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MG TD TF 1500 - TD low oil pressure - why?
|I'm stumped - all I did was take off the (spin-on) oil filter, put on a Ryco 145 as specified, and put in new 20W 50 motor oil. The oil pressure immediately dropped from 50 to 40 at operating temp. and 2500 revs. Figuring the oil pump might have let in an air lock or some such, and knowing that the springs in the pressure relief and bypass valves were far from new, I dropped the pump, cleaned and checked, put in new springs,filled with petroleum jelly, and ... now only 20psi ! I checked the archives - possibly the gauge is not working properly, but the timing of the pressure drop seems to match when I started fiddling; I have run oil into the priming plug via a plastic tube and funnel, until oil sits at the top of the plug hole; I have not tried releasing individual oil plugs in the gallery at side of block, I guess because I was hoping I might not have to - but I'm not prepared to run the car on 20 psi.|
Would anyone have encountered a similar problem, or have any suggestions as to how I might proceed? All advice gratefully received. John.
|My guess is that the pressure relief ball has a worn spot that is not in the same position as it was before. I believe that is removable without removing the pump.|
Try taking a look at it. It is just like a ball bearing and should be shiney and smooth all around.
|R. K. (Bob) Jeffers|
Before you do too much try switching out the new oil filter you installed...that's the one thing you changed initially that would have affected your oil pressure from the start.
|john, bob has a good suggestion, which i assume you followed when you pulled the spring or you would have changed out the ball then. i like gene's idea..go to the place where you were when the pressure dropped...the oil filter. try another. you may have to retrace your steps on a few of your other proceedures to see if you have induced further troubles..(ie. the drop from 40 to 20) it is also possible..it would be a strange coincidence..but it is possible something else happened at the same time you started this project..(cracked crank) i am curious as to why you are talking about pulling galley plugs??? is it to plug in a test gauge? i cannot think of another reason to do so. regards, tom|
|Hmm - spin on oil filter !.|
John you should be aware that while spin-on filters can look the same (and be cataloged as the same or "replacement"), some contain non-return or anti-syphon valves which mean the oil can only flow in one direction.
If you put one of these on your engine, you can lower/lose oil pressure FAST !.
You may in fact have a filter that is accepting no oil, and the engine is getting 100% unfiltered oil. I need to do more study on the filter bypass setup on an XPAG to be more specific - maybe tonight.
Don't be too worried about those readings - I work on the old rule of 10psi/1000rpm, so 20psi is OK to 2000rpm, and 50 psi is good to 5000rpm.
I hope I've helped in some way.
|Thanks fellow knitters for your ideas, and I'm happy to clarify:|
- the pressure relief ball appeared fine, smooth and shiny.
- I will certainly try another filter before panicking, but following Tony's input, I should try a filter without the anti drain-back feature, but I thought that feature superfluous because of the upside-down position of the filter on the TD ?
- regarding the gallery plugs in the block, I had read that it is possible to remove one or more, and force oil into the gallery to eliminate air lock. Sounds tricky, and I don't know how to force the oil in anyway!
- Tony: do you know of a filter I can try, available in Aus? PS - my oil pressure is 10 at idle, 20 at 1500 revs, and stays at 20 at any higher revs.
Thank you all for your input - I hope I can get to the bottom of this! John.
I take it the spin-on is a modified daptor of some sort to the original Ryco E10 filter.
I have seen two types of these kits, one type is crital not to have the drainvalve. If you look at the flow path of the oil and compare it to the filter, you can work out if the flow path will work.
You can get many filters that spin-on as the thread is quite common, but avoid any that have a flapper valve that prevents flow in one direction.
What are the number on the filters you have ?. Ryco 145 does not appear in a current Ryco catalogue ?. I will check my filters in the garage & get back here soon.
|John, I had a look in the shed !.|
The original filter was a Ryco E21 not E10 (don't know where I came up with that number).
