No oil pressure?!

[DuncanDonutz]

Hey y'all. The oil warning light and buzzer on my car aren't hooked up, so the PO put in an aftermarket gauge. I changed my oil yesterday, and when I started the car up I sat and waited for the pressure to go up around 70 psi where it usually does on start-up. After about 60 secs I noticed the gauge was still reading 0 psi. I checked under the hood and there was no oil flowing through the clear plastic tube that runs from the oil filter mount to the gauge. I freaked out and stopped the car. Is this a possible oil pump failure, or is something else going on? Or is my oil pressure gauge just broken? Any help would be greatly appreciated. Thanks guys.

[WaterWheels]

Just a guess but I would think a small piece of gunk came free because of the oil change and stopped the passage to the gauge tube. You could back-pressure it with air to see if it frees the tube. One of those cans of air for a computer cleaning might be enough pressure. Just for your own information, wrong place for a gauge to be connected. If a crank or rod bearing fails will you be informed? If for some reason oil fails to reach the cylinder head will you know it before the followers inform you? Placing a gauge at the source only tells you the source is working, not what's happening along the rest of the path. In other words you will be informed that the pump is working but not know you have a problem until it is probibly too late.

[DuncanDonutz]

What youre saying about the placement of the gauge makes sense to me. However, I have read that the oil pump doesnt actually create pressure, it just keeps the oil flowing...is this true? Anyway, I will try blowing out the tube with air like you suggested and see if that makes a difference. Im just worried about starting the car at all if I truly have no pressure, how long can I run the engine at idle without incurring engine damage?

[DuncanDonutz]

I've been looking around online quite a bit and pretty much all the aftermarket gauges I'm finding have the sender located in the same spot mine is (oil filter mount, where the factory high pressure warning sender was). Most of the ones I'm finding are electronic, whereas mine is mechanical...I guess my question is, where is the "correct" spot for a oil gauge sender to be placed?

[DuncanDonutz]

UPDATE: Tried the keyboard duster, started her up, still no oil moving through the gauge line or any reading on the gauge. I'm wondering if the brand of oil filter I put on after the oil change has anything to do with this, I usually just use the CarQuest brand but this time I went with a FRAM "6x microgard"...should I consider switching it out to my old brand and seeing if that makes a difference? Or is it possible I'm looking at a toasted oil pump? Any insight is appreciated guys.

[DuncanDonutz]

So here's where I'm at...thinking myself extremely clever, I moved the sender for the mechanical gauge into the side of the cylinder head where the low pressure sender (which is not plugged in anways) was, and put the old sender in the hole at the filter mount as a plug. Started the car up, and...nothing. No oil running into the tube, and of course no reading on the gauge. The good news is when I pulled the low pressure sender out quite a bit of oil poured out the hole, so there's some kind of oil movement going on right? Anyway, I only ran the car for about 30 seconds, I'm very wary of running an engine that might not be lubricating properly. So at this point, I'm thinking maybe the oil tube for the gauge is plugged? Well as it is now I have an oil pressure tester coming from Harbor Freight in a couple days so I can know for certain what my oil pressure situation is....thoughts? Comments?

[Fat Rabbit]

Over the years I have heard lots of folks say -- German car -- German oil filter. Mann, Mahle, Bosch etc. At the same time I used Fram almost 100% without problems.

Check the pressure with the gauge you ordered. If the other reading is accurate at "0" switch the oil filter -- try using a German filter or return to your old brand.

If it is still at "0" drop the oil pan and have a look see at the pick up. There was a nice picture of a plugged oil pick-up posted here on Vortex recently.

VWs that came with oil pressure gauges had them connected at the cylinder head. FR

[WaterWheels]

. . . I moved the sender for the mechanical gauge into the side of the cylinder head where the low pressure sender (which is not plugged in anways) was, and put the old sender in the hole at the filter mount as a plug. Started the car up, and...nothing. No oil running into the tube, and of course no reading on the gauge. The good news is when I pulled the low pressure sender out quite a bit of oil poured out the hole . . . Anyway, I only ran the car for about 30 seconds . . . I'm thinking maybe the oil tube for the gauge is plugged? Well as it is now I have an oil pressure tester coming from Harbor Freight in a couple days so I can know for certain what my oil pressure situation is....thoughts? Comments?

