MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: Adam0604 on April 12, 2022, 06:42:07 pm

Title: Coolant explode / Fans constantly on
Post by: Adam0604 on April 12, 2022, 06:42:07 pm
Hey all,

On way home from work tonight, my engine coolant light suddenly came on and noticed a fair amount of smoke coming from the bonnet.
Got home as was only couple mins away, popped the bonnet and the fans took 10 mins to turn off and I've got coolant all over the right hand side of my engine cover / bay.

I'm going back out in an hour once car has cooled down fully, but what should I look for when I top coolant back up with water / coolant.
Any common hoses to look that might have blown off / leaking?

Seems strange that the coolant would actually be on the engine cover, which makes me think it might be more than just a leaking hose?
Title: Re: Coolant explode / Fans constantly on
Post by: Hypertuned on April 13, 2022, 03:59:55 am
The coolant system is pressurised and even more so when the coolant is hot, so splashing all over the engine bay isn't a surprise.
Top it back up and look for physical cracks first. If you can't see them then run the engine so the pump runs, and you should see coolant or steam leaking from a pipe, pump or the radiator. Given the age my guess is the plastic radiator has sprung a leak and the fans helped spread coolant all over the underside of the bonnet.

Sent using Tapatalk
Title: Re: Coolant explode / Fans constantly on
Post by: pudding on April 13, 2022, 08:53:16 am
Check the small pipe that tees off half way down the right hand radiator top hose.  It's notorious for breaking off, especially with aftermarket intakes.
Title: Re: Coolant explode / Fans constantly on
Post by: Adam0604 on April 13, 2022, 11:36:16 am
Found the culprit, looks to be where the big top rad hose connects there:

(https://i.postimg.cc/52wP3pCn/20220413-112349.jpg) (https://postimg.cc/3kxCrX9v)
Title: Re: Coolant explode / Fans constantly on
Post by: LC5F on April 13, 2022, 03:52:17 pm
Yes - that's the one Pudding was describing
I manged to get ahead of the curve and replace mine before it snapped off - really terrible design.
Not too bad cost for pattern part, or you get them fabricated out of alloy.