riverstar Posted July 20, 2016 Report Share Posted July 20, 2016 Went out for a drive last night and everything was fine until I noticed that the oil pressure had dropped to zero so pulled off as soon as I could and checked the engine and couldn't find any sign of oil loss so got a recovery truck to ferry the car home. Until now I always enjoyed a healthy oil pressure and have never experienced any oil related problems so now I will need to track down the problem and would be grateful of any advice on the checks and process I should go through Thanks Chris Quote Link to post Share on other sites
RogerH Posted July 20, 2016 Report Share Posted July 20, 2016 Hi Chris, I hope no damage has been done. The most common item is the oil pump drive shaft. This is an extension of the dizzy. Item 37 http://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/engine/engines-components/internal-engine-components.html may be the fault. Roger Quote Link to post Share on other sites
John Morrison Posted July 20, 2016 Report Share Posted July 20, 2016 Was the car still running when you noticed the zero oil pressure? If Yes, was there any horrible ratles, noises etc? If No, think about the guage or oil feed pipe - simplest and cheapest things first! Good Luck. John. Quote Link to post Share on other sites
tim hunt Posted July 20, 2016 Report Share Posted July 20, 2016 For me this sudden drop in pressure in a healthy engine, not accompanied by catastrophic oil loss or untoward terminal noises points strongly to the ball in the pressure relief valve being held from its seating by some piece of foreign matter. Remove the complete assembly from the head of the oil filter, a 27 mm socket fits snugly, and I wouldn't mind betting that you find you can blow through the valve from the bottom. Measure the length of the assembly then loosen the lock nut and remove the adjusting screw, thoroughly clean all components and reassemble to the same length as previously measured, to preserve the adjustment. Check the sealing washer under the head of the valve and if it is chewed replace it. Refit the valve and hopefully oil pressure will be restored. AMHIK! Tim Quote Link to post Share on other sites
Lebro Posted July 20, 2016 Report Share Posted July 20, 2016 Was the car still running when you noticed the zero oil pressure? If Yes, was there any horrible ratles, noises etc? If No, think about the guage or oil feed pipe - simplest and cheapest things first! Good Luck. John. +1 Bob. Quote Link to post Share on other sites
ctc77965o Posted July 20, 2016 Report Share Posted July 20, 2016 I would look at the Pressure Relief Valve. Quote Link to post Share on other sites
MichaelH Posted July 20, 2016 Report Share Posted July 20, 2016 check the oil pump drive, from the cam skew drive to the dizzy/oil pump is dependent on a woodruff key which can fail If that is there is no answers with the pressure relief valve either way = good luck Michael Quote Link to post Share on other sites
peejay4A Posted July 20, 2016 Report Share Posted July 20, 2016 A stuck relief valve is unlikely to cause complete loss of oil pressure, reduced yes. As it's an easy check I'd look at it but with a sceptical eye. My money is on a failed pump drive. Quote Link to post Share on other sites
riverstar Posted July 21, 2016 Author Report Share Posted July 21, 2016 Thanks for all the advice I experienced no noise from the engine when I noticed the drop in pressure which could have happened anywhere in about a mile of 60mph driving. Will be getting the spanners out over the weekend starting with the relief valve, any advice on how the process to check the pump drive? Chris Quote Link to post Share on other sites
RogerH Posted July 21, 2016 Report Share Posted July 21, 2016 Hi Chris, Note where the rotor arm is pointing - it needs to go back here to keep the timing. remove the dizzy, remove the pedestal, withdraw the drive shaft. This is meshed with the cam so it will want to rotate slightly - remember this when you put it back The drive shaft is keyed into the gear - this key may have failed. TRy pulling the shaft out of the gear. Roger Quote Link to post Share on other sites
MichaelH Posted July 22, 2016 Report Share Posted July 22, 2016 It depends on how confident you are to reset the timing If you have done it before or have a workshop manual then is is easy, if not then you need a phone with a camera and you photograph everything as you take it apart so you can replace everything correctly as it goes back To do your investigation you just unbolt the dizzy and extract the skew gear to check the long central drive and check for the tang (like the end of a screw driver) which fits into the oil pump to send drive to the oil pump, and the woodruff key which transfers drive from the cam/skew gear to the central drive If both are ok it has to be something quite exotic as you said the engine was running ok but without oil pressure Thinks no oil? Look forward to a challenging TR week end and how pleased you will be when you have solved it and repaired it, don't forget a lot of these bits are fifty years old Michael Quote Link to post Share on other sites
boxofbits Posted July 22, 2016 Report Share Posted July 22, 2016 +1 on oil pump drive if complete loss of pressure, though could be a jammed relief valve if you were driving at speed. Spin it up with no plugs for testing but do not start it to check for pressure if you can help it, as to keep running it once it has fully drained and is dry could TRash it. Quote Link to post Share on other sites
riverstar Posted July 23, 2016 Author Report Share Posted July 23, 2016 I have taken the drive shaft and gear out and the shaft seems to be firmly in place in the drive gear I cant rotate it or pull it out so I assume that the key is still intact, just waiting for amazon to deliver a socket then will investigate the pressure relief valve. Quote Link to post Share on other sites
Rob Salisbury Posted July 23, 2016 Report Share Posted July 23, 2016 With a large screwdriver or other suitable drive shaft engage the oil pump drive at the bottom of the hole you can now see and rotate, anticlockwise, by hand the pump, if the pump driveshaft is OK then you will quickly feel the drive stiffen as the pump begins to suck up oil and build up pressure, if the driveshaft and rotor have lost interest in one another then the screwdriver will just loosely spin ...... (New pump needed). Have you tested the gauge? Cheers Rob Quote Link to post Share on other sites
