vonrottes Posted June 26, 2015 Report Share Posted June 26, 2015 Truck is running fine, but oil pressure plummets from 40-60psi to what I'm assuming is 5-10psi (my digital gauge reads a constant 2 bars so I think 5psi high.) managed to repeat the drop several times. 1. Accelerating from a stop (even lightly) 2. Accelerating at speed (especially up hill) 3. Making RIGHT turns 4. Loading the engine in gear I babied it from Etna to west Columbus keeping oil pressure by driving like an uninsured elderly person... When the engine free revs in P/N oil pressure will climb to 80psi like normal. but footbrake it in gear and the pressure drops like someone flipped a switch. at speed when it drops, the engine starts luggin and having a hard time keeping momentum. At a stop when the pressure dropped the lifters started ticking... If I shut the engine off when pressure holds low for more than a few seconds and start it back up it climbs up to 40-50psi idling. So I am assuming this is a REAL failure and not electrical. Thinking the pressure relief valve???? I did check the oil level and it was good... since the whole turning thing made me think the pickup was sucking air and I have put at least 10,000 miles on it since the swap so I don't think it is the pick up tube O-ring Quote Link to comment Share on other sites More sharing options...
Cordell Posted June 26, 2015 Report Share Posted June 26, 2015 Is it just oil pressure dropping and nothing else like voltage? Kind of sounds like what something would do if you alternator was dying or your grounds were coming apart somewhere. If the gauge is mechanical obviously this theory doesn't apply (since I'm not sure what vehicle you're talking about, especially if it's your custom truck). I'm not sure what would cause oil pressure to change like that under load, so I would be inclined to hook up a good mechanical gauge and see for sure what the oil psi was. Quote Link to comment Share on other sites More sharing options...
vonrottes Posted June 26, 2015 Author Report Share Posted June 26, 2015 Voltage holds at 14.7 my gauges are all electronic and if there is a short they all kind of ...freak out.. and yes it is on my S10. The oil gauge is a single wire run straight to the dash from the sending unit. Obviously I'll need to get a mechanical gauge to be sure, but like I said the lifters start making noise when it drops at a stop. Quote Link to comment Share on other sites More sharing options...
Cordell Posted June 26, 2015 Report Share Posted June 26, 2015 Sorry I missed the lifter noise comment in your first post. That's interesting, likely actual oil psi then. Usually when the pressure releif valve has an issue there is zero oil psi. Has to be bleeding it off somewhere, like it pushed a seal or o-ring or something like that if it hasn't opened up bearing clearance somewhere. Sounds like you may be tearing that down. Quote Link to comment Share on other sites More sharing options...
caseyctsv Posted June 26, 2015 Report Share Posted June 26, 2015 I have read situations where the relief valve is "sticky" and does not completely shut down the oil pressure. I would swap out the oil pump. Quote Link to comment Share on other sites More sharing options...
vonrottes Posted June 27, 2015 Author Report Share Posted June 27, 2015 Either way... Oil pump or bearing the engine has to come out. Stockish pump is $127 Good excuse to do some stuff I should have done when I put the engine in. Quote Link to comment Share on other sites More sharing options...
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