Hi guys, I bought my mk2 GTI a couple of weeks ago and Im in the process of getting it road legal and ready for an MOT. When I first got it I noticed the coolant tank was empty, but presumed as it had 'supposedly' been sat for a while someone had stripped it of its fluid so I topped it up. Anyway, earlier this morning I started the car and let it idle for 20 mins or so only to come back out to notice it was literally P*ssing out coolant from the side coolant flange on the head! Any ideas why this is? Just a new flange or a blockage in the system? Cheers in advance!
If you're lucky it will be a just cracked flange, no longer supporting the o-ring seal properly, and perhaps an original o-ring that has long ago lost its rubberiness. If you're less lucky it will have been gradually leaking worse and worse for years, and areas of the head underneath the o-ring will have been eroded away. Won't know 'til you look. Repairable, whatever has happened. Welcome to the forum by the way.
Thanks! Been nosing around it for a long time and thought it was about time I signed up! If it's the less lucky option what would these repairs include? Sorry if it's a stupid question lol, before this I had a faultless but slow 1.3 so never had to experience a problem like this!
Various options. Quick-and-dirty: just fit a new flange with a bit of suitable sealant (rated for use in that environment) to augment the o-ring, and keep an eye on it. Only likely to work if any pitting is very light. Surface will need a good clean-up if the sealant is to stand any chance of doing the job. Keep the quantity of any sealant used to the bare minimum; you don't want bits breaking away inside and blocking up stuff. More thorough: clean up the area very carefully, well enough that some chemical metal type stuff will stick to it, (over)fill any pitting and rub down to a smooth flat surface once the stuff has gone nice and hard. This option is much easier if the head is off the engine, but I certainly wouldn't suggest that just to do this repair. Flange is part number 026121144E according to here. It comes with a new o-ring usually. That partscats.info website is extremely handy for finding part numbers, once you learn to navigate around it.