Date: Thu, 17 May 2007 22:49:22 -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 -- next round
In-Reply-To: <002c01c79900$18412240$6501a8c0@oemcomputer>
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Hi Bob,
thanks for the reply.
There is actually another thread which will answer a lot of the open
question. Let me summarize:
Engine did give me some buzzer on and off which i did not took too
serious (yes I know my fault and ignorance ...) especially because in
the beginning it only occurred in curves. Well shortly after the first
buzzer I heard some weird noises from the engine and stopped. Got to a
garage and they said its somewhere inside the engine. As I did and do
not have lots of money I decided to strip it down by myself and bring
the parts to a machine shop who then can do all the required machining,
and then I put everything on together.
After taking everything apart it became quite obvious what the failure
was. one of the rod bearings was actually gone. OK took all parts to the
machine shop (Alecs Automotive in Vancouver, BC), and told them they
should measure everything and do what they have to do. They machined the
rods, machined the crank, redid one of the heads, had to change one
valve,machined the wrist pins and the piston holes and measured
everything. The cam was machined at another place. They ordered the
bearings for me as i did not measure the crank, but from the color i saw
when i reassembled it, that they ordered the original size. Well I
thought they measured it and they would know which size is the best.
Especially main bearing 4 was quite loose when I put it on, but I did
not get suspisous by the time. Anyway I ordered more new parts from
busdepot like oil pump dist drive shaft, dist drive gear, oil cooler,
cams pushrod tubes and other minor parts (oil filters .... )... only 6
out of the 8 ordered followers came. Apparently US customs opened it and
did not put everything back. Instead of waiting for the other two, which
busdepot would have sent, i told them I would get them from a local
dealer, which was more expensive but i had them faster. It turned out
not to be the exact same, but the same dimensions (busdepot sent these
with the U-spring at the end, whereas i got here 2 with a circlip, which
have to be filled slightly different with oil).
After taking everything together i started it up and it ran right away
(Before that, I only cranked it without the ignition ... yes I grounded
the ignition to no do damage to the ecu). So I thought wow thats cool,
and after about 10 minutes the light noise indicating that the lifters
were not completely full was also gone and everything sounded smooth.
I ideled it more, got the air out of the cooling system, but then the
buzzer cam on. i stopped it and looked what might be wrong. Changed
therefore the pressure relief spring, changed the 0.9bar sender. Changed
the oil to 20/50 and installed a mechanical gauge (not yet an electrical
one .. just for diagnostic ... Tabe, list member generously gave it to
me for testing). Then I did the pressure test with cold and then warm:
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, not 2000 strangely
enough). 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.
After this test I removed all stuff at the back (muffler, exhaust, tin
sheet, pulley, water pipe) and opened the oil pump. The gaskets are the
one that came with the set. I will measure them, but they are quite
thin. With the pump installed there was some oil around the cover
gasket, so I thought I did something wrong, but after opening, nothing
obvious came up. I sanded the old cover and reused it but there are new
scratches from these short runs already in. I bought a new one now.
Hm there are a few things that might have dropped the pressure a bit as
the two different lifters which i could not set the valves completely
right as they were not full of oil (they lost it right away after
filling .... different design not meant to hold it i guess) but nothing
that i would think is large to cause this low pressure.
Anyway thanks for the suggestion i will call you tomorrow.
Thanks and sorry to the group that you have to read it again ...
Thomas
Bob Donalds wrote:
> My ears are burning so I checked the list. I must admit to failings short
> term as a lerker and contributor
> I did my best to quickly reread the thread and to sumerize fresh
> rebuild 2.1
> with dynamic warning buzzer doing off and some 10 pds oil pressure at
> idle
> no one said hot or cold oil temps but I did read 20/50 is being used.
> Also
> new oil pump and bearings are in use.
