Valkyrie

I need to know whether the OMP (on the S5) pumps oil as soon as the engine fires up... or does it wait until the car is warm before pumping?


My lines are empty after working on the water pump housing (since you have to detach the lines, letting the oil drain out), and I don't see any oil coming into the lines...

I also had to remove my OMP to fix bad threads in one one of the banjo bolts holes, so I poured water into it to get rid of all the debris I could... I don't imagine this would damage it, since it's probably reasonable water resistant, and I let it dry for a whole day.

It doesn't inject anything even with I give it a bit of throttle.


Also, sometimes when I give it throttle and let off quickly, the engine buzzes like the ACV without a silencer, except that my air pump isn't attached right now.

This couldn't be related to having no oil injected, could it?


I sealed the OMP to the front cover with RTV, as well as the stock o-ring, although I don't know if that would really have an effect, since I didn't use that much.

SpooledupRacing

ok let me get a few things right.... u poured water in with your oil system.... that was a bad thing.

your omp only sprays oil once the car reaches 3000 rpm (possibly 3500)

your omp works by injecting oil from your engine into the intake which means when u pored the water into your omp u poured it into yoru engine and it is mixed with the oil (hopefully u did not pour in alot)

S5 omp are notroius for going out I would start mixing 1/2oz of 2 cycle per gallon of gas so u have some protection and then test you omp. (there is a write up on the how to in the faq)

as for the buzzing sorry I cant help u there

Valkyrie

The OMP was off the car when I poured water into it. I allowed plenty of time for it to dry.

OTOH, a little water in oil that is going to be burned in the engine anyway isn't going to hurt anything. My real concern was with the electronic parts (which have to be designed to be relatively water resistant, as engine bays tend to get wet... I didn't submerse it though).

Aluminum shavings on the other hand WOULD be a bad thing to put into the engine. Much worse than a bit of water.

If the OMP was actually fried electrically, it would be throwing a code (codes go off whenever there's short circuits or resistances out of certain ranges). The issue is why there isn't any oil in my lines... which is probably more of a mechanical problem.

For the record, I've only let the car run for maybe 5 minutes (not even long enough to warm up the coolant).

SpooledupRacing

the faq I believe tells u to pull the opm lines off and put a cup nder the opm and start the car and put the rpms to 3500 and hold it for 5 minutes then turn the car off and measure what u have...

and the oil that u are burning is the oil from your oil pan.. water inside the engine is bad plain and simple

Dave

Valkyrie

Regardless, no water is going to get into the oil pan, and water going into the combustion chamber is no big deal (such as the water treatment...just makes it run rough).

NZConvertible

The actual oil flow is very small, particularly at idle which it sounds like is all you've done. Put some premix in the tank and drive it normally until you see the oil lines have filled up. I have no idea how long that should actually take, but if it takes more than a few hours of driving then start looking for problems with the OMP. The premix will protect the engine in the mean time.

I hate to be having the same coversation with you in two threads, but why use RTV when the o-ring works fine? Using sealant like this risks it being sqeezed out wehn you bolt the OMP down and blocking the oil passages. I'm not saying that's happened, but it's a risk that I would definitely avoid.

Valkyrie

The problem being that the O-ring didn't seem be working fine (despite being brand new when I originally installed it), as the bottom OMP's body was horrifically oily (it seemed to be coming from the place where it was attached to the.

For the record, I just came back from a rather...eventful...test drive... and oil is definitely in the lines. Some have more than others... but at least two of the lines have a full feed, albiet two of them have air bubbles for some reason (but then again, they did before...). So that's one worry down...sort of.

I'm now pretty convinced that the buzzing (now sort of a roar) was actually just a big vacuum leak... which could be coming from a number of places... namely, the main intake hose, since I took it off a few days ago to replace the coolant hose to the water pump housing (while I was at it... I already had the hose, anyway), or one of it's two vacuum hoses, although this is a pretty mean-sounding leak, so I kind of doubt it. My other suspect would be the upper intake manifold... which I took off a number of weeks ago to fix...hell, I don't remember.

That would also explain why it suddenly started hesitating like a **** after driving for about 5 minutes...which ended up with me blocking traffic for about 5 minutes, until I could coax it up a hill (I had to crank it about 10 times...) and then to a nearby gas station...

It would also explain why I was getting pre-ignition so badly, although it doesn't really explain the pre-ignition sounds I had been having over a week ago (they were minor by comparison)...

I pulled my plugs to see if they were fouled or something, and they weren't, although the diode was a bit whitish. I had also just replaced the positive terminal because my old one went bad (those replacement kind that just sort of "squish" up on you SUCK...)....but the connection still seemed to be decent... Hell, I thought I might had run out of gas, without the fuel light coming on, but I still had 3 gallons in the tank.

I also thought maybe working in the rain allowed water into the ignition coils, but seeing as how the plugs weren't fouled, nor was the tach not working, I kind of doubt it... it had over a day to dry off anyway.


Perhaps my engine just has crappy compression (almost scared to test it...besides that, it's a PITA), and only runs well when it's got a bit of oil residue in the engine... I'm sure it'll get a bit better after I fix the vacuum leak, and drive it a bit more, but autocross isn't gonna happen tomorrow... crap.

