Oil Pressure Issues

**professorblaze** · 7-3-07, 16:22

When my 88 mx-6 turbo is started cold... oil pressure is fine... however the car warms up and as the car warms up, the oil pressure drops to where it is eventually at 5ish psi at idle and 15-20ish psi during regular driving. I would first assume an oil pump here. My uncle is a retired ford mechanic and says that issue reminds him of the classic ford problem of bad main bearings... anyone else ever had to combat this issue? thanks for the help

**professorblaze** · 7-4-07, 18:49

can someone help with this question? i just need yes or no for people who know what this is about. can anyone confirm this?

**defiler** · 7-4-07, 18:56

What brand of oil pressure gauge are you using, and how old is it?

**Zach** · 7-4-07, 21:37

Did the probe even come with a stock oil pressure gauge?

**defiler** · 7-4-07, 22:25

Yes, it came with a gauge, but they're notorious for being inaccurate.

I'd assume thats not what he's basing his measurements off, as ours didnt have numbers on them...

**professorblaze** · 7-4-07, 22:51

i am driving an 88 mx6 turbo. the pgt's came with the same engine so is the reason i asked my uncle who retired from ford in 2002. my car has an aftermarket gauge installed which shows 60psi when i start the car. as the engine slowly warms up, so slowly drops the oil pressure to where it only reads 5-10psi at idle. i was just wondering if anyone else ran into this issue cause my uncle said that sounds like a typical symptom for a ford's main bearings. i dont know if mazda or ford built the 2.2 turbo in our car but that matters none. the question is that if that is a "typical ford issue" could it be a mazda issue to... if anyone has had this problem... please help now cause i dont wana start throwing parts at this thing and be out time and money.

**defiler** · 7-4-07, 23:11

Mazda built the motor, just FYI. (I know it doesnt matter, but still nice to know)

**Zach** · 7-4-07, 23:50

not really knowing how oil pressure is read...I thought it was read from the oil pump?

**GotF2TinGD** · 7-5-07, 6:09

I got a/f oil pressure gauge

10w 40 super synthetic oil

at idle when cold - 60psi
at idle when warm - 20psi

when cruising when warm ie at like 100km/h in 5th usually sits around 40psi

how thick is your oil and how old is it?

**professorblaze** · 7-5-07, 10:56

fresh 20-50w oil. can not run synthetic for another 10k miles. so do i need an oil pump? or are my main bearings bad? i was originally gona put an oil pump on it but i dunno

**nmn** · 7-5-07, 13:08

How many miles?

**professorblaze** · 7-5-07, 14:11

the engine is suppose to only have 5-10k miles on it. the car was driven from AZ to WA and while driving through cali the oil pressure dropped so he towed the car up here and it was sold to me. the engine block has been painted red, the head looks new and so does the turbo. the story adds up so far...

**SixSick6** · 7-5-07, 14:26

Your uncle is right (in part) that when main bearings go bad your oil pressure drops.- Being a Ford tech he is used to seeing it from Ford but it is an automobile thing, not necessarily just a manufacturer thing. There are plenty of used Ford's and Mazda's on the road right now that have no issues whatsoever. Yours seems to be a rebuild issue over a manufacturer issue.

Unfortunately, if this is what is happening, then you will need to rebuild your engine including having the crankshaft checked and or turned and or oversized bearings. I'm guessing whomever rebuilt the engine skipped the most important steps and simply slapped it together knowing that it would then be dumped on some sucker.

As for the oil pressure (Zach) it can be checked and or a gauge installed at the oil sending unit on the back of the block near the knock sensor and oil cooler.

As for oil pressure, it should be 21-36 psi at 1,000 rpm and 43-57 psi ^ 3,000 rpm. If you're going to keep this used car for any considerable amount of time (providing that the gauge is incorrect and your car isn't about to die completely- highly unlikely) you really need to look into a shop manual:

http://www.mx6.com/forums/1g-mx6-gen...ml#post1832417 (Ebay Finds Thread Dump)

**professorblaze** · 7-5-07, 15:24

i have a shop manual for a '90 probe so i have one that is damn close. i am trying to get an answer of oil pump or main bearings... i will try and get an oil pressure gauge directly to the back of the block. if that pressure is low, can i get pressure from the oil pump somehow? i cant find it in the manual

**6ICK6** · 7-5-07, 20:13

i don't believe so. that is where you check it, where the stock oil pressure sending unit is at.
considering engine was just rebuilt, it could be a bad rebuild or coincidently the oil pump decided to take a dump. that's why you always replace since your down there.

