Engine rumbles at startup

ford
taurus

#1

What causes y ford taurus engine to rumbel when it starts up? I have repolaced wires, sparkplugs and the clock where all the wires come in


#2

How many miles on the car?

Could be momentary low oil pressure or worn rod bearings or both.


#3

The car has about 136000 miles on it and when I check the code for the engine light, it always shows #1 cylinder Misfire. And if I run fuel injector cleaner- the system seems to go away for a few days


#4

Whole new set of symptoms.

Inspect the spark plugs. Swap fuel injectors. Check for vacuum leak. Get a compression test.


#5

What year is it and when was the last tuneup?
How’s the maintenance history been?

Rumbling on startup is generally a symptom of a failure to be able to produce a good strong spark on cold cylinders. While your results with the fuel system cleaner suggest a gummed up injector…perhaps more than one, one sticking and triggering a fault code…a good strong ignition system is also important for a good strong spark when cold.


#6

If a customer told me their car “rumbled upon start-up” I would have to ask a couple of more questions to get on the same page,you seem to be right there,what is “rumble upon start-up”?


#7

I interpreted it to mean that throaty, shaking sound a cold engine makes when it’s struggling to get running smoothly. Sort of like an old cold diesel truck makes on a winter’s day.

But I see your point.

I wonder what the “clock where all the wires come in is”. The distributor perhaps?