Jump to content
SAU Community

Recommended Posts

So recently at the track had experienced a loss of throttle after a period of WOT after installing the emtron ecu, recently did some logging to troubleshoot the issue and found the ECU was cutting due to a low oil pressure issue. Going over the log can see that while accelerating at 4k rpm will see 100 PSI of pressure and holding steady at that level until getting off the throttle which then after can see as low as 25 PSI at 3-4k rpm and will recover back to a normal level after that.

 

Wondering if anyone has an idea what could be the cause as it just feels abit strange and i dont feel like it could be a sensor issues just due to it clearly sitting at a good pressure until off throttle, in the attached can see a 3rd and 4th gear pull but can even perform great through 3 and 4 gears of WOT but still once off throttle and getting back on it will see pressure drop.

r.PNG

h.PNG

Link to comment
https://www.sau.com.au/forums/topic/486211-low-oil-pressure-after-wot/
Share on other sites

As in an oil relocation block away from the motor?

This "may" be the cause of the inaccurate oil reading, however that's the same excuse I'm using with my shit box too lol.

On WOT you'll see a good 6 to 7bar of oil pressure and lift off, it drops to under 2 bar tripping the engine protection.

4 minutes ago, Dose Pipe Sutututu said:

As in an oil relocation block away from the motor?

This "may" be the cause of the inaccurate oil reading, however that's the same excuse I'm using with my shit box too lol.

On WOT you'll see a good 6 to 7bar of oil pressure and lift off, it drops to under 2 bar tripping the engine protection.

It's plugged into a grex sandwich plate so it's still bolted onto the motor.

 

Interesting im glad I'm not the only one to experience this then ahahah

2 minutes ago, Duncan said:

In those logs are you on a track (ie braking when the oil pressure dips) or on street/dyno etc. You might need baffles in the sump.

Alternatively.....turn the oil pressure protection down to 1.4bar?

In those logs I'm on the street but I did have to brake pretty hard, I had tried it where I also didn't get on the brakes too much after and still experienced the same issue. The sump has "some" baffles but I'd say it's fair to say not enough.

 

I would agree with you and just turn down the oil pressure protection at least for now, but was interested to hear some opinions as I couldn't find any info on the problem.

Yeah well I was thinking...there is nothing that happens when you get off the throttle that should cause low oil pressure, its not like clearances suddenly change or and the relief spring would close and in any case the sensor is on the feed side....so more likely there was no oil available to pick up

which means all the basic oil control stuff to:

1. keep oil out of the head (restrictors)

2. get it back out of the head when it gets there (external breathers/oil return, drilling out the block and head oil returns)

3. have more oil in the sump to pick up - larger capacity sump

4. have more oil near the pick up - baffles

  • Like 1

speaking of the relief spring and noting this is one of those stupid times where I understand imperial (psi) but the graph is in metric (kpa), it looks like the oil pressure is a little low at full noise too, isn't the relief spring 120psi/830kpa?

7 minutes ago, Duncan said:

Yeah well I was thinking...there is nothing that happens when you get off the throttle that should cause low oil pressure, its not like clearances suddenly change or and the relief spring would close and in any case the sensor is on the feed side....so more likely there was no oil available to pick up

which means all the basic oil control stuff to:

1. keep oil out of the head (restrictors)

2. get it back out of the head when it gets there (external breathers/oil return, drilling out the block and head oil returns)

3. have more oil in the sump to pick up - larger capacity sump

4. have more oil near the pick up - baffles

It certainly does make sense that there is just no oil to pick up, but I can go 3 or 4 gears of WOT and have no oil pressure issues too (I have no logs of this unfortunately) and I have a fair amount of oiling mods to try and help only thing I'm missing is a rear head drain which is potentially the most helpful. 

8 minutes ago, Duncan said:

speaking of the relief spring and noting this is one of those stupid times where I understand imperial (psi) but the graph is in metric (kpa), it looks like the oil pressure is a little low at full noise too, isn't the relief spring 120psi/830kpa?

I also understand psi but apparently most things make more sense in kpa oil pressure being one of a few exceptions so im trying to learn ahahahah, I have no idea of the relief spring pressure tbh I thought 110 which is the absolute peak it hits was about right, I was thinking of removing the relief and making sure it is in good condition, I would just replace it but couldn't find a replacement for an n1 pump too easily but I could just be blind.

