tailwind22

I'm currently doing headers and exhaust on my 89 C4. As I dug deeper I'm fixing leaks at the thermostat housing and noticed this line from the thermostat housing to the oil filter console. It obviously has leaked although the residue doesn't appear fresh. Also note the oil stain stops at approximately one third halfway up the hose. Is this the typical leaking hose that needs to be repaired or replaced or is something going on with it? Thanks for input.

tailwind22

Is it a fair assumption that it is leaking slowly at the crimped joint and slowly soaking and moving the oil line up the hose? I just thought the very sharp and defined oil line on the hose was odd.

Tomfun

That line looks pretty good to me, no action required. A little weeping is common, mine looks substantially wetter than yours.

Tom

wallra

my hose looked like that then I said 30 years old when I touch it it broke apart all rotted.

wallra

I did all the hose's when I did the job. think If the line blow's how fast the oil will come out. 3/4" in side

Goughary

There won't be anything wrong with that hose until you do anything that disturbs it. If you move it, it'll crack. They get super hard and brittle per the photo above. Virtually all of them that haven't been replaced are like this.

For now- wait until you have nothing else to do and then if you really want to...have at it. But unless oil is pouring out...leave it alone.

tailwind22

Thanks for the good input. Probably will replace since I'm addressing others.

koenig_roland

it you are intending, holding the car some years longer, i would in a "while you are in there" approach replace those lines... in my two 964s, i have in the end replaced every line that transfers oil and fuel and nearly every line was not ok anymore when inspecting them afterwards when it was removed from the car...
If a line shows this signs of shrinking and therefore reduced pressure from the clamp to secure the the hose to the fitting, i would replace it.... if you have time, go to a hose-builder an get them done.. That is, what i regularly do... but i am in the good situation having a dedicated hose-shop (which does everything you could imagine in context of hose for all applications) 2km away...

tailwind22

Thanks...

jibmaster1

Tailwind22,
I replaced this and all the other "while you are in there" hoses last Fall on my 90'. I bought the Cohline hose which ended up being slightly pinched as it travels down along the back side of the oil tank to the thermostat housing. I didn't want any oil flow starvation issues so I didn't install it. Instead I took my original hose and the Cohline fittings to a hose shop and used the more durable Parker "transportation hose". I made two of these lines with the two sets of fittings I had from other bad hoses. I had a hydraulic shop crimp one side, then ran home and installed the hose clocking the other end so it fit correctly. Like a glove. WAY better fitment and durability doing it this way. Look at Rob Goughary's "Oil Madness thread". Good info. He's a wealth of knowledge. I do have this line still hanging in my garage if you don't want to fight the battle of finding the hose, shop, etc. I had posted it in the used parts forum over on Pelican and had it sold, but the guy flaked on me. Msg me if you are interested and we can work a deal out. It is brand new and more durable than the original.
​​​​​​https://forums.pelicanparts.com/pors...ine-200-a.html
Replace them and have the peace of mind. I also discovered my oil cooler that sits in the front right fender was leaking a bit too. The bill added up fast! How many 964 owners can say they own a leak free car though?! I can!

tailwind22

PM sent, interested.