Hey everyone my truck is a 2wd 1991 4.9L 300 l6. I was changing my plugs and wires and I barely hit this little line thingy, and broke it. I think it's got something to do with the oil sending unit because my oil gauge isn't working now, but it's not hooked directly to the oil unit, it just loops around and is maybe 4 inches long. The truck still runs normal. I have no idea what it is, or what it's called or what it's for. It's on the back of the engine block. Please help. I circled it, you can see where it broke, it isn't wire because it's a hollow tube, but it's tiny. HALP MEH! Thanks everyone!

 

It looks like a vacume tube they get hard and break easy. I cant see from the picture where it goes but I would think the HVAC system check your heater defrost controles see if they work. either way just replace it with a piece of vacume hose.

 

Thats the green vacuum line for the EGR, You can repair that with a larger diameter tube (windshield wiper hose) and slide it over the broken end and put the other end on the EGR.

And you're oil sending unit wires probably got knocked when you changed plugs. The sending unit is on the drivers side of the engine block next to the bottom side of the distributor.

 

But it still runs fine, and what exactly is the EGR? I'm kinda new to this haha. We didn't hit the wires to the sending unit as far as I know, my dad helped me change them it was my frist time. Can you buy this hose? It's really tiny, not even 1/4th of an inch in diameter it seems to be.

 

EGR=Exhaust Gas Recirc.

emissions related

 

But what exactly does it do? (in laymen terms) and how harmful is it to drive without it?

 

the EGR helps with mpg and the cylinder gas mixture. it puts so much exhaust gases back into the intake to help with MPG. just so you know My egr has not worked for well over 3 years now in my truck Its not really necessary but you should fix it if you got the time. I for some reason just keep putting it off i got the parts and all too haha. my check engine light comes on after a few mins of running due to the egr system. its just the one code always the same no matter what for 3 years now.

 

im not exactly sure how it works

 

ok well can you buy the hose? because it looks pretty simple to replace. and what exactly would it be called? i cant find it online..

 

as another post mentioned you get a piece on 1/8in rubber hose (auto parts store) and cut a small length and slide it over each end as to splice it back together.... its brittle it breaks.

they are replaceable....not available