I will let you make the call here, but 30 seconds sometimes is not long enough. I have done oil changes or work on cars and when they were started it took more than a minute to show oil pressure again. Scary yes, but there should be enough film on the parts to protect them for a short time. You say you're thinking the tube is plugged for the gauge but you said you blew air into the fitting? Did you look at the fitting when you swapped it to the head? Why not? Have you got a vacuum pump? Some very thin wire long enough to run down the gauge tube? Waiting for a pressure gauge is fine but you can test for yourself sooner if you can prepare for a possible mess. Remove the tube from the fitting in the head and have a friend start the engine while you hold a container to catch oil if it comes out. If oil squirts out the open fitting, it will not be like a fire hose, then something in the gauge connection is clogged. Things just don't stop working because you change the oil, something became free and found a new home clogging your gauge feed tube.

[DuncanDonutz]

I tried running a wire into the gauge sender fitting...if its clogged its probably somewhere further up the line (maybe even at the gauge itself). Anyway, I'm not going to do anything more until my tester gets here, if the pressure checks out then I will just get a new gauge, if not it's probably time to look at pickup screen and/or pump. I've been thinking about upgrading to the ABA oil pump anyway since my motor is pretty high mileage, I figure that more oil flow can only help.

[DuncanDonutz]

Got my oil pressure tester from Harbor Freight today...screwed it into the oil sender hole on the side of the cylinder head, ran the motor for about 60 seconds, and got absolutely no reading. It didn't sound like it was oiling all that great, it was noisier than usual, particularly the valves. I just dont understand how I could have 0 oil pressure, even if the pump was bad shouldn't I be registering at least something? Anyways no more time to fiddle with it today, tomorrow if I have time I'll try changing out the filter, if that makes no difference I'll pull the pan and have a look-see at the oil pickup screen.

[ziddey]

Did you add oil after you drained it? Just kidding

Those higher end Fram filters are actually supposedly extremely high quality, according to the guys at BITOG.

I suppose if you're really worried about the motor, you could get one of those oil pump priming tools that attaches to a drill. Pull the distributor off and drive the pump directly.

[WaterWheels]

Got my oil pressure tester from Harbor Freight today...screwed it into the oil sender hole on the side of the cylinder head, ran the motor for about 60 seconds, and got absolutely no reading. It didn't sound like it was oiling all that great, it was noisier than usual, particularly the valves. I just dont understand how I could have 0 oil pressure, even if the pump was bad shouldn't I be registering at least something?

Don't fiddle any more as you might start/cause damage. You've run it more than once with it appearing to not have any oil being pumped. New gauge and still nothing shows after a minute, stop doing it! Drop the pan and look at the pick-up for the oil pump. Even if you don't save the new oil it will still be a heck of a lot cheaper than doing bearings or followers or a camshaft or . . . It's starting to make noise which means it is starting to run dry, stop and find out why! So first step is to determine if the pump pick-up is clogged, regardless as to why. Pumps don't really just stop working.

[DuncanDonutz]

I don't plan on running it anymore, not until I've checked the oil pick-up and put new oil in it. Is it possible to to prime the pump by turning the engine over by hand, or maybe loosening the timing belt and just turning the intermediate shaft? I really don't want to have to deal with removing the distributor and then re-timing the motor if I don't have to.

[WaterWheels]

Is it possible to to prime the pump by turning the engine over by hand, or maybe loosening the timing belt and just turning the intermediate shaft? I really don't want to have to deal with removing the distributor and then re-timing the motor if I don't have to.

That’s just plain old dumb! I don’t say it that way to harass you in any way or embarrass you in public, just to get your attention. Turning the engine by hand is no better than using the starter motor, worse really, and turning the intermediate shaft with the belt loosened means you have to do a more difficult task , mechanical timing of the engine, instead of a simple ignition timing adjustment. But the idea you have of conducting a pump test by doing an attempt to prime the oil system is good. Just do it the correct way by removing the ignition distributor.

It really is easy and no big task to get it back almost 100% to where it was before you removed it. You have to mark the distributor base at the engine block, felt pen works fine, and the rotor position (best to use the mark already on the distributor base which is intended for this purpose). When you go to re-insert the distributor you might have to adjust the pump shaft a few times before it sits down fully and in the correct position but it is no big deal. You will need a somewhat strong electric drill as those cheap ones don’t have the grunt required. For the slot in the oil pump shaft a screwdriver works (without the handle of course to fit the drill), a section of round stock ground down to fit or an old ignition distributor shaft. When you put everything back after trying to prime the system, it will start and run just fine and only maybe require a slight adjustment with a timing light.

