[onebluemcm]

Do the lines from the thermostat housing to the cooler frequently fail? I don't recall seeing this as a complaint or problem - like ever - on the forums, but good old Youtube might have one thinking otherwise.

When it comes to things that could leave you stranded on a long trip, hoses and lines carrying vital fluids come to mind. These flippin lines though, holy expensive for OE parts. There are chineses versions evidently, but then I think I'd take my luck with old BMW lines over those.

Curious to hear if I've missed any reports of failures on these.

[lowrydr310]

Yes they fail. Heat cycles and age. But it's not a common failure. Mine showed signs of failure after 170K miles and 17 years.

Up until last year my 335i still had the original radiator and most of the original hoses including upper and lower radiator hoses, and those were fine however one of my oil hoses from the thermostat to the cooler developed a pinhole leak. I tried to fix it by cutting the hose and adding a barbed coupler with hose clamps but the rubber inside the hose was so deteriorated and cracked that it still leaked. $150 later for a genuine BMW hose and all is good.

Now about a year later the oil return hose from the cooler to the thermostat is leaking at the crimp fittings.

In this case Genuine BMW parts should be the only option to consider.

[oVeRdOsE.]

im on forums and groups for a while and I dont see people complaining about this.

gaskets and coolant lines are common failure on those engine, but not the oil lines.

However, I see people having issue with aftermarket kits, expensive or not. Since the an line fitting seal depend greatly on the installer.

[onebluemcm]

Thanks. Yeah now it looks like BMW oil lines are $180 - 200+ a piece, but I agree, not an item to cut corners on.

[autoart]

I had a hose go as well. I cought it early. I was checking something under the hood and noticed some oil on the inside of the hood. I thought about getting a used one, but the used part would be at least 13 years old. I think it was around $130 about 2-3 years ago.

[lowrydr310]

Originally Posted by autoart

I had a hose go as well. I cought it early. I was checking something under the hood and noticed some oil on the inside of the hood. I thought about getting a used one, but the used part would be at least 13 years old. I think it was around $130 about 2-3 years ago.

Geez, I was looking at buying one a few months ago and it was well under $200. Actually after checking my invoice for one of the lines I replaced in December 2023 it was $197 (and that wasn't the cheapest place, it was the one that could get it to me the fastest.)

I went to buy one and it's $220 now, $290 from FCP!!! Madness.

[Gizm0]

Not the hoses themselves but the oring on the end of the hose where it goes into the oil filter housing. These orings are $2 on FCP Euro. Had a small leak there, easy fix

[lowrydr310]

Originally Posted by Gizm0

Not the hoses themselves but the oring on the end of the hose where it goes into the oil filter housing. These orings are $2 on FCP Euro. Had a small leak there, easy fix

I replaced both of them when I replaced my oil filter housing gasket. Fixed that small leak but soon after had one of the hoses leaking, pinhole leak in the rubber. Replaced that and soon after another hose is leaking where the metal line fitting is crimped to the rubber line.

[onebluemcm]

Same, I change all 4 o rings when I did the oil filter housing gasket and the CSF oil cooler. Lines look ok visually, but they probably always do until they are spurting oil.

[autoart]

Of the 2 lines the price is not the same. Mine leaked at the crimp also.