The spin-on filters that I use are Ryco Z82, which spin-on to a modified top half of an original E21 Filter.
|Are there any US owners using a Bob Grunau adapter? Which filter are you using with it? Maybe John can cross the number there in Australia.|
I use his vertical adapter (TC and early TD) and use a Fram PH-3600 filter.
|I use the hrizontal one on my later engine, see|
http://www.ttalk.info/Oil_filter.htm . I use the NAPA 1515 filter.
|Just checked the internet and that will cross to:|
Purolator Pure One PL30001
MOTORCRAFT Part# FL-1A
|Tony, Gene, Bud : am just off to work, but tonight our time I'll get back with clarification as to what type of adapter was installed back in 1990 when the car was ground-up rebuilt in Melbourne. Certainly the filter is upside down,(ie threaded end is pointed upwards), hence my thought that the inclusion of anti drain-back flap was superfluous. I'm very interested in the Grunau setup, if available. Thanks so much for your help so far gentlemen. John.|
|While a bit off the subject, oil filters are of interest to me. I always use the best possible filtration I can get, and use only a K&N HP2009 in Bob Grunau's spin-on kit (ya only gets what ya pays fer). I also use one of Mad Metrics, magnetic sump plug (you'd be surprised what lurks in your sump!)|
Bruce Knize did his original survey on oil filters back in 1999 and has cleaned it up since then. Have a look at http://www.knizefamily.net/minimopar/oilfilters/index.html and check some of the links.
From an enthusiast's point of view - no techie marketing crap. Makes for interesting reading.
|Gordon A. Clark|
The filter numbers Bud and I gave earlier are for the horizontally mounted filter set-up.
The Fram PH-3600 is the one I use for my vertical (upside down) installation. Maybe you can find a cross reference for that. And I'm pretty sure it has the anti-siphon feature in it (needed or not).
Actually, the filter you've always used should be good to use again...there's a chance that the new one you tried was defective (fingers crossed).
Bob's filter adapter is reasonable and is a work of art...he can be reached at email@example.com
I'm interested in a magnetic drain plug for my TD XPAG engine. The Mad Metrics magnetic plugs that I see don't match the part numbers in my MG factory Service Parts List. Ideally, I'd like to find a source for a magnetic plug from the US or Canada. Any suggestions?
|Back from work- to clarify further, it looks as though I have something like Tony's set-up, a vertical filter which spins up underneath the top half of an original E21 filter. I should also say that on mine the filter is completely sparated from the pump - it's about 4ins. to the right, with piping from pump to top of filter, and from lower on the filter assembly, to block.|
I'm not sure what the E21 refers to - is it a number I can find on the casing?
Gene, the Fram ph3600 will be one to cross-reference in Australia if I can - I will try tomorrow. I will also try to obtain an adapter from Bob Grunau, thanks for the contact details.
One other thought - when I was filling the primer hole via a funnel, I noticed that when I cranked the engine(with ign. off), while the clean new oil was still showing in the funnel, a dark thicker pool blurped up into the funnel, presumably from somewhere below the pump.I wonder whether I should somehow purge the oilway in the block, in case it is gummed up and compromising oil pressure at the gauge. Anyone have any thoughts on that one?
Look forward to any ideas - where did we go before we had the knitting circle to turn to??? John.
|Calling Tony Slattery - Tony, I'm having real trouble locating a spin-on filter without the anti-drain flap - did you mean the z82 had no flap? My local Repco doesn't have that filter, and can't tell me the info I need. See also my q's from the 10th. April, if you have any ideas.|
Any other readers have any comments on my qn about purging oil from the block gallery without removing the engine? I have the gear to lift the engine if no other option is available. Thanks all. John.
The Z82 is a Ryco oil filter - original fitment to 4 cyl Holden Torana 1971-75 and Leyland mini & moke 1975-1984. It does not have a drain valve.
|Yes John it sounds like you have a modified E21 filter (for TC, Y-Type and early TD).|
Have a look at your modified top half - which oil line is connected to the centre of the filter - the line on the top or on the side.
