TheSamba.com :: View topic

Thu Jul 17, 2008 7:30 pm

What markz said.

Mon Mar 19, 2012 9:31 pm

Hello All .I have read all the oil pressure questions on the Vanagons. Here is a good solution to the issue at hand... the idiot light does its job and will tell you its working every time you turn the key to the ign on position... the red light will come on and tell you after you start the engine if it comes on -you indeed have a problem .. Now here is why, All vw engines air cooled have too short a pressure relief plunger .. when you drive the plunger wears out the alluminum bore in the middle of the stroke where it spends most of its life.(all 356 and 912 engines do not have a plunger problem because the plunger is much longer) there is a good cure to the problem, you can repair in in 15 to 20 minutes. Adrian Audirac. makes a steel shaft that you put in the bore after you pull out the spring and plunger. It has an interference fit of 4 thousandths so you really have to install it with a good solid hammer.and brass drift or a socket extension You will know when its in all the way -you can hear it change tone when its all the way home... then the ball bearing goes in next and the original spring is cut 1.5 threads below the casting hole. put the cap back on and you have 75 pounds running pressure and about 35 pounds at idle on a hot engine. If you have hydraulic lifters they will quiet down in a few seconds after start up (cold) this will add many many more miles to your engine. you can run a manual guage on the engine and see for yourself.. the vw people never did correct the engineering problem... except on the porsche 356 and 912 ..give him a call 1760-727-1827. I have vanagons and stroker vw engines -- all with this system I have videos on youtube.to check out...I have over 50 photos of different subject matter under http://www.thesamba.com/vw/forum/album_search.php?search_author=LittleMicroCars http://www.thesamba.com/vw/forum/album_page.php?pic_id=747006 http://www.thesamba.com/vw/forum/album_page.php?pic_id=747007

Mon Jul 30, 2012 8:43 am

Well my Wife's 89 Bluestar was giving us the old oil pressure sender warnings lately so I proceeded to replace the .3 and .9 oil senders. The .3 was a blast and joy to work on, althought the old sender was leaking oil. However, the .9 is a bitch to consider. The Bentely suggests pushing the engine tin, or "exhaust cover" out of the way????? what? How? Ben suggests removing the water pump pully; this seems more practical, but how do you arrest the pully to remove those three pulley bolts? A previuos post suggested tension on the belt prior to removal, or a "water pump pulley clamp"? Can anyone elaborate on how I can feasibly get at that .9 sender?
Thanks

Mon Jul 30, 2012 12:50 pm

Mine was fiddly but I managed with a deep 24mm socket.
I had no issue with water pump, pulleys, or heat shields, but you'll definitely need to remove belts.

My version:
http://www.thesamba.com/vw/forum/viewtopic.php?t=478217

Fri Aug 10, 2012 9:13 am

Ok I finally got the .9 switch installed on the 89 Bluestar (2.1L ? miles), but the dash oil light continues to blink above 2000RPM. Well I had to borrow a oil pressure gauge to test my oil pressure. At first I tested it cold......duh, wasn't really knowing what I was doing. Finally after letting it idle and reving it I tested the pressure again and got:

At 2000RPM: 35-40 psi
At idle it was around 22, but then dropped to 20psi, and then 15psi.

I know this is not necessarily under a load, but will the test at least give us a clue?

I just finished reading this post this morning (after last night'd test) and it seems that my OP is at least acceptable. I am now wondering what is causing my blinking light problem. I suspect that I have an electrical oil light system issue. I have been searching for other threads, but can anyone give me a clue for some key words to search for, or suggestions for my next step?

Thanks

Fri Aug 10, 2012 11:03 am

Read Bentley 90.22 through 90.29

There is a detailed and extensive troubleshooting flow chart for the dynamic oil pressure monitoring system.

Also check for obvious signs of wire insulation damage to both of the senders. The wires can chafe through were they touch engine parts.

Good luck.

Fri Aug 10, 2012 3:56 pm

Hot OP test: Drive (yes - DRIVE) for 15 - 20 min. before testing.
You want the radiator fan to cycle at least 2 - 3 times...then test.

Keep working...

Fri Aug 10, 2012 4:23 pm

Thanks guys, for the reference and the tip. Will try again once I get it back from the wife.

