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Post by busaddict on Apr 23, 2015 7:22:02 GMT -8
The nuts securing the manifolds to my heads on the Riviera seem to keep coming loose. I'd tighten those up on yours first before taking everything apart. They are just a sled plate removal away and it might be a good way to see if that is indeed your problem. Unless your gaskets are blown out, but I don't know enough about that to know if it actually occurs Don, good suggestion. I did notice the one bolt on the right side of the manifold (where the noise is coming from) I had to use for the Bugpack bracket arm was a bit easy to undo, perhaps there are others. My exhaust had always been a bit loud, I thought it was my old cheapo Empi muffler. It's funny how an exhaust leak can sound like other things. Thanks for the input guys
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Post by busaddict on Apr 25, 2015 16:07:44 GMT -8
Good news, I have tracked the exhaust leak to the right side header-manifold to heater box joint, you know the one with 3 bolts. Definitely fumes blasting out from there. Just purchased some new gaskets and will be looking at it tomorrow. It would be nice if I could just tighten it up as only one side is leaking. Should I use Permatex to seal the new gaskets? The heads themselves seem to be OK.
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Post by busaddict on Apr 26, 2015 19:52:12 GMT -8
So I replaced the passenger side header exhaust to heater box gasket, the old one had vaporized. Put in new bolts and sealed everything up nice and tight. Although that leak is now sealed the exhaust is still pretty loud and I get that "pinking" like sound under load at times. Starts instantly and idles normally. I'm wondering, do I have a damaged valve? Maybe I timed it to #3 accidentally the last time I pulled the distributor out. Could there be too much advance in there? Any theories welcome.
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Post by Volktales on Apr 26, 2015 20:56:15 GMT -8
Pinking like sound under load usually is a result of too much timing, too lean running, crappy low octane fuel, too much compression due to carbon build up. How old is the fuel in your tank? I have worked on some cars that have been sitting awhile with pinging issues under load. Fuel loses its octane with age...
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Post by busaddict on Apr 26, 2015 21:14:52 GMT -8
Pinking like sound under load usually is a result of too much timing, too lean running, crappy low octane fuel, too much compression due to carbon build up. How old is the fuel in your tank? I have worked on some cars that have been sitting awhile with pinging issues under load. Fuel loses its octane with age... Thanks Russ, the pinking or clattering started on a trip through Duncan at the end of last summer, so the fuel would have been new at that time. I've run some 91 octane through it this spring. If one did set it to #3 by accident would it be very noticeable? I will probably try backing the timing off a couple of degrees, and will also check the #1valve position at TDC. Like many situations, there could be a couple of things going on.
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Post by busaddict on Apr 28, 2015 11:40:43 GMT -8
...Checked the distributor position, it's in there correctly. It's difficult to rotate the engine and watch the valves at the same time. I tried a mirror, but it was a bit far to see, so I set up a video camera and talked myself through the engine rotation and voila on playback I could clearly see my valves moving. Most notably the exhaust on number 2 moving when exhaust and intake on number 1 were closed at TDC.
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Post by PICTUP on Apr 28, 2015 15:47:25 GMT -8
Never done that before. Is there no mark on your distributor Tom? Just get to # 1 and follow steps thru to get to the one you are concerned about. I know many true mechanics cringe at John Muir's Compleat Idiot book, but it helped me a lot and still does at times
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Post by busaddict on Apr 28, 2015 16:22:17 GMT -8
Never done that before. Is there no mark on your distributor Tom? Just get to # 1 and follow steps thru to get to the one you are concerned about. I know many true mechanics cringe at John Muir's Compleat Idiot book, but it helped me a lot and still does at times Hey Don, sure I'm familiar with lining up the rotor with #1 etc. I have swapped out a couple of distributors with different #1 positions, so I was just making sure I hadn't done anything strange to complicate matters. The engine starts instantly and runs normally, but I'm still getting what sounds like an exhaust leak and what sounds like pinking (pinging?) when under load. The valves are set as I had done them before. One of the last things for me to look at is the fuel line, there are 3 filters. One off the tank, another in my Mr. Gasket electric fuel pump, and another before the firewall. They've been in there 2 years. The one off the tank looks dark, possibly gummy. The fuel lines themselves look solid, I usually only drive the '74 in summer. I think I'm going to replace the fuel lines to remove possible fuel starvation from the equation.
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Post by Volktales on Apr 28, 2015 17:24:07 GMT -8
If you are going to adjust your valves and are watching for "rocking", you must see the cylinder opposite the one you are adjusting rocking. By this I mean if you want to adjust cylinder number 1, then by moving the crank back and forth with the alternator nut, you should be watching for both rockers on cylinder number 3 moving back and forth. This shows number 1 is on the end of compression stroke (what you want) and number three is on the end of the exhaust stroke (exhaust closing, intake starting to open). This works the same way for cylinder number 2 and 4...
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Post by busaddict on Apr 28, 2015 18:51:52 GMT -8
Russ, OK, what I did do was see the #2 exhaust valve moving while I rocked the flywheel at the lined up TDC #1 mark. And just before that I could see the #1 intake close. I will try your tip next time I look at the valves. Thanks
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Post by busaddict on Apr 29, 2015 18:43:02 GMT -8
Today I replaced all the fuel lines and filters, and put in a new set of spark plugs. The old plugs weren't falling out, but they seemed a bit loose. The bus started up fine and drives about the same. Not giving its all, kinda loud here and there. What's up with my van? The fuel filter at the bottom was just below the tank, and the top one was just before the firewall.
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Post by Volktales on Apr 29, 2015 20:31:27 GMT -8
Cylinder 1 and 3 look a little more richer than 2 and 4. They don't share a carb, so that cannot be blamed. They do share the same cam lobes however. How was your compression? Is the mixture too lean? I have seen once where an engine suffered cam lobe failure causing a lack of power and poor running on two opposing cylinders. This was an aftermarket cam that failed, not an original VW one...
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Post by busaddict on Apr 29, 2015 21:08:43 GMT -8
Russ, I see I was talking about this issue on the old forum last fall when I was just beginning to figure it out. . The engine had a top end rebuild, pistons/cylinders and heads in 2003. Done by a previous owner, I have the receipt here. As I mentioned, it ran well until I noticed engine chatter under load on a trip up island at the end of summer 2014. I'm making a guess that these are the original cams. The van spent a lot of time garaged in winter over the years, so I believe it only has around 150,000 miles on it. If the cams are worn what are my options, engine rebuild, new motor, or? Can this be fixed with the engine in? (wishful thinking) And if it is the cam, is it OK to drive? I need to buy a compression gauge. Thanks for your advice
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Post by busaddict on Apr 30, 2015 11:38:38 GMT -8
Also, is it possible my cylinder heads need to be re-torqued?
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Post by busaddict on Apr 30, 2015 15:58:13 GMT -8
An improvement, today I re-timed the distributor. I think I was a couple of degrees too low, runs better, much more power like its old self. However, there is still the exhaust leak sound and occasional chatter under load. I also added some Seafoam, a third of a can to the crankcase, an ounce or so to each carb, and the rest to the tank with some fresh Chevron 94 octane fuel. I'm hoping I can fix this. Hey Russ, if you happen to be driving your new fastback to Victoria this weekend give me a shout, maybe you can have a look.
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