oil pressure
oil pressure
Hi im new to the forums as well as these cars and today i stuck my first issue. On my way home today i hit a pothole not even half a block later my oil pressure started droping and my car limited my revs to about 3000 but the car would run the same so long as i didnt try to get it up past 3000 i parked my car and as soon as i let off the gas the pressure droped to about .5 bar its normally at 4 under no load im not sure what caused this as i dont see any oil under my car yet. I have a 91 tt jdm manual if it helps. thanks in advanced for any help or ideas on what could be the cause.
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nissanfreak12
- Posts: 1709
- Joined: Sun Jan 23, 2011 4:07 pm
- Car: 92 300zx 2+2 TT
- Location: Denver, CO
Re: oil pressure
Look at the oil pan and make sure you didn't dent he oil pan. If its dented it blocks the pick up tube and starves the engine of oil.
Did you get a check engine light? Even if you didn't you should still check for codes, sometimes they dont pop up on the cluster, this may also assist on maybe something else is wrong. Check the codes and oil pan and let us know.
Did you get a check engine light? Even if you didn't you should still check for codes, sometimes they dont pop up on the cluster, this may also assist on maybe something else is wrong. Check the codes and oil pan and let us know.
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es.biggs
- Posts: 2120
- Joined: Sat Feb 20, 2010 10:32 am
- Car: 1990 300ZX 5sp NA
- Location: Charlotte, NC
Re: oil pressure
What up, Biggs 
I definitely agree, check your oil pan for dents, and are you hearing any noises? There's a tube that sucks up oil into the oil pump, and it sits in the pan - if that tube gets knocked around, you could be cutting the oil flow off or decreasing the flow - which could cause a lot of damage. I'd leave the engine off until you check the oil pan.
If it's not that, it could be another common problem:
Stock oil pressure sending units (OPSU) are known to fail all the time. That is what tells the gauge in your cluster what your oil pressure is. I think your issue could be from the OPSU that is starting to go bad. A lot of 300zx's have a bad OPSU and their gauges display incorrect oil pressure values, rather than a correct accurate reading. Mine used to float around a lot, and now it just sits at 0 most of the time. Normally that is something that would concern me, but I have verified my oil pressure a few times, using an "oil pressure tester" gauge.
Usually the part will go bad on it's own, and hitting a pothole wouldn't have much effect on it, so you could be looking at another problem.
If you want more information, try searching the forums on the topic, it's covered a lot. I would suggest checking the pressure or having it checked at a shop, with an accurate gauge.
I definitely agree, check your oil pan for dents, and are you hearing any noises? There's a tube that sucks up oil into the oil pump, and it sits in the pan - if that tube gets knocked around, you could be cutting the oil flow off or decreasing the flow - which could cause a lot of damage. I'd leave the engine off until you check the oil pan.
If it's not that, it could be another common problem:
Stock oil pressure sending units (OPSU) are known to fail all the time. That is what tells the gauge in your cluster what your oil pressure is. I think your issue could be from the OPSU that is starting to go bad. A lot of 300zx's have a bad OPSU and their gauges display incorrect oil pressure values, rather than a correct accurate reading. Mine used to float around a lot, and now it just sits at 0 most of the time. Normally that is something that would concern me, but I have verified my oil pressure a few times, using an "oil pressure tester" gauge.
Usually the part will go bad on it's own, and hitting a pothole wouldn't have much effect on it, so you could be looking at another problem.
If you want more information, try searching the forums on the topic, it's covered a lot. I would suggest checking the pressure or having it checked at a shop, with an accurate gauge.
Re: oil pressure
thanks guys i checked the pan its got a couple small dents in it, nothing to huge though. I did however discover what looks like a vacum line on the passanger side (jdm) beside the oil pan that looks damaged but the car started fine with full pressure on my dash gauge this morning and sat at about 5 bar.
How do I run the codes havent had to on an obd1 all my older cars all had obd2.
But my car will be going into a mechanic shortly as I have a 12 hour drive and back at the end of the month.
How do I run the codes havent had to on an obd1 all my older cars all had obd2.
But my car will be going into a mechanic shortly as I have a 12 hour drive and back at the end of the month.
Re: oil pressure
Ok guys sorry for the noobish questions but im new to this turbo thing first nice car ive owned. So my roomate and i were checking out some stuff on my car and with your input we think we know what it might be, just thought id run it by you guys for a little input.
We discovered a few dents in the oil pan nothing huge but a couple moderate dents however while we were looking we found what looks like a vacume line beside it that looks split which is were we think the roughness in the engine when my turbos start spooling is coming from. The car runs great untill the turbos get involved. We also noted that the oil pressure gauge droped down to 0 and then up to 8 bar, and with input from biggs seems like my oil pressure sending unit or the gauge might be on its way out.
Thanks for all the help ill be ordering all the parts in friday and hopefully have her all fixed in a couple weeks if not I'll be back for more help.
We discovered a few dents in the oil pan nothing huge but a couple moderate dents however while we were looking we found what looks like a vacume line beside it that looks split which is were we think the roughness in the engine when my turbos start spooling is coming from. The car runs great untill the turbos get involved. We also noted that the oil pressure gauge droped down to 0 and then up to 8 bar, and with input from biggs seems like my oil pressure sending unit or the gauge might be on its way out.
Thanks for all the help ill be ordering all the parts in friday and hopefully have her all fixed in a couple weeks if not I'll be back for more help.