foster461 Posted August 23, 2008 Report Share Posted August 23, 2008 Driving home from an event on Thursday I noticed when we got home that the oil pressure light was glowing dimly but the gauge was registering presure so I assumed it was something stupid that I would easily track down. Started the engine this morning and no oil pressure after 30 seconds. I checked the oil level, pulled the relief valve out and that doesnt seem to be stuck and I checked that the drive dog is engaged and that the top of the oil pump shaft turns. Before I drop the sump and pull the oil pump is there anything else that would explain this ? Oil and filter (spin on type) are relatively new, less than 200 miles. Stan Quote Link to post Share on other sites
currylager Posted August 23, 2008 Report Share Posted August 23, 2008 Driving home from an event on Thursday I noticed when we got home that the oil pressure light was glowing dimly but the gauge was registering presure so I assumed it was something stupid that I would easily track down. Started the engine this morning and no oil pressure after 30 seconds. I checked the oil level, pulled the relief valve out and that doesnt seem to be stuck and I checked that the drive dog is engaged and that the top of the oil pump shaft turns. Before I drop the sump and pull the oil pump is there anything else that would explain this ? Oil and filter (spin on type) are relatively new, less than 200 miles. Stan Is it worth trying to refit the original filter set up, it sounds strange if the car was ok before you did the spin on conversion, if thats what you did??. Might be worth trying before stripping the engine perhaps Quote Link to post Share on other sites
Guest ntc Posted August 23, 2008 Report Share Posted August 23, 2008 Driving home from an event on Thursday I noticed when we got home that the oil pressure light was glowing dimly but the gauge was registering presure so I assumed it was something stupid that I would easily track down. Started the engine this morning and no oil pressure after 30 seconds. I checked the oil level, pulled the relief valve out and that doesnt seem to be stuck and I checked that the drive dog is engaged and that the top of the oil pump shaft turns. Before I drop the sump and pull the oil pump is there anything else that would explain this ? Oil and filter (spin on type) are relatively new, less than 200 miles. Stan Stan The answers are on this forum ie (tale of woe)( spin on oil filter)and initial start up. I would check the the oil pump first Quote Link to post Share on other sites
foster461 Posted August 23, 2008 Author Report Share Posted August 23, 2008 Is it worth trying to refit the original filter set up, it sounds strange if the car was ok before you did the spin on conversion, if thats what you did??. Might be worth trying before stripping the engine perhaps The spin on adapter has been installed for years, it was a just a new filter with the last oil change as usual. Quote Link to post Share on other sites
Richard Crawley Posted August 23, 2008 Report Share Posted August 23, 2008 (edited) Have you got the later spin on conversion with the sprung loaded inner seal? Did you remove the old sealing ring from the block; sorry if I’m insulting your intelligence Stan but this & the above are know causes of problems with the earlier spin on conversions. Are you sure it’s not the gauge? I keep a small auxiliary gauge I know works & screw this directly into the pressure sensor hole on the block is I suspect problems with a pressure sensor or gauge. Are you sure it's a suitable filter? Edited August 23, 2008 by Richard Crawley Quote Link to post Share on other sites
foster461 Posted August 23, 2008 Author Report Share Posted August 23, 2008 Have you got the later spin on conversion with the sprung loaded inner seal? Did you remove the old sealing ring from the block; sorry if I'm insulting your intelligence Stan but this & the above are know causes of problems with the earlier spin on conversions. Are you sure it's not the gauge? I keep a small auxiliary gauge I know works & screw this directly into the pressure sensor hole on the block is I suspect problems with a pressure sensor or gauge. Are you sure it's a suitable filter? If it was just the lamp or just the gauge I would be looking for an instrumentation problem but both were telling me that I have no oil pressure. The spin-on is the old type but was installed with new seals after the rebuild and I have done 1000 miles since then. The filter is a popular NAPA filter for this application, lots of us here in the US use it. I'll spin it up again with the plugs out to double check and if I still have nothing on the meter I'll go after the pump. It just seems odd for a pump to just fail like that. Stan Quote Link to post Share on other sites
TR6 Poor Posted August 23, 2008 Report Share Posted August 23, 2008 I'd pull the dist. and gear, use the homemade oil primer bolt hooked to the electric drill and see if I can get oil pressure, if not, drop pan, and see if maybe sump fell off pump, or engine needs rebuild......... Quote Link to post Share on other sites
