Smokey Posted September 26, 2008 Report Share Posted September 26, 2008 My 1962 TR4 has fluctuating oil pressure on the highway when the engine is fully warmed up. At a constant 3000 rpm, the oil pressure gauge will fluctuate in an irregular manner between 50 and 70 psi. I remember having this symptom on the 1965 TR4 I had for five years in the 1960s, and ignored it since the pressure was still in an acceptable range and my funds were limited. My plan is to renew the spring and ball in the pressure limiting valve, but are there any other ideas as to what might cause this? Quote Link to post Share on other sites
stuart Posted September 26, 2008 Report Share Posted September 26, 2008 My 1962 TR4 has fluctuating oil pressure on the highway when the engine is fully warmed up. At a constant 3000 rpm, the oil pressure gauge will fluctuate in an irregular manner between 50 and 70 psi. I remember having this symptom on the 1965 TR4 I had for five years in the 1960s, and ignored it since the pressure was still in an acceptable range and my funds were limited. My plan is to renew the spring and ball in the pressure limiting valve, but are there any other ideas as to what might cause this? Bit of a messy job but you could try bleeding the gauge out as well. Stuart. Quote Link to post Share on other sites
Smokey Posted September 26, 2008 Author Report Share Posted September 26, 2008 Stuart, good pointer, hadn't thought of that. How do I bleed out the gauge? Fill it with oil with the gauge face down until there are no bubbles? And how do I then connect the oil pipe without getting any air into the gauge? I will also check all the connections on the oil pipe to the gauge, including the flex hose. I figured if there was a leak, I'd see some oil around, but maybe not. Quote Link to post Share on other sites
stuart Posted September 26, 2008 Report Share Posted September 26, 2008 Stuart, good pointer, hadn't thought of that. How do I bleed out the gauge? Fill it with oil with the gauge face down until there are no bubbles? And how do I then connect the oil pipe without getting any air into the gauge? I will also check all the connections on the oil pipe to the gauge, including the flex hose. I figured if there was a leak, I'd see some oil around, but maybe not. As I said a messy business. Release the gauge, pull gauge forward and just slacken the nut on the feed pipe with engine ticking over until you get covered in oil! Keep a rag around it and you shouldnt make too much mess.(hopefully) This may not cure your problem but its one less variable. Have you tried another gauge? Stuart Quote Link to post Share on other sites
Smokey Posted September 26, 2008 Author Report Share Posted September 26, 2008 Have you tried another gauge?Stuart I don't have another gauge at hand (although I have spares for almost everything - I feel like I'm running a Standard-Triumph parts department) so I'll look into it. I think my first test will be the spring and ball on the pressure relief valve - less messy. Quote Link to post Share on other sites
shuey Posted September 26, 2008 Report Share Posted September 26, 2008 just a thought I had a similar prob on my 6 turned out to be the strainer/pick up pipe had fallen off the pump Quote Link to post Share on other sites
Smokey Posted September 26, 2008 Author Report Share Posted September 26, 2008 just a thought I had a similar prob on my 6 turned out to be the strainer/pick up pipe had fallen off the pump A problem with the oil pump is a more serious possibility. If you had similar symptoms, the pick up pipe is definitely something I'll check out. The engine was supposedly rebuilt by the PO, but I've found a number of issues, like a distributor drive gear that was misaligned and a worn key on the front crankshaft pulley. Quote Link to post Share on other sites
piman Posted September 26, 2008 Report Share Posted September 26, 2008 Hello Stuart, surely air in the oil pressure gauge line won't have any effect on the indicated pressure? The pressure in the line will be equal be it air or oil. It's not the same situation as air in the brakes as there is a finite amount of fluid available. Alec Quote Link to post Share on other sites
shuey Posted September 26, 2008 Report Share Posted September 26, 2008 just a thought I had a similar prob on my 6 turned out to be the strainer/pick up pipe had fallen off the pump my engine was ment to have been rebuilt by a "pro" he`d left the lock nut off the pick up pipe amongst other things that have since come to light Quote Link to post Share on other sites