|Tony - thanks for getting back. I checked on the YA, and they're the same - pipe goes from top of pump to top of the assembly to which the filter screws, and from lower on filter assy. to block. Although the TD is a late one (Sep 53), the PO a guy called Paul Malone I think, in Melbourne, for whatever reason replaced the late motor(28962) with a very early one (no. 5970)! Thus I have an odd mixture - Ray Skewes in Melbourne did a good job of sorting out the mechanicals. I plan to double-check that I've put back the pump correctly, particularly the relief and filter-bypass springs etc; try to flush out oilways; put in better quality oil and hopefully a filter without drain-back flap; and even attach a temporary oil pressure gauge, to see what reading I get. After that, I'm out of ideas, and I think the engine will have to come out! Thanks again for your attempts to help, and I'll let you and other threaders know how I go. Regards, John.|
|john, i have never heard of the need to "bleed the block". if the pump is primed...think about it..the clearances on a well rebuilt motor are still "loose" enough for thick oil to pass...how could those same clearances be air tight??? before you pull the motor ..a lot can be seen from the bottom end. i suggest BEFORE you pull the motor that you run a list of things that could be causing this problem...i believe you will find ALL of them can be verified without pulling the block...you drop the pan you can pull caps from the big ends and the mains to inspect...you can charge up a tank with oil and an aircharge and tap into the main galley and with the pan off (and a LARGE catch basin underneath)see where the oil is coming from.you should have simlar streams from all big ends and similar streams of oil from all main caps. please do some more head scratching before you pull the engine. regards, tom|
|Tom - I couldn't agree more, even though I only just put the sump (pan) back on having cleaned and checked the oil pickup, strainer etc. When you say "tap into the main galley", do you mean into one of the pairs of 7/16 plugs visible along the side of the block? That's where I was thinking of going with a bit of pressurised oil flow, to see if any gunk is lurking in the oilway, without dropping the whole engine. John.|
|Have you replaced the new oil filter you put in yet?|
|gblawson (gordon)- TD#27667|
|Hi Gordon - no, not yet, because I'm trying to locate one without the anti- drainback flap. Not because I think this will cure the problem, but because I want to see what if any difference it makes.Regards, John.|
|john, you could tap in at one of the two main oil galley plugs you see or into the pipe that feeds the rocker shaft in the head...if your oil pressure pickup is on the block you could connect there with your pessurized oil tank. i do have a question that is in regard to your last post...when did you drop the pan? the reason i ask is if it was in the middle of trying to track this problem and the pressure was lower after the pan was reinstalled...the next time you drop the pan i would check the seal where the oil pick up tube passes from the pan to the block..if it is not a good seal the pump will draw more air than oil. regards, tom|
|Thanks for your comments Tom. No, I dropped the sump after the drop to 20psi,so I think(hope!) everything is ok in there. But I do have in mind checking all gaskets and seals some time soon. Your advice is appreciated re. the oil gallery purging - I reckon I'll try a pressure feed of oil in via the pressure gauge pickup point, and out via the plug nearest the front of the block.|
By the way - In a fit of pique this weekend, I borrowed the oil pump off the YA; the fixed drive felt tighter, and the clearance between cogs and inner wall, lower. The result was a slight improvement - 18 to 20psi idle pressure, and rising to nearly 30 if I rev it up a bit! That's still well short of the desirable 45psi, but gives me the ability to use the car for short runs while I continue to investigate the oil filter situation. Thanks Tom, and all others again. Regards, John.
Why don't you retro-fit the original oil filter. This is what I would do. Even if you don't have the parts, they are all available.
|John - mea culpa -I committed the cardinal sin of throwing away the filter without noting its brand or number! That's why I'm now looking for one without anti drain-back feature. Desperate measures by a desperate TD owner. John.|
By retro fit I mean back to the "original" XPAG oil filter.
|john, i believe i am not communicating effectively about the use of the oil pressure tank. i say this with some degree of confidence..if your pump is primed, has a supply of oil, and there are no air leaks in the SUPPLY side, the pump WILL move air out of the system. i am NOT advocating you waste your time "bleeding" the oil system. what i am saying is you can use this tank to pressurize the main oil galley to watch for oil flow at the bearings. with the pan down and a catch basin under the car you can see which bearings have the greatest "leakage" therefore the largest clearance(or cracked journal). this is just one troubleshooting technique used with engines that, during operation, have experienced a loss of oil pressure. i am hearing you say your loss of pressure occurred AFTER you began working on the motor. if it was my car i would pay attention to that. it is possible you could have had a simultaneous failure somewhere else, but how likely is that? i guess what i am saying is the idea of pulling a motor when the oil pressure drops after a filter change seems like an extreme measure. when trying to fix a problem it is easy to get sidetracked from good troubleshooting techniques and become fixated on a problem and start chasing ideas. it may be time to step back and regroup..take a couple of deep breaths and walk yourself through the events again. in 32 years as a mechanic,i have never read or heard mention of "bleeding" an oil system in any maintenance manual i have owned or mechanics class i have taken. best of luck. some ties these old cars can be frustrating but the rewards are so great when you get them sorted out. regards, tom|
Not sure if this is worth anything or just oversimplifying yor situation (and I don't mean to). Have you checked needle on the gague. I had similar problem - new motor first oil change after run in period changed oil and low oil pressure. Same as you checked pump etc.still no improvement. Sitting in car with engine going watching low pressure thinking -gave the gague a thump and needle fell to zero.
Long story short dismantled gague and found needle was not grasping the shaft of the gague correctly giving intermittent and low readings. Pressed needle on and no further problems.
|I think the problem is in the filter used. Almost all modern spin-on oil filter operate with oil flow from the OUTSIDE of the filter to the center. If you are using the original TC oil line set-up, the flow is from the INSIDE to the outside. Or reversed. If the filter has a flap anti-drain valve, then no oil will flow through the filter. I suspect you are only getting unfiltered oil through the bypass valve in the block. Even if no flap valve, most ( if not all ) spin-on filters still want to have oil flow from the outside to inside and that is why you have a reinforcing mesh screen on the inside. If you reverse the flow, the outside circumference of the filter may "blow-out" as there is usually no outside screen reinforcement.|
My TC oil filter adapter is made to have the correct TC oil line connections as original. It uses original oil lines, banjo bolts and bvlock fitting. BUT the adapter is cross drilled to correct the oil flow through the filter from outside to inside. So a flap valve, as used in a Fram PH-3600 filter, does not impede oil flow. I can send photos of the adapter if you contact me off list.
|Tom - your advice is crystal clear, and very much appreciated. I am not a mechanic's bootlace,but learn with book in one hand and spanner in the other.So the experience that people like yourself, Dave du Bois and others pass on to all of us, is like gold dust.You give me the confidence to "have a go", but staying always within my limitations.I'm sorry if the questions, and my search for answers, are at times frustrating. I am in fact leaving the TD alone for a while, just as you suggest; a new filter will be fitted when I find one, and we'll go from there.P.S. - you're right about the old cars being rewarding - in my garage I have only one vaguely new car - a 10 year old Discovery (love it); the others are YA, TD, BGT and mini Clubman. My dear Joanne would rather drive the Y than anything else, but wonders whether we should get rid of the Discovery and buy a new MG instead! We both have the disease - watch this space. |
Bill C. - yup, that's another avenue that I think I'll check, just in case!Interesting that your gauge played up after an oil change. Thanks mate.
|From Bob's description, I wouldn't run the car until I either found a filter sans valve or get his adapter so you can use common filters. Or use the original, as suggested further up in the thread.|
|Bob Grunau, Bill, Tom et al - there's a common thread coming through now - get a Grunau adapter and suitable filter, asap! Bob, although you've commented on TC oil lines etc., I presume the principle applies to TD also. I will certainly contact you direct.|
To everyone else who has contributed to this thread, I thank you most sincerely - it has been a wonderful resource, and I hope one day to be able to put something in, instead of just taking out! Regards to all. John.
|First - Larry, sorry to take so long to respond. Roger Furneaux of Mad Metrics sold me the magnetic sump plug directly. I have no idea where you got a factory part number for it. As far as I know, he is the only one (I have ever seen) to offer a magnetic sump plug for the TD/TF, and I don't recall the factory ever mentioning it in any data I have.|
Secondly - I have serious reservations 'bout the Fram PH3600 oil filter. From the reviews I have read, it is just about the worst possible filter available. Its sells here in WalMart for about $4. I chose to use the K&N HP2009 as it seems to have all the quality features I want and is noticably heavier. It sells at Advance Auto, etc, over in NY state (a 15-minute drive from Rockburn) for about $13 US. Big difference in price, but a noticable difference in performance. I installed it for my trip to Gatlinburg, and the oil at the end of the summer was noticable lighter in colour, compared to the previous summer when I used the Fram PH3600, and I assume that there were less suspended particles.
Combined with the magnetic sump plug, I am confident my engine is well protected. Now, if I can just stop some of the leaks ...
|Gordon A. Clark|
Thanks...I'll check out the K&N filter...but since I change my oil every 1000 miles (personal preference) or so the Fram is probably just as good.
|My oil filter adapter is identical for TC and early TD with the separate cannister filter. The oil lines themselves are slightly different, but operation is the same. Both TD and TC oil lines allow oil to enter the filter in the top center, exit rear side. |
I agree about the Fram 3600 filter not being the beat. However I bought a case of 12 some time ago and am using them up, then I will change to a better filter.
|Gordon A. Clark|
This thread was discussed between 08/04/2008 and 17/04/2008
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