riverstar Posted July 23, 2016 Author Report Share Posted July 23, 2016 Rob, done that and when rotated oil wells up through the hole into the shaft housing, is that how it should be? Chris Quote Link to post Share on other sites
TR 2100 Posted July 23, 2016 Report Share Posted July 23, 2016 A stuck relief valve is unlikely to cause complete loss of oil pressure, reduced yes. As it's an easy check I'd look at it but with a sceptical eye. My money is on a failed pump drive. +1 on oil pump drive if complete loss of pressure, though could be a jammed relief valve if you were driving at speed. Spin it up with no plugs for testing but do not start it to check for pressure if you can help it, as to keep running it once it has fully drained and is dry could TRash it. +1 for these comments. Just can't see it being a stuck pressure relief valve when there is NO oil pressure. AlanR Quote Link to post Share on other sites
Rob Salisbury Posted July 23, 2016 Report Share Posted July 23, 2016 With what you've learnt so far I think your pump and drive gear are working, so stick it all back together and disconnect the oil gauge feed at the dash end, with the plugs out and some means of containing the oil (it can get very messy!!), spin the engine over on the starter motor and see if any oil comes out of the pipe (or substitute another gauge) .... oil comes out ... must be the gauge .... no oil ... relief valve stuck or some related problem. Cheers Rob Quote Link to post Share on other sites
riverstar Posted July 24, 2016 Author Report Share Posted July 24, 2016 (edited) Here is the latest. I removed the dizzy and pedestal inserted a screwdriver into the oil pump and when rotated anticlockwise resistance was felt and oil quickly welled up through the shaft onto the pedestal I then removed the pressure relief valve which was closed but opened and closed freely when pressure was applied to the ball Disconnected the feed pipe to the oil gauge turned the engine over and nothing came out so disconnected the engine end and flushed it out suspecting a blockage however everything was fine. When turning the engine over without plugs I do get oil from the pipe coming out of the block but I expected a spurt?? not a flow which can easily be stopped by putting my finger over the end. Any more thoughts or advice gratefully received Chris Edited July 24, 2016 by riverstar Quote Link to post Share on other sites
RogerH Posted July 24, 2016 Report Share Posted July 24, 2016 Hi Chris, the pressure relief valve shouldn't open easily. It is meant to provide 70psi. Remove the ball from the cage and inspect the spring. If OK put it all back and screw the adjuster down past the dirt line on the screw. The oil from the block pipe probably should be a flow at 70 psi. I would not have thought you could have stopped it. You do not need oil all the way up the gauge pipe for it to work - it will compress the air on the gauge side. If the pump is working OK and the pressure relief is functioning OK then the oil is escaping somewhere. If it is not external then it is inside the engine. The biggest oil leak disaster is a broken crank. This could make a significant knocking noise but then again perhaps not. Roger Quote Link to post Share on other sites
nigethomas Posted July 24, 2016 Report Share Posted July 24, 2016 Hi riverstar I had same problem on my 4a and there is a previous thread on this subject.I did all the checks like you have removed all dizzy etc ano it turned out to be just spring in pressure relief valve. Nige Quote Link to post Share on other sites
Dick Posted July 24, 2016 Report Share Posted July 24, 2016 Collapse oil filter element? Quote Link to post Share on other sites
boxofbits Posted July 24, 2016 Report Share Posted July 24, 2016 You may even have something more serious like crankshaft main bearing failure as you are getting pressure manually at the pump, but very little at the guage block connection. Provided the pump is being driven the pressure has to be dissipating somewhere like the crankshaft or leaking oil galley. Kevin Quote Link to post Share on other sites
peter clarke Posted July 26, 2016 Report Share Posted July 26, 2016 Usually the rotor of the oil pump is drilled and pinned to its spindle but I have seen pumps that have no pin just pressed on. Long shot but it is possible for loose rotor to slip on spindle and not pump. Quote Link to post Share on other sites
RogerH Posted July 26, 2016 Report Share Posted July 26, 2016 Hi Chris, I keep coming back to the pump. If there was a leak removing all the pressure it would be noticeable. Others have doubted whether the pressure relief valve could do that - possibly. You would need fully spring collapse/destruction. You have checked the drive shaft key and it feels good. As above I would be concerned about the rotor/shaft pin (within the pump body). There may be enough friction to turn it slowly with a screwdriver and no back pressure. With speed and back pressure the rotor may be slipping on its shaft.. If you can't find the leak you may well have ot remove the sump and take the pump out. Roger Quote Link to post Share on other sites
ctc77965o Posted July 26, 2016 Report Share Posted July 26, 2016 I think theres a risk that everyone is over-thinking this based on one bad gauge reading. i would reassemble the cleaned PRV, top up the oil & start it...let it run for 30 seconds...not shorter...if the gauge responds then leave it running...if it doesnt then shut it off and assume the worst. These engines have huge bearings, they will run on litle oil pressure just fine (without full-power stress)...you will not destroy the engine with 30 seconds running.....i am concerned that these suggestions to partially strip the engine can waste months of your life....during the summer when TRs are meant to swarm the streets....... I had a low pressure event once (Zero below 2000 rpm)..that was the PRV with a bit of **** holding it open...how it got there dunno...but I cleaned it, reassembled & adjusted and never thought about it again. Quote Link to post Share on other sites
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