2.1 oil pressure questions

[fastwagens]

well the oil pressure warning light/buzzer started coming on. checked oil level and it was fine. I went ahead and did an oil change, still flickering on and off. It does not seam to happen at idle but turns on at higher RPMs. What do the two oil switches sense? the bentley shows one an Normally open and the other normally closed. and could it be the pressure relief spring?

Any ideas?

[tencentlife]

I would explain but we've already collectively written the book on this. So, youse should use da soich!

[Rhinoculips]

First of all, what weight of oil are you using and are you using the Mann filter? DO NOT USE ANYTHING BUT A BLACK OEM FILTER. Fram or others just dont cut it with a Vanagon.

These are always the first places to start. The pressure sender between the tubes is for times when rpm's are under 2000rpms. The rear one is for over 2000 rpm.

I have heard of some people replacing or some just stretch the spring (I don't recommend this) in the pressure relief valve with some success. A new spring and valve is only 10-12 bucks, i.e. a cheap thing to try.

I think every and all Vanagons should have an actual oil pressure gauge. Idiot lights are worthless. This would mean replacing the original sender from between the tubes with a two signal sender that needs to be connected to the engine via an adapter hose. I bought my set up from Van-Cafe at http://www.volkscafe.com/main.jsp?pa=p&p=297115875&pct=1167066442&ct=1713238847

I have also heard that the L-shaped circuit board under the instrument cluster that controls the oil pressure sensing can go bad. Anyone know if this is a regular occurance?

Here are more links to a more detailed run down on how to handle your pressure problems.

http://www.vanagain.com/flicker1.htm
http://www.vanagon.com/info/articles/oil-pressure-probs/index.html
http://www.benplace.com/oil_pressure_sender.htm
http://www.vanagain.com/buzzer2.htm

There are also tons of info on this site. Do a search and let us know how things turn out.

[fastwagens]

Thanks that should get me started in the right direction.

[bucko]

[tencentlife]

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 malfuntioning 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.

[Rhinoculips]

WOW!

Nice write up Tencent. One of the best OP explanations I have seen and I bet I have read them all.

You are correct the OP System does serve a purpose of alerting us the moment something starts going wrong. I must admit that I was a little harsh on saying it is worthless. I guess that since I am a pilot, I have the habit of always scanning my instruments even while in my car. An info junky, I am.

I have always been fascinated how the pressure switchs come on only if it drops below 2psi and 10.9psi. Seems really low if you ask me, but I guess they knew what they were doing.

So you think 18 psi at 2000 rpms is on the very low end but still ok? What is your ideal pressure for a car with 170,000 miles that has been well cared for?

Can you clarify the crank pulley play test? This is new to me. Do you take the belts off? Where exactly do you put the feeler gauge? What are the wear limits? Releaving the clutch arm pressure is simply in neutral with the clutch out or in? I know its a daft question but hey I am far from knowing it all.

Thanks again for the write up. Your time spent sharing your infinite wisdom with us is appreciated!
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[tencentlife]

Having a gauge and the warning system offers redundancy in monitoring a key operating condition, so that's definitely a good thing. They offer different approaches so they can be used to help confirm each other if an anomaly crops up. So having both is a great benefit. But as a stock system sans gauges the dynamic OP system offers a level of critical warning that you just can't get with just an idiot light. Addig a gauge just gives you an even better view.

[riceye]

I'm bumping this up to suggest it be added to the "Links to the best threads on the Vanagon Forum" thread.

Great write-up. Thanks for the info!

Salud,
Ric
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'87 Westy Weekender - daily driver on salt-free roads

There's gonna be some changes made.

“I find that things usually go well right up until the moment they don't.” - Ahwahnee

"Quality isn't method. It's the goal toward which the method is aimed." - Socrates, later quoted by R.M. Pirsig

[Rhinoculips]

[simd0ggie]

My grey pressure switch near the pulleys has the terminal broken off, wire missing. I have read that this is supposed to be a brown wire. I found the brown wire going down near cylinder 3, coming from a white 2 position connector, with harness side wire colors blu/blk and yellow. The other position of this connector has a suspicious looking yellow wire to ground (beside ingnition module). So what I'm wondering is: Should this yellow wire be removed and replaced with a brown wire to my gray pressure switch??

Thanks, and I agree this is the best post on this - I have been searching for about 4 hours now... Waiting for Bentley to arrive any day now...
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-Matt
'85 Westfalia w/EJ25, '14 Tiguan R-Line 4 Motion

"There are two possible outcomes: if the result confirms the hypothesis, then you've made a measurement. If the result is contrary to the hypothesis, then you've made a discovery.”

