Coolant drain plug

[RebelGT]

Just making sure, the coolant drain plug in the block next to the oil filter becomes the coolant feed correct?

 

And does anyknow know what size fitting that is, and what size fitting the oil is as well would be handy.

[brian89gp]

Well, on my 3.4 DOHC the coolat tap and the oil pressure sender are both 1/4 NPT, I'm assuming the TGP is the same.

[RebelGT]

i think the oil is 1/4 inch, the coolant plug looked bigger though.

[brian89gp]

On mine they were both the same. Something I found interesting though, a 1/4 NPT fitting is the same ID as a 1/2" hose. I would think that a 1/4 would be a 1/4.

[RebelGT]

so can anyone tell me if its true that the coolant drain becomes the coolant feed?

[Chris A]

Well, i'm not sure I can answer that as I don't have a coolant drain!

 

But if you are talking about the coolant port about midway on the side of the block then yes it is the coolant feed for the oil cooler, and turbo. I posted a pretty lengthy description of the coolant system elsewhere so you may wish to do a search for it.

 

Chris

[RebelGT]

yeah, thats what i'm talking about, its the coolant drain plug for the block, next to the one for the oill

[RebelGT]

i found your old post, good info, do you know what size fittings those are?

[brian89gp]

1/4NPT x 1/2"hose

 

Unless GM changed the block casting for the 3.4, which is doubtfull.

[RebelGT]

i reached my hand down there and the plug felt bigger than 1/4 inch, heres a pic i got from someone on gmforums.