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Discussion Starter · #1 ·
Ever since ive owned my 1997 f350 with a 7.3L its had a knock in the engine. Ive been trying to figure out what it was, theres no real loss of power but i get terrible fuel economy. Im pritty sure its a injector now from the reasearch ive done. but im not sure which injector it is or how to change it out. how do i figure out which injector it is and can i change just the one or do i have to change out all of them. id like to go the cheapest way about this. thanks a lot.
 

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You should be able to tell which side its on. If you can't, you can always try disconnecting each valvecover connector when running (one at a time) and see which disconnection makes no difference. Maybe remove the valvecover and observe the oil flow out the injector discharge spouts for uniformity between them (the one not spitting much oil would be bad). If you need to change one, there are plenty of posts to read before you go there. Cheers!
 

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Discussion Starter · #3 ·
thanks a lot for the advice, im also worryed about the engine hydro locking after i put the new injector in. i understand that there cant be any oil or fuel in the injector sleve but how many times should i turn the engine over to get out all the oil and fuel from the heads so i dont destrou my engine?
 

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hydrolock

I had to change all 8 injectors in my 1994 f250 and it did hydroloc i read somewhere if you turn the engine over with the glow plugs out it would blow the oil out bad idea. I would suggest using a wrench on the crank and turn it by hand. The oil that came out of my engine cut through the matting on the underside of hood. And i had the shop vac there when i pulled each injector and sucked up as much oil as i could. Good luck
 

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You need to have the injectors installed AND the glowplugs out when turning the engine over (by hand or with the starter). Otherwise the fluids will be pumped right back down the injector holes from the fuel and oil rails. I use a MightyVac to get most of it out, then turn it over by hand with the plugs out, then with the valve covers stuck in place use the starter. Cheers!
 
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