Hi. folks. Here's one for you, I noticed the other day that the oil pres. was reading low on my 88 GL10 T. It's a JDM engine and has always held 50 -60 PSI, even when hot, but now when at operating temp. would drop to 25 - 30. I drove it a little yesterday and realized that the pressure was being affected by throttle opening. I'm fairly certain that it's being caused by vacume and crank case pressure. As I add throttle and load, vacume falls off and so does oil pres., back out and pres. comes back up. No leaks any where, no smoke, I've never seen anything like it. I'm speculating on a bad oil pump shaft seal, torn perhaps and maybe increased vacume pulls the seal tighter. The only other thing I could think of is the oil pick up tube o-ring, but that doesn't seem as likely to me. I've ordered up a pump seal kit, but I'm certainly open to other ideas. Thank much, S.

Bad Oil Pressure sender.

 

Happens alot...

 

I doubt you actually have a real Oil Pressure issues.

my oil pressure monitoring system: if it aint tickin, its got oil pressure.

my oil pressure monitoring system: if it aint tickin, its got oil pressure.

 

Where's the "Like" button?

Yes, I Agree ... ... We need a "Like" button here.

 

But one Question: have you changed the Oil viscosity?

Bad Oil Pressure sender.

 

Happens alot...

 

 

I'm asuming Steve's looking at the factory gage? Personally, I haven't had a sending unit that totally flaked out on me. I've replaced a couple three for being leakers. Yea, screwing in a known good one is easy enough. Or.

 

Screw in a mechanical gage to the oil pump under the hood. It's an EA 82T.

 

But one Question: have you changed the Oil viscosity?

 

And what oil are you running? You might not have a good enough oil in it, or the right additive package for 1988 Turbo. But yea, tell us more.

 

Doug

Edited September 29, 201213 yr by Quidam

Hi guys, thanks for the response. Well, this has all happened since a recent oil and filter change, so no change in viscosity or anything else. I'ts a near new VDO gauge and sender, no factory gauge, but I backed it up with a mechanical and same reading. It's a real puzzlement to me. Thanks, S.

Probably not vacuum related. What brand of oil filter did you use? I hope it wasn't a Fram. Since this started immediately after an oil change, it stands to reason something that was changed could be at fault.

Sorry, not a fresh oil and filter, but a few weeks ago. Performed normally until a few days. The filter is Car Quest's better one, I think made by Wix. While driving it around yesterday, I spun a new one on just cuz, and no change. Thanks, S.

Hi guys, thanks for the response. Well, this has all happened since a recent oil and filter change, so no change in viscosity or anything else. I'ts a near new VDO gauge and sender, no factory gauge, but I backed it up with a mechanical and same reading. It's a real puzzlement to me. Thanks, S.

 

That new oil pump kit, once you do that it will tell you a lot. Last Mickey Mouse I replaced, and IIRC all I've replaced, cave in on the top port on the pump. That supplies the main galley after the filter. The bottom port Mickey is supply to the filter.

 

Just for grins, if you would, check the crank for in and out movement. Just wondering about your thrust bearing.

 

Doug

 

Edited September 29, 201213 yr by Quidam

Never mind I didnt see that last post by the op. oops

Thanks Doug. I hadn't thot about Mickey's ears, but that really could be it. I'll check end play too, also a good thot. It's my daily, so I've need to get after it. Thanks, S.