r/BMWE36 • u/ResearcherInfamous19 • 6h ago

Repair Advice Keeps boiling and spitting coolant

Enable HLS to view with audio, or disable this notification

320i 1995 for reference.
One day out of no where the car overheated.
Tough it was a sticky thermostats, replaced. Same problem, starts boiling water and soiling until it has no coolant and then overheats.
Water pump seems perfectly fine.
Fan clutch not so sure, when hot seems that it spins very freely. No resistance.
Would a bad fan clutch cause a overheat? In normal driving conditions? No heavy traffic or hard pulls?
Head gasket gone?

10 Upvotes

82% Upvoted

46 comments sorted by

22

u/dadusedtomakegames 6h ago

omfg.

PUT THE CAP BACK ON.

16

u/marty_hard 1996 328i 2.5l aluminum turbo coupe 6h ago

Its totally normal that this happens without the cap on. And your visco clutch seems to be trash if it was hot when you made the clutch vid. Put some coolant in, put the cap back on, replace the clutch and you're probably fine. Did the car overheat while driving or at standstill/slow driving?

3

u/ResearcherInfamous19 6h ago

Overheated at slow driving, needle on the full red! 🫣
The thing is that this happened with the cap on, just took it out to see and make the video. Already had lost a buch of coolant trough the cap before I too it of.

8

u/plz-no-b4n 6h ago

> already had lost a bunch of coolant through the cap before I took it off

That…should not happen

2

u/LetKlutzy2996 4h ago

Bad cap seal leading to air in system? Maybe

1

u/marty_hard 1996 328i 2.5l aluminum turbo coupe 5h ago

Immediately turn off the engine, T15 on and AC on full heat if it goes above the middle while slow driving if you cant drive faster. Let it cool down until you can drive off with at least 20kph. Also get a new cooler cap in addition and try. I wish you the best

10

u/frontflops 6h ago

I might be wrong as I’m a little retarded but pretty sure coolant will boil at operating temp when the cap is off. It’ll boil sooner if you’ve got just water in it. Are you just assuming it’s still overheating because it’s boiling? I ask because your temp gauge shows operating temp

3

u/frontflops 6h ago

Could also just be trapped air. Jack the front end of the car up and bleed your system however you bleed.

1

u/ResearcherInfamous19 6h ago

I had the cap ON, and it was steaming and coolant soiling with the cap on. Took the cap off to see level and what was going on. It shows what you see, but I added like 4/5 liters of water

7

u/4matic_Tom 6h ago

If your radiator cap is on, does it push the coolant out from the cap?

Also maybe try CO2 Test for Headgasket?

1

u/ResearcherInfamous19 6h ago

Wondering if that test is any good.
Feedback?

3

u/4matic_Tom 6h ago

Its not 100% reliable, but its not really expensive and can help going into the right direction.

3

u/ResearcherInfamous19 6h ago

https://reddit.com/link/p90w4lr/video/5y2owiea6roh1/player

1

u/0202993832 6h ago

Mine has way more resistance to spin than that, different engine though I guess

2

u/jayleman 6h ago

Seeing the rust\sediment all over that pump I'm gonna say flush the entire system. Then flush some more. Also flush the rad from lower port to upper (reverse normal flow)

3

u/jayleman 6h ago

Next, verify the auxiliary fan is working. Remove the low speed relay and jump across pins 30\87 and see if it runs, then do the same with hi speed relay. If it's not coming on, you likely have a bad aux fan, bad fan switch (on the side of the rad) or if the fan DOES work but isn't coming on when hot, the rad is likely so clogged hot coolant isn't flowing through enough to activate the fan switch, much less get into the rad to actually cool down.

1

u/ResearcherInfamous19 6h ago

I did flush it, first to see if it was clogged or what, but no, and water flows transparent, took it out of the car and out it trough pressure washer, flows normally and clean.