[DuncanDonutz]

It really is easy and no big task to get it back almost 100% to where it was before you removed it. You have to mark the distributor base at the engine block, felt pen works fine, and the rotor position (best to use the mark already on the distributor base which is intended for this purpose). When you go to re-insert the distributor you might have to adjust the pump shaft a few times before it sits down fully and in the correct position but it is no big deal. You will need a somewhat strong electric drill as those cheap ones don’t have the grunt required. For the slot in the oil pump shaft a screwdriver works (without the handle of course to fit the drill), a section of round stock ground down to fit or an old ignition distributor shaft. When you put everything back after trying to prime the system, it will start and run just fine and only maybe require a slight adjustment with a timing light.

The deal is, the last time I did my timing belt I marked it and all the pulleys in very specific positions so that anytime it's removed setting up mechanical timing would be easier. So in my case, yes, it is easier to loosen the belt and spin the shaft than it is to remove the distributor. Which is why I said, I don't want to deal with removing the distributor in the first place. Thanks for answering my question in a roundabout and unnecessarily rude manner. IMO setting up the mechanical timing would be easier than timing the Digi II with a timing light even if I hadn't made marks on the belt and pulleys, what a PITA.

[ziddey]

You're saying you'd rather do an hour job instead of a minute job.

[DuncanDonutz]

You're saying you'd rather do an hour job instead of a minute job.

Dude, did you even read my post? It takes me just as much time to do the valve timing as the ignition timing and I find it to be much less of a headache. If I have to f*** with either I'd rather it be the mechanical. I made my own mark on the distributor for where the rotor should be with #1 cylinder at TDC, I made marks on all the pulleys that correspond to teeth on the belt, it hardly takes me anytime to re-install the belt. My only question was if it would work to prime the pump, I appreciate your advice but sometimes it's just easier to do something you've done a few times then mess around with an unfamiliar procedure i.e. removing the dizzy and spinning the intermediate shaft that way. I'm sure what WaterWheels proposed is a perfectly sound method for priming the pump, it just sounds more complicated to me overall than using the intermediate shaft sprocket.

[ziddey]

Good luck

[WaterWheels]

The deal is, the last time I did my timing belt I marked it and all the pulleys in very specific positions so that anytime it's removed setting up mechanical timing would be easier. . . Thanks for answering my question in a roundabout and unnecessarily rude manner.

. . . I made my own mark on the distributor for where the rotor should be with #1 cylinder at TDC, I made marks on all the pulleys that correspond to teeth on the belt, . . . My only question was if it would work to prime the pump, . . . i.e. removing the dizzy and spinning the intermediate shaft that way.

So what you are saying is that you drive around, or plan to the rest of your life, with the belt covers removed, hoping your marks never wash or fade away. Have some particular problem with attempting to learn something? I believe you do not understand the concept here of priming the oil system "i.e. removing the dizzy and spinning the intermediate shaft that way." You don't remove the distributor and rotate the intermediate shaft, the oil pump can be rotated all alone by removing the distributor. The intermediate shaft does not turn at all. That's the idea, pre-lube the engine without having to rotate any parts. Made your own mark on the distributor? What was wrong with the permanent one VW made? Why would you have to if the engine was set up correctly in the first place?

OK, to answer your only question, yes. If you were to pull the timing belt away from the intermediate shaft, and hold it that way and you could somehow rotate the shaft fast enough you could prime the oiling system. ". . . unnecessarily rude manner . . .", not yet but I have a feeling it may be comming. So ditto, have fun and good luck.

[DuncanDonutz]

A little clarification. The mark I made myself on the distributor is not for #1 TDC, it's for 6 deg BTDC. (3.4 mm to the right of factory mark) Actually has nothing to do with the valve timing, in my haste I misspoke. Again, removing the distributor isn't something Ive ever done on an 8v, so I wasnt 100 % certain what you were suggesting or what it looks like after it's been removed. I guess that's my fault for not be clear enough. I was just seeing if there was an 'easier' way of doing what you were suggesting, not necesarrily less time consuming but just something that was more in my comfort zone....which setting up mechanical timing is, at least for me. I HATE doing the ignition timing on Digifants, its a PITA and took me forever last time....I've seen procedures on here for a 'static' method using a DVOM...maybe I'll use that this time.