7-3-07, 16:22	#1 (permalink)
professorblaze That soldier boy Join Date: Jun 2007 Location: Lakewood, WA, USA Age: 26 iTrader: (10)	Oil Pressure Issues When my 88 mx-6 turbo is started cold... oil pressure is fine... however the car warms up and as the car warms up, the oil pressure drops to where it is eventually at 5ish psi at idle and 15-20ish psi during regular driving. I would first assume an oil pump here. My uncle is a retired ford mechanic and says that issue reminds him of the classic ford problem of bad main bearings... anyone else ever had to combat this issue? thanks for the help

7-5-07, 13:08	#11 (permalink)
nmn night shift Join Date: May 2006 Location: Kingston, TN, USA Age: 25 iTrader: (0)	How many miles?
	John McCain for President

7-5-07, 20:13	#15 (permalink)
6ICK6 Join Date: Mar 2005 Location: , WI, USA iTrader: (0)	i don't believe so. that is where you check it, where the stock oil pressure sending unit is at. considering engine was just rebuilt, it could be a bad rebuild or coincidently the oil pump decided to take a dump. that's why you always replace since your down there.
	go ahead and laugh. just don't lose.

7-4-07, 18:49	#2 (permalink)
professorblaze That soldier boy Join Date: Jun 2007 Location: Lakewood, WA, USA Age: 26 iTrader: (10)	can someone help with this question? i just need yes or no for people who know what this is about. can anyone confirm this?

7-4-07, 21:37	#4 (permalink)
Zach All aboard the B& V& Join Date: Nov 2004 Location: Age: 32 iTrader: (6)	Did the probe even come with a stock oil pressure gauge?

7-4-07, 22:51	#6 (permalink)
professorblaze That soldier boy Join Date: Jun 2007 Location: Lakewood, WA, USA Age: 26 iTrader: (10)	i am driving an 88 mx6 turbo. the pgt's came with the same engine so is the reason i asked my uncle who retired from ford in 2002. my car has an aftermarket gauge installed which shows 60psi when i start the car. as the engine slowly warms up, so slowly drops the oil pressure to where it only reads 5-10psi at idle. i was just wondering if anyone else ran into this issue cause my uncle said that sounds like a typical symptom for a ford's main bearings. i dont know if mazda or ford built the 2.2 turbo in our car but that matters none. the question is that if that is a "typical ford issue" could it be a mazda issue to... if anyone has had this problem... please help now cause i dont wana start throwing parts at this thing and be out time and money.

7-4-07, 23:50	#8 (permalink)
Zach All aboard the B& V& Join Date: Nov 2004 Location: Age: 32 iTrader: (6)	not really knowing how oil pressure is read...I thought it was read from the oil pump?

7-5-07, 10:56	#10 (permalink)
professorblaze That soldier boy Join Date: Jun 2007 Location: Lakewood, WA, USA Age: 26 iTrader: (10)	fresh 20-50w oil. can not run synthetic for another 10k miles. so do i need an oil pump? or are my main bearings bad? i was originally gona put an oil pump on it but i dunno

7-5-07, 14:11	#12 (permalink)
professorblaze That soldier boy Join Date: Jun 2007 Location: Lakewood, WA, USA Age: 26 iTrader: (10)	the engine is suppose to only have 5-10k miles on it. the car was driven from AZ to WA and while driving through cali the oil pressure dropped so he towed the car up here and it was sold to me. the engine block has been painted red, the head looks new and so does the turbo. the story adds up so far...

7-5-07, 15:24	#14 (permalink)
professorblaze That soldier boy Join Date: Jun 2007 Location: Lakewood, WA, USA Age: 26 iTrader: (10)	i have a shop manual for a '90 probe so i have one that is damn close. i am trying to get an answer of oil pump or main bearings... i will try and get an oil pressure gauge directly to the back of the block. if that pressure is low, can i get pressure from the oil pump somehow? i cant find it in the manual