Date: Sat, 12 May 2007 13:55:27 -0700
Reply-To: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
Organization: University of British Columbia
Subject: Re: oil pressure
In-Reply-To: <BAY125-F1855406C8D33B6FD267641A0440@phx.gbl>
Content-Type: text/plain; charset=windows-1252; format=flowed
Hi everybody,
I do have a low oil pressure problem. Luckily, Tabe send me an email so
I could borrow his pressure gauge and IR thermometer.
here is the reading (use timed new roman for proper display):
(the tubing is about 2.5 meters long, hence I expect a small drop
compared to what is the real reading as well as a delay. therefore
readings are carried out at about 3 minutes of respective rpm) . I began
at about 3 to 4 minutes after starting up.
_rpm _ 1000 2000 1000 2000 __ 1000 2000 1000 2000_
_pressure [psi] | 55 60 | 25 30 | _ 15 20 | 10 *12.5 * |_ _
waterpump T [deg C] | 25 33 | 59 72 | 86 95 | 95 97 |
oil cooler T [deg C] | 25 33 | 55 66 | 74 81 | 88 90 |
oil pick up T [deg C] | 25 30 | 40 45 | 52 65 | 57 79 |
heads from below T [deg C] | 55 71 | 90 100 | 110 120 | 115 130 |
Then I stopped to not cause any damage. The fan did not yet kick in, but
the radiator was heating up, so I would expected it to kick in fairly
soon. however the pressure was so low so I did not want to rev higher
(2600 to have the other sensor read the pressure). Its quite obvious, I
am loosing pressure when it is getting hot (OK I know pressure supposed
to drop but not so much) and the revs are higher.
Anyway I will change the oil pump cover and see what is wrong with the
gaskets. I had another look and there is quite a gap of at least 0.5mm
between cover and pump (gasket is 0.2mm). I don't think i put the wrong
gaskets in, as they have different inner diameters for the big hole,
however I might have added an O-ring to the groove where oil is supposed
to flow around the oil pump ... who knows I just try to see what mistake
I could have made. Anyhow there is a gap which is too large and i see
oil coming out. Not a lot, nothing is dripping, but its oily. Directly
at the pump even a bit of a leak, or too much gap between the gears and
the cover is for sure a cause for low oil pressure (I hope ;-)) .
So I will follow Dennis suggestion and support the engine, remove the
muffler/catalytic converter and the tin. I hope that I can get the
engine holding bracket out without having to undo the exhaust pipe to
the heads. Then I hope that the water pipe i high enough to take the
cover off. Then I see what kind of gasket is in and decide whether I
have to get the pump out as well, to replace the inner gasket. This
might be a pain to do with the water pipe/pulley in place but well, I'll
give it a try. Lets hope there is something wrong and i do not have to
take everything apart again.
Thanks a for all your help. Suggestions about what i could do better or
should do before this job are always welcome.
I will let you know what happens when I am done.
Cheers
Thomas
Dennis Haynes wrote:
> If you have the thick gasket between the pump cover and body, that is
> a major part of your problem. Removing the muffler and rear tin will
> give you access to it. Supporting the engine and removing the rear
> mount will make it easy. You should be able to change the cover gasket
> with the pulley in place.
>
> For checking oil and case temperatures, an infrared thermometer will
> get you close enough. Some experience will tell you what areas to aim
> it at such as the oil filter. The gun can also be used to check water
> temps and aiming at the exhaust it can also help find mis firing
> cylinders.
>
> Dennis
>
>
>> From: Thomas Pfrommer <pfrommer@phas.ubc.ca>
>> To: Dennis <d23haynes57@HOTMAIL.COM>
>> CC: vanagon@GERRY.VANAGON.COM
>> Subject: Re: oil pressure
>> Date: Tue, 08 May 2007 00:17:48 -0700
>>
>> Dennis wrote:
>>> Unless the relief spring and piston is extremely loaded with crud,
>>> it does
>>> not fail. The 2,600 rpm vs. 2,000 rpm buzzer issue is strictly an
>>> electrical issue with the dynamic oil pressure board and I have seen a
>>> number that operate at that RPM. My guess is that there was a
>>> revision at
>>> some point to quiet the noisy buzzers.
>>>
>> I agree. Is there am easy way to change this or how are these
>> revision usually made? Well I am getting ahead of myself anyway ...
>> first the manual gauge ....
>>> A healthy engine should be able to maintain ~ 10psi/1,000 rpm. If you
>>> can’t hold .9 bar at 2,000 or 2,600 rpm, something is wrong. Since
>>> you are
>>> having trouble once warm you have to consider viscosity, temperature, a
>>> clogged inlet screen or excessive clearances somewhere. You need the
>>> test
>>> the oil pressure with an oil pressure gauge. You need to check the
>>> relief
>>> valve with a cold engine
>> Hm how can I check whether its working or not? the piston is clean
>> and the spring is new.
