I.Mupferit Posted September 5, 2005 Share Posted September 5, 2005 When I first built my car and installed the 2.3 Duratec, I put in semi-synthetic oil for the initial 'breaking in' period. At 500 miles I drained this out, changed the filter and filled with a top quality fully synthetic. All was well for the next 1500 miles but then I started to notice that when the oil was good and hot, if the engine was run at 4500 rpm + for more than a few seconds, the oil pressure which is normally 5 bar starts to dip towards 4 bar and stay there. As soon as I dropped back below 4500, it rose again nearer 5 bar and behaved normally with idle pressure at around 1.5 bar. When cold, the pressure could rise to 6 - 7 bar+ without revving the engine too highly . I have spoken to a couple of luminaries who thought maybe the relief valve is sticking open as apparently the Duratec starts to dump a lot of oil back into the sump at 4 - 4500 rpm. This sounded feasible and although I know the pressure senders are a bit flakey to say the least, I didn't think it could be that as it behaves normally all other times. Anyhow, I decided to change the oil and filter on Saturday just to see if that had any effect and put the same type of fully synthetic oil in at a current odometer reading of nearly 3000 miles so the old oil had only been in the engine for less than 2500. Well now, everything has returned to normal and when cold the oil pressure goes up to only around 6 bar but, more importantly, is now a rock steady 5 bar at prolonged running over 4500 - 5000 rpm with the same idle pressure as before of 1.5 bar. Nothing else has changed, so I can't get my head around what was happening with the last sump full of oil. It was obviously alarming to watch the gauge dipping above 4500 rpm and then continuing down the faster you went. Could it be cavitation maybe or a dodgy batch of oil perhaps and whilst I know oil deteriorates with mileage, surely 1500 miles of fairly gentle usage whilst touring isn't a lot for a top quality oil 🤔 And why would the cold oil pressure be higher with the previous sump full of the same type of oil 🤔 Any ideas 🤔 Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Edited by - BRENT CHISWICK on 5 Sep 2005 09:14:35 Edited by - Brent Chiswick on 5 Sep 2005 18:38:53 Link to comment Share on other sites More sharing options...
Paul Formston Posted September 5, 2005 Share Posted September 5, 2005 Hi Brent you don't mension which oil pressure gauge you are using, if it is the standard caterham one don't take any notice of it thay are rubbish, I am on my second sender since June and my oil pressure is all over the place on my Zetec, but I no the the oil pressure is ok so I have ordered another sender, they reccon that its water ingress that coures the problem because the car is so low to the ground so im going to seal the next one with electrical varnish and silicone. Thay could be right because I went though to bad storms in Germany Regards Paul Link to comment Share on other sites More sharing options...
I.Mupferit Posted September 5, 2005 Author Share Posted September 5, 2005 Paul, it is the CC gauge but as I said before, I don't believe it is that which is at fault on this occasion. Literally all I did on Saturday was to change the oil and filter and that was enough to alter the readings quite dramatically. I didn't even touch the sender or its connections and the way it behaved before the oil change was consistent ie it didn't keep changing, reading high one minute then low the next. If it is a faulty gauge/sender then it seems a bit too coincidental that is should suddenly start behaving itself when all I did was drain and refill the sump and change the filter. Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Link to comment Share on other sites More sharing options...
Manxseven Posted September 5, 2005 Share Posted September 5, 2005 Brent, Did you check the oil level? Maybe it was 'down a bit, but now you have changed it and filled it back up, it is at the correct level to be a happy duratec again L7 BDA Supersprint Joy here 😬 Link to comment Share on other sites More sharing options...
stevefoster Posted September 5, 2005 Share Posted September 5, 2005 Are Duratec's critical to have a 5 bar? Seems odd that a change of oil should fix it, unless the pressure relief valve is sticking and the oil change procedure unstuck it? Do you plugs out and crank up some pressure or just fire it up after the change? I once observed oil pressure fluctation on my VX after it had been off the road for upgrades during winter and not been used for 2 months. As soon as it got going properly it cleared and I've never had a problem since (3 yrs ago) - same sender all the time. If you do not have an oil warning switch / lamp at ~36psi I would fit one. Hants (north) / Berkshire club here Area meeting pics here My Racing here Link to comment Share on other sites More sharing options...
I.Mupferit Posted September 5, 2005 Author Share Posted September 5, 2005 Yep, plugs out and inertia switch unplugged to crank it over for oil pressure. I don't know that 5 bar is critical to a Duratec but the worrying aspect of this was that the pressure dropped, the faster I went Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Link to comment Share on other sites More sharing options...
Beelzebub Posted September 5, 2005 Share Posted September 5, 2005 Had a V. similar problem on a Land Rover once. The voltage stabiliser that powered the gauges was 🙆🏻 Just a thought 😬 Link to comment Share on other sites More sharing options...