Thu Oct 11, 2012 10:16 pm

I have been reading with much interest about oil pressure, as i have recently purchased my first vanagon and on my first trip,after 200 mi had a horrific rattle which didn't seem to change under load at low speeds/idle.i couldn't hear at high speeds-too much wind noise. I believe it to be the cat. converter coming apart inside{ i can get a slight rattle out of it when hitting it}, But what confuses me is the fact of it being worse when hot. Has anyones low OP caused a rattle in the engine close to cat conv. location?sorry not sure of cyl. # . I plan to buy a bentley and do some testing soon. The engine has been replaced{ evident by vw of canada reman sticker } not sure of mileage though. Thanks for your thoughts

Sat Oct 13, 2012 8:04 am

Well i ordered a bentley, and a VC guage kit, and new cat.converter. Hopefully my luck is ok and the rattle is completely gone,and i have good oil pressure

Wed Feb 13, 2013 1:16 pm

Another pretty easy way to replace the hi-OP switch, easier than removing the w/p pulley, is if you have a 24mm box-end wrench, take off the oil filter and you can get in above it with the box-end.

Fri May 10, 2013 9:34 am

tencentlife wrote: The dynamic OP warning system gets a lot of bad press, but VW put it on practically all their cars from about 1983 on, and it's one of the more simple and intelligent features I've seen in a car. The fact that it acts up for many van owners (do you ever hear of it causing problems for Golf owners? hardly) has more to do with the inherently low OP with age that the boxer engines produce and with neglected maintenance that we see so often in these old vans than any faults in the design of the system. I like a gauge, too, because I'm an info nut and when it comes to vital OP I want both to be forewarned of degradation in the system and to be able to track the wear in the engine's bottom end, but I appreciate the dynamic system because a gauge won't make an annoying sound to alert me if something suddenly ruptures while I'm going down the road. Most of the time when the light flickers at hot idle it's for a good reason: the OP is lower than the switch's setpoint range and the warning system is doing its job exactly as designed. In those cases the problem isn't the warning system, it's the worn out oil pump, weak relief spring, loosening rod bearings and excessive crankshaft endplay that indicate that the engine is in need of an overhaul. When the light starts to flash and the buzzer sound at running revs, it seems like it's a toss-up between the warning actually being due to insufficient OP and the high-pressure switch beginning to malfunction. In either case, most drivers, as you would expect, prefer to blame the warning system rather than face the disheartening reality that they are going to have to lay down some real buck for an engine overhaul to keep their beloved barn on the road. In many other cases, the warning is untimely due to the pressure switches beginning to function outside their range, meaning the warning system is receiving bad inputs, which you would expect from simple switches that have been in service for many years. Apart from the switches, rarely is it the fault of the monitoring system itself, although failures of the control board are bound to happen in some cases, and damage to the switch leads in and around the engine is quite common.

So, rather than wondering and guessing, there is a logical way to approach the problem. Don't place your faith in superstitions about oil filters and such; swapping a crappy filter for the OEM one may achieve the marginal increase in pressure under the suspect conditions that will stop the light from flickering due to an aged switch or a worn motor, but it's a band-aid that merely covers the problem and allows you to ignore it for a while longer.

Based on the 98% safe assumption that the warning control board is not at fault, there is a series of checks that need to be done.

First off, you should act as if the warning system is actually doing its job and, Hello!, check the oil pressure. Who cares that you've managed to trick the system into not annoying you for awhile when your rod bearings are about to spin into meltdown? Get a real pressure gauge, remove the bottom tin and the low pressure switch, screw the gauge into the hole, get the engine good and hot, and see what you really have driving down the road under load. That may mean having one person drive while another watches the gauge at the back with the engine cover off.

Whatever oil you're using, and whatever filter, the engine should be able to raise an absolute minimum of 6psi at idle, jump to 18 by 2000, and get over 26 by 3000. It should continue to rise over 3000 but max out by 4000. These are bare minimum figures and well below VW's published figures, which are actually realistic for a fairly fresh engine but will rarely be met by an older one. Some will dispute my figures and cite their own anecdotal experiences and that's fine; this is my opinion based on 30 years of working on these cars and several hundred engine overhauls under my belt, and you can take them for what they're worth. I'm erring on the very low side and would not personally be comfortable with OP as low as this in any car I was driving. You can establish your own comfort level, but if your OP is this low I don't think any driver should feel comfortable, although I would alow a little leeway on the idle pressure.

The pressures at off-idle rpms should be seen with the engine hot and actually under load, meaning driving, not just revving on the garage floor. Who cares what pressure you have revving in neutral? you don't get anywhere that way, you need to simulate real conditions if you want to know what's going on. By hot I mean oil at over 200deg.F. Just waiting until the radiator fan cycles once is not hot enough. Drive hard at least 5 miles or wait until the fan has cycled at least 10 times at idle and the oil should be hot enough. Oil takes more than twice the time to reach running temp than the water does, so give it plenty of time to get there or your tests will be false.

If it fails the OP tests, then assess what to do next by the age and maintenance records of the engine, and whether it is a 1.9 or a 2.1. The 1.9 did not have the dynamic OP warning system, only a simple idiot light circuit, but if you see a warning light you should test the OP nonetheless. If it's a 1.9 and coming up on a quarter-million miles and fails the OP tests, you should plan on an overhaul.

