Date: Sun, 16 Aug 2009 22:41:01 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: temperature-oil pressure (rather long)
In-Reply-To: <29302892.14858.1249785210470.JavaMail.mcneely4@127.0.0.1>
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Failing to develop oil pressure on a cold engine indicates a clogged inlet filter screen. Unfortunately in the Water Boxer there is no way to really clean this screen without separating the case. This can also cause low pressure after warm up. How does the inside of the engine look? Remove the valve covers. If the top of the heads is filled with all sorts of junk and carbon, the engine has been badly neglected and a tear down may be needed just to clean it. Heavy carbon does not remove easily with oil flush products. Normal oil pressure should be ~10 psi/1,000 rpm and 28 psi @4,000 rpm is a wear limit.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Dave Mcneely
Sent: Saturday, August 08, 2009 10:34 PM
To: vanagon@GERRY.VANAGON.COM
Subject: temperature-oil pressure (rather long)
My '91 Vanagon GL Campmobile 2.1 VW engine shows evidence of oil
pressure drop at running temperature -- but I'm not sure it is running
at the right temperature, either.
Everything seemed ok with regard to both for the first 3 months I had
this beast (at least once I got the after market oil pressure gauge
working by replacing the sensor and making sure the wires were tight at
both ends). I had a tech check the oil pressure as part of a
prepurchase exam, and he said it was fine, nothing to worry about. I
didn't worry until I took it on it's first highway speed sustained trip.
Ambient temperature was around 102 - 105 F, and I drove around
sixty-five mph (3200 rpm) for several hours. The temperature gauge
gradually rose so that it sat above the LED, with a slight space between
the bulb and the needle. Oil pressure dropped to around 15 psi on the
gauge.
When I stopped the van, the oil pressure reading on the gauge dropped to
near zero at idle.
I was running Castrol 20W-50 oil, with a Mehle (sp?) filter as
recommended by my mechanic, David Hesse of Norman, Oklahoma.
I took the van to Mister Mechanic (Rocky Mountain Westy) in Fort
Collins, Colorado. Mike Labate and other techs there were very desirous
to help, and tried cheap fixes first. They cleaned up all oil pressure
electrical leads first, and after checking the oil pressure, concluded
that my gauge was off by about 5 psi, and that the vehicle should really
be ok. In fact, they thought that the oil pressure was running around
30 psi at 2000 rpm, and higher at higher rpm (they checked it with their
own gauge, of course).
I was pleased, and resumed my drive, headed toward Spokane, Washington.
But, as I got out to the highway, the oil pressure reading began
dropping, and fell to around 10 psi. I went back, at which point the
guys checked the pressure again, this time running the engine at high
rpm until the cooling fan came on. Pressure dropped on their gauge,
too. On noting that the air flow meter had recently been changed, the
techs suggested the engine may have been running rich and contaminated
the oil prior to the AFM change. I was eager for a cheap fix, and
though I'd changed the oil after David Hesse had put the new AFM on, I
went along with the oil change. New Castrol 20W-50 and new Bosche
filter. Same situation. Mike recommended a new oil pump.
I agreed to the new pump, which meant an overnight stay in Fort Collins.
Camped along the Poudre River west of town overnight -- nice.
Next day, new oil pump, and new water pump, found to be leaking when van
was raised to put in the new oil pmp. I wasn't happy about the leaking
water pump, as I had just replaced it, but it was clearly leaking.
Mike showed me the old oil pump, and what he said was "some wear" on the
gears. Also, the tech who actually put the pump in showed me on the old
pump where he said sealant had been gunked on too thick, which he said
might have allowed the pump not to engage the oil properly (slight
reduction in the depth to which the gears penetrated into the oil).
There was even some sealant on the pump gears themselves. At any rate,
new pump -- expensive.
Made no difference. Mike then said that the oil pressure was adequate,
despite the readings on my after-market gauge, and I really should
complete my trip without worrying. I explained that my immediate
destination was Spokane, long drives, long climbs on grades to get
there, then to Great Basin National Park in Nevada -- through hot
country, long, steep climbs. He repeatedly said he thought the engine
was oiling adequately, especially since it ran so well, never clattered
or knocked -- in fact ran very smoothly. With few other options for the
time, I continued toward Spokane, but planning to check further there,
when I would have more time, and almost certainly not to complete the
hotter, steeper legs of the trip beyond. On a test drive with a tech,
the tech noted that the temp gauge was running above the level that he
thought was "normal." The needle on mine holds above the LED (slight
space), whereas he thought "normal" was for the needle to hide the bulb.
First overnight revealed further deterioration in the oil pressure
readings. Whereas before, the after market gauge showed readings around
40 psi when cold at idle, and 60 psi when cold at running speed, jumping
up immediately upon start, now the gauge read zero at cold idle until
the engine warmed, and it took a bit before the pressure would rise. It
wavered about as it rose slowly. I let it rise before driving it.
When it did rise, it would read around 40 psi until it reached operating
temperature -- temp gauge needle above the LED slightly, then the
pressure would drop to around 15-20 psi on the gauge. By this time I
was several hundred miles from Fort Collins toward Spokane. I elected
to continue the trip, but not to drive the van in the mornings until the
pressure rose. At operating temp, again, the gauge read around 15-20
psi, and near zero at hot idle.