1 hour ago, pogman said:

plugged into a grex sandwich plate so it's still bolted onto the motor.

Well that rules out the relocation theory, however with no load, you're still getting 1.5bar of oil pressure.

Can you present that data in a scatter graph over longer period? Would really highly the anomalies.

Wish Haltech could do that.

Can you log battery voltage, and TPS, and put all four of those into a single image (even as split graphs)?

 

The oil pressure drops aren't following RPM as such.

I'm intrigued if you may have a ground loop between different sensors.

With the engine not running, log your sensors and for example cycle the throttle pedal. See if any sensor values flutter or move about. This won't be a perfect test either as the ECU won't be cycling all of its actuators like it would be while running.

What EMTRON do you have? Do you have a link to the wiring guide for that ECU?

  • Like 1

You are also getting pressure dips on gear shifts.

They're just not dipping as far, but they're dipping quite below the amount of oil pressure you should be seeing, for how much RPM drops.

 

It quite little could be the oil pressure relief valve is starting to stick open a little/is slow to close.

1 hour ago, pogman said:

I also understand psi but apparently most things make more sense in kpa oil pressure being one of a few exceptions so im trying to learn ahahahah, I have no idea of the relief spring pressure tbh I thought 110 which is the absolute peak it hits was about right, I was thinking of removing the relief and making sure it is in good condition, I would just replace it but couldn't find a replacement for an n1 pump too easily but I could just be blind.

Yeah so N1 and any other larger than factory pump are pretty famous for pumping the sump dry...obviously we don't often get to spend 20 or 30 seconds at high rpm/full noise on the road so I'd still be suspicious that is what is happening here.

  • Like 1

Get more oil pressure sensors. I have 3 purely because trust no-one.

It would be worth checking (if not already) if it happens on every shift. Like boring, 2-3 shifts at 60kph making 10kw with no obvious G-force on a shift with mega power. Does it still drop? Does it drop less?

What if you shift at 5000rpm or what have you with no load?

  • Like 2
2 hours ago, GTSBoy said:

Log voltage. I'm suspecting the alternator.

Or even maybe a bad earth somewhere.

ie, seeing as it is rev dependent, I am thinking it is alternator dependent.

It doesn't seem to follow revs. Oddly it seems to follow TPS a little bit from what I can see, but with some delay a bit.

IE end of the graph, when he lets off throttle fully, pressure drops a lot, then slowly builds back up, but rpm is on a nice cruisey drop off.

I do agree though, it seems very electrically.

  • Like 1
10 hours ago, Dose Pipe Sutututu said:

Well that rules out the relocation theory, however with no load, you're still getting 1.5bar of oil pressure.

Can you present that data in a scatter graph over longer period? Would really highly the anomalies.

Wish Haltech could do that.

im surpirsed a halaltech doesnt show that. this scatter is from a 45 second long log

oil scatter.PNG

3 minutes ago, pogman said:

im surpirsed a halaltech doesnt show that. this scatter is from a 45 second long log

oil scatter.PNG

Definitely looks like an outlier, perhaps there may be some electrical issues like others have pointed out earlier.

My pressure drop I can replicate over and over again, which I'm blaming the relocation block for, however yours is mounted right up the block.

