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oil pressure

2K views 25 replies 5 participants last post by  WSC 
#1 ·
first proper ride since getting my old tbs back and once warmed up the oil light flickers at idle, it goes out over 1200 rpm, but i just unscrewed the oil sender and bolted in a snapon oil pressure tester, it was showing 8 at idle and only 20 at 3000rpm, book says should be 40 at 5000rpm, i couldnt get pressure above 20! previous owner knows nothing about these so whilst he had it the local triumph dealer serviced it and stripped sump plug! they pulled pan and fixed this and can only assume they would have checked or cleaned filter etc while pan was off, bike runs on motul 7100 full syn and is fresh, i am at 90000km but it runs ok, would it be more likely to be oil pump or relief valve/ or should oil pressure be checked at the pipe to head and not switch? although i would think it should give same reading, dont want to pull pan yet as dont have gaskets and will probably need to order them in, thoughts??
 
#2 ·
thoughts??
Don't ride it.

Pressure at the pipe will be lower, if anything.

No reason not to check the relief valve, but, if it's leaking because of debris, you have to consider where the debris could have come from. A bit of carbon isn't much to worry about, but a piece of metal is a different story. I'd pull the filter apart and inspect it for metal. You might want to consider an oil analysis, too. (Don't bother if the oil is new.)

I suppose there could be a problem from the oil pan R&R.
 
#5 ·
Both the idiot light AND the gauge are telling you "Som-Ting-Wong". I would not run it until I found out what is going on. Putting on a different gauge is not going to help fix an obvious problem. ...J.D.
 
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#8 ·
finally got rear suspension off to allow access to one bolt on oilpan! there were aluminum filings in the gauze filter from when the helicoil was done by the dealer! according to the invoice they removed pan to do it but not so sure looking at this crap!, oil relief valve was clean and smooth to push in with no binding, the gasket where it surrounds where the oil filter goes was off to one side so was not fully sealing pan to main block, could this cause low oil pressure!
 

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#13 ·
i have sent pics to the shop it was serviced at to see how they deal with this! hoping a new o ring will sort the oil pressure issue, it was only by chance i saw the recess and thought the filter went into it so looked in the manual and saw a pic of the o ring being replaced and checked my engine , it definately hasnt fell out while i have been working on it as it would still be on the mat under the bike,
 
#18 ·
With marginal oil pressure the first thing that usually goes is one of the rod bearings. Since you didn't see copper in the oil or the filter, there's a good chance no serious damage has been done. If you still have the oil you drained out, you might consider having a sample analyzed. Blackstone Labs is a good place for that.
 
#19 ·
so after gettin an email from the dealer stating that the mechanic thoroughly cleaned the oilpan after doing helicoil but said he didnt put a new o ring in there as there wasnt one there in the first place!! i kid you not, the last time the pan was off was at least 12000km ago so no way would the engine have lived that long on low oil pressure, at least i have it in writing that they never fitted one if i have to take it further. i decided to put it back together with an o ring in place just to see if pressure returned or pump was shot, it was too high now which led to a stuck relief valve so i pulled the pan again and checked the valve and it slid in and out smoothly pushing it with a screw driver so i put it back together again and still high, havnt taken it out yet though and oil may not have been up to temp so will ride it tomorrow, no rod knock though which is promising! though these motors sound noisy at best of times lol, might have dodged a bullet this time though,
 
#20 · (Edited)
How high is too high? There is no spec for maximum, only minimum. A rule of thumb is to have 10 psi per 1000 RPM, so if you're running the engine up to 9000RPM, 90 psi is reasonable.

Cold oil will overwhelm the bypass circuit, so don't be concerned with a cold reading. This is one reason why you don't race a cold engine; high pressure comes at the expense of oil flow.
 
#26 ·
Yeah, that is what it looks like, but, bottom line, the only way you'll get too much is if the relief valve sticks shut. As you increase RPM the pressure should increase until the relief valve starts to open, then it should pretty much level off.

Good job finding the missing o-ring!
 
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