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Boogar69
Samba Member
Joined: January 30, 2003
Posts: 17
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 Posted: Tue Sep 30, 2003 10:47 am Post subject: I think I dropped a valve seat... HELP??? |
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I was wondering how intense it is to pull a head (pass side) while the motor is still in a '77 FI bus? I suspect I dropped a seat or something of the sort. Either way, I'm gonna have to pull the head to find out more, and I'm not looking forward to it. Can it be pulled while in the van or do I have to pull the whole motor? It was driving fine, then just started acting like it was mis-firing. Even the wife noticed... and thats saying a lot. Could it have messed up the piston or anything else? Thanks for any help...
Mike B |
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Randy in Maine
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Joined: August 03, 2003
Posts: 34890
Location: The Beach
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| Posted: Tue Sep 30, 2003 11:42 am Post subject: |
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First off, why do you think it is a dropped valve seat? How did you reach that conclusion?
If it is a valve seat or something similar going on with the head, you will still have to do the fix to both sides. It is important that both sides are exactly the same for it to run correctly.
If it does come down to something serious, I would just pull out the motor where you can have a look at the big picture, start working on it, figure out what exactly is wrong, and fix it.
It really is not a big deal to pull it out, and much easier to work on when it is. |
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Boogar69
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Joined: January 30, 2003
Posts: 17
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| Posted: Tue Sep 30, 2003 12:14 pm Post subject: dropped valve seat |
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| The bus started running crappy the other night after driving it a few miles. I finally got time today to check the adjustment of the valves and noticed that the valves/spring assembly on the aft #1 was loose. I pulled the rocker assy off the #1 and noticed there was about a 1/4" difference between the heights #1 fwd and aft valves. I pulled the rocker off the #2 and both of those valves were the same height as the fwd #1 valve. Thats how I came to that conclusion. The van still ran, just sounded like it was missing. Also, the pass side intake manifold was warmer than the drivers side. Both normally cool to the touch. It wasn't HOT, just warmer than normal. I didn't think much of it, until today. The #1 spark plug was also a little oily. Hope this helps. |
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ratwell
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Joined: April 26, 2003
Posts: 8717
Location: Victoria, BC
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keifernet
Samba Search & Rescue
Joined: May 11, 2002
Posts: 19395
Location: Samba Center for Behavioral Science
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| Posted: Tue Sep 30, 2003 3:05 pm Post subject: Re: dropped valve seat |
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| Boogar69 wrote: |
| The bus started running crappy the other night after driving it a few miles. I finally got time today to check the adjustment of the valves and noticed that the valves/spring assembly on the aft #1 was loose. I pulled the rocker assy off the #1 and noticed there was about a 1/4" difference between the heights #1 fwd and aft valves. I pulled the rocker off the #2 and both of those valves were the same height as the fwd #1 valve. Thats how I came to that conclusion. The van still ran, just sounded like it was missing. Also, the pass side intake manifold was warmer than the drivers side. Both normally cool to the touch. It wasn't HOT, just warmer than normal. I didn't think much of it, until today. The #1 spark plug was also a little oily. Hope this helps. |
By your description you definanantly have a valve/ seat problem.
As everyone else stated it is much easier to work on with the engine out of the bus and up on a bench/ table at a decent working height ( not necessary to have an engine stand if not tearing down the whole engine)
You may be lucky and the head of the valve may have just badly distorted and or the seat has come loose but nothing has " dropped" out and smashed the top of the piston. However the metal debris may have been enough to ruin the piston and cylinder. Obviously You will not know the extent of the damage until you pull the head.
I also would recommend you do both heads at once and if the one piston/cylinder is damaged and the others are showing miles/wear that you buy a complete set.
Also Do not run the engine any more... drain the oil and take out the screen/ drain plate and look for large pieces of debris/ metal.
If there is not alot then your lower end may still be good... if there is stuff get a magnet and see what may be metal and what may be non ferrous like piston material. Only then will you be able to make a determination as to whether or not you may need to rebuild the whole thing.
There will be the temptation to " poor boy " and do just the one head and the one piston/cylinder... just remember you get what you pay for... that is often a big gamble IMO....
I hope it works out for you, keep us posted. |
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[email protected]
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Joined: March 14, 2003
Posts: 33
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| Posted: Tue Sep 30, 2003 4:46 pm Post subject: |
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I agree. Do both heads if you're going to do anything. I've had dropped valve seats twice, and both times it was evidenced in the compression test (30 psi). If you're going to work on / replace the heads, definitely drop the engine. It's much easier in the long run. The trouble with trying to pull the heads with the engine in is the tin. There are a couple of pieces that you would have to really bend the crap out of to get the heads on and off --- trust me, I've been down that road, and it's not worth it. It may sound like more work to drop the engine, but it isn't. Besides, your sanity has a better chance of surviving in tact. If you're seats are dropped, and you get new/rebuilt heads, there are a few threads with recommendations. I've personally had good dealings with AVP, and I've heard Rimco is top-notch. Both of those companies address the dropped seat problem.