stuart Posted September 26, 2008 Report Share Posted September 26, 2008 Hello Stuart, surely air in the oil pressure gauge line won't have any effect on the indicated pressure? The pressure in the line will be equal be it air or oil. It's not the same situation as air in the brakes as there is a finite amount of fluid available. Alec Alec the only reason I suggested it was I have known it happen before, although not on a TR engine. Stuart Quote Link to post Share on other sites
Badfrog Posted September 27, 2008 Report Share Posted September 27, 2008 (edited) I'd vote for something loose in the oil pump : the pump itself, the lower plate, the pick-up tube... A loose pump may lead to air intake and a loose plate might cause the gears to take a wrong position and cavitate or grip. Air bubble in the mano won't do much harm, but it's a symptom of a problem in the oil pump system. BTW, what about the oil filter stand and the adjustable ball and spring ? Everything fastened OK around there? Edited September 30, 2008 by Badfrog Quote Link to post Share on other sites
Don Elliott Posted September 30, 2008 Report Share Posted September 30, 2008 We all assume that the oil level in your sump is correct. Quote Link to post Share on other sites
Smokey Posted September 30, 2008 Author Report Share Posted September 30, 2008 Hi Don, the oil level was the first thing I checked when I saw the fluctuating pressure on the drive from Toronto to the VTR Convention in Ypsilanti. The oil was a little low but still above the bottom mark, and I brought it up to the top mark, but the fluctation was still there. I have a new spring and ball on order for the pressure regulator, and I'll check all the connections around it at that time. I also have a new pump driveshaft on order with the key and the pin. Checking the oil pump and peripherals will have to wait until the next oil change. Can the pump and peripherals be checked just by removing the oil pan? Quote Link to post Share on other sites
TR 2100 Posted September 30, 2008 Report Share Posted September 30, 2008 Can the pump and peripherals be checked just by removing the oil pan? Yes. AlanR Quote Link to post Share on other sites
MikeF Posted October 4, 2008 Report Share Posted October 4, 2008 Alec the only reason I suggested it was I have known it happen before, although not on a TR engine.Stuart Mine was zizzing around as described , and I did fix it by bleeding the air (and a load of sludge) from pipe. Its esier to get acces to back of gauge if you undo the pipe clip on underbonnet bulk head, Mike Quote Link to post Share on other sites
Smokey Posted November 24, 2008 Author Report Share Posted November 24, 2008 Re the fluctuating oil pressure, I replaced the spring and ball in the oil pressure regulator, and the fluctuation seems to have disappeared. I'll know for sure next summer when the weather is warmer, but maybe the ball was worn, and would cause the fluctuation. Quote Link to post Share on other sites
john.r.davies Posted November 24, 2008 Report Share Posted November 24, 2008 Well done, Smokey! KISS, as they say, and none of this complex, doom laden stuff. Very good news. And thank you for the feed back, it all helps the data base! John Quote Link to post Share on other sites
TR4Geoff Posted November 25, 2008 Report Share Posted November 25, 2008 Stuart, good pointer, hadn't thought of that. How do I bleed out the gauge? Fill it with oil with the gauge face down until there are no bubbles? And how do I then connect the oil pipe without getting any air into the gauge? I will also check all the connections on the oil pipe to the gauge, including the flex hose. I figured if there was a leak, I'd see some oil around, but maybe not. Hi Smokey Glad to see you seem to have sorted your problem - just thought I would mention for future reference that if there are any leaks in this area you will certainly see them! Earlier this year my ?nylon flexi pipe developed the most minute pin hole. I lost a pint of oil in 10 miles and had my own personal 'gusher' under the bonnet - thank goodness it was under the bonnet and not behind the dash! Geoff Quote Link to post Share on other sites
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