Oil pressure question

[Jonny Cash]

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I was reading a thread earlier about " how much beating can a v6 SHO take, and I wanted to ask some basic engine questions.


I always only get 50 psi of oil pressure on cold start up. And then between 180-210 degrees, Im only getting 10psi per 1000 rpms. Could it be bearing related? Leaks, oil pump etc. ( The bearings were replaced 2 1/2 years ago )

At low rpm at max running temp. 220. I run really rich, and ping a decent amount at low rpms. So I installed a 180 T-stat, and colder plugs, and reprogrammed my LPM. It got better, and leaned out quite a bit. But I forgot ask to program my fan to kick on before 220. So any temp over 200 Im pinging, and oil pressure goes close to 0 psi at idle (1000-1100). Does anyone have a remedy besides saying screw it and tuning it myself? Is the low oil pressure at 220 deg. something to seriously worry about? Can someone diagnose this for me?

Jay

 

[Jonny Cash]

I was reading a thread earlier about " how much beating can a v6 SHO take, and I wanted to ask some basic engine questions.


I always only get 50 psi of oil pressure on cold start up. And then between 180-210 degrees, Im only getting 10psi per 1000 rpms. Could it be bearing related? Leaks, oil pump etc. ( The bearings were replaced 2 1/2 years ago )

At low rpm at max running temp. 220. I run really rich, and ping a decent amount at low rpms. So I installed a 180 T-stat, and colder plugs, and reprogrammed my LPM. It got better, and leaned out quite a bit. But I forgot ask to program my fan to kick on before 220. So any temp over 200 Im pinging, and oil pressure goes close to 0 psi at idle (1000-1100). Does anyone have a remedy besides saying screw it and tuning it myself? Is the low oil pressure at 220 deg. something to seriously worry about? Can someone diagnose this for me?

 

[F-22 Raptor SHO]

10 psi per 1000 rpms is about right for a healthy motor (I get 12). You changed alot of stuff to address pinging when I'm not sure that it wasnt just poor gas. Did it ping at idle or under low rpm load?

The 220 degree temps are not good. Hottest my car ever runs is 210. Get the fan to come on. 0 psi at 1000 has me very worried as well. Did this occur before you started the tuning? At 1000 rpms, I get 12 to 14 psi.

 

[Jonny Cash]

10 psi per 1000 rpms is about right for a healthy motor (I get 12). You changed alot of stuff to address pinging when I'm not sure that it wasnt just poor gas. Did it ping at idle or under low rpm load?

The 220 degree temps are not good. Hottest my car ever runs is 210. Get the fan to come on. 0 psi at 1000 has me very worried as well. Did this occur before you started the tuning? At 1000 rpms, I get 12 to 14 psi.

Thanks for the response. I always use premium gas, so I know that isnt responsible for the ping.

It does ping between 1000-2500-3000 rpms. Before, and after tuning. I always knew that 220 was a little too high for the fan to kick on for my application especially.

Before I tuned it, I had an LPM, but noone knows what it was programmed for. Fred said that he had it laying around, and they just threw it in to see what it would do.( ran very rich ) So I had it tuned for the few little mods I had done, and it was alot better, but I still had hot spots over 210 degrees.

The oil pressure was always at zero before and after tuning at idle. Which has me worried crazy. That is my main concern. When I met Kirk and told him about it he just shook me off, and told me " it always did that " Which didnt make me feel to good. I still knew something was wrong.

I am leaking oil. I dont know exactly where, but I was told that a bolt was broken off at the oil pump, and more or less " shimmied back together for a quick fix. But I cant imagine it being the culprit. It wasnt barely anything when I bought the car, and now it gets worse and worse. I am gonna attempt to fix it when I do my clutch, but are there any other things I should look for to get my pressure back??

 

[BeautifulDisasterSho]

This bolt that your talking about on the oil pump, is it possible the oil pickup tube and it is sucking half of nothing from the bottom of the oil pan? No oil, lots of friction, heat occurs.

 

[Mels]

Hey Jay :wave:

Have you tried swapping in a new oil pressure sending unit? I just wonder if the pressure information you're getting is accurate. Or, are you using an analog guage plumbed in somewhere?

I can't imagine this engine lasting this long with no oil pressure at idle.

 

[Jonny Cash]

Hey Jay :wave:

Have you tried swapping in a new oil pressure sending unit? I just wonder if the pressure information you're getting is accurate. Or, are you using an analog guage plumbed in somewhere?

I can't imagine this engine lasting this long with no oil pressure at idle.

haha.. hey Mel

I do have an aftermarket pressure guage ( autometer ). I havent tried replacing the sending unit. I have thought of that, but I always thought that 50 psi at cold start up was normal which led me to beleive my guage was accurate.

You do have a point because I forgot to mention that when Im running 200-220 degrees, Im not getting 1000rpms per 10psi. It falls a little lower than that. Is the sending unit tricky to locate? I guess I would just have to follow the line.

 

[Jonny Cash]

This bolt that your talking about on the oil pump, is it possible the oil pickup tube and it is sucking half of nothing from the bottom of the oil pan? No oil, lots of friction, heat occurs.

I wouldnt think so. I always thought that all stock car ECU's were set at 220 before the fan kicked on. I would think that a car with advanced timing would be set up to run cooler.

Its not like the car gets hot fast, its just that when it eventually gets there, my plugs arent igniting exactly all the fuel thats running through. I have driven the car in all weather conditions, and the difference is very minimal. So having low pressure worries me.

