I’m seeking some expert guidance regarding my 1968 4020 diesel tractor. It’s been experiencing excessive slobbering from the exhaust stack and down the engine block. Recently, I replaced both the injection pump and injectors, and I also adjusted the valve tappets. The tractor runs smoothly overall, but I suspect something’s off with the #1 cylinder—it seemed wet when I removed the manifold. Additionally, the temperature gauge takes a while to climb, especially in cold conditions. Any thoughts on what might be causing these issues?
This sounds like a case of wet stacking, which is a common issue with diesel engines that aren’t operated under sufficient load or don’t reach proper operating temperatures. Wet stacking often occurs when the engine runs too cool or is used for light tasks over long periods. Since you’ve already checked the timing and confirmed the cylinders are firing, I’d suggest focusing on the #1 injector. A faulty injector can cause excess fuel to enter the cylinder, resulting in slobbering.
Another factor could be how the tractor is being used. If it’s primarily performing light-duty tasks, it might not be reaching the necessary operating temperatures, which exacerbates the issue. Running the engine under load for a while could help burn off carbon deposits and improve combustion. However, if the problem persists, it might be worth inspecting the valve guides and seals, as they could also contribute to the slobbering.
That explanation makes sense! I’ve been consistently using a diesel fuel additive, but I’m still concerned about potential valve issues. Do you think it’s worth testing the injectors, or could working the tractor harder solve the problem?
Testing the injectors is a smart move, especially since you suspect an issue with #1. Running the tractor under a heavier load is also highly recommended. Operating at higher RPMs while under load will help the engine reach optimal temperatures and clear any residual buildup. If slobbering continues despite these steps, a closer inspection of the valve guides and seals would be the next logical step. Ensuring all components are functioning properly is key to keeping the engine in top shape.
Thank you so much for your advice! I truly appreciate you taking the time to share your expertise. Your input has been incredibly helpful in guiding me through this issue. I’ll start by testing the #1 injector as you suggested and see how it goes. I’m really grateful for your support and feel much more confident about the next steps!
