Anyone ever have to replace an engine oil cooler line?

Glava2876 · January 3, 2020

How many miles? Did you check with a dealer - I just had them find that problem on my 2015. I have about 48,000 miles on it and they replaced them under the drivetrain warranty.

voyager1500 · June 26, 2020

Dealer told me that it wasnt under warranty cause its external, not part of drivetrain warranty. I have about 30k on mine. I am going to replace them with AN lines and fittings rather than this problematic setup from GM. Then if it leaks again, I can simply replace the hose without fighting in tight spaces to get to the bypass at the filter. Very poor customer service on both the dealer and factory sides.

Edited June 26, 2020 by voyager1500

voyager1500 · June 26, 2020

Has anyone done the AN line conversion on these trucks yet ? if so , any recomendations on what fittings to use ? Hose lengths ? I found that Derale makes the block adapter that fits the 5.3 in the trucks, it has the in and out ports with 10An fittings, so then 10an hose from there up to the radiator. From what I can see online the fittings in radiator are metric 20mm x 1.5 ? Can anyone confirm this ? Thank you

voyager1500 · July 8, 2020

On 6/26/2020 at 12:03 PM, voyager1500 said:

Has anyone done the AN line conversion on these trucks yet ? if so , any recomendations on what fittings to use ? Hose lengths ? I found that Derale makes the block adapter that fits the 5.3 in the trucks, it has the in and out ports with 10An fittings, so then 10an hose from there up to the radiator. From what I can see online the fittings in radiator are metric 20mm x 1.5 ? Can anyone confirm this ? Thank you

So, I got the 20mm fittings, and they DO NOT fit the 2017 radiator. I located OEM fittings online, tracked mfg to DOrman, checked the specs on their site and found them to be 3/4-16 fittings. Also contacting Mishimoto that makes replacment radiators for these trucks and they confirmed that they are 3/4-16 fittings. So not sure how some people were using the 20mm fittings, but guessing they made a change at some point and the newer ones run the SAE fittings. Anyhow... This weekend I will pull apart again and try to get the AN lines installed to replace the OEM oil cooler lines. If this works out good, I can then add a nice Mishimoto AN type oil cooler externally down the road to aid in cooling during warmer months pulling camper or slow off roading.

voyager1500 · July 13, 2020

On 6/26/2020 at 12:03 PM, voyager1500 said:

Has anyone done the AN line conversion on these trucks yet ? if so , any recomendations on what fittings to use ? Hose lengths ? I found that Derale makes the block adapter that fits the 5.3 in the trucks, it has the in and out ports with 10An fittings, so then 10an hose from there up to the radiator. From what I can see online the fittings in radiator are metric 20mm x 1.5 ? Can anyone confirm this ? Thank you

Try number 2...... The Derale oil cooler adapter does not fit truck blocks. the spacing for the mounting bolts is too narrow. upon more research I found that Earls has an adapter that is specifically for the trucks and corvettes ? it has the correct spacing, but also requires a spacer for the trucks. Gen V LT motors. 1126 and then the spacer is 1127. So I will get those parts and try this again. 3rd times the charm so they say.

Anthony Hooper · August 9, 2020

Yeah...I just did this today (2014 Silverado 1500 5.3L). 100% wouldn't recommend doing it if you don't have to. Glad I read the above post about dropping the front axle a bit to get the oil cooler lines out/in. Also just getting on the bolts to take the cooler in/out was very difficult. I ended up pulling the driver front fender skirt so I could come in from the top side...still needed 18" of socket extensions and a 3/8" u-joint to make it work. Maybe someone with smaller hands could do it more easily; idk. Also in dropping the axle there was a complication because 1 of the 4 bolts was covered up by something...not even sure what it is. Had to remove 3 electrical plugs (which also was not easy...broke the securing clip on one of them) just to get enough space to put a wrench on it. Fortunately they weren't torqued too tight, because the wrench had to go on very slanted. Suffice to say, it's not an easy job. If I had the $600 in labor to pay the dealership, I'd have let them do it.

14LTZ-1LZ · August 9, 2020

On 2/10/2018 at 10:39 AM, Eddie 70 said:

Just found this thread and I just found the hose leaking on my 2014. I am at 97k miles. For those that have replaced the line, I can see the block just above the oil filter, where is the cooler end located? I believe mine is also leaking at that end because there is oil at the radiator/condenser support also on mine.

You should still be under the 6 yr/100000 miles power train warranty. Check with your dealer. I also saw this leak when I was changing oil, dealer said it was covered they also found that the seal around the oil pan was leaking took care of both problem under warranty.

Edited August 9, 2020 by 14LTZ-1LZ

Carlos Insaurralde · February 1, 2021

hello, is there any decent aftermarket trans/oil cooler lines out there?, i have to do both the trans and oil cooler lines, this is the second time that i have to replace this lines on my 2014 Sierra 5.3 and i am not planning on putting the same shitty factory lines back on it, any help would be much appreciated.

davester · February 4, 2021

People have taken the old lines, cut off the rubber sections (while noting the relative orientation of the ends and the length of the rubber section), and had a hydraulic shop crimp on hydraulic hose to the existing metal lines, then install those. The hydraulic crimps work much better at not leaking..

Bryan Suess · March 21, 2022

So I have a 2016 Chevy Silverado 5.3 four wheel drive and replaced my transmission and engine cooling lines. The transmission lines would be better with two people to help guide in the new ones. Also make sure you get ones marked 70C. The engine cooling lines, remove the plastic sheild and lower the front differential down on the driver's side. Not all of the way out but close then pull the block towards the front.