I got climbing around under my blazer yesterday and took the cover off by the oil filter just to look around and I noticed something that is on the passenger side of the oil filter that has two hoses that come down from the engine block and combine into one hose before going into this thing. The output hose goes a quarter of the way up the radiator then doubles backs and just ends with no cap or anything on it.

Also on the driver side behind the grill but in front of the AC condensor there is a metal tube that snakes back and forth and then disappears into the engine compartment (I lose sight of behind the driver side turn lamp).

I'm just curious as to what these are since I could not find them in my chiltons book. Thanks.

 

The metal tube in front of the AC condensor is the power steering fluid cooler

The other hose you're talking about sounds like the vent tube for the front diff...

 

The hoses on the remote oil filter housing do not combine, they are just attached via 1 bolt. You have lines (feed & return) from the engine block to the remote housing as well as lines (feed & return) from the remote housing to the oil cooler in the driver's side radiator tank. The filter is on one side of this loop.

Be something like this, but I am unsure of the exact location of all of these components in the loop.

One line from the engine feeds to the oil filter through the remote oil filter housing. Oil then feeds to the oil cooler in the radiator. It then returns to the remote oil filter housing where it is directed to the return line back to the engine block.

So you have a total of 4 lines, 2 feeds and 2 returns. It could have been simplified slightly by having the line from the oil cooler go directly back to the engine, but that would have been a bit more complicated of an assembly for the attachment method chosen and the tight confines it would have been required to fit in.

 

I know which ones are the oil lines by doing my own oil changes and thatI've also had to have two of them replaced due to leaks. What I was wondering about is what is (looking at the front of the truck) to the left of the oil filter and the lines for it. From what I could tell there are two metal lines that run (one from each side of the engine block) roughly about the level of the exhaust manifolds that combine into one hose at a T junction and then go into this thing. There are, I think, two electrical connections coming off of it and also the hose that goes a quarter of the way up the radiator before it doubles back over and ends about 5 inches later.

 

It might be the air injection that was an option on some models of the engine, I don't know what it does but it makes it harder to get headers and to change the spark plugs IIRC. I am sure swartlkk will answer soon.

 

Yup, those are the AIR (air injection reaction) supply lines that run to the exhaust manifolds.

 

Thanks now I know what they are but hopefully I'll never have to mess with them.