  • Like 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • PayPal is a safe, online payment system that enables businesses and individuals to safely send and receive money, making it an indispensable tool in both personal and professional contexts. However, many users wonder how to send money on PayPal? Don't be alarmed if PayPal is new to you - all the steps can be found by visiting merchant sites with links marked "Pay or send money". Once clicked, select payment method, amount, and add message or note for recipient(s). Upon successful transaction completion you will receive an email containing details of transaction. Let’s start by understanding how PayPal works, how money transfers from banks to PayPal and using various payment methods. Moreover, to transfer money between PayPal and bank, head to the Wallet section and click "Add Account", selecting either "Transfer within seconds with debit" or "Transfer between 3-5 days with bank", and following any instructions shown on screen until completed successfully.   How to Send Money Over PayPal: The Basics Before sending money through PayPal, first create an account. Here is how to set-up a PayPal account: ·         Click “Sign Up” on either the PayPal website or app to enter your basic information such as email address or name into their system. ·         Link your bank account, debit card or credit card directly with PayPal so you can fund transactions directly using these accounts. ·         Verifying your PayPal account will enable you to send and receive more funds. Typically, PayPal requires that you verify your credit card or bank account by making small deposits into it. ·         Once your PayPal account has been established, you can send money through it.   How Do I Send Money to Someone on PayPal? After creating a PayPal account, you can easily send money through it. Here is how to send money to someone on PayPal: ·         First of all log into your PayPal account ·         Once on your dashboard, click on "Send & Request Tab." ·         After this enter the recipient's email or mobile phone number. ·         Enter the amount you wish to send to someone. ·         At last, recheck all the details and click "Send Payment" to complete your transaction if everything looks in order.   How Can I Send Money PayPal for Goods and Services? PayPal provides a safe method for individuals and businesses alike to transfer funds online, both personally and commercially. When paying for goods or services there are additional protections in place both for buyers and sellers. PayPal Buyer Protection offers you peace of mind when paying for products or services with PayPal. In the unlikely event that there is an issue with a transaction, if there are any discrepancies you may dispute it and be eligible for a possible refund. You need to follow the same steps to send money, but select Paying for Services or Goods when prompted. In fact, this extra layer of protection will keep your account safe from fraudulent attacks.   How to Transfer Money to PayPal from Bank? Here is how to transfer money from PayPal from bank: ·         Log into PayPal using either its app or website. ·         Click "Add Funds" in the Wallet section, and add money directly from your bank to your PayPal account. ·         If you have linked your bank account with PayPal, select it under Funding options to select it as your funding option. ·         Enter the amount you would like to transfer to PayPal from your bank balance. ·         Click Add Funds. It typically takes several days for funds to arrive on your PayPal account.   FAQ How can I send money PayPal? Log into your PayPal account, select "Send and Request," enter in your recipient's phone number or email address, select the amount due, payment method of choice and click on "Send Now" - quickly and safely sending money via PayPal is now an efficient method of money transfers!   How do I transfer money to PayPal from a bank? Log into PayPal and select "Add Funds" to transfer money from your bank to PayPal. Select your account number, input an amount, and confirm it. Though the transfer may take up to several days for completion.   How do you send money to someone on PayPal? Simply log into your PayPal account, select "Send and Request", enter the recipient's phone number or email address, select the amount to send, and click "Send Now".   How can I receive payment through PayPal? Senders can easily accept payments with PayPal by providing your PayPal email address and being notified via email when a payment has been completed. When funds appear in your PayPal account, they will appear instantly!
    • At least yours have parkour down pat. One of mine will still trip over his own shadow and fall over... He's a special type of cat... Ha ha ha
    • The question then becomes - was there any fluid coming from that hole before you did the rebuild ?    You may not have noticed, of course.   Depending on how you did the rebuild, the possibility has to be considered that somehow (cleaning ?)  fluid entered that hole and is now being 'forced'  out by small movements of the proportioning valve.   From the factory, there's actually a small rubber plug in that hole but with age and under-bonnet heat it's quite common for it to 'go missing'.  That rubber plug is designed to allow the venting process but also to prevent 'stuff' getting to the area (prevent corrosion, etc).   The plug is also not available as a spare part AFAIA. Personally I wouldn't race and buy a new master just yet but keep an eye on the area to see if the 'leak' continues.   If you're concerned about brake fluid damaging nearby paintwork, cable tie a piece of suitable absorbant material over the hole and remove/monitor occasionally.    Operation of the proportioning valve and the brake master itself won't be affected, but also keep an eye on brake fluid level, of course. In terms of a new master, the genuine part is getting expensive, unfortunately.  Amayama is showing AUD900+.   I was searching recently and there's an aftermarket part available from Japan made by 'Parts Assist': https://zenmarket.jp/en/yahoo.aspx?q=BNR32%2bBM50&p=1 Whether it's any good I have no idea, although in my experience Japanese aftermarket stuff is pretty good quality-wise.   The above site allows overseas buyers to purchase stuff more easily from Japan but there are fees and shipping costs, of course.   The original Japanese seller page is here: https://auctions.yahoo.co.jp/jp/auction/p1197401228 Copper/Nickel is fine but I still prefer bundy tube and it's also cheaper.
    • Your chihuahuas look weird!
×
×
  • Create New...