Mk2 Golf Heating

Hi everyone
I have a lovely MK2 Golf GTI 16v in cracking condition. It had an engine re-build 10000 miles ago and drives sweetly. Not too long after the re-build I lost heating in the car. generally, during the summer months hot air blows out (high temp gauge) on the motorway normal temp gauge around town and during winter months arctic air out (low temp gauge) on motorway and normal again around town. All fluid levels are good and no signs of any coolent leaking and radiator fan working normally. Hope that all makes sense!
So, do I need a new heater matrix? I have read that if there are no leaks then a flush should do it. Is this correct and what does this involve?

Cheers

maybe thermostat. i had the same thing on my jetta. replaced stat when i did water pump and was spot on after that

Thanks for your reply. The thermostat has been checked recently and working, apparently, with valve opening/closing etc. A few mechanics have scratched their heads but not convinced they totally know what they are talking about. Finding it hard to find a good mechanic who knows their way around the old models.

More often than not the thermostat is the culprit here, just replace it, the next thing to do is get the bypass valve and bin it, theyre crap and cause more trouble than theyre worth, I dont know of anyone who have had a matrix explode and burn themselves.

Whilst its off back flush the heater matrix, I'm betting that at some point in its life someone has chucked in a bottle of radweld and it always ends up sitting in the matrix not allowing the heat into the car.
Back flushing it may cure it but the only sure way is to replace the heater matrix.
It's a shitty job I hate doing it as it takes so bloody long as the dash has to come off totally, there is no short cut to this job.

If you ever want it done I have a flat charge of £75 for this job with you supplying the matrix, I provide everything else... antifreeze etc.

I love mk2's, I currently have three, I work on a lot of the forum members mk2's on here, and it's me they turn to when after advice.

I hope this helps you out, if not then call or txt me and I'll fit you in one weekend, my numbers 07791 001385

i agree with the above.

change the stat first. an easyish job, can be a bit fiddly getting the stat in place and bolting up the housing when laying on your back. also if you got PAS its a bit fildly getting the belt back on when putting it all back together. (PAS sits over the stat and housing so it has to come off first)

and yep while your there give the radiator and matrix a flush.

regarding the bypass valves, make sure they are on the right way round!

but i agree theyre more trouble than theyre possibly worth. ive had knackered ones before and have knocked the valve out so it permantly open.

ive replaced 2 matrix's and as Guy say's its a sh!t job but its doable. ONLY DO THIS WHEN NOTHING ELSE WORKS CUZ ITS SUCH A SH!T JOB



oh and finally are you sure your system hasnt got air in it.

take the cap off, turn your blowers on setting 3 and on hot. run your engine for a few minutes with your foot on the pedal iving it some rev, maybe 3-4000 constantly.

if any air is in your system it will gurgle out of the expansion bottle.

this is often the cause of crap heating.


ive owned and worked on loads of mk2's. you'll get there in the end

Guy replaced a matrix for me, did a good job and knows his way around a mk2!

thanks chaps. some good advice there. will give a few things a try and get back to you.
All the best

Just re read your first post again, with the hot cold antics It's displaying its the stat without a doubt, the matrix may well be clogged too but deffo the stat.

Don't take no for an answer and have them check it out , just tell them to put a new one in and have them show you the old.
Insist on a genuine one from VW all the others are questionable quality.

Cheers Guy. will give it a go