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Date:         Mon, 9 Jan 2012 18:16:14 -0500
Reply-To:     Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject:      Re: Smoke after head replacement
Comments: To: Gregg Carlen <gregg.carlen@GMAIL.COM>
In-Reply-To:  <CAK-ud2jTVrQT3y+kUngbViPeZnQF-DUEJrbx7j1-NZruak25+Q@mail.gmail.com>
Content-Type: text/plain; charset="US-ASCII"

For a novice the single gauge Milton is the easiest to use. The measurement is not that critical. The ultimate test is to secure the engine from turning and then using full shop air charge the cylinder and listen to where the air escapes. Do this with the coolant pressure cap removed and tank topped off. Any movement of the coolant level is an immediate problem.

The metal gaskets at the top of the cylinders are where the real sealing occurs. The green rings are just there to keep the liquid away from that gasket junction. It won't hold back anything once that metal gasket fails. When re-using the heads and cylinders one has to be real careful the surfaces are clean. Any carbon will make the seal fail. I pull the cylinders and use lapping compound and turn them into the heads to get both surfaces polished up ready to seal. Proper torque of the head studs is extremely critical here. The nuts really should be replaced or at least chase the threads with a tap. The threads need a lubricant and only the face gets the yellow sealant. If a stud twists and springs back during final torque the threads were not prepped right or the stud is defective. The outer rubber only holds the coolant in and will have no effect on engine operation except the loss of coolant.

Dennis

-----Original Message----- From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Gregg Carlen Sent: Monday, January 09, 2012 10:52 AM To: vanagon@GERRY.VANAGON.COM Subject: Re: Smoke after head replacement

Yes, Dennis, I agree. Seems like a cylinder isn't firing. Going to re-check obvious things as soon as I have a chance (plug wires, etc).

I don't have a leak-down tester, so will have to get one ASAP (what's the advantage of a 2-guage vs single guage leak-down tester?). However, I really suspect I've messed something up during installation of the head because I think there is definately a coolant leak getting through to the exhaust. I drained 1.5 gallons of coolant when I pulled the head and I've returned a little more than 2 gallons now and it still wants more. I also noticed if I put a piece of cardboard behind the exhaust and let the mist collect into droplets, it's coolant.

The only things that come to mind that would cause a significant coolant leak like this is one of the green o-rings came out of place during head installation, or perhaps the head didn't seat correctly against the cylinders. Or, one of the metal cylcinder gaskets (between the head and top of the cylinders) slipped out of place during installation (and I crushed it a wierd way during head installation).

If I had a valve that was open all the time or more than it is supposed to, I wouldn't think that would have anything to do with allowing coolant through the combusion chamber, right? Althought that might account for a cylinder not firing/exhausting at the right time..

A few things I did that I second-guess in hind-sight: Installed the green o-rings without any kind of lubricant When I inspected the head after cleaning, I noticed the over-flow port (where the small-diameter coolant hose goes between the overflow rail to the adapter plate on the front end of the head) had one screw hole that was very deep and had an opening in the bottom into what I think is the exhaust chamber. I would if this leaked coolant or exhaust, I think it would be allowing exhaust to escape to the outside of the engine since the bolt hole is in the flange of the overflow adapter. When I first put the head on by hand, I could only get it up to about 1" to the engine case/gasket. From there, I tightened the head bolts in proper sequence until tight. It seemed like the bottom of the head mated with the engine case/gasket before the top of the head did (bottom of head made contact with top of head still having about 1/4 gap). Perhaps I incorrectly installed the head???

I just wanted to share these observations at this point. Next step is to get a leak-down tester to learn more about what is truly occuring, but until I verify I have all 4 cylinders firing, I don't want to drive or run it more just yet.

Any guidance appreciated.

-Gregg

On Sun, Jan 8, 2012 at 9:07 PM, Dennis Haynes <d23haynes57@hotmail.com>wrote:

> For starters that engine is running really bad. Find which cylinder is > not firing. You may have a push rod that is not seated properly in the > lifter keeping a valve open. That will also keep some unburned fuel > going into the exhaust. > > Shortly after a major engine repair a compression/leak down test > should be performed again to confirm the success of the repairs. Check > to make sure that coolant is not now getting into the cylinders. This > will quickly damage the cylinders and pistons. Coolant in the oil will > also damage the bearings. > > Dennis > > > -----Original Message----- > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On > Behalf Of Gregg Carlen > Sent: Sunday, January 08, 2012 2:16 PM > To: vanagon@GERRY.VANAGON.COM > Subject: Smoke after head replacement > > Hi folks, > > Similar to Todd Last's collapsed lifter that he shared a video about, > I've got a similar situation on my 91 Westy. Oh yeah, I'm in Oakton, VA. > > I had the classic water gasket leaking coolant. I removed the > passenger side head with engine in the van, cleaned it up, checked it > for leaking using Scott's recommendation to check the valve guides > using gas (I used parts cleaner instead of gas with no signs of > leaking along the valve > guides) and reinstalled. Did the fuel lines while I was on that side > of the van as well. New gromets, gaskets, etc all the way around, > nothing rubber reused. (I repalced the green o-rings on the cylinders, > but no the black one's back inside the engine since I didn't remove the cylinder sleeves). > So, all back together, she fires right up on the first try. Usual > bleeding of the coolant, etc. > > Now, as I expected, there should be some smoke as oil/coolant that may > have gottent to places it shouldn't have. There was. A lot of it. I > thought at first it might be a collapsed lifter (one was squishy when > I put the push rods back in). However, I don't have the knocking sound > that Todd had in his video, just lots of smoke. > > I've run it about 10 minutes total and still no change. I'm wondering > if I've managed to mess something up and actually have coolant getting > into the combusion process. > > Any advice as to what to check first? Or, just need to run it more? I > did NOT adjust the valves, just replaced the assemble as I had taken it off. > Perhaps I need to go through the valve adjustment process? (Although I > don't here anything abnormal from that area). > > A short video is here: > > https://picasaweb.google.com/lh/sredir?uname=113741720077010029753&tar > get=AL > BUM&id=5695338093044400273&authkey=Gv1sRgCIeJqISt-qiL5gE&feat=email > > > Gregg > Blueberry - 91 Westy (2.1L stock) > Oakton, VA > >


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