[simd0ggie]

I'm an idiot, you already described exactly what I needed... Should have read the whole thing.
Wire cutters, check!

Matt
_________________
-Matt
'85 Westfalia w/EJ25, '14 Tiguan R-Line 4 Motion

"There are two possible outcomes: if the result confirms the hypothesis, then you've made a measurement. If the result is contrary to the hypothesis, then you've made a discovery.”

[tencentlife]

Sounds like someone grounded out the high-pressure switch wire. That defeats the dynamic warning system, but the low-pressure idiot light will work as normal.

My guess is they saw the broken gray switch and didn't want to get in there and change it out. It looks a bitch-and-a-half, but it's not too bad to get to if you remove the water pump/alt belt, then undo the three bolts to take the pulley halves off the water pump. Then you can get at the thing. I have a giant pair of channel-locks (called "water pump pliers", I wonder why?) to hold the pulley wheel still while I break loose the three bolts. You could probably break them loose before removing the belt by holding tension on the belt to immobilize the pulley.
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[simd0ggie]

That's how I've pieces together the chain of events also. They bandaided it with jumper to ground, but now the connections in the connector were also bad, so the light/buzzer started coming on again...

I repaired all the connections, waiting on a new switch now. Thanks for the tip about the pulley, I was getting pretty frustrated trying to get at that damn thing!
_________________
-Matt
'85 Westfalia w/EJ25, '14 Tiguan R-Line 4 Motion

"There are two possible outcomes: if the result confirms the hypothesis, then you've made a measurement. If the result is contrary to the hypothesis, then you've made a discovery.”

[Alan Brase]

Last summer I picked up a 87 Wolfsburg Westy with a blown motor. Upon taking the motor apart later, I found a very nice oil pressur switch harness which grounded the the hp switch wire. Right next to the hole in the block caused by the exiting rod. I thought it was a fitting sight, juxtaposed like that.
Al
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Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home

[tencentlife]

Yeah, you can just follow the trail.

I picked up a couple motors from the wrecker. One had a rod that was melted, looked like it happened pretty quick as there wasn't chronic low-OP-type damage on the other bearings. It looked like the heads were just changed out, they were brand new AMC's. Then I noticed the oil pickup tube galley plug was missing. Hmmmm. Follow the trail.
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Please don't PM here, I will not reply.

Experience is kryptonite to doctrine.

[Alan Brase]

[tencentlife]

That sucks. I could see where your story was going, but was thinking with only short trips at highway speeds that the thing was probably going to be OK. Guess the rods were farther gone than you suspected. And either your guy is embarrassed and covering for not doing anything earlier when he heard the engine rapping, or he had it revving pretty high which hastened the failure but prevented him hearing it, or he's just friggin' deaf so what can you do?

But they do self-destruct very thoroughly when the rods do go that way, especially if the revs are high at the moment it happens. And right at the magic number, too: 160k. How about that?

The one I tore down must have been revving pretty low when all the oil fell out of the sump. The #2 rod just got very hot, melted at the base of the shank and bent over against the direction of rotation, which just brought the crank to a stop. You could still turn the crank most of the way around, but couldn't go past the bottom of the #2 stroke because the piston was now way too close to the crank to clear. Some scraping damage to the bottom of the piston, the bent rod and nothing else. The crank will be reusable after regrinding, and the case is fine, it already got dipped and checked out. Plus I got this perfect pair of AMC's outa the deal for what I normally pay for a core motor, whereas I scrap the VW heads that are usually on them as a mater of course. My motor customers always get a brand new pair, but I'll use these for my Syncro motor.
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Please don't PM here, I will not reply.

Experience is kryptonite to doctrine.

[weatherbill]

my oil light and buzzer starte dgoing off ever since I did an oil chang eto full synthetic, but put in the wrong weight, so I will try a different weight synthetic to see if that corrects it. It only goes off after a long highway drive, when I'm coming off the highway, slowing down and only buzzes for like 5-10 seconds, then everything is fine.

[simd0ggie]

Okay, so I replaced the broken white switch with the correct grey one, hooked the new wire up, and voila, all is good. Thanks for the tip on the water pump pulley removal! This is awesome, I just got a 90 Vanagon GL, supposedly needing a rebuild because of oil pressure problems and head gasket leaks, for $1100.00. Oil pressure, check. Cleaned the engine top and bottom, now waiting to see if I have a head gasket leak, It does not seem as if I do... Thanks again!
_________________
-Matt
'85 Westfalia w/EJ25, '14 Tiguan R-Line 4 Motion

"There are two possible outcomes: if the result confirms the hypothesis, then you've made a measurement. If the result is contrary to the hypothesis, then you've made a discovery.”