Sticky pressure relief valve?, Erratic oil pressure issues with new T4 motor |
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Sticky pressure relief valve?, Erratic oil pressure issues with new T4 motor |
RoadGlue |
May 27 2019, 07:22 PM
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#1
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Sonoma County Gear Head Group: Admin Posts: 2,033 Joined: 8-January 03 From: Santa Rosa, CA Member No.: 108 Region Association: Northern California |
Hey everyone, hope you're all doing well.
My newly built four banger's oil pressure is all over the board and I'd really appreciate any advice you might have. When the pressure is behaving normally, I'm seeing a pretty normal fluctuation from 10 PSI at idle to 40-something at cruise. However it seems that depending on direction I'm turning (maybe!?) the pressure can jet up to 65+ PSI which of course is alarming. Worried I'm going to blow out seals. It doesn't always jump up though. It's rather inconsistent. At idle I've had it stick at around 60 lbs as well. Giving the throttle a jab seems to free it up and it'll drop back down to where it's supposed to be. I think it's a stuck pressure relief valve. If it were stuck in a high pressure state, would cornering have some effect on the pressure spikes? I'm using Penn 20-50 and everything I listed was at normal operating temps (130-180 F). Thanks!! |
ChrisFoley |
May 28 2019, 05:46 AM
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#2
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I am Tangerine Racing Group: Members Posts: 7,934 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None |
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RoadGlue |
May 28 2019, 11:29 AM
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#3
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Sonoma County Gear Head Group: Admin Posts: 2,033 Joined: 8-January 03 From: Santa Rosa, CA Member No.: 108 Region Association: Northern California |
... I think it's a stuck pressure relief valve. If it were stuck in a high pressure state, would cornering have some effect on the pressure spikes? ... This is unlikely. Due to the pressure changes when cornering as that wouldn't be related to the relief valve, right? I'm at a loss. If it's something related to the pick-up tube, then I'd expect to see drops in pressure, not spikes. The gauge and sender are old, so I'll get new gear just to rule those out. If it's not that, then what next? (IMG:style_emoticons/default/blink.gif) |
ChrisFoley |
May 28 2019, 06:35 PM
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#4
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I am Tangerine Racing Group: Members Posts: 7,934 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None |
I say its unlikely because the pressure relief valve doesn't work the way you imagine it does. But it is hard to imagine how going around a corner could affect the relief circuit.
Another point - oil pressure above 65 psi will not blow seals. My modified pressure relief valve raises the max pressure to 75 psi. In fact, the first thing to fail if oil pressure actually gets too high will most likely be a galley plug. Cold oil pressure can easily exceed relief valve design pressure simply because the return passage is too small to bleed off all the excess oil when it's thick. |
Tdskip |
May 29 2019, 09:28 AM
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#5
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Advanced Member Group: Members Posts: 3,686 Joined: 1-December 17 From: soCal Member No.: 21,666 Region Association: None |
Gauge / sender correct for each other and everything right?
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McMark |
May 29 2019, 11:21 AM
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#6
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
You running a tuna can on this beast?
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RoadGlue |
May 29 2019, 12:59 PM
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#7
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Sonoma County Gear Head Group: Admin Posts: 2,033 Joined: 8-January 03 From: Santa Rosa, CA Member No.: 108 Region Association: Northern California |
I say its unlikely because the pressure relief valve doesn't work the way you imagine it does. But it is hard to imagine how going around a corner could affect the relief circuit. Another point - oil pressure above 65 psi will not blow seals. My modified pressure relief valve raises the max pressure to 75 psi. In fact, the first thing to fail if oil pressure actually gets too high will most likely be a galley plug. Cold oil pressure can easily exceed relief valve design pressure simply because the return passage is too small to bleed off all the excess oil when it's thick. Thanks for this! The more data the better. |
RoadGlue |
May 29 2019, 01:01 PM
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#8
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Sonoma County Gear Head Group: Admin Posts: 2,033 Joined: 8-January 03 From: Santa Rosa, CA Member No.: 108 Region Association: Northern California |
Gauge / sender correct for each other and everything right? Yes! They're matched. However I'm starting to think that perhaps the sender is intermittently sticking internally. I've ordered a new sender/gauge. Hoping it's just that, but I'll report back either way. |
RoadGlue |
May 29 2019, 01:03 PM
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#9
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Sonoma County Gear Head Group: Admin Posts: 2,033 Joined: 8-January 03 From: Santa Rosa, CA Member No.: 108 Region Association: Northern California |
You running a tuna can on this beast? Hey Mark! Nah, not on this motor. The windage tray seals are new from 914rubber.com, but if the new gauge and sender combo doesn't fix this, I'll drop the screen filter and plate and see if there's anything that could possibly be floating around in the sump. I'd just expect to see pressure dip vs. spikes if that was the case. I'll report back once I have the new sender and gauge installed. Thanks buddy! |
Mark Henry |
May 29 2019, 03:14 PM
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#10
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
You don't have a dangling, cut or loose wire anywhere? You go around a corner and something touches another wire?
I agree with Chris, plus another area for too high of pressure would be the filter can blowing up like a frozen pop can. Seen this happen with cheap filters. BTW I think you guys call them soda cans. |
jim_hoyland |
May 29 2019, 03:15 PM
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#11
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Get that VIN ? Group: Members Posts: 9,317 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California |
Connections? At the sender ? Sender grounded ?
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RoadGlue |
Jun 24 2019, 09:28 PM
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#12
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Sonoma County Gear Head Group: Admin Posts: 2,033 Joined: 8-January 03 From: Santa Rosa, CA Member No.: 108 Region Association: Northern California |
I replaced the pressure sender this evening and now the oil pressure is rock solid at 60 psi when cold, 50 psi cruising when warmed up and idles and 10 psi.
The old sender seemed to be leaking a little oil from a seam too. Thanks everyone! (IMG:style_emoticons/default/beerchug.gif) |
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