4.8is coolant leak take 2

[FourPointEight-is]

I’m pretty sure it’s an impending sign of gasket failure.

The gasket breaks down and lets some coolant or oil out then after a few heat/cool cycles it reforms or moves slightly so that it seals properly again. Only a matter of time til it lets go permanently, probably when you’re halfway through a road trip in the middle of nowhere.

Fuck I wish they didn’t use these cheap shit-based gaskets all over the engine in their flagship SUV.

[DanielQR79]

Originally Posted by FourPointEight-is

I’m pretty sure it’s an impending sign of gasket failure.

Headgasket?

[FourPointEight-is]

No, rubber gasket. This engine (and every other engine ever made) has a lot of rubber gaskets. There are gaskets in the cooling system, gaskets where oil pipes connect to heat exchangers/block, gaskets where the valley pan bolts onto the engine. And they’re ALL ticking time bombs.

The problem is that after about 10-15 years they all seem to let go catastrophically. This is why the alternator bracket leak (the leak of the rubber gasket between the engine block and the pipes for the heat exchanger that carry oil to the front of the car for cooling) is a common issue on these cars. The leak takes 5+ hours of labour to fix, all for a $5 gasket.

Just a few months ago my radiator blew so I replaced it. Immediately after some rubber o-ring also went, disabling the car. When I took out the failed o-ring it disintegrated in my hands and it was brittle as shit.

I’ve owned many old shitty badly maintained 15-20 year old cars back in the day and I don’t recall having such issues on any of them.

Car is clearly not built to last. I mean I love bmws but I’m having a very hard time reconciling the fact that the cars are essentially disposable, built with a service life of 5-7 years at most versus the fact that they’re so much fun to drive.

[DanielQR79]

It happened again, after having the car sit for a few days, I found all the coolant on my driveway, the leak comes from the back of the engine, any ideas what it could be?

Thanks.

[FourPointEight-is]

If it is a 4.8is, it could be this: https://www.youtube.com/watch?v=F_gjFZJbAoE or your valley pan gasket.

Both are extremely labour intensive to fix.

This engine is full of shitty rubber gaskets that are ticking time bombs

[DanielQR79]

Originally Posted by FourPointEight-is

If it is a 4.8is, it could be this: https://www.youtube.com/watch?v=F_gjFZJbAoE or your valley pan gasket.

Both are extremely labour intensive to fix.

This engine is full of shitty rubber gaskets that are ticking time bombs

I'm leaning towards the valley pan gasket (some wishful thinking), I have to do the stem valve seals on both my cars anyways I will be getting into it in the next couple of weeks.

[DanielQR79]

Originally Posted by FourPointEight-is

If it is a 4.8is, it could be this: https://www.youtube.com/watch?v=F_gjFZJbAoE or your valley pan gasket.

Both are extremely labour intensive to fix.

This engine is full of shitty rubber gaskets that are ticking time bombs

Looks like it's the valley pan gasket, it's leaking coolant from the top of the engine in both sides not from the transmission.

I just used Bimmerfix a few weeks ago, if I do the valley pan gasket should I do the cooling pipe also or would the bimmerfix stent would be fine?

[FourPointEight-is]

Do the pipe. It’s a ton of work to get to the gasket so you may as well do the pipe.

Especially if you’re keeping it long term.

[Geneticfreak]

The Bimmerfix is a permanent solution. Unless they pipe itself is damaged in some way, there is no need to replace it. The Bimmerfix stent eliminates the need for the gasket that failed. Replacing the pipe puts the failure prone gasket back in play and you could be in the same situation when, not if, it fails again.


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[DanielQR79]

I took everything apart today, overall pretty easy took me about 2 hours to take the manifold off, it was the valley pan gasket.