> Having bought alot of cores some blocks have come to me torn down and
> looking like they had just been redone and then taken apart. While that
> might sound like a good thing its not. This sends red flags flying
> this is a
> sign of an abandonded progect
> and I do not want have the same fate time wasted ego brused and so on.
>
> Rods do distort and fail when reused but do not have symtoms of this type
> Crank bores also distort mostly center main bores and oposit the parting
> line they typicly gain .0015ths no big deal.
> Other main bearing problems incorrect sizes. when this happens much noise
> and 0 pressure
> If the main siezed the block might not touch and this would cause a
> gap and
> oil pressure would not as much of a problem as leaking oil.
> I am always looking for that dam reman stickers on the blocks I take
> back in
> and when I see it I pay extra attenton to the main rod and cam
> bearings as
> the engne comes apart. The dealer remain program tried alot of ways to
> reuse
> blocks some where not pritty. I oftens see cam main bores that have been
> bored and need oversize Od bearings. I suspect this as on of the possible
> problems Thomas has. I stock these if needed
> Some other possiblitys are trusting the oil pump cover gaskets provided
> with the gasket set to be the correct thickness. I have seen them as
> thick
> as .013ths when they need to be .004ths. This is all it would take to
> create
> the low oil pressure problem
> we are talking about.
> Oils have changed and I do note see the at speed temps the bentleys
> suggests
> When talking about the oil pressure I first ask hot or cold is the
> light out
> and do you have that dam VDO gauge sender combo. it shows no oil pressure
> hot at idle and makes the light come on if you use the switch they
> provide
>
> a couple of last thoughts bad gauge wrong switches stuck oil relief
> plunger
> Call me if you like and we can spend some time going over any details
> I may
> have misunderstood or any follow up info
>
> Its always good info to know why the engine was taken apart what was
> found.
> oil pressure is about clearances and oil temps and viscosity
> measure measure measure
>
> Bob Donalds
> Boston Engine
> 508 358 6264
>
>
>
>
>
>
>
>
>
> ----- Original Message -----
> From: "Dennis Haynes" <d23haynes57@HOTMAIL.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Thursday, May 17, 2007 6:10 PM
> Subject: Re: oil pressure -- next round
>
>
>> Maybe Boston Bob can chime in here. It sounds to me like the case needed
>> an
>> align bore and the rods needed to be resized.
>>
>> Dennis
>>
>>
>>> From: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
>>> Reply-To: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
>>> To: vanagon@GERRY.VANAGON.COM
>>> Subject: Re: oil pressure -- next round
>>> Date: Thu, 17 May 2007 10:04:03 -0700
>>>
>>> Hi Dennis,
>>> I was using 20W50.
>>> Yes O had new gears and a new pump housing in, but the old cover, which
>>> i will replace now. I know that I am almost above the pressure, and
>>> this
>>> is OK. However that was measured without load. I did try it without the
>>> pressure gauge before and had it run for more than half an hour. No
>>> buzzer. Ok Lets go on a small trip (a couple of hundred meters). As
>>> soon
>>> as i was outside, the buzzer went on.
>>> So It is really something wrong when the engine gets hot. I will check
>>> the housing for wear but I ordered it from busdepot just before
>>> reassembly, and the engine run in total after reassembly not more than
>>> say 1.5 hours. The scratches though are weird. I did sand the cover
>>> down
>>> and now there are clear scratches again. Perhaps I am sucking air and
>>> not oil, as David suggested. Hm Will see.
>>> I am not sure about the loose mains, I brought it to a shop with good
>>> reputation to to the job and they ordered the bearings for me. Also
>>> I do
>>> not have a cam bearing left around, so I doubt I forgot one. They were
>>> new as well. I did the valve adjustment as written down in the Bentley,
>>> but for the two cam followers (see my reply from 11:41 PDT last night
>>> why two were different), it was a bit hard as they were not completely
>>> filled with oil, hence i could not feel the exact point when to start
>>> counting the 1 3/4 turns. Could these two followers (actually the valve
>>> adjustment) cause such a pressure drop? Hm will check again when the
>>> engine is filled with oil ....
