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Q: Possible Carb issue or other?

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I recently got my truck back from my mechanic who i trust completely. I noticed that it still has some issues that i cant figure out, its got a sluggish response time when i gas it, it cant stay up to speed without spuddering, ive also noticed that Ive got GAS in the oil. (yes it is gas) Should i rebuild my carb, and get the valves done or should i just by a new carb and get the valves done. Also low compression in cylinders one and four.

My car has 147000 miles.
My car has a manual transmission.

Let me start off by saying that, with the list of symptoms that you are listing, it is possible that there may be more than one issue being exhibited. The gas in the oil grabs my attention first. There could be an issue with the carburetor that is flooding the cylinder and allowing the fuel to drain past the piston rings, and get into the oil. Or, it could be that the rings themselves are stuck, or damaged. I would personally lean more towards a ring problem, as if it were the carburetor, it seems that the middle two cylinders would show the low compression numbers, instead of 1 and 4. But, it’s not impossible. I think I would do a leakdown test, to figure out if it is a valve problem, or a piston ring problem. A proper leakdown test should be able to tell you what the overall state of the components are in, as well as if the source of the compression loss is from the valves, or from the piston rings. When executing a leakdown test, pressurized air is pumped into the cylinders, the amount of air can be metered to see how much air is being lost (as a percentage, to evaluate the overall condition), plus you will be able to track where the air is escaping (intake=intake valve, exhaust=exhaust valve, oil fill cap=rings, etc). I would really like to tell you I know what’s going on, and be able to tell you exactly what it would take to fix, but the truth is, there are several possible causes for the issues you have outlined and it will take some good old fashioned diagnostic work to figure out exactly what is going on. If you feel you need a hand in diagnosing the situation and/or repairing the problem(s), contact a certified mechanic, like those available at YourMechanic.com.

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