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Oil Pressure Issues...Please Help....


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I know this has been a common discussion and please bear with my ignorance. I have searched the threads and gather some information.

 

Here is my issue:

 

I have an '88 XT6. I was running Delo 400 15W-40 with no issues for a while. Then I started having lifter noises after the car was warm at an idle. My Oil pressure guage seemed to be funky so I hooked up a mechanical guage. When the engine was cold the oil pressure was 75psi at idle and up to 90psi at 3500rpm. Once warmed up the oil pressure was 20psi at idle and 50psi at 3500rpm. However the oil pressure drops to zero if I let the engine idle for about 2 minutes with out reving it up.

 

First I took off the cam covers and cleaned out the pressure relief valves in each side and streched out the spring a little. This made no changes.

 

I thought the oil might be tired as I had ran it pretty hard for about 1000 miles. Note: this is an offroad beast with 33" tires and toyota axles and I use it off road!

 

So, as an experiment I tried some straight 50 weight racing oil. This proved to not be a good oil selection. Even when warmed up the lifters clacked liked mad even when revved up. The clacking with this oil was much worse than the old oil.

 

Soooo, I drained that oil, put on a new filter and added some Castrol Syntec 5W-50 oil. After warmed up the oil pressure still drops to zero after idling for a couple minutes but it takes another couple minutes for the lifters to start clacking again. If I rev up the engine a little the lifters stop clacking until it has been let to idle for a couple minutes at zero oil pressure again. This oil did not affect the oil pressure readings but it did cause the lifters to clack much less.

 

In all above statements lifters clacking = Drivers side/Front set of lifters. They seem to be the only ones clacking.

 

Questions: Zero oil pressure does not seem normal to me after idleing for a couple minutes. Is this normal????

 

Is there a pressure relief valve inside the oil pump that could be sticking??

 

A new oil pump from Subaru is $170, ouch!!! Is there an after market high volume oil pump for less money????

 

Thanks in advance for the help.

 

Mike

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This is a really perplexing issue for me as well. There are so many EA82/ER27 engines with low oil pressure that don't make a single tick, and there are a bunch with great oil pressure that sound like they're coming apart.

 

There are several things that could contribute to low pressure. You're on the right track with the relief valve thing, but I think that if the valve was bad or the spring worn, it would NEVER have much pressure, which doesn't seem to be the case here. The pressure reliefs in the cam cases could also be suspect though. I don't know if there is any way to test this, but it's possible that you just need a new spring in there entirely. If that piece is bad, the engine could still build pressure when cold, but it would be enough of a bypass to let it get down really low once the oil is warm. One of the most common causes is needing to reseal the oil pump, which is quite possible. Not only can the pressure get low, but the pump can suck air in and put bubbles in the oil, which is not good for the lifters. I would recommend pulling the pump out and measuring it to see if it's still within factory specs. If it is, I'd reseal. If not, or if it's shady, I would check on www.1stsubaruparts.com for a new pump. I dunno if it's the same pump as the EA82, but mine cost less than $120. It is also entirely possible, especially since you indicate that the noise is localized to a couple of lifters, that those HVLA's are just bad. Have you disassembled the lifters to see what sort of condition they are in? New ones are expensive, but somebody recently found a place that sells rebuilt ones for like $8 apiece. I bet you could find the thread with a search.

 

I hope that some of that long-winded diatribe helps:rolleyes: .

 

Oh yeah, I forgot to mention that the pressure readings you describe, though not what I would consider to be normal, are apparently "OK". In my owners manual it says that it is "normal" for the pressure to drop to zero, at least on the factory gauge, while idling.

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Hi, I think you may need to put new seals in the oil pump, it has fixed several clicking engines for me . be sure to inspect the pump for wear marks also.

I know this has been a common discussion and please bear with my ignorance. I have searched the threads and gather some information.

 

Here is my issue:

 

I have an '88 XT6. I was running Delo 400 15W-40 with no issues for a while. Then I started having lifter noises after the car was warm at an idle. My Oil pressure guage seemed to be funky so I hooked up a mechanical guage. When the engine was cold the oil pressure was 75psi at idle and up to 90psi at 3500rpm. Once warmed up the oil pressure was 20psi at idle and 50psi at 3500rpm. However the oil pressure drops to zero if I let the engine idle for about 2 minutes with out reving it up.

 

First I took off the cam covers and cleaned out the pressure relief valves in each side and streched out the spring a little. This made no changes.

 

I thought the oil might be tired as I had ran it pretty hard for about 1000 miles. Note: this is an offroad beast with 33" tires and toyota axles and I use it off road!

 

So, as an experiment I tried some straight 50 weight racing oil. This proved to not be a good oil selection. Even when warmed up the lifters clacked liked mad even when revved up. The clacking with this oil was much worse than the old oil.

 

Soooo, I drained that oil, put on a new filter and added some Castrol Syntec 5W-50 oil. After warmed up the oil pressure still drops to zero after idling for a couple minutes but it takes another couple minutes for the lifters to start clacking again. If I rev up the engine a little the lifters stop clacking until it has been let to idle for a couple minutes at zero oil pressure again. This oil did not affect the oil pressure readings but it did cause the lifters to clack much less.

 

In all above statements lifters clacking = Drivers side/Front set of lifters. They seem to be the only ones clacking.

 

Questions: Zero oil pressure does not seem normal to me after idleing for a couple minutes. Is this normal????

 

Is there a pressure relief valve inside the oil pump that could be sticking??

 

A new oil pump from Subaru is $170, ouch!!! Is there an after market high volume oil pump for less money????

 

Thanks in advance for the help.

 

Mike

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Interesting findings;

 

Last night I put the synthetic oil in and the lifter seemed to clack less and take longer to start clacking.

 

This morning, the oil pressure still drops to zero at idle but after running errands all over town I let the beast sit at an idle for about 5min or so and the lifters never started ticking...

 

Could the synthetic oil really be that much better???

 

It blows my mind that an engine can sit and run with zero oil pressure and not self destruct!

 

Will re-sealing the oil pump improve my oil pressure or was that just going to fix the lifter noise. As it appears the synthetic oil has fixed the lifter noise I don't want to tear the front of the car off to re-seal the oil pump if it's not going to improve oil pressure.

 

I just always figured my dash oil pressure guage was just screwed up until I hooked up the mechanical oil pressure guage and found I was actually at zero oil pressure. I wonder if I hooked the mechanical guage in the wrong place?? I hooked it up onto the oil pump in one of the holes filled with a plug next to the factory sending unit. I wonder if oil pressure is getting to the engine but not to that portion of the oil pump at idle????

 

Are there any places to test oil pressure on the engine block itself?

 

RallyRuss here is a link to some pics: http://www.ultimatesubaru.org/photos/showgallery.php?cat=500&ppuser=3017

 

Thanks for all the input!

Mike

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Guest taprackready
Interesting findings;

Could the synthetic oil really be that much better???

 

Thanks for all the input!

Mike

Synthetic's have more detergents and clean out built up crude inside the engine including the lifters. I would run it for a while. You might check it for color and if its looking really black in a short period of time then change it again. Its cleaning out the crude built up over the years.

 

Bill

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I've seen this in EA82's before, and it does not appear to cause any short-term problems. But I would still attempt to deal with it if you plan to keep this beast around for awhile.

 

Resealing will help if low pressure is your only problem. But from what you describe, it may already be too late. The fact that synthetic oil quieted your lifters down tells me you probably have some internal damage (most likely from low pressure for an extended period of time).

 

Unfortuantely, you'll probably have to address both if you want strong oil pressure and a smooth running motor.

 

good luck, John

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