Date: Mon, 28 Jul 2008 20:18:38 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Different Kind Of Valve Adjustment Question? NOW What's next?
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one thing about any 'two door' thermostat , which is all modern thermostats
mostly ..............
when it has the main passage closed off, it has a 'bypass' circuti open.
when the main circuit is open. as in when things are up to temp ..........it
closes off the bypass circuit.
with no t-stat at all, both circuits are open, and the bypass circuit
doesn't go through the radiator or heater cores....
so there's no cooling in that cirucit, so only a portion of the coolnat
heated by the engine gets to any heat exchanger for cooling.
i.e. 'it can't work.'
you gotta have a t-stat.
or somehow block off the bypass portion of the circuit to run without one.
I'd watch the rockers to see if they all have the same amont of linear
travel at the pushrods - looking for worn lobes for the cylinder in
question. I 'don't beleive in' worn cam lobes in waterboxer engines since
the cam gets lots of oil on it down there below the crank.........
and btw, how many miles on this engine ? I'm starting to count waterboxer
engines with over 200K on them as 'pretty tired' ........
like if you can do rod bearings on them, keep proper oil clearance
there............then maybe it can still be OK with new rings, or new
pistons and barrels and a real valve job and new head gaskets.
And i've seen worn out rocker screws.
was there much oil in the valve cover, or was it dirty and crusty and dry in
there ?
I'm starting to treat a lot of oil with Marvel Mystery oil ......
i've had a few very clanky waterboxer engines respond very nicely to a fresh
oil and filter change with Cheron Delo 15W40 plus a cleaner additive in the
oil, Rislone, or as I'm not doing, Marvel Mystery oil. Bought a gallon of
it.
I also did a top end job on a 90 Vanagon, and it had some rough valve
adjustment screws ...........looking through all my other engines and rocker
arm screws, I found none as big as the ones in this '90
engine...........just mentioning that in case someone changed your rocker
amrs to a different type or whatever.
do you have the stock 2.1 electronic idle control valve and control unit
behind the right rear tail light ?
I'd consider those.
Vangons use a 3 wire oxygen sensor, two are just for heat, and are not even
really really needed for the 02 to work.
Would have minimal affect on idle, if at all.
you can always try it with the 02 disconnected too.
but you can't run with no thermostat, unless you block off the bypass
cirucit somehow.
scott
www.turbovans.com
----- Original Message -----
From: "Max Wellhouse" <dimwittedmoose@CFU.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, July 28, 2008 7:07 PM
Subject: Re: Different Kind Of Valve Adjustment Question? NOW What's next?
> >Thanks to Jake and Scott and all that replied either publicly or
>>privately. Forthose of you just joining in, we're talking aout a
>>90GL 2.1 with a Haltech engine
>
>
> So far, the compression for cylinders 1, 2 and 4 is around 130 with
> 1.5 turns and #3 is around 115. A day or two later while in WI., I
> pulled the rocker covers off and #3 had slipped to the point of the
> pushrods now spinning by thumb and index finger once more. I
> tightened them to 1.5 turns, but now I'm almost out of
> adjustment(rocker arm screw is pretty much flush with the jam nut)
> and I'm wondering if this could be both #3 lifters leaking
> simultaneously or whether both intake and exhaust valves are getting
> ready to fly or whether it's just worn adjuster screws. I have a
> feeling that the screws will be the cheaper fix, then lifters, then
> new heads or camshaft. At some point, a warm engine compression test
> with all plugs out and throttle body wide open has yielded higher
> compression readings than the 130.
>
> The motor's symptoms over vacation are as follows.
> 1. With a new 87 degree thermostat in place and new radiator and a
> bled cooling system, the motor warms up way too quickly and has
> forced me to drive without the T stat for now. I do know of the
> consequences of doing that. I also replaced the Fan switch and have
> heard it run at low speed during idling and traffic. As I drive on
> the highway, as long as the water temp stays in the 100C range, the
> motor doesn't stumble very often, but if it gets below 90 C., then it
> will stumble more. Most stumbling occurs at about the time you would
> expect the accelerator pump to kick in if the engine were
> carburetted. It does stumble from a cold start, but not overly
> so. When stuck in traffic the motor still gets way too hot for my
> liking despite the Tstat being gone. Resuming to highway speeds
> cools things back down to normal.
> 2. Engine power is not great and the motor will not idle under most
> circumstances. I have a VDO vacuum gauge hooked up to the dash and
> monitor it closely. Mopst of the highway driving at 60 or so with a
> moderate load of vacation gear would yield vacuum readings in the
> 5-10 in. range. The times it does idle in the 1200rpm range the idle
> vacuum is in the 15in. range. I sprayed ether all over the normal
> leak-prone spots on the motor, and got no engine rpm rise, so I am
> assuming that a vacuum leak is not the problem. Low compression
> might be the reason for lack of vacuum. The trip up to Wisconsin, I
> had a mild tailwind and was getting over 19MPG, which is outstanding
> for this particular van. Even towing the 91 automatic shell back
> home, I got 15 despite all this other crap going on. The engine has
> never died or quit running for me, but my dash-mounted fuel pressure
> gauge has been reading about 5-6psi low at both idle and full
> power(24psi under high vacuum and maybe 30psi floored). I used a
> known good spare fuel pump and replaced both upstream and downstream
> fuel filters and no improvement. I wondered if the Fuel Pressure
> Regulator might be going bad, but it may not be getting enough vacuum
> to operate properly. I have a known good one I could swap.
> 3. The thought has occurred to me that the O2 sensor might be toast,
> but the gas mileage isn't bad enough to have that problem is it? I
> don't know if I've replaced the O2 sensor since Boston Bob rebuilt
> the motor in 2001, so I guess it is possible that's one of the problems.
>
> 4. The fuel injectors are the originals from 1990, but I didn't want
> to pull them out for testing while in the boonies in WI., for fear of
> ripping a seal that I couldn't replace. I should test them also for
> spray pattern and volume.
>
> 5. I don't think the rebuilt Haltech unit is to blame either,
> although I've not tried to re-program it since it came back from AUS.
>
> Summary: The hot motor could be from a stealth air pocket, but the
> motor has been started and stopped enough now that I have no air at
> all in the expansion tank and the cap is a new blue one and the
> coolant level has stabilized in the overflow tank. The motor was
> running hot before the new radiator and fresh coolant, so the new
> parts didn't help there. I guess the low compression could be
> causing the hot motor issues too. I will test the O2 sensor although
> the Haltech sensor is a 3 wire and not the 4 wire like VW uses. The
> Haltech coolant temp and air temp sensors are only 3 months old, so I
> don't suspect them. The timing is right on as well.
>
> This maybe TMI, but better to offer too much.
>
> Thanks
>
> DM&FS
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