Upon reaching Spokane, I called a called a vanagon mechanic who was too
busy to help me, but who referred me to another shop whom he said also
had expertise in vanagons, Barry's Downtown Automotive Specialists.
That was on Friday, and Barry said he could look at the van on Monday.
When I got there Monday morning I noticed several old VWs, including a
couple of Vanagons, in the lot.
Barry suggested the best thing to do for the immediate term was to
change the oil to 50W Valvoline, and to baby the vehicle home. I
agreed, we changed the oil and filter, and the vehicle has been running
good oil pressure at running speed and hot idle, but still has to be
warmed up to get the pressure up from a cold start. Still wavers, still
climbs in fits, up to around 40 psi on the gauge, holding at around 10
psi at hot idle, 30 psi when at 60 mph, 3200 rpm, temp gauge slightly
above the LED.
But, at high ambient temperatures, long drives, climbs, the pressure
still drops some, lower on my gauge than I'd like. I talked with a
couple of other mechanics, one including my brother, all of whom
suggested I had more of a perceptual problem than a real one, and that I
should go ahead with my trip, and as some said, drive it until something
breaks, which likely won't happen for many thousands of miles. The
vehicle is oiling well if smooth running with no noise is evidence.
I did complete the trip, driving down through southern Washington,
across Oregon and Nevada, to Great Basin National Park (8% grade for 12
miles, that one) through 100+ FA temps at times in Washington and Oregon
desert country. The van never showed any sign of poor oiling -- no
rattles, clatters, knocks. Used no oil. But, on the climbs, I had to
rest the vehicle. Temp gauge neared to next higher line, and touched it
on a couple of occasions. Twice, the coolant warning light flashed.
When I rested the vehicle, it cooled incredibly fast, and so I was able
to complete a climb even if the gauge needle rose. But, I must rest the
vehicle, and the oil pressure reading is clearly inverse to the
temperature, even with the 50W oil.
I made it home with no problems, including steep country in northern
Utah and Colorado, but once I got back into hot country (eastern
Colorado, Oklahoma) the van generally ran with more space between the
temp needle and the temp LED. Oil pressure was ok, and I never
experienced a mechanical problem. I finally tried the air conditioner
on the final leg home, as the outside temperature was well above 100 F.
Temp needle rose to slightly above the middle of the space between the
LED and the next line. Of course, the owner's manual defines this as
within the "normal" temperature reading range.
Through all this, oil showed full on the stick, and coolant level was
never low. Both low and high speed fan operation was fine. Boy, the
high speed one really roars! On downhills, the temp needle drops so
that it touches the top of the LED.
This Westy shows 140K on the odometer. I got a receipt from the seller
showing an engine replacement (rebuilt, but not bored to a higher
displacement) at 110K.
On the trip home, I stopped back by Rocky Mountain Westy and talked with
Mike again. He offered to check the oil pressure cold -- would need the
van overnight to be confident it was cold. I had to get home. Also
offered to check actual operating temperature to be sure gauge was
correct, but realistically, the behavior shows coolant operating
properly -- fans kick on as expected, everything heats up as expected,
engine cools rapidly when resting and on downhills. Oh, the van has a
new thermostat.
Mike discouraged me from thinking that flushing the cooling system was a
helpful approach -- suggesting that he'd essentially already done that
when he drained the coolant when changing the water pump, and that due
to the radiator configuration, flushing doesn't clean it any better than
simple draining. Hmmmmm. He did suggest changing the fan switches to
cooler ones -- cheap, might help. He couldn't get the switches early
enough since I had to continue home (and I was confident at this point
that I'd make it home).
So, I drove the thing over 4,900 miles, mostly at highway speeds, made
some long, steep climbs. It did get hot but didn't overheat --
certainly not seriously, but ran continuously hotter that some folks
said was "normal." I would rather be able to use 20W-50 oil than 50
weight. I also don't like having to warm the vehicle up to get the oil
pressure up -- one isn't supposed to do that with any engine built since
the sixties -- though VW does say drive gently until it is warm. This
one had good oil pressure when cold until the new oil pump was
installed.
Fixes I've considered include trying the flush despite Mike's dissuasion
to see if that helps with the temperature, and therefore indirectly with
the oil pressure. But it won't help the cold oil pressure, that's
certain. Then if the flush doesn't help, move to trying to change out
cooling system components in order of expense -- cheapest first, moving
up to the radiator. I can't believe that the water pump is weak again
-- I put a new one on it when I first got the vehicle, then it leaked
and I put the second one on. New thermostat -- guess I could try
another, but it really seems to be working well -- coolant temperature
rises steadily until it stabilizes just above the LED on the gauge.
Any suggestions from anyone who has been patient enough to read this far
would be much appreciated. I really am now convinced that the original
oil pressure drop was due to high operating temperature, but -- the
newly cropped up problem of low pressure until slightly warmed up -- the
new oil pump is weak? It is supposed to be a "heavy duty" pump.
David McNeely, Edmond, Oklahoma
Thanks in advance, David McNeely, Edmond, Oklahoma
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