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BOD - it hurts my ears!
Posted: 11 Jul 2010, 07:31
by italianjob
morning all
1.9 DG petrol engine 85 registered C reg
originally posted under 'oil warning light not on - clearly in my case it is)
I've recently developed the notorious BOD syndrome amd I want to try and sort it out. BOD only comes on after about 30 seconds from setting off and takes anything up to 30 minutes to go off - bliss. Its been like this for the last 6 weeks - I've checked the oli and water levels and all is fine.
Was recently services a month or so before the whole BOD thing kicked off. So I'm thinking its either the low/high pressure sensors or the PCB.
Now, I've read through the wiki and most of the posts relating to the BOD - as a 'quick fix' can I simply disconnect the PCB connect from the back of the speedo to shut the thing off

As a fix so I can go away in the van next weekend because I'm the support crew for a Trialwalker Team down on the southdowns.
How does the resistor fix work

How does the connector go back in if there's a resistor fixed to it - or does the resistor fit on the back

I promise I will get it fixed properly when I've got the money and time!
thanks for now -and as always, any advice would be gratefully recieved.
Ta

Re: BOD - it hurts my ears!
Posted: 11 Jul 2010, 07:56
by Aidan
recently serviced, by whom, what oil, what filter fitted ?
Re: BOD - it hurts my ears!
Posted: 11 Jul 2010, 11:00
by AngeloEvs
I mentioned in your other post that if the High oil pressure switch is missing or faulty then the wire that connects to it must be connected to chassis and not left floating/disconnected. Earlier vans did not have the Oil pressure warning PCB and buzzer of doom, the LED was connected directly to the low oil pressure switch via a resistor mounted on the flexible membrane circuit. If you leave the resistor connected (as shown in the other thread) you are basically converting back to the original system and you leave it like that. You can ignore the PCB or remove it altogether. Might be an idea to get the oil pressure checked at your local garage (since your High oil pressure switch is missing) but if the engine sounds fine at normal temperature chances are that everythiong is ok other than the lack of this switch.
Re: BOD - it hurts my ears!
Posted: 11 Jul 2010, 14:37
by italianjob
Bit more info for you
the van wass erviced by my regular garage of 4 years at the start of May. All was running OK, no buzzer. I was advised that the clutch was on its way out and would require changing (I knew this but was trying to delay the expenditure) - so the van went in 2 weeks later.
Clutch changed, all running OK, no BOD. MOT at the end of May (I thought it was in July, so it was a very last minute thing). Failed on the rear number plate bulbs which required connectors cleaning up and replacement of the terminals. Within 2 mins of driving away from the garage the BOD went off

. Now, in hindesite I should have taken the van straight back in BUT it was my mates wedding the next day and we were booked into a camp site and I had to use the van.
The day after, we drove down to Surrey - when the engine was ticking over on the drive no BOD. Within 2 mins of setting off - BOD for about 15 mins then nothing for the rest of the journey. Same on the return. Infact same for the whole of June up until last week when the BOD now refuses to give me a break.
Oil and water checked and everything seems OK. Engine sounds and runs OK. PCB at the back of the speedo looks OK - therefore Mr Watson surely this must just be either an electrical connection issue caused by the garage when they sorted out the rear lights, or just a coincidence and one of the oil pressure switches has packed up - hopefully.
Point taken - I will book the van in for a oil pressure test and ask them what grade of oil went in.
In the mean time - can I simply disconnect the PCB connector to get some peace from the dreaded BOD
as always - ta for any tips/advice
Re: BOD - it hurts my ears!
Posted: 11 Jul 2010, 16:45
by italianjob
the sound of silence.........for now anyway. Made a temporary fix and took her for a test run and no BOD.
Followed a link from aprevious post to some wiki information on the brickyard site concerning fixes for the dreaded BOD. Basically, for petrol models without a rev counter you can disconnect one of the green wires coming from ignition coil which fools the BOD thingy into thinking the engine isn't running. And hey presto no more BOD. Lieterally, the sound of silence
This is only a temporary fix until I get things sorted 'proper' so to speak. So that will be a oil pressure test and then replacement of the offending oil pressure switch/fix any loose connections.
Interesting points (to some)-
even though mine is an '85 registered van, I seem to both the low and high pressure oil switches. First registered in september '85.
there were 2 green wires connected to the ignition coil - the smaller of the 2 is the one to disconnect. With both of them disconnected the engine would turn-over but not fire.
The box contain all the electrical conenctions in the engine bay (looking at the engine, its at the clutch end of the bay on the left hand side) is one hell of a mass of wires and connections.
I'll let you know how it goes.
ta for now