If it's a factory 2.1 and has 150k miles or more, and fails the OP test, you would be very wise to save your money and schedule a full overhaul. You are facing the classic rod bolt failure any time now. Trying to improve OP by renewing the pump or fiddling with the relief valve may delay the inevitable, but the day of reckoning is approaching and you should try to avoid it proactively.

If you notice that the OP is Ok at idle but rises to the low 20's and no higher as revs increase, and the engine has mileage less than stated above, the oil pump may merely have excessive wear. In this case I feel it is worthwhile to replace the pump and pressure relief valve, and run the tests again. Before doing so, though, you should set up a dial indicator or feeler gauge stop at the crankshaft pulley, relieve the clutch arm pressure, and measure the crank endplay. If it is outside wear limits, then the engine is in need of overhaul and even though a new pump may improve OP, it is basically a waste of time.

If the motor passes the minimum OP tests, then you can concentrate on the warning system. While you still have the OP test gauge in place, you can test if your switches are activating at their prescribed pressures. On a 2.1 car, both final switch leads are brown but connect to a two-pin connector which is near the thermostat housing, and you can test the switches' operation from there. The brown lead that joins to the blue/black wire is for the low switch; the one that joins the yellow wire is the high. The low switch is normally-closed and should open at 2psi (the range is 0.3bar +/- 0.15bar, or 2-6.5psi). The high switch is normally open and should close at 10.9psi (0.9bar +/- 0.15bar, or 10.9-14.8psi).

The general function of the warning system and procedures for testing have been covered in earlier threads so I'm not going to spell them out again. What I really wanted to stress is that this is basically a sensible and trustworthy system, and when it provides warnings the wisest course of action is to assume that it is working properly and first assess the condition of your engine. When you are satisfied that the motor is making sufficient OP then you should track down faults in the system, which are almost always due to malfunctioning pressure switches or damage to their wiring leads. If the monitor board in the speedo head and the wiring check out, is a good idea to replace both switches periodically, since they are cheap and can easily malfunction with age. Both switches are about $10 each, and if you know what you're doing can be replaced in about an hour's work.

The day of reckoning is upon me. My oil pressure buzzer and light came on briefly after a run up to Tacoma and back yesterday. The WBX has ~200k. Color me escared of the impending darkness. The cruel irony is that after nine years of unflinching reliability during occasional use, now that I'm ready to begin using it as a bidness hauler, it starts to flag. Life is like a box of chocolate-coated coprolites

Fri May 10, 2013 9:44 am

Quote: Life is like a box of chocolate-coated coprolites

Fossil car.
Fossil fuel.
Fossil bon-bons.

Makes sense to me.

Fri May 10, 2013 11:23 am

A real external oil cooler can extend the inevitable and then you can use it on your next engine. They are not immortal but there is reincarnation.

Fri May 10, 2013 4:04 pm

Good things can happen. I went from screaming OP buzzer to silence after replacing my oil pump (fingers still crossed). Although it was probably just the gigantically thick cover plate gasket causing the problem, I bought a quality pump to help get every benefit I could. I started at about 6 psi at idle and 12 at 2000 rpm and now have about 10 psi at idle and about 22 at 2000 rpm, with a normal increase above that.

But know this... after reading all the horror stories about what MIGHT happen, I will not drive in total peace until I finally open up the bottom end of this beast to find out what is in there. At least I have a new baseline of oil pressure readings which I can now watch for a while to see if it gets worse.

Fri May 10, 2013 4:20 pm

Last Summer I installed an oil pressure gauge up front, but I still need to plumb in the sender, so that I can grab some measurements. Does anyone see any reason why I can't use brand new MB brake line to thread into the case and run to a distribution block for the gauge sender and low rpm sender? It's the same thread pitch. The distribution block is from my Audi V6 and uses the same pitch crush-washer through-bolt. I'll electrically ground the sender through the mount.

Fri May 10, 2013 5:16 pm

The only thing I would question is the effect of air trapped in a plumbed line...pressure on an air column should be equal to oil pressure, so perhaps a non-issue.

Fri May 10, 2013 5:50 pm

denwood wrote: The only thing I would question is the effect of air trapped in a plumbed line...pressure on an air column should be equal to oil pressure, so perhaps a non-issue.

Doesn't happen.

Fri May 10, 2013 6:06 pm

Chris, i was referring to zeitgeists question on plumbing in a brake line to a distribution block. If the brake line goes vertical from the block stock sender location to a distribution block, air would be trapped there permanently. My guess though is that the gauge would still read fine.

Fri May 10, 2013 6:25 pm

When you take out a switch or sender on an elevated manifold that has run awhile, the oil is right there in the hole. You can ponder the physics if you want, but I won't join you. It just works.