bolt, but there is no more give. I can with difficulty reach the bolt with a 10mm socket but won't budge to undo and remove. I assume these are not normally loctited by the workshop manual.

There are some other odd bolt situations in the immediate area:

- a pipe is tapping against the pressure regulator pod, which it should not; the bolt that should hold this pipe out of the way is missing
- a thin metal plate or shield should be secured against the underside of the inlet manifold by two bolts screwed into the manifold - the bolts are there, positioning the plate, but they are way too long (by about 10-15mm) to have any hold down or pinch effect on the plate - the bolts seem wound into the manifold as far as they will go and sit way proud of where they should be.

I see some threads about replacing the FPR that require removing bolts in the immediate area to release fixtures to provide work room. I'm only guessing that in reassembly the wrong bolt has been used in holding the mounting block, slightly overlong. And if not a mistake by the independent, then somewhere else in previous ownership.

I guess what I need to know:
- does it sound like I have a good regulator pod and just a dodgy bolt?
- any instances where the bolt hole wall is too thin/damaged and has become open to the fuel channel?
- are leaking bolts a common issue under 'failing FPR'?
- can a failing regulator pod cause leaking elsewhere other than in its immediate area ie from under a bolt head?
- am I missing a bigger issue, leak coming from somewhere else, ie inside engine until it finds a bolt hole out?

Of course it is possible if the bolt is not quite pinching tightly enough that fuel could get under the steel gasket to and out the bolt hole, but I would have also expected fuel to be coming out elsewhere along the gasket line.

If i get the bolt out and it seems over length, or deeply scored under head then will try to get a new one. If the bolt is not over length or general condition is OK then I was thinking of putting a soft copper washer under the bolt head - see any issues with copper/aluminium/steel/fuel contacts?

Wife is not happy driving my beaten up D1 (after her old Corolla died) and is pressuring (pun) that the FPR be fixed!

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Far left the gasket fitted by the mechanic. It is the wrong gasket. You can see some of the embossing was not compressed because it lay over rather than around the channel it was meant to isolate.

Second from left. Spoke to MRAuto about the issue and said they use this same gasket for both the 2 & 3 pipe blocks.

Centre. Gaskets side by side.

Second from right. Close up, where you can see the channel 'shadow' around the embossing that should have been crushed.

Far right. Shows the channel and how the new gasket should cover it.

How the mechanic could fail to see the mismatch is beyond me. I reckon the mechanic saw it leaking because the three bolts were so tight in attempts to stop the leak that I had to use an extension on the spanners to undo the bolts. The leaking bolt also had plumbers tape wrapped under the head in an attempt to stop the leak. Each bolt head was partially rounded - even before i started .

Took me about 3 hours to get the aluminium block off, but only 30 minutes to put it all back in place. Now I know the process I could do it in an hour all up. Spent time trying to disconnect the push on fuel line connection, but was full of muck because the protective rubber boot was missing. Very careful to position spanners and extension bars not wanting to round the bolt heads any further. Used Metrinch sockets to work on face of bolt rather than corners. I couldn't apply a torque wrench to the bolts when being done up due to the limited space, so tightened them firmly with hand tools, no where as tight as the mechanic had; reckon I'm lucky the threads in the holes weren't pulled.

Great suggestion about removing the drivers front tyre. This allowed me to push an extension rod with attached 10mm socket between the chassis rail and wheel well guard straight to the bottom bolt - dare I say making removal of the bottom bolt dead easy, given the general comments about how hard it is to access the bottom bolt.

Bled the fuel line by switching the key to position 2, pumping the accelerator 5 times, and when purging finished it fired up first time.

Took it for a test drive and touch wood no leaks so far.