Coolant pipe O-ring size and part number.

[Mike1955]

2015 hatch LT "H" Flex 1.8 engine. Problems with old leaking o rings around the thermostat housing - that little pipe under the thermostat that has 2 bolts and the other end just press fits into the oil cooler with a simple o ring holding back the hot coolant under pressure. (really idiot design). I fixed the o ring under the thermostat with the bolt end - rubber completely crushed flat, and was dripping. new o ring with some gasket sealer solved that.

BUT - that round pipe rotates. i found that odd. After reading online i found out that the other end does not have a bolted side or clamps of any kind. It just pushed into the oil cooler housing with an o ring seal. That is where my new leak is. Behind a mountain of exhaust manifold, heat shielding, O2 sensors, and dipsticks. 1 simple little o ring causing me grief and has the potential of burning up the engine if the coolant get low. So - its parked for now.

Here is the good part. Went to a local parts store. there was an o ring noted that 'fits my car' for 7 bucks. (i know). took it back home, pulled out the pipe from behind the mountain of metal hiding the oil cooler, saw the gasket was compressed and replaced it with the new one. the new one was too big. Tried to force it blindly into the open oil cooler opening and wound up with a split o ring and a lot of leaking water.

I need a source that directs me to the correct part number and o ring size that presses into the oil cooler from the thermostat housing side.

A GM parts site is giving me about 4 different part numbers to pick from, i do believe I have that HENGST oil filter cap for what its worth. i would like to find out who engineered this retarded design of press fit o-ring seal for high pressure hot coolant when just about everything else in the system has a clamp holding the hoses in place. Designed to fail: there is a name for it-called 'planned obsolescence'. Designed to fail so you have to buy a new product from them after a period of time.

Part # / Description

Price





Thermal Bypass Pipe Seal (O-Ring)
24445723

GM

Engine Coolant Pipe O-Ring

All Required. Oil Cooler Outlet Pipe. Filter Cap Marked HENGST. #1. #2. This GM Genuine Part is designed, engineered, and tested to rigorous standards and is backed by General Motors Original equipment parts are designed to work with your GM vehicle safety systems -- aftermarket replacement parts may not meet the same OE safety regulations, depending on the part type

MSRP $22.94

$14.45








Engine Coolant Pipe O-Ring
55354068

GM

These are Sold Individually. All Required. Oil Cooler Inlet Pipe. #1. #2.

MSRP $1.90

$1.37








Engine Oil Cooler Outlet Pipe Seal
25194222

GM

Engine Coolant Pipe O-Ring

All Required. Oil Cooler Inlet Pipe. #2. #1. This GM Genuine Part is designed, engineered, and tested to rigorous standards and is backed by General Motors

MSRP $5.51

$3.52








Engine Coolant Pipe O-Ring
55353331

GM

All Required. Oil Cooler Outlet Pipe. Filter Cap Marked HENGST. #2. #1.

MSRP $7.20

$5.25

 

[Mike1955]

if it helps - the old flattened o ring that is on the oil cooler side does is a smooth round donut. doesn;t have any little spikes on the inside. just don't want to go through a half dozen o rings to find the correct size - especially since it is the ONLY thing holding that hot coolant in place. (idiot design)

 

[Kgfreeze]

I believe 25194222 is what you are looking for.
They discuss it in this video