Jump to content

Oil pressure switch


Recommended Posts

On 4/28/2020 at 10:31 AM, western said:

200Tdi oil pressure switch PRC6387 

so you don't have to strain yourself BUT make sure you are sat down when you see the price----  Genuine LR switch https://www.brit-car.co.uk/product.php/89829/0/oil_pressure_engine_switch___2_25l___2_5l_4_cylinder_petrol___diesel___200___300_tdi___2_5l_vm__defender___range_rover_classic

HOW MUCH. The last one I bought was a fiver

Link to comment
Share on other sites

Update.

 

Two days after fitting the replacement, it's failed, so I've ordered a Lucas unit (£6.00) and an Intermotor unit (£7.00)

According to a friend who knows this stuff, the cheaper units are often unable to operate at the lower pressures experienced in a Tdi at tick-over...  He also said 'don't by cheap carp'

  • Like 1
Link to comment
Share on other sites

Normally the lower threshold of the switches is ca. 0.3 bar. A good Tdi would operate the switch surely because pressure when idle is ca. 1 bar when hot. I'd recommend to measure!

I never experienced that bad switches.

Link to comment
Share on other sites

1 hour ago, Sigi_H said:

Normally the lower threshold of the switches is ca. 0.3 bar. A good Tdi would operate the switch surely because pressure when idle is ca. 1 bar when hot. I'd recommend to measure!

I never experienced that bad switches.

If you read the thread, you'll see I've had a test gauge on it. Of the 11 200 Tdi's I've had, this has the best oil pressure! It's 38psi (2.6bar) at warm/hot idle (850rpm). After the new switch started to flicker red, I tested it again. same figure

Link to comment
Share on other sites

  • 2 weeks later...

Getting annoyed now.

Third pressure switch is still showing on at hot tick-over

I've checked for Cam Creep, although this shouldn't cause an issue at one single point, but across the scale, it was fine

So now I have grabbed the test gauge and will fit it, then run it up to hot, rather than warm and see what I'm getting.  Off the back of there likely being a problem, then I will be looking to change the oil pump.  I can check the big ends then.

Anyone any sensible, balanced opinions on a Britpart Oil Pump?

 

Link to comment
Share on other sites

3 minutes ago, Nonimouse said:

Anyone any sensible, balanced opinions on a Britpart Oil Pump?

Had one for a series engine once, I then spent days disassembling the engine to work out what the horrific noise was (I'd had a lot of the engine apart, head off, pistons out, even the cam out), and eventually put the old oil pump back in upon which the engine went silent.

Not what you would call unbiased, but I wouldn't do it again.

  • Confused 1
Link to comment
Share on other sites

You know any oil pressure switch with the right thread will pretty much work - I used to have a scan of the Intermotor/Ci catalogue that listed all their switches, the fitting threads and the actuation pressures, very handy.

Not sure what I've done with it now mind :ph34r:

Link to comment
Share on other sites

What about getting just the relief valve plunger and spring from Turner?  Probably Britpart, but hopefully they’ve scrutinised them.

What exactly do you look for on the cam bearings?  I looked at mine and they looked to be longitudinally aligned with their sections on the shaft, but is there anything else to check?

Link to comment
Share on other sites

Fridge, I'm fine with a mechanical test gauge, for a hot,hot test - if that shows that all the switches are pants, I'll simply fit an electrical gauge - that I have.

My issue is the pump - it's the next thing, if not the only thing that it could be. I don't want to buy a rebuild kit, as that means (sod's law) that it will be something else... added to which I am limited to about two hours turn round as I need the vehicle back on the road.I don't have the luxury or vehicle off the road for a prolonged amount of time.  So pump it is... sadly it's recon of eBay or probably Britpart. The if pump doesn't work, its a replacement engine - as that is fast turn round

I'm reasoning that not all Britpart stuff is bad - both experience and odds say not

Nick, I'm reckoning a visual will tell me something. An overly maintained 115k 200tdi should not have this issue. It has to be a failure of a part..

Link to comment
Share on other sites

Visual inspection of bearings or the relief valve piston may be indicative, but not the relief valve spring - you won’t be able to tell anything about it’s stiffness from its appearance or even from measuring its length (contrary to workshop manuals).  It’s a cheap part to try.

Link to comment
Share on other sites

53 minutes ago, Snagger said:

Visual inspection of bearings or the relief valve piston may be indicative, but not the relief valve spring - you won’t be able to tell anything about it’s stiffness from its appearance or even from measuring its length (contrary to workshop manuals).  It’s a cheap part to try.

Nick, isn't the relief valve part of the pump though - so changing the pump is the same as...?

Link to comment
Share on other sites

2 hours ago, Nonimouse said:

Nick, isn't the relief valve part of the pump though - so changing the pump is the same as...?

It’s inside the pump, but is a pretty simple job and a lot cheaper.