[DuncanDonutz]

Finally had time to tackle this again today. Pulled the oil pan, doesn't appear to be any blockage in the pickup screen at all. In fact, as you can see in one of these pictures, a little excess oil drained back out of the pump through the screen. So, next step is to re-fill with oil and try priming the pump via a drill as WaterWheels suggested, or is it worth my time to pull the pump and inspect? Let me know what you guys think.

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[DuncanDonutz]

Bump

[antichristonwheels]

yea looks pretty clear. def go for the priming exercise.

[WaterWheels]

Pulled the oil pan, doesn't appear to be any blockage in the pickup screen at all. . . So, next step is to re-fill with oil and try priming the pump via a drill as WaterWheels suggested, or is it worth my time to pull the pump and inspect?

You have the pan down and all the oil which would drip onto the floor or your head and eyes has already done that so pull the pump. Not that I think the pump is bad, although it is possible, but because it is only two bolts and why leave question marks in your head. Once out you can break it down and inspect for any serious wear or loose shaft. You can check the tolerances, even if only for practice, and remove the wear from the cover plate. Heck, for the price of a new one you can just swap another one in and be 100% sure the oil pump is OK. You have it right there in front of you, don't just call it a day and close things back up. It has a pressure relief valve located on it, try to determine if it is maybe stuck open from some crud which got into it. If that valve is open the pump will just pump much or all of the oil back into the pan. Don't button it all back up before being sure the pump is fine and taking the time to learn more about the engine.

[DuncanDonutz]

The only tolerance mentioned in the Bentley is the gear backlash, is there anything else I should check besides that and a loose drive shaft? Where exactly on the pump is the relief valve? Thanks.

[WaterWheels]

The oil pump is divided shall we say in two halves. One half contains the gears and the shaft which is pressed onto one of them. The other half, I’ll call it the cover, contains the pressure relief valve and mounting point for the pick-up tube. Oil is under pressure where the red arrow (see picture below), yeah bad arrows, is pointing. The black arrow is pointing to the relief valve housing (it is of course cast into the whole cover).

Inside the relief valve housing is a plug at the end (has a small hole in it), a spring and a plunger. When pressure is too high for some reason, cold oil, clog, etc., the plunger moves and the oil is dumped back out at that shinny metal section in the cover between the two gears (that is the plunger and it slides away opening that hole). You can fill that cavity where the red arrow is pointing and hold it up with the relief valve facing down and no oil should leak out.

There are two checks with a feeler gauge the Bentley tells you to make, backlash and axial. The backlash is hard with some feeler gauges as they are kind of wide. The axial play is easy but I just use some emery cloth (fine) on a flat surface, glass or a granit stone I have, and clean away the ring marks made by the gears. If it is so bad that doing this will remove the oiling groves in the cover then trash the cover at least. Although I have never found a pump to be bad in the axial play area, if you find yours to be too large a gap then remove the gears and dress the surface like I described above for the cover.

Zero pressure at either the cylinder head or the filter flange would indicate a problem between the oil pump, seeing as the screen is free, and the entrance point of the oil back into the block after being filtered. I will assume you are using a correct filter as even if the filter were to be blocked it would have a by-pass to keep the oil flowing. I think it might be time to remove the filter mount and look for a clog in the passages there.

[DuncanDonutz]

Thanks for all the info WaterWheels. Before I saw this post I ordered an ABA oil pump from GAP, figured I'd replace and upgrade as long as I have the oil drained and easy access. Also ordered one of those rubber pan gasket...anyway I agree that its worth the time to remove the filter mount and make sure theres no blockage there. I will post an update as soon as I do those things. Thanks again for the help and advice.

[DuncanDonutz]

Alright, I tore into this again today. Got the old pump removed. Just for s***s and giggles I took it apart and checked it per WaterWheels' instruction, and sure enough it was skookem-do. All the clearances were the same as the day it left the factory. Also removed the oil filter mount and there didn't seem to be any plugs in it or the passages into it. Starting to think this might just be a case of the pump not being primed when I did the oil change. Speaking of priming, I'm wondering about WaterWheels earlier mention of priming it with a screwdriver.

