<![CDATA[M42 plastic coolant pipe DIYs]]>1991 318is, unknown mileage (approx 250-300k), infamous black plastic coolant pipe on the block went from slight occasional weep to a constant small leak yesterday with coolant pooling on the block near the oil filter housing. Figured best to address this before the pipe goes and engine gets fried.  Any good DIYs out there and/or has anyone has the pleasure of doing this?  Looks like you need to remove the upper and maybe lower intake manifolds to get to it, and the common advice is replace with the BMW part.

]]>https://wibimmers.com/topic/5473/m42-plastic-coolant-pipe-diysRSS for NodeWed, 16 Sep 2026 04:05:04 GMTThu, 15 Nov 2018 15:19:29 GMT60<![CDATA[Reply to M42 plastic coolant pipe DIYs on Fri, 16 Nov 2018 19:53:08 GMT]]>Hah, replaced the OFH gasket and oring a few years ago but could be going again and weeping a bit towards the front. These engines leak/seep like crazy. Keeps things from rusting but still. I've got a skid plate so oil will pool over time and then drip off the edge of the plate.  The pooling on the ground though was still more than I've ever seen.

Cleaned it up and drove it for a while and so far found only small things: loose bolt in the timing case cover leading to oil weep down the passenger side, two rear valve cover bolts are loose and need to be helicoiled and oil is leaking enough that it pooled down on the control arm near the CAB. Oil pan bolts are tight and upper and lower didn't seem to be leaking. I'll let it sit for bit and see what other surprises there are.

]]>https://wibimmers.com/post/95970https://wibimmers.com/post/95970Fri, 16 Nov 2018 19:53:08 GMT<![CDATA[Reply to M42 plastic coolant pipe DIYs on Fri, 16 Nov 2018 16:13:49 GMT]]>Could also be the oil filter housing o-ring. These damn things love to leak haha

]]>https://wibimmers.com/post/95953https://wibimmers.com/post/95953Fri, 16 Nov 2018 16:13:49 GMT<![CDATA[Reply to M42 plastic coolant pipe DIYs on Fri, 16 Nov 2018 15:55:36 GMT]]>

Boris3 said:

Thanks guys. Yes the grand logic of BMW design. Sure let's put a plastic pipe there and surround it with a rat's nest of hoses.

Not sure yet how bad things actually are aside from the pipe (what hoses #4, 18, 26 attach to, for folks unfamiliar). I parked the car Wednesday night and yesterday morning also noticed very large puddle of oil underneath the front of the engine. Didn't overheat on Wednesday but could be ugly.  I'll take a closer look today.

image.png

Fingers crossed its something minor! A common oil leak at the front is the profile gasket, but that shouldn't leak that much while the engine isn't running. Maybe lower oil pan gasket? I believe it is below the level of the oil.

]]>https://wibimmers.com/post/95950https://wibimmers.com/post/95950Fri, 16 Nov 2018 15:55:36 GMT<![CDATA[Reply to M42 plastic coolant pipe DIYs on Fri, 16 Nov 2018 14:18:22 GMT]]>Thanks guys. Yes the grand logic of BMW design. Sure let's put a plastic pipe there and surround it with a rat's nest of hoses.

Not sure yet how bad things actually are aside from the pipe (what hoses #4, 18, 26 attach to, for folks unfamiliar). I parked the car Wednesday night and yesterday morning also noticed very large puddle of oil underneath the front of the engine. Didn't overheat on Wednesday but could be ugly.  I'll take a closer look today.

image.png

]]>https://wibimmers.com/post/95941https://wibimmers.com/post/95941Fri, 16 Nov 2018 14:18:22 GMT<![CDATA[Reply to M42 plastic coolant pipe DIYs on Fri, 16 Nov 2018 04:43:42 GMT]]>i was thinking that the m50/s50 spider hose was obnoxious until i looked up this pipe you speak of. i can only imagine the bit that goes into the block with an o-ring is as bad as other bmw plastic pipes with crumbling and fusing to the block surface. blah!

]]>https://wibimmers.com/post/95939https://wibimmers.com/post/95939Fri, 16 Nov 2018 04:43:42 GMT<![CDATA[Reply to M42 plastic coolant pipe DIYs on Fri, 16 Nov 2018 02:51:03 GMT]]>Definitely get the OEM part. I've tried aftermarket ones and they fit terribly. Removing the entire manifold makes it a quick job

]]>https://wibimmers.com/post/95934https://wibimmers.com/post/95934Fri, 16 Nov 2018 02:51:03 GMT