Date: Thu, 13 Sep 2007 10:01:10 -0700
Reply-To: Bob Donalds <donalds1@VERIZON.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Bob Donalds <donalds1@VERIZON.NET>
Subject: Re: Flickering Oil Light 84 auto
Content-type: text/plain; format=flowed; charset=iso-8859-1; reply-type=original
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Ed
Sent: Wednesday, September 12, 2007 8:03 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Flickering Oil Light 84 auto
I have an 84 vanagon, automatic, after it gets good and warm and has been
driven vfor a while I notice at idle I get a flickering oil light. Oil
level is good, rasing the RPM's ever so slightly makes it go away, as does
putting it in park and letting it idle.
Any ideas?
Thanks,
Ed Maikranz
Abilene, TX
1984 Vanagon
1972 Riviera
I wrote this a while ago hope this helps
Bob
Main bearing info or Boston Bob's Tales of an engine stripper 1.9
In my time I have taken a couple of 1.9 engines apart and I would like to
share with you some of the things I have seen and learned. Most 1.9 engines
are pretty tired by the time I get them in fact they are mostly turned in
cores in exchange for fresh rebuilds but some come from stripped vans that
had other problems. The one thing that is consistent in all 1.9 engine
blocks is that the crank bore in the case are out of spec. The
specifications for the crankshaft bore size and the amount of bearing crush
is not listed in any book I have seen. This leaves allot of room for a
judgment calls based on past experience or advise from others and lack of
other options. Some would tell you that if the bearing sits in the web and
seems tight then that's OK and if the engine does not bind when you tighten
the case bolts then you are good to go. Now we are getting to the difference
between going threw an engine and rebuilding an engine. As I said not
knowing the specs makes the job a little tricky so in order to understand
the intent of the manufacturer I have looked back at some of the older
engine specs to see if there is any details that we can use to interpret the
intent of those who designed the WBX engine. The type 2/4 engine and the
bug engine do have specs for the case bores and wear limits listed in the
without guesswork book. The without guesswork book was handed out to techs
as they went threw the dealer training programs back in the sixties and
seventies. As it turns out there is some good info we can use to determine
the intent of the designers of the WBX engines. First the nose bearing is
the same on all flat 4 VW engines since 1961 right threw to the 91 WBX
engine. The size of the bore for the nose bearing is 50 mm to 50.03 mm. and
the wear limit is 50.04 mm. The next thing I noticed is that the Main
bearings bore sizes are all in round numbers. Yah got to love those Germans
need for order and straightforward simplicity. The two middle main bearings
bores are in fact the same size on the bug main bearings bores as they are
on the 1.9 WBX engine and that is 65 mm. with a wear limit of 65.03 mm. The
type 2/4 main bearings bores are the same bore size as the rear main WBX
bearing no big surprise! (no its not the same bearing ) The rear main
bearing bore for the type 2/4 engines is 70 mm with a wear limit of 70.03
mm. With all of that in mind we can now go back and look at the WBX block
and use these dimensions to determine the condition of the used 1.9 cases.
The next dimensions we need to determine if the case is in useable condition
is the actual size of the bearings and then we can do the math and determine
the bearing crush IF ANY!!!
To repeat the statement I made at the beginning of this rant. The one thing
that is consistent in all 1.9 engines is that the crank bore in the case are
out of spec. With that said I can tell you that the new 1.9 bearings are 3
ths or .12 mm larger than the main bearing bore specs I have listed above.
So with all this we can do the math and see that the case crush on the
bearing is intended to be between .002ths. And .003ths.
Measuring the WBX block to determine the size of the crank bore can't be
done without a good bore micrometer and a lot of practice. The other thing I
has noticed is that the case halves tent not to bolt together as intended.
The WBX block has two locating pins as do all VW air and water-cooled flat 4
engines this is done to hold the block in place so it can be machined and so
the halves will return to there machined position when assembled. Over time
the case halves do shift you can in fact feel the shift at the parting line
when a used case is bolted and torqued together without any bearings in
place. The case shift is commonly .002 to .005 ths. at the parting line and
this can vary from end to end. I have tried to use a block of wood and
hammer to align the halves as I bring the case halves together before I
align bore with limited success and have had to developed tooling do get the
cases halves back where they belong in order to align bore. This is
important because when the case is not properly centered the cam bore and
oil pump bores will be permanently misaligned by the new bearings in the
nice round holes for the main bearing once we align bore the crank bore. One
other note about used 1.9 blocks is that the thrust surface can take a
pounding and the new main bearings can be loose and the case needs a thrust
cut. You bug types might remember that the bug blocks commonly needed the
thrust cut to keep the rear main bearing from moving.
I have also had made 20 and 40 over and thrust bearings made for the
discriminating engine builder.
Be aware of cheap imitations bearings the tolerances are not what they
should be
All rights reserved
Bob Donalds
Boston Engine Exchange
The Engine Exchange Deluxe
http://www.bostonengine.com
