1990 F150 5.0 intake manifold gasket

[Corollaman]

Just had this replaced, was leaking coolant outside the block. Can a bad intake manifold gasket cause performance issues? This truck is 27 years old original engine never been opened until this repair. 116,000 miles. I've noticed some "rattle" under acceleration that I had not noticed prior to the repair. I was thinking of using a higher viscosity oil than the 5w30.

 

[OVERKILL]

If it is rattling, double-check your base-timing. They probably removed the distributor when they did the intake and the base timing might be off. Should be 10BTDC with the SPOUT connector out.

 

[9050lx]

Good advice.Double throttle body intake? Are the heads E7TE heads?AOD transmission? Pretty reliable setup.I would put new plugs in and pick up another (used OK) MAP sensor to see if it makes a difference.Might want to check harmonic balancer rubber for intactness, sometimes they can slip.May want to find #1 TDC and check timing marks.could also swap out the TFI module, get a motorcraft branded one.I always have spare sensors around to diagnose problems, as to me it is faster to swap them and test drive.The ECU will probably eventually malfunction, are cheap to pick up used.You could convert it to mass air setup pretty cheap.Might bump gas mileage by 1or2 mpg. I like 5w30 for the original 5.0.