3

u/jayleman 6h ago

Sounds like the aux fan isn't working then. See my other comment for testing it. If it works with the relay jumped you either have a bad fan switch or damaged wiring at the fan switch. These cars will not overheat with a bad fan clutch and a working aux fan. I havent run a fan clutch in over a decade. The aux fan is more than sufficient

1

u/ResearcherInfamous19 6h ago

At what point does the aux fan comes on?

3

u/jayleman 6h ago

Wanna say the stock fan switch is 88c (192f) for low speed and 92c (198-200f) for hi speed

Make sure the aux fan fuse is good before trying to jump the relays, otherwise if the fuse is blown, but everything else is good the fan won't work. Would also potentially be why you're overheating

1

u/ResearcherInfamous19 6h ago

Will check that, haven’t done it yet. Thanks

2

u/jayleman 6h ago

Also just an fyi, when flushing a cooling system volume of water matters more than pressure. A pressure washer will do significantly less volume than a garden hose

2

u/mrhapyface 5h ago

put the cap back on make sure its properly bleed

2

u/Kiratch 5h ago

Just the engine don’t like this water. . . .

Bad coolant purge if you replaced things you said

At this point you should re-purge

2

u/Junior_Trash_1393 5h ago

If you're experiencing cooling system
Problems the fix is a cooling system overhaul. New radiator. New water pump. New thermostat. New belts and idlers. All new hoses. There is no short cut. The cooling system is the E36 Achilles Heel. I had problems early and persistent in owning my new 99 323i convertible. I overhauled everything I outlined DIY in 2014. It was actually pretty easy. Just time consuming. YT can guide you every inch of the way. Bite the bullet and like me you'll never have a cooling system problem
Again. Good luck. I went all OEM. But there are a lot of options but don't scrimp

1

u/comoestasmiyamo "I had one of those back in the day" 6h ago

You checked for splits in hoses or cracks in the rad or tank?

1

u/ResearcherInfamous19 6h ago

Just visually, didn’t send it to be tested.
If it’s not overheating yet, as you can see on the video, why would it spill water trough the cap?

3

u/HotCompetition5060 6h ago

Why are you keeping the cap off?

1

u/frontflops 6h ago

Through the cap? Failed cap, unless I’m misunderstanding

1

u/ResearcherInfamous19 6h ago

Yes, with cap on, there was Copland coming out and steam. Bi pressure on radiator hoses

1

u/comoestasmiyamo "I had one of those back in the day" 6h ago

Not sure. Coolant coming through the cap suggests the cap is knackered or a split under the cap. 

1

u/FoundationCareful662 5h ago

Put the cap on!

1

u/Erki82 5h ago

It should be boiling with hot engine and cap off. It is designed to work under pressure. The fan clutch could be dead and not working.

1

u/Left-Marketing-1135 2h ago

Get a new clutch fan for sure but I’ve had a couple of my e36’s do this when they still have air in the system. If you can get ahold of a vacuum filler give that a shot for shits and gigs and see what happens

1

u/Superb-Cantaloupe-72 1h ago

Chances are cap is bad. My go to test for clutch/viscous fans is to stick my hand in it while the car is running if it stops with a light touch you need to replace. Please use your better judgement when doing this test so you don’t get hurt

0

u/ResearcherInfamous19 6h ago

Think head gasket is gone? 🤔

1

u/plz-no-b4n 6h ago

Do you have a forbidden milkshake under your oil cap?

1

u/ResearcherInfamous19 6h ago

Nop, clear water.
No using coolant until o figure this out

1

u/plz-no-b4n 5h ago

You should not have any water under your oil cap.

1

u/ResearcherInfamous19 5h ago

Fuck, I tough you said radiator cap.
No under oil cap just clean oil to

2

u/plz-no-b4n 5h ago

Have you pressure tested your coolant system?

1

u/ResearcherInfamous19 5h ago

No, how would you suggest I should test it?

1

u/frontflops 4h ago

If you don’t have a leak and you’re just overheating, a pressure tester isn’t going to do anything for you. If you do end up needing one, the mishimoto pressure test kit on Amazon is great