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521 radiator gurgling on shutdown


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hey guys, is it normal to have a little gurgling from the radiator after shutdown?


-Thermostat guage shows NO overheating (needle 3/4 to right)

-NEw Radiator cap

-Recent radiator flush

-Overflow tube connected to a puke tank.

-Just had filled w/ coolant 50/50 (1/2" from bottom of neck.)

-Filled really slow (w/ heater valve switched 'on' as to not trap air in the system.)


Also the first time after I ran after filling (1/2 from neck) I had coolent on top of the radiator. As if it were coming from the cap or from where the overflow hose attaches to the neck.


The second and much longer drive produced a drop in the same area, but not much more and not as much as the first leak.


Just extra coolant run off? Gurgling normal?



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Yes, totally normal. After shut down there is still lots of 'stored' heat in the block and there is now no circulation, and so it will boil and often push some coolant out the over flow pipe. If you replace with a proper coolant recovery cap, yes they are different from a regular rad cap, the expelled coolant will siphon back into the rad as it cools. Running coolant an inch lower sometimes helps, as this leave room for expansion.

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Thanks Mike! You put me at ease for sure!


The only thing still bothering me is that when I drove it this morning and popped the hood I saw what appeared to be oil (hard to tell) coming fron the 3rd sparkplug back. NOW my oil filler cap was also leaking (infact it busted off in my hand when I tried to tighten it. I can only hope the oil somehow got back to that third sparkplug from the cap, and that is what I saw.


I also hear that this is often caused by a bad valve gasket sometimes dripping down. So if I see it again I will replace it.


Just praying it isn't actually coming from inside the head! I guess i should pull the spark and have a look too.


But now I am off to my first car meet with the 521! Wish me luck!

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L valve covers are notorious for leaking oil from the gasket. Try to avoid those silicone sealers, they are so unprofessional looking. (at least get it in black so it isn't as noticeable) Also, too much and it flakes off later and ends up stuck in the oil pick up screen.

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