Thinking about saving a C4
Although I understand the working principle (air pressure holds valve against seat), I was surprised to hear air escaping at a slow but very steady rate when the tool was inserted and connected to the compressed air system ... I was guessing it had to be escaping past the piston rings at the time (no obvious sound from the intake or the mufflers).
We took a very looooooong time to check everything before attempting to compress the valve spring, and took our time afterwards to check everything, so the compressed air had to be flowing for about 15-20 minutes.
And since compressed air obeys the gas laws (the physics kind, not the polite company kind), as a compressed gas expands it will cool and release any vapor captured when compressed, and SoCa does have humidity, in spite of what the Californians will tell you, it deposited the water vapor into the cylinder, and the air pressure was sufficient that it was driven into the sump. Weird as hell .... I have searched on air hold tool usage and no one has mentioned this phenomenon.
Either way, the water in the oil had to come from somewhere, and my money was on the compressed air.
Since that time, Tim has about two hours and 75 miles on an engine running on all 8 cylinders, and still no sign of any water in the oil.
The clutch, however, is toast! Slips easily at 2000 rpm in second. I've searched the C4 tech section for a good article on a clutch replacement but have not found anything that mentioned how to do determine how to test the dual mass flywheel for reuse ... which would work for us since the previous owner had left a complete clutch kit in the car!
Tony
Last edited by atgordon; Nov 10, 2011 at 12:41 AM.
I drove her from Oceanside to Encinitas on Coast Highway, great drive 50mph to help smooth out the square tires. She ran beautifully the whole way. I was very soft on her the whole drive, and might have gotten a little overzealous...
I decided to try the freeway, and then I decided that I really liked how going from 6th to 3rd gear felt so I did that a few times. Now the clutch is really toast. It makes a nice "I'm dying" noise when you engage it. I've also managed to get the car misfiring again and not sounding too happy. I kinda feel bad, but then again you sorta have to slowly increase how rough you are on the car to see what gives. So, hoping for a bad plug wire, they look shot... gonna check the plugs see how they look etc... She isn't a happy motor again but I think a lot has to do with the clutch. Although usually once a clutch is done it doesn't really interfere with the motor. So I'm missing something. There is still enough bite to drive so its time to explore into this.
Drive, Break, Fix... thats how its done around here
Last edited by TGTINT; Sep 29, 2010 at 01:12 AM.







Last edited by onedef92; Sep 29, 2010 at 02:56 PM.
The Best of Corvette for Corvette Enthusiasts
I'm not doing another thing to this car until I have adjusted and checked the torque on the valve train. This car sure is testing us! Passenger side this time. The keeper did not come out thankfully this time.
Rant* I had to yank the belt & alt to pull this valve cover and that damn coolant temp sensor makes pulling the belt such a pain in the ***. I could care less about adjusting the rockers, such a pain in the *** to pull a belt... SMH
The problem with the upper end of this motor may be telling you something. While you have the cover off, you may want to be checking everything up there. I would, at least, be changing out all the pushrods to better ones. You may also want to check for cam lobe ware, while you're there. This can cause problems like these.
It really sounds like your patience are being tested.
Hang in there. Back off of it, for awhile, if you have to. Try to keep smiling and remember that all of us are pulling for you and this Vette. It will come out great.
I worked on adjusting the valve train last night and will finish it today. I'll be checking every single pushrod. Anyone got a good thread on adjusting the rockers? I searched but opinions seem to vary a great deal on this process. My mustang is torque then a half turn this seems to be slightly different.
Rant* I had to yank the belt & alt to pull this valve cover and that damn coolant temp sensor makes pulling the belt such a pain in the ***. I could care less about adjusting the rockers, such a pain in the *** to pull a belt... SMH[/QUOTE]
Just in case you have to pull the belt again.
Thinking I'm gonna park her for a few days, I had her in my garage all day and we had rain in Socal all day on my poor Mustang. I'm running out of steam and looking at the filthy engine just makes me want to pull it and clean everything up.
Adjusted the rockers properly this time. Wow sure would be nice if GM thought to put timing marks on this motor
Anyhow she runs smooth, we will see if this happens again. Now we are positive we have properly adjusted rockers we can tell if this is something else causing this.
Also cleaned out the coolant overflow since it looked horrible. Washed her up, she looks clean but the picture is deceiving.
Needs to be wheeled out badly, carpets need steam cleaning, engine bay is just plain horrible but she looks a million times better than when we first found her in the field.
Dad is back here late October to help wrench and golf a little. We are both thinking hard about pulling the motor. We have an oil leak around the opti spark. So we could pull the motor, do the clutch, clean the block and engine bay properly. Install a new opti and water pump, plug wires and whatever else we decide at that time. I cannot stand this filthy engine bay.
Here she is lookin purty












