AlC Posted October 23, 2011 Share Posted October 23, 2011 Hi all Decided to go out for a drive this afternoon - turned out to be rather shorter than expected. About a mile from home noticed that the oil pressure was a lot more variable than normal (typically sits around 4-5 whatevers (psi?) and is pretty solid at that point, dropping to about 2 when idling). Today it was varying all the time with engine speed, and when first noticed was hitting 4 at about 3000 rpm, and less at lower speed. Kept a careful eye on it and it slowly started falling till by the time I got home (5 miles - narrow country lane, unable to turn) it was peaking about 2. So I ended up feeling I was nursing home with concern that pressure was dropping into red on idle. So I avoided idling. To my naive, inexperienced mind there are a number of possibilities here: - Faulty measurement - Faulty gauge - seems unlikely - Faulty sensor - more likely? - Genuine low oil pressure - Low oil level - checked at home with engine off - looked like it might be okay (well above max mark - bearing in mind it is supposed to be checked with engine running etc and has been okay - no oil marks in garage from engine) - Faulty pump - Pump not being driven correctly, how is it driven? - Blockage somewhere. My car is new (only collected after PBC/IVA in early August) and has 600 miles on the clock. Oil & filter were changed at 359 miles on 7 Sept and I was just lining things up for first formal service. It is 1.6 K series Supersport. I presume any parts would be covered by Caterham warranty. Must admit I am tempted by the idea of getting the service arranged & get them to look at this at same time - oil pressure seems something not to mess around with. I presume I could call my breakdown service & get them to transport the car to CC. All looks normal under bonnet, and engine temperature was exactly normal. Anyone got any advice as to where I should look first or approach to take? Thanks Al Link to comment Share on other sites More sharing options...
Grubbster Posted October 23, 2011 Share Posted October 23, 2011 Very likely to be a failing sensor, this is typical and far from uncommon. A lot of people fit a mechanical gauge instead (other electrical products are also available that are more reliable). Link to comment Share on other sites More sharing options...
Area Representative skeetsy Posted October 23, 2011 Area Representative Share Posted October 23, 2011 I Agree.... I recently changed the oil in mine and after seeing poor oil pressure with the engine hot, I decided to go for a motorsport grade oil 5W/50 rather than the standard 5W/40. I did take the opportunity to remove the foam sump baffle and undertook Oily's gasket modification during the oil change and then after it was all back together topped up and ready to go, with very healthy oil pressure , I took it for a quick blat as you do... About 5 miles into my blat the oil pressure dropped to zero and didn't come back up I quickly found a spot to stop and switched off the motor expecting to see a trail of oil behind me, but everything was fine, no leaks, plenty of oil on the dipstick, all was seemingly ok I then started it up again, no oil pressure ☹️ but no nasty noises or smoke, etc. and so drove home very gingerly thinking all the time, b@*!?ks I'm probably wrecking the thing (in my mind I had imagined that the oil pressure relief valve had stuck open due to the lovely new thick oil) After putting the car in the garage and checking for unpleasant noises which still weren't there, I did some frantic research on line (thankyou blatchat archives!) and then went back out under the car and had a fiddle with the spade connector on the oil pressure sender. Upon restarting the oil pressure came back instantly and it's been fine since But a mechanical oil pressure gauge is now on my to do list. All the best Richard Link to comment Share on other sites More sharing options...
AlC Posted October 23, 2011 Author Share Posted October 23, 2011 Seems quite hard to get less reliable! 600 miles and about 10 weeks. But I think a faulty sensor is probably the most palatable of the options (price wise). I presume it would be one of these or these? Dumb question, but whereabouts on the engine is it? And how do I test it? Edited by - AlC on 23 Oct 2011 21:03:25 Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted October 23, 2011 Share Posted October 23, 2011 On the oil filter housing. Pull wire off it and ground wire on the engine with the ignition on. Gauge should go full scale. Bin the electric sender and fit a mechanical OPG for little extra than the cost of a new sender. Easy to fit. Locals can help - the real power of BC ! Edit - it is the first link in your above post. Edited by - Stationary M25 Traveller on 23 Oct 2011 21:07:49 Link to comment Share on other sites More sharing options...
Area Representative Paul Richards Posted October 23, 2011 Area Representative Share Posted October 23, 2011 Edited to save me looking a fool. LADS TOP TIP:- If you do fit a new sender, put silicon around the terminal to stop ingress of water - it will prolong the life of the sender. Edited by - Paul Richards on 23 Oct 2011 21:18:49 Edited by - Paul Richards on 23 Oct 2011 21:20:45 Link to comment Share on other sites More sharing options...
anthonym Posted October 23, 2011 Share Posted October 23, 2011 this happened to me recently, the "sump" had a hole in it and I had half litre of oil left. so... check your oil level just though I'd add some balance to the faulty gauge crowd, who I suspect are perfectly correct in your case. Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted October 23, 2011 Share Posted October 23, 2011 I tried the silicone sealant around the terminal and the outer of the body on a new sender. Made little difference to the life. Link to comment Share on other sites More sharing options...
CageyH Posted October 24, 2011 Share Posted October 24, 2011 The other option, is to relocate the electrical sender. There is a kit somewhere on the Caterham store that allows you to do this. Link to comment Share on other sites More sharing options...
