When I went to adjust the valves for the first time, the #1 intake was tight; I set at at .018, then about a thousand miles later, it was at .016 (all the other valves were .018) so I reset it to .018. #1 cylinder is practically dead at idle, but seems to be running at highway speeds. Anyone else have this problem, and is there hope that the valve will eventually seat? Thanks.
ISUZU NPR 1990 DIESEL #1 CYLINDER INTAKE VALVE LEAKING
Jun 13, 2006
3 Replies
How tight was it before you set it the first time? You may be loosing the valve. Better get a compression check and fix whatever is wrong. If you drop a valve in that engine it's going to hurt your wallet bad.
Al
The valve stem stretches where it's attached to the valve head. Then the head breaks off and kills the engine. Sometimes the valve head sinks into the seat, or the head of the valve "bells." Either way you better get after it before it's too late.
To answer your question, no I am not familiar with this engine. Removed a head and had a valve job done and replaced the head, but that's it. However, what you're describing, the valve clearance closing, I have seen on many other engines. It has to be the valve or seat. Wear in the rocker arm, cam follower (lifter) or push rod will only make the clearance larger.
Al
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