jp7 Posted April 1, 2011 Share Posted April 1, 2011 Hi all, after getting the car mot'ed on wednesday, set off fo a 50mile blat today, the first since 2009. Today, after the initial 6 bar pressure reading when the oil is cold (normal on past experience), it drops off to 5 bar when hot, today it didnt, it stayed at 6 bar and when i rev'ed above 6000, the oil pressure increased nearer to 7 bar. At idle pressure drops to 4 bar hot, which from memory hasnt changed. I use mobil 1 motorsport 15w50 and have never had a problem in the 6 years i've been using it. I changed the oil + filter for new last week. Any thoughts? Is the pressure relief valve stuck?,dodgy sender? The car is 95 Kseries with a dry sump and VDO gauges. cheers Jon Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted April 1, 2011 Share Posted April 1, 2011 If it is an electrical sender, change it to a mechanical gauge Costs little more for the whole setup than for a new electrical sender. Link to comment Share on other sites More sharing options...
Sheds Moderator Posted April 1, 2011 Share Posted April 1, 2011 If you can get the standard gauge to do anything but wander about and tell you that there may be some oil pressure, probably, somewhere, you are a better man than I, Gunga Din. It's bobbins. Link to comment Share on other sites More sharing options...
Racingshoe Posted April 1, 2011 Share Posted April 1, 2011 I had similar symptoms earlier this year with my VDO electrical oil pressure gauge. After blowing 2 crank oil seals i've invested in a mechanical gauge and also sent my dry-sump pump off to Titan for a refresh. I think that in the cold weather my oil was too thick and my pump couldn't keep up. I got my Stack mechanical gauge from Merlin Motorsport for under 50 quid Link to comment Share on other sites More sharing options...
Dignity Posted April 1, 2011 Share Posted April 1, 2011 Hi Jon, I can only agree with all of the above comments. As you will see here I wanted to stay with the electrical but was persuaded to go mechanical. I bought all of the parts needed from Think Auto which they delivered for £50 quid. Easiest upgrade I have carried out and one of the best. The gauge is much easier to read and gives me a lot more confidence. Send me a blatmail if you want the part numbers. Regards Dignity Link to comment Share on other sites More sharing options...
jp7 Posted April 2, 2011 Author Share Posted April 2, 2011 Thanks guys for your replies, i think i'll get a mechanical sender fitted and see where we are at. I think i'll take the pressure relief out as well to give it a check and clean, cheers Jon Link to comment Share on other sites More sharing options...
ECR Posted April 2, 2011 Share Posted April 2, 2011 A mechanical gauge is the best solution. I have experienced apparent overpressure with a standard electric sender when the contact at the sender was a little loose/dirty. Cleaning and tightening solved it. Link to comment Share on other sites More sharing options...
Dignity Posted April 2, 2011 Share Posted April 2, 2011 jp7 and Mad Malc YHM Regards Dignity Link to comment Share on other sites More sharing options...
glasgow Posted April 5, 2011 Share Posted April 5, 2011 Guys, Please execuse my ignorance.... My understanding is - and please correct me if i am wrong - if the car is running fine and the oil level is not low pressure reading problems are due to either faulty sender or faulty gauge...... So, if there is no problem in the car and the oil level is ok, do we need to bother about oil pressure?! Many of modern cars don't have oil pressure gauge.... Link to comment Share on other sites More sharing options...
Racingshoe Posted April 5, 2011 Share Posted April 5, 2011 not necessarily... you can have overly high oil pressure for a number of reasons. These could be caused by your scavenge pump being knackered (my problem I think), blocked oilways, poor sealing on 1 or more pistons increasing crankcase pressure..... it is vital you know what is going on. Link to comment Share on other sites More sharing options...
Mick Day Posted April 6, 2011 Share Posted April 6, 2011 Why would a knackered scavenge pump cause high oil pressure? Pressure is a product of the pump output multiplied by the resistance to flow. So either the pump output has gone up (is there an adjustment on the pump?? Pace pump??) or the flow has been restricted. What oil filter are you using??? Is it a different brand to previous? Personally I've found VDO gauges/senders to be very reliable. Link to comment Share on other sites More sharing options...
jp7 Posted April 7, 2011 Author Share Posted April 7, 2011 Hi all, just back from a few days away with work. Champion filter, same as before. Nothing wrong with scavenge pump, same oil as before. Tomorrow i will clean up the contacts on the sender and see if it makes a difference. All i can think if it isnt the sender is a sticking pressure relief valve. cheers Jon Link to comment Share on other sites More sharing options...
CharlesElliott Posted April 7, 2011 Share Posted April 7, 2011 I don't agree that a mechanical gauge is the best solution. It is generally more highly damped than an electrical sender and means you have to bring oil through the bulkhead. However, it does have the advantage of being cheaper than a good electrical setup. Although the default Caterham senders are not good (and also mounted in a position that makes them highly vulnerable), I wouldn't therefore assume that all electrical senders are rubbish. Link to comment Share on other sites More sharing options...
6speedmanual Posted April 7, 2011 Share Posted April 7, 2011 Come on jp, TTIUW.......... Fulldata plots of pressure, revs, G. See here! How do you expect POBC when you don't give all the information? Peter Link to comment Share on other sites More sharing options...
jp7 Posted April 9, 2011 Author Share Posted April 9, 2011 Damn, i dont understand it, let alone be able to produce it!! Anyway, cleaned up the contacts on the sender and its all back to normal . 3.5bar idle and 5.5 bar @7000. So happy now with that, however, i thought the car was pretty loud so borrowed a noise meter, 108dB @ 4500rpm, so it looks like i will have to buy a new silencer now cheers Jon Link to comment Share on other sites More sharing options...
ECR Posted April 9, 2011 Share Posted April 9, 2011 Link to comment Share on other sites More sharing options...
FlymoFraser Posted April 9, 2011 Share Posted April 9, 2011 Just following Glasgows point. With a K series wet sump, other than on a sharp bend where you may get oil starvation because of the shape of the pan, I've not seen any comments on here about oil pressure gradually getting lower (as you do in an X flow). -With a K series oil pressure is either normal or catastrophic not "a bit low" - Is that statement correct? If it is, presumably we could just make do with a low pressure light to try to save something from a catastrophic oil failure?. Link to comment Share on other sites More sharing options...
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