Expert: Brad Sears - 2/11/2010

Question
QUESTION: Hi Brad,
I recently removed the head on the passenger side of my 1972 Eldorado 8.2L in order to change valves seals. I marked everything before removal (wires, firing order, rocker train assembly) and replaced it all in proper order with new head and exaust gasket. When I started it up it ran very rough and wouldn't idle I had to keep my foot on accelerator to run it. It also sounded very strange like it was running oil dry perhaps. Needles to say I did not run it for long. What's going on here? Any information you can provide is greatly appreciated.

ANSWER: Did you replace the intake manifold gasket? I would start with a good check of all the vacuum lines for leaks. Then I would use carburetor spray cleaner around the intake manifold gasket with the engine e running checking for leaks. The engine speed will change when the carb cleaner hits the leak. Next I would pull the valve cover and watch the rockers and push rods. One of the push rods may not have been seated correctly and bent when you started the engine. I would then take a compression test to make sure that there was not any internal damage. If that all checked out I would start disassembling the engine one part at a time.
Brad

---------- FOLLOW-UP ----------

QUESTION: Bingo! You nailed it. I bent a pushrod. Is there a way to tell if the pushrods are seated properly without taking off the intake manifold and looking.

Answer
Dropping the push rods in is a touchy feely thingy as Sarah Palin says. You can with a little practice feel the push rod drop into the seat in the center of the lifter. My concern now is that the valve on that cylinder is not bent. A compression check is in order.
Brad