>>
>>> ant them map oil pressure a various oil
>>> temperatures and engine speeds.
>>>
>> Yes the pressure gauge is what i will do next .... temperature gauge
>> will also be implemented. I keep you posted with the results ...
>>> If the oil pup has a gasket between the pump body and cover, and that
>>> gasket is not so thin as to rip by merely looking at it, you have the
>>> wrong gasket there.
>>>
>> Hm it seems that I accidentally changed the two gaskets, I cannot see
>> the one between pump and case, but between cover and pump, a ~1mm
>> thick gasket is visible. is there an easy way to get to change this?
>> I.e. letting the engine to the ground onto some lumber, taking the
>> exhaust off (is there enough space or do I have to get the rear tires
>> a bit higher?) , taking the engine bracket off and then taking the
>> cover off? Or is the coolant pipe in the way? Meaning I have to undo
>> the pulley as well?
>> Well This will be the next step after the manual oil pressure I guess
>> ...
>>> What level is the oil filled to? Any chance it is too high. At or above
>>> the top mark on the dip stick is too much.
>> It is at the high side ... I will let a bit out but my guess is
>> perhaps 200ml too much if that. Could this cause the low oil pressure?
>>
>>> Is water flowing through the
>>> oil cooler?
>> The oil cooler is new, How could I check? Just with the hands if it
>> is running to feel the flow?
>>> What is the coolant and oil temps.
>> Coolant temps is just above center of gauge. Don't have an oil temp
>> gauge yet.
>>> Without using an oil
>>> pressure gauge and doing some real diagnostic testing, you only
>>> grasping
>>> at straws and hoping for a miracle.
>>>
>> Yes I agree thats why the pressure gauge is the next step. I still
>> hope that i do not have to do a major change ....
>> Thanks a lot for your thoughts and help!
>> Cheers
>> Thomas
>>> Dennis
>>>
>>>
>>> -----Original Message-----
>>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
>>> Behalf Of
>>> Thomas Pfrommer
>>> Sent: Monday, May 07, 2007 1:52 PM
>>> To: vanagon@GERRY.VANAGON.COM
>>> Subject: Re: oil pressure
>>>
>>> David Kao wrote:
>>>
>>>> --- Thomas Pfrommer <pfrommer@phas.ubc.ca> wrote:
>>>>
>>>>
>>>>
>>>>> Actually i do not get a blinking, meaning even with a hot engine and
>>>>> idling now warning occurs. With a cold engine the same, and also
>>>>> when i
>>>>> rev above 2600 rpms everything is fine. BUT when the engine is hot
>>>>> and
>>>>>
>>> I
>>>
>>>>> rev above 2600 at some point, not right away the buzzer+warning light
>>>>> gets on. A small tip on the accelerator to bring the engine at about
>>>>> 2800 stops the buzzer/warning light. Going then back to idle no
>>>>> blinking occurs. I believe that there is certainly a low oil pressure
>>>>> problem, as at 2600 or 2800 the pressure is not supposed to be around
>>>>> 0.9bar but rather 2 to 3 bar. I am certainly above 0.3bar while
>>>>> idling.
>>>>> The 0.9bar switch is new. What is strange is that the change from the
>>>>> 0.3bar switch to the 0.9bar switch occurs at 2600rpm and not at
>>>>> 2000. I
>>>>> tested it by disconnecting the cable to the 0.9bar switch.
>>>>> Thanks
>>>>> Thomas
>>>>>
>>>>>
>>>> Thomas:
>>>>
>>>> So it is unrelated to overheating. Have you checked your oil pressure
>>>>
>>> relieve valve?
>>>
>>>> If the sping is stuck and compressed you will get constant low oil
>>>>
>>> pressure.
>>>
>>>>
>>> I changes the spring last week as I also thought this is the problem.
>>> However I am not sure if it is stuck ... how can i tell? the piston
>>> came
>>> out nicely when I changed it and I cleaned everything and put it back
>>> together, with the groove being farther away from the spring .... I
>>> hope
>>> that was the right direction ... the bentley for the 2.1l 87 does not
>>> show which site of the piston faces upward, but for the air-cooled
>>> it is
>>> shown nicely and i assumed it will be the same way. that means the
>>> spring connects to the outer ring of the piston and it is hollow at the
>>> spring site. The piston is flat facing the engine ... makes sens to
>>> me...
>>>
>>> aaarrrgggghhhhhh I am running out of ideas what it could be WITHOUT
>>> talking the monster out/apart again NNNOOOOOOO!!!
>>>
>>> Thanks
>>> Thomas
>>>
>>>> Overheating and rod bearing clearance problem will cause blinking
>>>>
>>> warning light.
>>>
>>>> David
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>> __________________________________________________________________________
>>>
>>> __________
>>>
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>>>>
>>
>
>
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