I do have a double core radiator also.

 

[NotSoSlowSHO]

I have thought of that, but I always thought that 50 psi at cold start up was normal which led me to beleive my guage was accurate.

It may be acurate at that particular point, but not at low PSIs.

What scale is the gauge on, probably a 0-100PSI?

I have a 0-100 PSI gauge and it reads zero at idle. But I know damn well that it doesnt mean I have no pressure, as the low oil pressure "idiot" lamp does not come on.

Typically I see:

Cold idle 50PSI
Cold 3K rpm 75PSI max (oil pressure relief valve)

Hot idle 0-5 PSI
Hot 3k rpm 50PSI

 

[F-22 Raptor SHO]

1: Stock oil pressure sending unit is the little plug with a wire on it on the rear of the engine block...seen from under the car.

2: I have a mechanical autometer gauge, never do I get 0 unless the car is off.

3: Fan kicks on at 210, not 220.

4: Does your oil idiot light even turn on at key on engine off?

 

[Jonny Cash]

1: Stock oil pressure sending unit is the little plug with a wire on it on the rear of the engine block...seen from under the car.

2: I have a mechanical autometer gauge, never do I get 0 unless the car is off.

3: Fan kicks on at 210, not 220.

4: Does your oil idiot light even turn on at key on engine off?

I just checked. My idiot light DOES NOT COME ON. Im mortified right now. Can someone please help me?

 

[Jonny Cash]

It may be acurate at that particular point, but not at low PSIs.

What scale is the gauge on, probably a 0-100PSI?

I have a 0-100 PSI gauge and it reads zero at idle. But I know damn well that it doesnt mean I have no pressure, as the low oil pressure "idiot" lamp does not come on.

Typically I see:

Cold idle 50PSI
Cold 3K rpm 75PSI max (oil pressure relief valve)

Hot idle 0-5 PSI
Hot 3k rpm 50PSI

It is in fact on a 1-100 scale. And my numbers are WAY lower than those listed... I realize the guage isnt exactly accurate, but I know I have some pressure. How couldnt I ??

 

[Rockledge]

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At low rpm at max running temp. 220. I run really rich, and ping a decent amount at low rpms. So I installed a 180 T-stat, and colder plugs, and reprogrammed my LPM. It got better, and leaned out quite a bit. But I forgot ask to program my fan to kick on before 220. So any temp over 200 Im pinging, and oil pressure goes close to 0 psi at idle (1000-1100). Does anyone have a remedy besides saying screw it and tuning it myself? Is the low oil pressure at 220 deg. something to seriously worry about? Can someone diagnose this for me?

The engine shouldn't be pinging. Are you sure that's what you are hearing?

Pinging is caused by high combustion chamber temps, which in many (if not most) cases can be traced to a lean condition. Which is why it's strange that yours is running rich and yet you say it pings. Moreover, the Yamaha engine utilizes a knock sensor which causes the PCM to retard the timing if it senses engine knock.

 

[Jonny Cash]

[/IMG]


In this pic you can clearly see me well above 3000 rpms. The bottom guage is the OP. The middle one is temp. The temp is around 210, and the OP is only around 25 psi.

 

[Jonny Cash]

The engine shouldn't be pinging. Are you sure that's what you are hearing?

Pinging is caused by high combustion chamber temps, which in many (if not most) cases can be traced to a lean condition. Which is why it's strange that yours is running rich and yet you say it pings. Moreover, the Yamaha engine utilizes a knock sensor which causes the PCM to retard the timing if it senses engine knock.

I am pretty sure thats what Im hearing. I does lean out a little too much during deceleration, but thats not when Im hearing it.

And if my timing was being ******** by the PCM wouldnt I get a light?

 

[Rockledge]

And if my timing was being ******** by the PCM wouldnt I get a light?

No CEL when that happens. But performance takes a hit.

 

[NotSoSlowSHO]

Did you say you are loosing oil? Are you burning any?

Ive recently cleared up a PCV problem on my SHO. It was DRINKING oil thru the intake because of it. I was loosing nearly a qt every 500 miles or so.

Anyways, injesting so much oil, the factory O2 sensors saw a lean condition, and my wideband saw a rich condition. I was also having pretty bad timing retard.

Once I fixed the PCV problem, oil usage went down, A/F ration went back to normal, and I found my lost power due to the timing being bumped back to where it should be.

Oil in the combustion chamber effectively reduces the octane of gas.

Lots of timing retard, lean condition, and running warm.

Sound familiar? Just a thought.

 

[Jonny Cash]

That would sound right, but Im pretty sure Im not burning oil. I am leaking about 1 quart every 3-400 miles, and its not coming from the oil pan gasket. The leak is higher from the oil pan.

Although I do have quite a bit of condensation coming from the exhaust on cold start up. Actually.. Sometimes I swear I can smell burning oil, but I always thought the slight smell was from it leaking on the block and burning off.

When you say PCV you are taliking about an ATX, or a Cali MTX? I have no PCV valve

 

[Sh03d]

Doesn't the SHO not have a PCV valve at all?? It's a closed system right?

http://www.shoforum.com/showthread.php?t=53523&highlight=pcv

 

[Jonny Cash]

Doesn't the SHO not have a PCV valve at all?? It's a closed system right?

http://www.shoforum.com/showthread.php?t=53523&highlight=pcv

California MTX's have PCV valves.