You will need a somewhat strong electric drill as those cheap ones don’t have the grunt required. For the slot in the oil pump shaft a screwdriver works (without the handle of course to fit the drill), a section of round stock ground down to fit or an old ignition distributor shaft.

As you can see from the below picture, the shaft for the pump doesn't have an indented slot it has an "outie" (not sure of the technical term for that ), so how exactly am I to fit a screw driver on it? Just wondering if you had any more input WaterWheels. Anyway, when it quits raining I will install my new oil pump, replace the oil filter mount gasket and put the mount back on, and go from there.




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[WaterWheels]

. . . Also removed the oil filter mount and there didn't seem to be any plugs in it or the passages into it. Starting to think this might just be a case of the pump not being primed when I did the oil change. . . . As you can see from the below picture, the shaft for the pump doesn't have an indented slot it has an "outie" (not sure of the technical term for that ), so how exactly am I to fit a screw driver on it?

Guess old age is creeping in faster than I expected. I can only assume I was thinking of a different car when I said a screwdriver can be used to spin the oil pump. I remember using them on some car in my younger years but on a 1.8L 8v Volkswagen it would not work. A section of bar stock (round stock) with a slot cut into it was the original thing I used, then I took an old ignition distributor and made my own tool. So it has been 20 years or more since doing it without my tool so I guess the gray matter got a little screwy, sorry. I do use a screwdriver to line the tab up when re-inserting the ignition distributor though

The pump is self priming, or it should anyway. There really is no good way to "prime" the pump anyway. I do spray a small amount of WD-40 or smear some engine oil on the gears before installing one just to be sure it does not self destruct before it sucks up some oil.

I am really finding it harder and harder to understand where your problem lies. OK, an internal blockage is possible but I have never seen or even heard of one. There is one thing I have come across, many years ago, which might be wise to ask you about. You say "PO" (prior owner) in the original post, how long have you owned the car and in what state did you buy it? The bottom end seems to be getting oil from looking at the pictures, was a cylinder head installed prior to your buying the car? But then again you said there was no pressure at the filter mount either. Running out of logical ideas

[DuncanDonutz]

I've owed the car since September 2009. Guy I bought it from was a VW mechanic who worked at my local dealership. The bottom end has about 220k on it and is the original block, the cylinder head was rebuilt about 15k miles before I bought it. I haven't had any major problems except a blown head gasket in late 2010, (due to overheating) and I had to replace the steering rack last summer (broken teeth on the rack, cost me $1100 to get fixed...ouch). When I replaced the head gasket, I did a lot of other work, including pretty much redoing the whole cooling system (only thing I didn't replace was the radiator and heater core). I had the head re-surfaced-luckily wasn't warped from the overheat-and had it thoroughly checked and tested, everything was great. I always keep an eye on the oil pressure, especially on start-up, and it's always been the same before the last oil change when this problem started. I'm also doubting an internal blockage, all the parts and passages I have examined are relatively clean and varnish/gunk free, I'm pretty particular about changing my oil every 3-3500 miles.

[WaterWheels]

The reason I was asking is due to how the cylinder head receives it's oil. I had seen one time where the owner used silicone on the head bolts, maybe thought they went into the water jacket like on some cars, and it squeezed out into the space around the head bolt in the head stopping oil flow. Was thinking this could be something to ask about but then remembered you stating that there was no pressure at the filter mount also.

I am thinking at this point that making a tool to use to operate the oil pump might be the best way to start tracking down the problem. Either making one out of some bar stock or out of an old ignition distributor (can be clamped down that way) to run the pump and check where the oil flows or doesn't. Again, this is a bit of an interesting puzzle you have unless it is something you just forgot to mention or do.

[DuncanDonutz]

So got everything back together on Sunday, fired her up...and instantly had a cold pressure of 90 psi at the head. Drove her around for a while, pressure at running temp was exactly what it was supposed to be. I have no idea what the original problem was, I think maybe my old pump just didn't prime correctly when I changed the oil, maybe an air bubble got in there or something? Anyway, she runs and drives great now, besides oil leaking from the sender hole on the cylinder head, which I had relocated the brass fitting for the oil gauge sender to. I temporarily put the old sender in there just to stop the leak, and this weekend I will install the gauge sender with Teflon tape on the threads and maybe a little RTV sealant on the outside to prevent any more leaking.