Oly Posted October 24, 2011 Share Posted October 24, 2011 I have a similar thing on my 1.8vvc k series. Oil pressure starts fine but on the move tends to vary around and can dip to red. I had only had for a week, but looking through he receipts given to me when I bought it has had a new oil pressure sensor every 2 years. As you say a quick search on BC has bought up lots of this type of issue. Link to comment Share on other sites More sharing options...
David Brown Posted October 24, 2011 Share Posted October 24, 2011 Surprised no-one has commented on a new K registered in 2011. Are CC still supplying them? David Link to comment Share on other sites More sharing options...
Grubbster Posted October 24, 2011 Share Posted October 24, 2011 They are still on the price list 1.4 or 1.6 K's for the Classic only Link to comment Share on other sites More sharing options...
oilyhands Posted October 24, 2011 Share Posted October 24, 2011 In the last 6 months I have had 4 Caterhams with OP problems which were assumed to be the sender, 3 of these were pickups blocked almost entirely by broken up and hardened sump foam. oily Link to comment Share on other sites More sharing options...
Stu_I Posted October 24, 2011 Share Posted October 24, 2011 Had similar irregularities with my OP and decided to eliminate the not knowing and fit a mechanical gauge. Works a treat and OP readings were what expected. Very easy to fit, not expensive considering price of new sender, and know the reading your getting is accurate. I documented the assembly if your interested based on BC help. BM me and I can send you it. Stu Link to comment Share on other sites More sharing options...
Dignity Posted October 24, 2011 Share Posted October 24, 2011 Quoting Stationary M25 Traveller: Bin the electric sender and fit a mechanical OPG for little extra than the cost of a new sender. Easy to fit. Locals can help - the real power of BC ! This is what I would be doing. My old sender had an intermittant problem and the danger was that I had become used to it. If a real problem came along such as Oily has described then I wouldn't have done anything about it until it was too late. A mechanical "Kit" is only around £70 quid all in and even a numpty like me can fit it. It's been said on BC that it isn't the ultimate solution but its a big improvement for not much money. I have a parts list from Think Auto if you send me a BM. That matched with Stu_I 's assembly guide and you can't go wrong Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted October 24, 2011 Share Posted October 24, 2011 ... or even less than that ! Link to comment Share on other sites More sharing options...
Grubbster Posted October 24, 2011 Share Posted October 24, 2011 Oily also makes a very valid point so worth checking this as well. In the last 6 months I have had 4 Caterhams with OP problems which were assumed to be the sender, 3 of these were pickups blocked almost entirely by broken up and hardened sump foam. Link to comment Share on other sites More sharing options...
Dignity Posted October 24, 2011 Share Posted October 24, 2011 Quoting Stationary M25 Traveller: ... or even less than that ! Yes you are right I just looked it up I paid £51 Link to comment Share on other sites More sharing options...
AlC Posted October 24, 2011 Author Share Posted October 24, 2011 So I have a number of votes for faulty sender, suggestion of oil level, and the old foam chestnut. I need to identify the immediate problem before I worry about "enhancements". At the moment I'm too worried to start the engine in case there is a real problem. I lean away from oil level. I don't know how high I should expect it to be without the engine running, but it's well above the max mark, and in fact above the kink on the dipstick. That sort of seems okay - said without knowing where to expect it to be... SM25T has told me how to check the gauge (job for another night when I can get home earlier). But how do I check the sender? I presume it is a resistance to ground varying with OP (which would suggest lots of OP = 0 ohms by SM25T suggestion?) Is this right? Anyone know what the static measurement would be, or another way to test the sensor without replacing it? Assuming my foam is intact, then that sounds like a job for the near future. But I would like to think that it would last more than 600 miles. Anyone had problems at this sort of mileage? So I think my next step is to check the sender if that is possible. Ideas appreciated. Thanks all Stu_I & Dignity - you both have BM. Link to comment Share on other sites More sharing options...
Dignity Posted October 24, 2011 Share Posted October 24, 2011 Al, Replied to your BM Link to comment Share on other sites More sharing options...
AlC Posted October 24, 2011 Author Share Posted October 24, 2011 Flippin' heck guys - I can't keep up. Thanks Link to comment Share on other sites More sharing options...
Stu_I Posted October 24, 2011 Share Posted October 24, 2011 You have a reply 😬 I have part list so you should enough to shop around if you decide to fit the MOPG . Think it took me a few hours to fit and was very easy to do. Best money I've spent on car. Good luck. Stu Link to comment Share on other sites More sharing options...
micksmetafors Posted October 25, 2011 Share Posted October 25, 2011 I've used both the Racetech and Stack variants of Mechanical OPG and both proved excellent. The illumination swings it towards Stack for me though. Very easy thing to fit and reliable. I've just bought one from Merlin and I think it was £34 plus VAT. You'll need an adaptor, in my case it was a M10 X 1.5 thread and most K engines seem to need this thread. Early ones have a different one I believe. Cheers, Steve Link to comment Share on other sites More sharing options...
Stu_I Posted October 25, 2011 Share Posted October 25, 2011 My 1.8 VVC K series needed a M12 x 1.5 adaptor. Also agree with stack illumination. Only problem is it puts the other gauges to shame and you realise how bad they are! Mine is a 2003 car 😬 Edited by - Stu_I on 25 Oct 2011 17:06:40 Link to comment Share on other sites More sharing options...
Roger Ford Posted October 25, 2011 Share Posted October 25, 2011 But then when you want a simple analogue clock for your dash you have to spend £72 on a Stack one so it matches Link to comment Share on other sites More sharing options...
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