>>> But first i will check all other stuff once it is open ....
>>>
>>> Thanks a lot
>>> Thomas
>>>
>>>
>>>
>>> Dennis Haynes wrote:
>>>> What viscosity oil are you using? This may have been mentioned but
>>>> remind me.
>>>> I doubt you have a blockage. The lenght of hose going to the guage
>>>> will not efect the reading unless you are actually flowing oil. It may
>>>> delay the reading but the final pressure reading is good.
>>>> Scratches in the oil cover is common. Dirt. Was it a new pump and
>>>> housing? You can check the housing for wear with a striaght edge and
>>>> feeler guages. The Bentley has the specs.
>>>>
>>>> 12.5 psi is almost .9 bar. While not quite the pressure that should be
>>>> there you are clsoe to satifying the switch, (.9 Bar). If you can get
>>>> maintain 2 bar, (28 psi) at 4,000 rpm, you should be safe to run.
>>>> These pressures are an indication of loose mains or out of round rods
>>>> or a missing/bad cam bearing shell. Also, how are the vlaves adjusted?
>>>> If you set the lifters with clearance, you will have some excess flow
>>>> there. They should be tight, ( touching + 1-2 turns) so that all oil
>>>> flowing through has to get forced through the rockers.
>>>>
>>>> Dennis
>>>>
>>>>> From: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
>>>>> Reply-To: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
>>>>> To: vanagon@GERRY.VANAGON.COM
>>>>> Subject: oil pressure -- next round
>>>>> Date: Wed, 16 May 2007 22:03:22 -0700
>>>>>
>>>>> Hi again,
>>>>> OK I am in bad luck i guess .....
>>>>> after I measured the pressure (I posted the readings a few days
>>>>> ago) I
>>>>> realized its really oil pressure and not electronics or other
>>>>> stuff. OK
>>>>> got the muffler off, got the tin sheet off (I really hate this f!@#$%
>>>>> sheet), and the engine support bracket. Unfortunately, the water pipe
>>>>> did not allow to unscrew the upper nuts completely, so in the end
>>>>> I had
>>>>> to get the pulley off and then the water pipe.
>>>>>
>>>>> I did not make any mistakes with the gaskets. Everything as it is
>>>>> supposed to be. BUT I do see quite obvious new scratches in the
>>>>> cover.
>>>>> Together with the bit of oil that I saw at the pump after I ran the
>>>>> engine a bit, it looks like I have some backpressure and a blockage
>>>>> somewhere. Any other ideas? Hm in cold run I got 55psi at 1000rpm.
>>>>> Only
>>>>> when it warmed up, I had 12.5psi at 2000rpm (and 3 meters of tubing
>>>>> before the gauge, which will drop the pressure a bit, but not that
>>>>> much
>>>>> I guess). Also that was still beofer the fan of the radiator went on,
>>>>> but the engine was quite hot already.
>>>>>
>>>>> I have to admit I don't know what to do any more. I just don't
>>>>> want to
>>>>> open the beast again ..... I checked all oil gallys with an air
>>>>> pump and
>>>>> felt air coming equally out of every opening. I could not sense any
>>>>> obstacle sitting somewhere. Also the indication of the new
>>>>> scratches on
>>>>> the cover rather show some backpressure than too loose bearings or
>>>>> similar. I sanded the old cover flat before I put it on (now I have a
>>>>> new cover ready to be put on). Also the scratches show that all areas
>>>>> are equally scratched, so i did not flatten it at an angle.
>>>>>
>>>>> Hope someone can help me. Oh man, I hope i could drive around now,
>>>>> and
>>>>> now it seems that all effort wasn't worth it (besides the gain in
>>>>> knowledge about these engines ...)
>>>>>
>>>>> I need rum now
>>>>> Cheers
>>>>> Thomas
>>>>
>>>>
>>
>
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