Valkyrie

Turns out the noise was coming from the air control valve...although it was being sucked into where the air pump hooks up to it... IIRC this is probably due to the anti-afterburn valve (or maybe my check valve has gone bad... I think I can hear the exhaust through the ACV...). On the other hand, removing and resealing my intake hose and ACV seemed to do the trick with the driveability issues.

I will have to admit... the ACV seal is one that is best left up to paper gaskets, because of all the small holes.

Either way, I'm now back to where I was (after screwing with it for 4 days), plus a minor issue that was bugging me in the first place (although I thought I had fixed it by replacing the ACV (with another used one)... well, either way... maybe I'll just get a blockoff plate for it.

Guess autocross will have to wait until next week...

RyoFC3S

iTrader: (1)

I havn't read everything in this thread, but take it from me: REMOVE your OMP (block it off) and premix!!! I had to rebuild my engine (lots of time and $$$) just because my OMP stopped working-- it lost compression over time from the apex seals flattening out (among other things). Just get rid of the system.

You can get a really high quality OMP blockoff plate here: http://www.2751engineering.com/2751parts.html

Also, you're going to need to leave it plugged in or else your ECU will go into limp mode. Because of this I left mine tied back under the cruise control unit (where the wiring harness goes through the fire wall).

When I premix, I do 1 oz. per gallon of gas. It isn't much more expensive to premix (I think a 1 qt. bottle is like $2...). You only use 1/2 of 1 qt. bottle of oil ever FULL tank. Stopping for gas takes about 30 seconds to 1 minute longer than it used to. Big deal.

Good luck, I hope your engine is okay! Mine wasn't so fortunate......

NZConvertible

How do you know for sure the OMP was the cause? The S5 ECU goes into limp mode if there's any problem with the OMP, to protect the engine. I find it hard to believe it stopped working and you were still able to drive for long enough to do damage.

shrek

It is definately possible to continue driving the car. I just realized I had been driving my 90 N/A the past 300+ miles with a bad OMP. I tested it per the FSM. The readings at the position sensor when the car was running where way off. It should have been 1.1V at idle and raise to 4V+ with throttle. The voltage wasnt able to get over 1V at any RPM. All other checks where good and the resistance at the stepper motor was only 5ohms high.

Do you know how to get to that section of the FSM?

Does anyone know which part of the OMP went bad to cause this problem? I am ordering a new pump ASAP.

zetecr

What made you suspect the OMP wasn't working? I've had my car for 3 months (a S5 TII) and only recently became aware of the whole OMP business. Are there tell-tale signs one can look for to at least have some confidence it is working? I'm a little worried as there has been no noticeable oil consumption over ~3000kms. On the other hand, the oil injection point is about 3000rpm (according to a post I just read above), above which I don't spend much time in my daily driving. Which also begs the question: Am I doing more damage than good by not revving it higher often enough?

HAILERS

I can assure you the three thousand rpm figure is bogus.

NZConvertible

That's BS like the man said. Oil is always being injected, with the amount determined mainly by load and rpm.

pyroal188

i recently found out i have a bad OMP. what kind of damage can be done from doing this.

now my car makes a KNOCKING kind of sound at idle (a little) and when i rev it up.

i olny recently started to premix to lubracate the rotors. after 15 min of running it still made the sound

HAILERS

Aw shucks. Come on man. The OMP has zip to do with whatever knocking sound you have.

Really. I'm serious. Very serious. The OMP has nothing to do with rotor bearings, eccentric shafts etc. Bad apex seals don't knock. They just roll over and go out the exhaust and the engine starts running real crummy right then and there.

tomoaac

Hi guys

So if you block off the oil metering pump what other tasks need to be done?

Ie what happens to the oil injectors? are they ok to be left as they are.
And whats this about the ecu going in to limp mode, Could a resistor be placed in the loop to stop this happening?

ericgrau

iTrader: (1)

Water always get into the oil system and it will boil off as soon as you go on a long drive. All oils contain anti-corrosion additives for this reason, but they can get used up. This is why you're supposed to change your oil sooner if you go on a lot of short drives.

A bad OMP will cause severe apex seal, side seal, and housing wear. You're looking at a possible engine rebuild or drop in compression. I'd:
1. Test the OMP using the procedure in the Haynes manual or FSM (forum FAQ will show you where to download it). If it's bad, continue to next steps.
2. (just my opinion) Pour a little 2 stroke oil in the spark plug holes so that the engine won't go another moment without lubrication.
3. Add 2 stroke oil to your gas tank at about 1 oz. of oil per gallon of gas. Do this every time you fill up your gas tank. This will completely replace the lubrication provided by the OMP, and you could do it forever if you really wanted. Any TCW-13 certified 2 stroke will work fine.
4. Compression test your motor to see how bad it is. If you need a rebuild then don't be surprised if you need to pay an extra $600 for new housings.
5. If you don't have any real problems, you can continue to drive your car like this. I'd replace the OMP soon though, since adding 2 stroke at every gas fillup will be a pain.

Aaron Cake

iTrader: (1)

There is a detailed writeup in the Archives which covers converting to premix.

You cannot replace the S5 metering oil pump with a resistor. It's actually a servo and the ECU expects to see it's position not just a single value.