It's a bummer you have to go through a major fix like this, but at the same time it is a great opportunity to take advantage of the fact that your engine is on your garage floor. You can do all the little things you've wanted to for so long... Good luck.
Cheers,
Richard |
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NeverHadaBeetle
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Joined: October 08, 2002
Posts: 442
Location: Missouri
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| Posted: Tue Sep 30, 2003 5:38 pm Post subject: |
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I have removed and replaced the driver's side head with the engine in place. Never again. It was a serious pain in the a$$ and took as much time as removing and replacing the entire engine.
_________________
"Well, we shot the line and we went for broke
With a thousand screamin' trucks
An' eleven long-haired friends a' Jesus
In a chartreuse micra-bus." |
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Boogar69
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Joined: January 30, 2003
Posts: 17
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| Posted: Tue Sep 30, 2003 7:02 pm Post subject: more questions |
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| When I bought this bus, back in early July, it had the heads reworked and a top-end rebuild accomplished. That is one reason I thought about just accomplishing the one side of the engine. I will be pulling the engine. The more I look at it, the more it seems to be a pain with the cooling tins. What causes a dropped valve? Can the head be repaired and what kind of price am I looking at? What do new/rebuilt heads run from Rimco or AVP run? What about the FI part? Is it a pain to pull and re-install? What should I be looking for? I think the FI is the part that worries me the most... |
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ratwell
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Joined: April 26, 2003
Posts: 8717
Location: Victoria, BC
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| Posted: Tue Sep 30, 2003 8:00 pm Post subject: Re: more questions |
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| Boogar69 wrote: |
| When I bought this bus, back in early July, it had the heads reworked and a top-end rebuild accomplished. That is one reason I thought about just accomplishing the one side of the engine. I will be pulling the engine. The more I look at it, the more it seems to be a pain with the cooling tins. |
The first time I did it it took 2 hours to remove and less to put it back. You should have a friend for help. See some of the general steps.
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| What causes a dropped valve? |
Heat. The head is aluminum but the seat and valve and guide are not and it get pounded into the head.
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| Can the head be repaired and what kind of price am I looking at? What do new/rebuilt heads run from Rimco or AVP run? |
Most certainly, a common repair. $190 for a head from AVP and you'll get one that came from another bus. Better call Rimco to find out what they'll charge to machine your german heads.
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| What about the FI part? Is it a pain to pull and re-install? What should I be looking for? I think the FI is the part that worries me the most... |
Most of it stays attached to the engine, you just disconnect the plugs from the firewall, remove the flying saucer (decel valve), take off the air cleaner, AFM and boot, then unhook from the computer and that's it. The brake booster tube has to come out also but you'll figure that out when you remove the decel valve.
The rest of the wires are common to every other baywindow (starter, iginition) and you'll need to disconnect the two fuel lines. Like everything else, it's easy when you know how and you'll master it the first time. The only difficulty you may have is forgetting to connect a wire and you'll have a starting problem which may panic you.
My advice is to use ziplock bags to label the bolts you remove, tape and label the wires you undo and simply go in reverse on installation. Pictures help a ton.
_________________
'78 Westfalia CDN
'76 Doublecab
Read the Baywindow FAQ
Last edited by ratwell on Thu Oct 02, 2003 5:52 pm; edited 1 time in total |
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saltfactor
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Joined: January 25, 2003
Posts: 507
Location: Wilmington, NC
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| Posted: Thu Oct 02, 2003 4:55 pm Post subject: |
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Last edited by saltfactor on Sat Oct 04, 2003 4:21 pm; edited 1 time in total |
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Boogar69
Samba Member
Joined: January 30, 2003
Posts: 17
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| Posted: Sat Oct 04, 2003 7:56 am Post subject: Wow, Ratwell |
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Ratwell-
It seems like you have done this a time or two.
I'm still not sure about why I have to do both of them. If I replace it with a stock head, shouldn't it be the same as what I took off? I'm not trying to half-ass this job, but I just don't see the need to replace both heads.
Mike B |
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keifernet
Samba Search & Rescue
Joined: May 11, 2002
Posts: 19395
Location: Samba Center for Behavioral Science
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| Posted: Sat Oct 04, 2003 9:08 am Post subject: |
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Not trying to jump in on Ratwell next post, I'm sure he will be along with his reply,
but there are things to consider in relation to the heads.
First do you see any rebuilders stampings on them inside the valve cover/ rocker area ....like GEX, SIR, AVP whatever?
if so then they were of course rebuilt once ( or more already) and if one of them dropped a seat, are you going to want to trust the other?
and if you leave the one on and get another, new or rebuilt, you may not get one with the same combustion chamber size ( and even valve size ) unless you pull the other head and compare it to the replacement
Plus depending on the milage ,the rebuilder, the installer, you may find some pretty wierd shit.... I have seen some scary combinations/ things done by "alleged" VW shops/mechanics... and parts that were "rebuilt" were not or were done shoddly and fail in short milage/time
this is (IMO) you best oppourtunity to sort it out.
Others may be able to add some more reasoning to this scenario, good luck! |
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keifernet
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Location: Samba Center for Behavioral Science
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