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Old 05-25-2011, 10:24 PM
tomscat1 tomscat1 is offline
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Join Date: Feb 2011
Posts: 182
Originally Posted by Biodiesel300TD View Post
If it still runs and isn't running away then it's not too much blowby!
Is the engine cold or running at operating temp? If it's cold then try it again when it's warm. Also how long ago was the valve adjustment? If it was just was the day you took the video, try it again after you run the car for a couple days. The valves may reseat a little and reduce the blow by.
Other than a rebuild, unfortunately not much can be done about blowby. One thing you can try is pouring a little bit of Marvel Mystery Oil or brake fluid into the cylinders and let it sit for a while. This will break any gummed up piston rings. You'll have to remove the injectors to do this. Change the oil post soak, to remove any fluid that drained down.
You can use thicker oil to help reduce the oil loss to blowby, I've also seen people put filters in the bypass hose to filter out the oil so they don't burn it.
That blow-by video was done with the engine cold, about 15 minutes after I adjusted the valves. Don't forget, I was working under considerable pressure that day, what with the end of the world fast approaching, and all that. I wanted to get that video in the can, so to speak, before the Rapture.

Thanks for those suggestions... I plan to do a leak down test shortly, and proceed from there based on what I find. I may take that suggestion about the Marvel Mystery Oil after I do the leak down.... Then do another leak down to see if it made a difference. If the problem seems to be limited to the cylinder head, e.g., valve stem guides and seals, I will probably have the head redone. If there are significant issues in the bottom end also, I may opt to just swap in a good used engine. Assuming that is something that can be found.

Anyway, thanks for your input.
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1975 W115 300D

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