foster461 Posted August 23, 2008 Author Report Share Posted August 23, 2008 I'd pull the dist. and gear, use the homemade oil primer bolt hooked to the electric drill and see if I can get oil pressure, if not, drop pan, and see if maybe sump fell off pump, or engine needs rebuild......... Inerestingly when spun with a drill I do get a large volume of oil welling up in the dizzy hole AND I can hear the anti run on valve switching on which says I am building pressure with the drill. When I install the dizzy drive dog though I am having no luck getting it to engage with the oil pump. This is never a simple task but usually I can eyeball where the oil pump needs to be and drop the drive dog in after a few attempts. Today I cannot get it to engage, or at least if it is engaged it is not turning the pump. The drive dog looks fine, no sheared pin or obvious problem with the end. When I turn the engine over the dizzy drive gear turns so I dont think it is the cam end. I may have to pull the pump just to get a good look at the end and to engage it with the dizzy drive from underneath. Engine should not need a rebuild, it has less than 1000 miles on it. Stan Quote Link to post Share on other sites
TR6 Poor Posted August 24, 2008 Report Share Posted August 24, 2008 Wonder if the 3 bolts that hold the pump on have come lose and the pump has dropped down? Quote Link to post Share on other sites
foster461 Posted August 24, 2008 Author Report Share Posted August 24, 2008 Wonder if the 3 bolts that hold the pump on have come lose and the pump has dropped down? That is what I am begining to wonder. I measured the distance between the top surface that the drive dog sits on and the topmost part of the pump drive shaft. Then I measured the shaft of the drive gear and there is very little difference, perhaps less than 1mm for engagement. I have the oil draining, I'll pull the oil pan off tomorrow morning and get a better look at the pump. Stan Quote Link to post Share on other sites
marvmul Posted August 24, 2008 Report Share Posted August 24, 2008 That is what I am begining to wonder. I measured the distance between the top surface that the drive dog sits on and the topmost part of the pump drive shaft. Then I measured the shaft of the drive gear and there is very little difference, perhaps less than 1mm for engagement. I have the oil draining, I'll pull the oil pan off tomorrow morning and get a better look at the pump. Stan Rather then 3 loose bolts, the pin (or only knurkels on some aftermarket pumps I think to remember!!) that holds the shaft to the inner rotor will have failed : in that case this shaft can drop a few milimeter onto the closing plate of the pump. As a precaution (for racing admittedly) some advice to fit a screw (after drilling and tapping the rotor) instead of the pin. Quote Link to post Share on other sites
Guest ntc Posted August 24, 2008 Report Share Posted August 24, 2008 Inerestingly when spun with a drill I do get a large volume of oil welling up in the dizzy hole AND I can hear the anti run on valve switching on which says I am building pressure with the drill. When I install the dizzy drive dog though I am having no luck getting it to engage with the oil pump. This is never a simple task but usually I can eyeball where the oil pump needs to be and drop the drive dog in after a few attempts. Today I cannot get it to engage, or at least if it is engaged it is not turning the pump. The drive dog looks fine, no sheared pin or obvious problem with the end. When I turn the engine over the dizzy drive gear turns so I dont think it is the cam end. I may have to pull the pump just to get a good look at the end and to engage it with the dizzy drive from underneath. Engine should not need a rebuild, it has less than 1000 miles on it. Stan Stan The easiest way to engage the drive onto the pump is to remove the spark plugs engage gear and rock the car forward or back and you will see it drop in Quote Link to post Share on other sites
TR6 Poor Posted August 24, 2008 Report Share Posted August 24, 2008 Here is what looks like an OEM pump on ebay. http://cgi.ebay.com/ebaymotors/ws/eBayISAP...001296&rd=1 Quote Link to post Share on other sites
foster461 Posted August 24, 2008 Author Report Share Posted August 24, 2008 Here is what looks like an OEM pump on ebay. http://cgi.ebay.com/ebaymotors/ws/eBayISAP...001296&rd=1 I'm nervous enough at this point that I'm going to pull the pump out as soon as I've had my pancakes.. I have a new spare pump. Re Neil's rule of engagement.. I normally dont have a problem getting them to mesh and my feeling is there is something odd about the way the pump is sitting and the dizzy drive shaft is not quite or barely reaching it. Stan Quote Link to post Share on other sites