I.Mupferit Posted September 5, 2005 Author Share Posted September 5, 2005 I would love to think it is the gauge/sender but it is the sudden coincidence of changing the oil then the gauge immediately showing normal behaviour that I find baffling. And that was on a round trip of 150 miles yesterday during which it read exactly as I would expect whatever the engine rpm. Think I might change to a mechanical gauge for peace of mind though. Anybody know of a good mechanical gauge that looks similar to the CC ones 🤔 But I would still like to understand what was going on with the last sump of oil if anybody has any ideas. Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Link to comment Share on other sites More sharing options...
I.Mupferit Posted September 5, 2005 Author Share Posted September 5, 2005 Manxseven sorry, I didn't mean to ignore you. No the oil level hadn't moved and was exactly the same level as the new 5 litres I put in on Saturday, so can't be that. I really am beginning to suspect the oil itself is the culprit although I don't understand why yet. Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Link to comment Share on other sites More sharing options...
Rob Walker Posted September 5, 2005 Share Posted September 5, 2005 Faulty pressure dump valve within the oil filter? They should only open when the filter gets blocked to prevent the filter case splitting. I always fit filters that do not have this valve because should this valve open all the crud that the filter has removed will be released around the engine. Filters without this valve are getting harder to find. Link to comment Share on other sites More sharing options...
Big Brother Posted September 5, 2005 Share Posted September 5, 2005 If it is the oil that caused the problem, hopefully Oilman will be along shortly to tell us how this can happen. Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
Mr Locust Posted September 5, 2005 Share Posted September 5, 2005 Have you checked that the oil level is correct as Simon says? The first thing that comes to mind is oil starvation. Presumably the sump you are using is not the standard unit for the engine, so the dipstick level may not be correct. Now you are starting to use the RPM after running in the oil flow will increase so more oil will be at the top of the engine and draining back to the sump. Maybe there isn't enough total oil in the system to keep the pickup immersed.....? Ian Green and Silver Roadsport 😬 Link to comment Share on other sites More sharing options...
I.Mupferit Posted September 5, 2005 Author Share Posted September 5, 2005 Mr L, it is a Raceline wet sump as used by countless others with no probs so I know that is ok and as I said above, the oil level was fine at all times. The sump takes 5 Litres which, if you include the filter, is pretty much what came out which I know for sure because I poured it back into the 5L container the fresh oil came in. It can't be a problem with sump capacity or oil not draining back quickly enough as it is absolutely fine now at all engine speeds. I just don't like problems such as this which can't be explained so remedial steps can be taken to prevent a recurrence. Maybe as Rob suggests it was the valve within the filter as that was obviously changed as well and disposed of so I guess I may never know for sure. ☹️ Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Link to comment Share on other sites More sharing options...
moosetestbestanden Posted September 5, 2005 Share Posted September 5, 2005 Brent, I changed the oil in my 2.0L yesterday. I put Castrol semi-syn in a 5W20 in the engine. I have the Raceline sump as well. I took the car out for a short drive. I experienced exactly the same phenomenon as you. This has happened before. Changing the oil again seemed to cure the problem as the oil pressure becomes Rock Steady again, as in your case. How much oil are you putting in the engine? Edited by - moosetestbestanden on 5 Sep 2005 15:19:09 Link to comment Share on other sites More sharing options...
I.Mupferit Posted September 5, 2005 Author Share Posted September 5, 2005 Not just me then, how bizarre 5 Litres of oil as recommended by Pete McEwen at Raceline. In fact it does show on the dipstick as slightly higher than the full mark but since I buy the oil in 5L containers, I figure that I am putting in the right amount each time. Ok, I realise there will still be some oil left in the galleries and head etc after draining but probably not enough to make a significant difference to the level. How often has yours done this 🤔 Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Edited by - Brent Chiswick on 5 Sep 2005 15:30:21 Link to comment Share on other sites More sharing options...
neil.cavanagh Posted September 5, 2005 Share Posted September 5, 2005 but think of the weight of that extra oil Brent... 😬 😬 and YHM @ tesco.... Link to comment Share on other sites More sharing options...
moosetestbestanden Posted September 5, 2005 Share Posted September 5, 2005 This is the 2nd time. My dipstick cannot be anywhere near correct for the engine's configuration as it shows at max. level after just 3 quarts. I'm pretty sure the local dealer sourced it from the Who Knows Where parts catalogue (my car is one of the earliest Duratecs over here). I'm going to change the oil again today to see if the problem goes away. ------- Chris Vitural distance is only as far as you think it is Link to comment Share on other sites More sharing options...