Link to comment
Share on other sites

17 hours ago, Snagger said:

It’s inside the pump, but is a pretty simple job and a lot cheaper.

I've bought the new pump and some shells off Turners (excellent service and good prices)

My strategy (as always) is, when unsure of the root cause, is replace with new, good quality parts until the problem is now more.

I do the same with almost everything - change brake pads, so renew seals on ss pistons, put in fresh fluid. change the cam belt, change the water pump and cam and crank seals at the same time...

A second hand vehicles is only as good as the previous owners maintenance, so knowing what you have replaced is peace of mind. The Disco is my DD and works vehicle (especially with the modus sorned) and with the wife driving a T4 (entertaining lack of reliability), I need reliability

Edited by Nonimouse
Link to comment
Share on other sites

Pump was fine - same pressures with the new one.

So we started changing the shells - well first we checked them. Having a). access to a  two poster is very useful and b). a very talented and knowledgeable friend, with ALL the kit, who is happy to help , at a social distance; all makes things much simpler.

We checked the end float on the crank - comfortably in tolerance. The shells on number 1 and 2 are fine, but 3 to 5 get progressively more worn. Same with the mains. So all were inspected by end of play yesterday, then loosely put back together for replacement on Wednesday.

We checked the cam again, no creep

So fingers crossed, a bottom end re-build will sort it out

I'm surprised at the wear though - this is a 115k engine, I'm the second owner. It's got full dealer service history to when I bought it, then I've almost over-serviced it since. Quality oil, only genuine or Mahl filters...I don't thrash it...Hey ho

Link to comment
Share on other sites

If it got worked hard at low rpm, and hence low oil pressure, then that would explain the bearing wear.

Ralph has commented a few times about the banjo bolts on the piston oil jets having valves that can stick.  I had reused the old bolts, but will be replacing them as a possible cause - I had already replaced the oil pump, and the crank was unblemished and all it’s shells replaced with new.  The cam shells are in the correct place, but weren’t replaced as everyone advises they’re very rarely worn and on,y give trouble when they slip.  It’d be my luck to be the exception to the rule...

What about the turbocharger?  Could that be taking too much oil flow?

Link to comment
Share on other sites

9 minutes ago, Snagger said:

If it got worked hard at low rpm, and hence low oil pressure, then that would explain the bearing wear.

Ralph has commented a few times about the banjo bolts on the piston oil jets having valves that can stick.  I had reused the old bolts, but will be replacing them as a possible cause - I had already replaced the oil pump, and the crank was unblemished and all it’s shells replaced with new.  The cam shells are in the correct place, but weren’t replaced as everyone advises they’re very rarely worn and on,y give trouble when they slip.  It’d be my luck to be the exception to the rule...

What about the turbocharger?  Could that be taking too much oil flow?

We checked the oil piston jets were all still there, but didn't dismantle - that's one to bare in mind...

I don't think the turbo is taking too much flow - but that's the next thing to look at

I'd not thought about the low rpm hard work thing. I do have a habit of pulling away on tick-over, then bringing in the throttle once the clutch is engaged fully. It's one of the things I love about the tdi, it's lugging capability. I do this with big loads on the back as well...

 

Link to comment
Share on other sites

9 minutes ago, Nonimouse said:

I do have a habit of pulling away on tick-over, then bringing in the throttle once the clutch is engaged fully. It's one of the things I love about the tdi, it's lugging capability. I do this with big loads on the back as well...

 

That’s softer on all of the transmission, but brutal on the crank shaft.

Link to comment
Share on other sites

5 minutes ago, Snagger said:

That’s softer on all of the transmission, but brutal on the crank shaft.

Why?

It is more important to protect the gearbox than the crankshaft. The needle bearings in the gearbox are much more sensitive. Plain bearings on the crank can carry a lot more load.

Link to comment
Share on other sites

Because you’re applying as much torque as the engine can muster (albeit below boost rpms), so maximum pressure on the shells on the thrust side of the journals (conrod side) and main bearings (cap side) as the pistons are forced down, but with minimum oil pressure to protect them.  That not only increases the wear on those shells, but also on the crank faces, so they’ll end up out of round, particularly the journals as they only ever take significant loads on one side.

It’s better all round to let the engine spin up a little bit to generate oil pressure and gently let the clutch out.

For the same reason, I’d expect increased wear on all the bearings of a vehicle that is often idled for extended periods - the thrust loads on the crank are less,, but so is the oil pressure.

The cam shaft loads will vary with rpm, the valves being forced faster or slower into high pressure environments and having to cope with the valve gear inertia, so radial forces of the shaft downward onto its bearings will increase with rpm too, but I have no idea how much.  Again, the oil pressure increase of elevated rpm will offer better protection.  
 

It doesn’t take much of an increase in rpm to raise oil pressure well up to the full 55psi in a healthy engine.  I wonder if that was part of why the FFR Series LRs had such a high idle on their rudimentary hand throttle, since the generators worked well below that rpm.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy