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Jazz13

1974 TR6 Oil pressure issue

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Have been trying to solve low oil pressure issue on my TR6.

Only seeing 10 psi on cold start up with 20/50 oil.

Replaced oil pump with new unit, primed the pump, saw 50 psi upon start up for a brief moment.

Dropped back down to 10 psi.

Replaced oil pressure relief valve, stem and spring.

Having a difficult time seeing oil pressure after start up.

Every time there after, only 10 psi.

Any advice?

Thank you

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If the gauge was reading better pressures with the old oil pump then the gauge is probably OK, I'd look at the new pump's drive shaft, especially its engagement.

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How worn is your engine?

Cheers

Tim

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Good info Peter, thank you.

Waldi

Waldi,

Did you read the other items on that link/home page. They are informative and helpful.

Peter W

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Is a oil cooler fitted with thermostat.

 

Refitting new oil pipes.

 

Accidental reconnected my pipes on the thermostat the incorrect way & caused drastic low oil pressure reversed pipes & oil pressure returned to normal

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Have been trying to solve low oil pressure issue on my TR6.

Only seeing 10 psi on cold start up with 20/50 oil.

Replaced oil pump with new unit, primed the pump, saw 50 psi upon start up for a brief moment.

Dropped back down to 10 psi.

Replaced oil pressure relief valve, stem and spring.

Having a difficult time seeing oil pressure after start up.

Every time there after, only 10 psi.

Any advice?

Thank you

How good is the seating of your pressure relief valve? Is it being held off for any reason i.e. a lump of crud or a worn seating?

 

Bruce.

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Thanks Peter,

Made a link on my PC to the VTR site, I never came across this before.

Waldi

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Did you compare the old and new spring lengths and check for washers used as spacers on the old PRV? It's amazing what has been done to oil PRV's over the years by various owners..

 

My spring length was too short according to the BB ( but oil pressure was acceptable).When I replaced the short spring with the correct item the oil pressure went to 100+ psi on cold, fast idle- so I went back to the old spring and accept that some things in my 1969 engine are no longer in accordance with the BB due to modifications made by various parties over the tears.

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As we seem to have lept to the now, how about a bit of history to when this started.

 

Like since you have owned the car, only this summer after 30K otherwise good miles, slowly dropped off over the last few years, after you changed an oil filter?

 

How have you fitted a gauge to the relief valve?

 

Alan

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And did the new plunjer move freely in the casing? My new plunjer had a very narrow clearance, radially, one burr will make it stick, resukting at low oil pressure at low revs.

Waldi

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Bought the car beginning of the year, and started to restore the interior. New seats and carpet.

Needed a new alternator and did the usual oil change etc. But never drove it since the interior needed attention.

Had an oil change on the relief valve which showed the same as gage.psi.

Have two sets of dash board, gages, oil pumps, all from a gentleman which rebuild his car from scratch.

Plunger is moving freely. Rebuild the two Stromberg carbs.

Engine was supposedly rebuild a couple of years ago, and car had been sitting since then.

Next option would be to check main bearings, to see if oil leaks through them?

Going to measure with plasti gage and determine size. Might have been machined and wrong set installed?

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I guess the car had low oil pressure when you bought it- hence the oil pump change. The brief 50 psi on start up indicates that the main bearings were OK but something has moved somewhere in the lubrication system/components.

 

Maybe check the main bearings and oil pick up- if only to give you peace of mind.

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Does it have a remote oil feed to the rocker shaft?

Check the crank end float,

Pull the bearings and check the condition of the shells. Mains and big ends. Dont get them mixed up!!

Does it rattle on start up cold?

 

I would think if its giving 10psi at all times then the drive to the pump is ok

Edited by DaveN

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Had an oil change on the relief valve which showed the same as gage.psi.

Have two sets of dash board, gages, oil pumps, all from a gentleman which rebuild his car from scratch.

 

Going to measure with plasti gage and determine size. Might have been machined and wrong set installed?

 

I may be being thick but how did you get an oil pressure reading at the relief valve?

 

So both oil pumps were new or used?

 

10 psi on cold oil, says either no/very little oil is being pumped (what style of oil pump is it?) or its pissing out somewhere and way more than I think even standard shells on a -0.030 grind would do (I'll accept correction on that) but as you have no obvious external leaks it would either have to be something like a badly fitting oil cooler adaptor plate (have you a spin on filter adaption?) or one of the gallery end core plugs missing that is miraculously leaking back down into the block/sump and not to the outside.

 

Alan

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I think standard shells on a reground crank would rattle like hell from the rod ends with an associated loud grumble and vibration from the the mains!

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