I.Mupferit Posted September 5, 2005 Author Share Posted September 5, 2005 Would it be worth just changing the filter first and seeing if that solves the problem as I am now beginning to think there is something weird going on with that. I can't really understand how the oil itself can cause such a fluctuation but it might, at least, isolate the problem by only changing 1 thing at a time. Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Link to comment Share on other sites More sharing options...
I.Mupferit Posted September 5, 2005 Author Share Posted September 5, 2005 Can you remember if you have used the same make and type of filter each time? The filter I used this time around is a different make to the previous item so maybe that could provide the explanation, although I don't yet understand why. Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Edited by - Brent Chiswick on 5 Sep 2005 16:23:38 Link to comment Share on other sites More sharing options...
I.Mupferit Posted September 5, 2005 Author Share Posted September 5, 2005 Update on the oil pressure problem. I spoke with Pete McEwen to discuss the oil filter theory and he confirms that most modern filters have this sprung valve arrangement which can, indeed, restrict the oil flow to a dangerous level at higher rpm. This is why he specifies the old 'Motorcraft' (in his words) "sh1tty old crossflow filter" which doesn't have this valve. He thought I was using one of these so didn't think to mention it when I discussed the problem with him on Saturday morning. Said he had seen a very expensive engine destroyed on a dyno years ago just because they had fitted the wrong type of filter. The filter I was using was a Halfords HOF 200 which I had a look at in Halfords tonight to compare with the Champion filter I now have fitted (C103) and sure enough the Halfords jobby has this valve arrangement whereas the Champion one doesn't ❗ It looks, therefore, like the mystery may be solved so Moosetestbestanden, I would look very carefully at your filter type and quickly get rid of it if it has the valve arrangement fitted. So I guess the moral of the story is to always take the advice of your engine builder ❗ Mind you I don't recall him making a very big issue of it at the time and I guess it just proves we can all still learn something. Thankyou B/Chat for pointing me in the right direction yet again *thumbup* Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Link to comment Share on other sites More sharing options...
moosetestbestanden Posted September 5, 2005 Share Posted September 5, 2005 I had to switch filters from the Bosch that came w/ the engine to a Fram because at the time I could not source the Bosch. At the switch is when the problem 1st showed up. I used the same type (for the same reason) on the next oil change and the problem went away. Bleah. For this most recent oil change I used the Fram again, one that I had purchased previously. I have had the same thought as you - just chenge the filter and see what happens. More empirical that way. Unfortunately now I can't find the Fram but have found the Bosch. I will change just the filter just the same, but 1st I'm going to add more oil. I've always put 4 quarts in as that was how much I was told to use by the dealer. I agree w/ you in as much as I can't see any reason why one type of oil would be any different than any other. ------- Chris Vitural distance is only as far as you think it is Link to comment Share on other sites More sharing options...
I.Mupferit Posted September 5, 2005 Author Share Posted September 5, 2005 Chris, Let me know how you get on when you have changed the filter as I would be interested to have the theory confirmed by a second Duratec user. Incidentally, 5 Litres as Pete McEwen (designer of the Raceline sump) recommends is just over 4 quarts at nearly 4.4. Although come to think of it, I believe a U.S. pint and presumably a quart also, is different to an imperial pint/quart isn't it 🤔 I'll check it out. Just did a Google search and sure enough the US quart is different to the UK measure and the site I found converts 5 Litres to 5.283441 (nothing like a bit of accuracy 😬) quarts so it appears that your measure of 4 quarts could be well short of design. Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Edited by - Brent Chiswick on 5 Sep 2005 23:36:32 Link to comment Share on other sites More sharing options...
Dobuy Posted September 6, 2005 Share Posted September 6, 2005 Hi Brent, I am using the Halfords HOF203 as recommended by Peter McKewan. This is the X-flow filter, Peter said that the Halfords filters were good as they had larger holes on the rim of the filter and gave good flow. I wonder what the difference between it and the HOF200 is? Duratec SV, built in Dubai Link to comment Share on other sites More sharing options...
I.Mupferit Posted September 6, 2005 Author Share Posted September 6, 2005 Neil, I had a look at both of these last night in Halfords and the HOF203 doesn't have this valve arrangement which the 200 does. I have to say that I hadn't really ever given this a thought before and certainly didn't realise that some had this valve where others didn't. The HOF203 is the equivalent of the Champion C103 so it seems both these are ok. Just glad I found out now rather than after the bearings had been run ❗ I think I might get a stock of the correct ones in just to avoid any future problems though. Brent 2.3 DURATEC SV Reassuringly Expensive R 417.39 😬 Link to comment Share on other sites More sharing options...
Bozz Posted September 6, 2005 Share Posted September 6, 2005 Brent Is this filter relief valve just a Duratec issue then or would it apply equally to other engines i.e. K series, Zetec etc 🤔 Bozz It's not MANGO it's TANGO (McLaren Orange and Black 1.6SS) Link to comment Share on other sites More sharing options...
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