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I'm asking because it is not obvious to me, if i'm being as thick as F*&%, i do apologise, but i asked the question in good faith, after reading the whole post.

I'm trying to make sense of the problem in my own head to help me fix it!
 
Discussion starter · #22 ·
I'm asking because it is not obvious to me, if i'm being as thick as F*&%, i do apologise, but i asked the question in good faith, after reading the whole post.

I'm trying to make sense of the problem in my own head to help me fix it!
This bit of post #1 should kinda give it away...

...monitors the low pressure sensor when the engine is below 2000 rpm and the high pressure sensor above 2000 RPM. This is done via the instrument panel which uses the 'w' terminal on the alternator to measure engine RPM...
 
Ok Can I ask and forgive me if this is stupid, but is this Petrol engines and diesels or just one?
I have no buzzer noises and no flashing lights whilst driving, but I do have an intermittent starting issue (see other post) that when It wont start, after cranking the oil light flashes
any advice please?
 
I know this is probably irrelevant to the T4 but on some of the earlier 1.8T petrol engines there was an oil pressure issue which triggers the low pressure warning light & buzzer, but this is caused by the sump pick up being blocked. This happens on the early ones because the sump was too small which causes the oil in the sump to too hot which in turn burns the oil on the inside of the sump, these burnt bits then break loose & start blocking the sump pick up. It's a simple one to sort out but a difficult one to diagnose. It's a good reason to use good quality oil.
RichT:
 
Discussion starter · #25 ·
Ok Can I ask and forgive me if this is stupid, but is this Petrol engines and diesels or just one?
Nope - applies to petrol engines also

I have no buzzer noises and no flashing lights whilst driving, but I do have an intermittent starting issue (see other post) that when It wont start, after cranking the oil light flashes
any advice please?
The light flashes because the engine is not running... i.e. no oil pressure = the oil pressure warning is working!
 
Discussion starter · #26 ·
I know this is probably irrelevant to the T4 but on some of the earlier 1.8T petrol engines there was an oil pressure issue which triggers the low pressure warning light & buzzer, but this is caused by the sump pick up being blocked. This happens on the early ones because the sump was too small which causes the oil in the sump to too hot which in turn burns the oil on the inside of the sump, these burnt bits then break loose & start blocking the sump pick up. It's a simple one to sort out but a difficult one to diagnose. It's a good reason to use good quality oil.
RichT:
Forgive me, but it is difficult to see how this (although useful information to someone with 1.8T I'm sure) is of relevance to the DOP oil pressure warning system faults. 1.8T-engined vehicles didn't have DOP and nor was such an engine ever available in the T4...unless you converted but then one would also change the sump which you indicate is the root of the problem.
 
Just goes to show, listen people befoire opver-complicating things with your own confused mind!

Front end on axle stands, sump guard off, quick check over everything and there it is......

...both wires going into alternator had been cut and badly re-acquainted!

Stripped them, soldered them heat wrapped them and went for a spin - not a peep.

Thank you Penbryn and plese forive my initial tardy attitude I:
 
Hi Penbryn, I have the common oil light flashing at all rev's , I checked the wires off the back of the alternator and although they are waring through near the alternator there is no break and resistance is ok to dashboard. Do you know how to test the signal the alternator is giving off for reveal counter? I put a multimeter on the blue wire and got just over 14v with engine running, is this correct?
 
Cheers Penbryn

Really good summary and offers good clarity, I have got the same issue. Would you have any advise on removing the dials on instrument panel so I can replace a broken Oil LED, just bought a 2.4 T4 and previous owner addressed this issue by cutting wires and busting the LED to stop flashing(reckon he tried to get led out with a hammer :)). Its a good engine and bus and deserves some TLC.
 