Guest ntc Posted August 24, 2008 Report Share Posted August 24, 2008 (edited) I'm nervous enough at this point that I'm going to pull the pump out as soon as I've had my pancakes.. I have a new spare pump. Re Neil's rule of engagement.. I normally dont have a problem getting them to mesh and my feeling is there is something odd about the way the pump is sitting and the dizzy drive shaft is not quite or barely reaching it. Stan Stan The amount of engagement as you call it should be visible 1 mm as you stated is not enough. don't panic yet there are a few more avenues to go down Edited August 24, 2008 by ntc Quote Link to post Share on other sites
foster461 Posted August 24, 2008 Author Report Share Posted August 24, 2008 Ok, here we go. Took the bottom off the oil pump, tried to engage bottom of drive slot by rotating the pump shaft. No luck, Apparently cant get the two to meet let alone mesh. Hmm. Removed the pump, removed the dizzy drive. Cant get the end of the pump to engage with the slot in the drive shaft. The end of the pump has been worn in a way that the edges are hammered over and it is too wide for the slot. Go get new pump and compare the shafts. The old shaft is almost a quater of an inch SHORTER than the shaft in the new pump. http://i38.photobucket.com/albums/e119/fos...shaftLength.jpg http://i38.photobucket.com/albums/e119/fos...mp/Tipruler.jpg The end of the old pump is worn at the corners http://i38.photobucket.com/albums/e119/fos...20Pump/Tips.jpg http://i38.photobucket.com/albums/e119/fos...ump/tipwear.jpg Its not clear why the old shaft is shorter. I did notice that the shaft fits further into the vane section of the pump in the old shaft than it does on the new one plus the new pump has a pin in the shaft to secure it. The old pump has no such pin. http://i38.photobucket.com/albums/e119/fos...%20Pump/pin.jpg Current working theory: Pump is the the original pump. Long story as to why that is the case but I measured it and it was well within spec. Cam is new, dizzy drive dog is a replacement for the original (another long story). New/different cam and different drive dog with short pump shaft allowed the slot in the dizzy drive to barely kiss the end of the oil pump shaft. Enough to rotate it initially but the end of the pump shaft wore and got hammered to the point that the two would no longer mate/mesh and I lost oil pressure. Why the shafts are different lengths I dont know. Maybe the shaft in the old pump moved although I was unable to move it myself. It does sit visbly further into the pump vane than the new shaft does. I'm off to get some new 20/50 and put this lot back together. Stan Quote Link to post Share on other sites
Richard Crawley Posted August 24, 2008 Report Share Posted August 24, 2008 Cripes Stan, sounds weird, surely not a problem associated with standard components! A bit more mind stretching than I want to handle at the moment but perhaps the grey matter is being subdued by the Costa Blanca sun & Sangria! Hope it all works out OK. Quote Link to post Share on other sites
foster461 Posted August 25, 2008 Author Report Share Posted August 25, 2008 Cripes Stan, sounds weird, surely not a problem associated with standard components! A bit more mind stretching than I want to handle at the moment but perhaps the grey matter is being subdued by the Costa Blanca sun & Sangria! Hope it all works out OK. Hi Richard, really hope you are having a great time and that the weather is cooperating for you. After I buttoned everything up and verified that I have oil pressure once again I went back to the old pump. I put the shaft upside down with the vanes resting on the jaws of the vice and the shaft below and I found that after heating up the vanes I could tap the shaft up and down. The lack of a pin to secure the shaft to the vanes had almost certainly allowed the shaft to migrate down about .25 inch and eventually clear the slot in the drive shaft. That pump has been in the car for over 26 years so it took a while. Not quite how I had planned to spend my Sunday but very glad this came up while I was at home and not on a trip. It is getting a bit late to start the beast up (this town goes to bed at 9:00pm..) but I get a solid 100 lbs spinning the motor with the starter and I'll fire it up tomorrow. Stan Quote Link to post Share on other sites
foster461 Posted August 25, 2008 Author Report Share Posted August 25, 2008 Rather then 3 loose bolts, the pin (or only knurkels on some aftermarket pumps I think to remember!!) that holds the shaft to the inner rotor will have failed : in that case this shaftcan drop a few milimeter onto the closing plate of the pump. As a precaution (for racing admittedly) some advice to fit a screw (after drilling and tapping the rotor) instead of the pin. Well you were right on the money. It was not a failed pin but a totally missing pin that was the problem and indeed the lack of that pin allows the shaft to migrate down and eventually lose contact with its drive slot. Stan Quote Link to post Share on other sites
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