The truck ran fine beforehand I mean didnt skip a beat but I took intake and edelbrock carb off to clean and I haven’t messed with anything else (also took valve cover off for new gaskets ) put everything back together and it seemed to struggled to turn over so I pulled 2 plugs and tried to turned over a little faster so I put the plugs back and it still turned over faster ( odd) and crunk up but it’s got a terrible terrible terrible knock and I don’t get what I could have done so wronf if it was fine before I assume the slow turn over was due to engine tryinf to hydro lock but hope im wronf
What makes this problem better or worse?
When turning over
How long has your 1990 Ford F-150 had this problem?
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Hi, this is Bo, an auto expert on RepairPal's Car Genius team!
Sounds like your F-150 went from purring to pounding after the intake and carb cleanup. Since it ran fine before and now has a “terrible terrible terrible” knock, I’d say something went sideways during reassembly.
First thought: if you cleaned the intake and carb, it’s possible some cleaner or debris got into the intake runners, and if any liquid made it into a cylinder, you could’ve had a hydrolock situation—which can bend a connecting rod. That would explain the slow crank and now the knock.
Also, double-check your valve train. If a pushrod got misaligned or a rocker arm isn’t seated right after the valve cover work, it could cause a nasty top-end knock. Pull the valve covers again and take a look while it’s cranking (or running, if you're brave and careful).
If it’s a deep knock that follows engine speed, you might be looking at internal damage. Hopefully not, but it’s worth checking the simple stuff first.
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