Hi all. I'm new to all this, so I'm not sure if this is the correct way to get a question answered. Apologies if I'm hijacking etc. My problem is the oil pressure warning light and buzzer going off. I looked at Penbryn's troubleshooting guide but hit a few snags. Here's what's occurring in more detail:- T4, engine AJT 65kW TDi, 02 reg. Problem first occurred a couple of times one day 1 month ago on a long high speed journey, red oil warning light and buzzer goes off typically around the 2000rpm mark, often when cruising down in a higher gear for a junction (but not always). Dropped a gear, increased revs, light and buzzer stop flashing and sounding. No problem for another month, during which time I have changed oil and filter (10 days ago). Two days ago, oil light/buzzer problem starts again, but requires a 30minute drive (to get oil nice and hot I presume) before it does it. Still stops once I increase engine speed, but re-occurs fairly frequently.

Following Penbryn's guide, I look for the two oil pressure sensors, but I can only find one. I'm aware he notes that later engines do not have DOP, so assume maybe this engine does only have one oil sensor. The sensor I find is a brown sensor located at the front of the crankcase, just O/S of A/C compressor, with a yellow wire. I followed the high pressure sensor test list and with yellow wire disconnected, oil light does not come on at below 1800 rpm, oil light+buzzer sound at 2000+rpm. With yellow wire grounded the light+buzzer does not sound at 2000+rpm. When I connected a light between sensor and battery, the light came on at idle speedsand stays on at higher speeds, but I now realise that the engine was not hot during that test.

Can anyone tell me, is there another oil sensor on my engine? I looked on top of the filter/cooler housing, around the cylinder head, all over the place, but there is a lot of stuff in the way to hide a sensor behind. From what I've found, the brown sensor appears to be a 0.55-0.85 bar sensor- is this correct? I note that this pressure range is in the middle of the pressures quoted by Penbryn for the low pressure (~0.3bar) and high pressure (~1.4+) sensors, so maybe having one mid-range sensor is an attempt to replace the theoretically better but temperamental DOP system with high and low pressure sensors, with a practical working single sensor. If there is only one sensor, I don't understand why oil light does not flash at low engine speeds with yellow wire disconnected.

Any suggestions? For peace of mind, my next move was to get oil pressure checked by a workshop as I do not have a pressure guage or know where to attach one, but if there are any other checks I can make before handing my wallet over, I'm listening.

Cheers
 
if im driving along and go up a hill if im in forth gear my red light comes on but if i change gear the light goes out ive a couple of small leaks nothing too much but should i check the sensors or get my cylinder head gasket changed great thread very useful T:
 
Well after reading this I went out and had a wee poke... If I start van ('02 1.9td) and don't give it a little rev, the battery light stays on and after a couple of seconds the oil light flashes and warning sound. As this is happening the rev counter diddles around and keeps dropping to nowt.

If I give the van a few gentle revs its all goes out!

So, do I look at alternator first? I can only see one oil pressure switch by the filter.

Any advice would be great as this van is my daily and I love it T:
 
Cheers for the riddle penbryn lol

My pal is gonna drop the alternator today and take it to a local specialist to test it, its only charging at 12-12.6v at the battery so fingers crossed its not a new one as the cost may kill me :)

Anyhoo what the hell is it with different alternators!?! Local place popped reg in and it brought three up and none matched mine :*
 
Hi does any one have a part number or something for the high pressure sensor located in the oil filter housing..., mine appears to be leaking... Is this common??? Where do i get one from.. My van is a 1.9TD.,.... Thanks in advance
 
I had a similar problem with my T5 transporter, Red warning light appeared on the dash and a beeping sound, It turned out to be the hand brake switch at the back and base of the hand brake, once this had been refitted into its correct position all was hunky dory again....Hope this helps someone.
Cheers
Steve
 
thanks for all the replys, just turned the tick over back up as a m8 told me if the tick over is to low then the pump runs off the engine and my be the cause not getting enough oil up the engine quick enough. when it happened the twice i only had to touch the throttle peddle to make oil light stop flashing, so fingers crossed just need to give it a run now over 70mph to test it. the fella with the lose oil pick up pipe as made me a bit paranoid I:, so might still get that checked now though for piece of mind.
 
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