Well...Just completed my first DIY job on a Skoda Felicia...

I registered here to have a browse before I actually did the job, and didn't come accross the issue I encountered...

I'm a reasonably competent mechanic, but I'm a BMW man, as a rule (currently own 2 E30s including an M3), although I've worked on many different vehicles over time...

My girlfriend drives a 1998 Felicia estate GLXi 1.6MPI and when I drove it I noticed that it wouldn't heat up properly unless stopped in traffic...

After establishing that the temprature gauge was working and the sender also was working and that the radiator hoses got hot equally, I diagnosed a faulty 'stat...

Collected the part from GSF and got to work on what looked like a simple job....Two 8mm head bolts, it appeared, held the housing together...undid them removed the (very seized) old 'stat and sealing ring, replaced both items and went to refit the housing...

Only to find that the plastic (FFS) helicoil in the plastic housing had come out with the "bolt" and meant that the lower fixing couldn't be tightened up...

After a bit of head-scratching, I decided to re-design the (crap) effort that Skoda/VAG had made...

I drilled a 6mm hole all the way through the housing and secured the 2 halfs of the 'stat housing with 40mm M6 bolts and nuts!

Can't quite understand why plastic helicoils and plastic housings were used in the first instance...But jobs' a goodun' and it saved trying to find a housing assembly on a Sunday lunchtime!

well done.... that's the same thing i've had happen on loads of polo engines, i cant imagine what they were thinking when they decided to use a bush pressed into a piece of plastic... if you are drilling into the side of the cylinder head you so have to be carefull because the casting isn't very thick there and ther is the possibilty you can go straight through into the water jacket

Usually we just replace the whole housing, costs less than £30 and you get a new coolant temp sensor with it also.

Quite often its not the stat that is faulty on the 1.6 engine, a piece of plastic breaks off the end cap. This means as the thermostat opens it has nothing to push against and stays shut. You put a new stat in and it still overheats.

Hmm...as it happens, the small bit of plastic WAS missing in the housing...BUT it did appear that the 'stat was doing the job after changing it...the old one was seized solid...Although thinking about it, it may have been the bit of plastic that was jamming it open!!

I will be changing the housing at the earliest opportunity...

Just at 1pm on Sunday it was gonna prove impossible to get...hence the "bodge" fix

BTW TT: the drilling action wasn't into the head at all...the stat housing sits to one side, although the same plastic moulding does screw/bolt onto the head...

ah, i get you.... normally i find it's the flange that bolts to the head that gives the trouble, or worse is when the bolt shears off in the head

Usually we just replace the whole housing, costs less than

Got to do the same some time soon on my 2000 felicia 1.3, temp gauge doesn't move at all unless you leave it running on drive for 10 mins after a long run and heater only runs luke warm on hottest setting. Pipes in and out of rad warm after a run also so guessing valve has jammed open.

NB

Have seen 2 head bolts on therm housing but is there a third one hidden under and round back ?

Is the replacement thermostat housing an improvement on original or is it going to break just like original has done ?

think that is what I asked...

Do you know if there is a better type of housing at all? Perhaps something from a racing/rally engine...I know the Felicia was rallied and presume the base for that was the 1.6MPI....

Can't believe they would have retained the flimsy plastic housing...

haven't had an answer, yet

No..new one is identical to old..another VW 'improvement' on the way Skoda used to do it. . Never had a thermostat fail on the older ones (carb Fav. and 2 x single point Inj), and then the plastic housing fails on the MPI one. Its not pricey, just irritating. Expect component lifespan of about 60,000 miles, so you probably only replace it once. Ours is 1.3 engine, but i suspect its the same component as the 1.6. Sounds like it anyhow.

Alfie 168

to be honest some of what you guys are typing is lost on me, but i am noticing problems with my temp gauge in my felicia 1.6 petrol estate. It over heated the first time out on a long run, turned out the fan wasnt working at all, the switch was replaced and that works now.

However it seems to heat up real quick, 5mins driving will see it 1/2 way to full and the fan is having to work on about every journey out even in this cold. To be honest i never noticed what heat guages do, my last car just had a warning light. But at the moment im spending most my time watching it shoot up to 3/4 then drop when the fan kicks in, then back to 3/4. leads for quite paranoid driving experience :( is this related to the problem your dicussing in this thread you think?

The 1.3 and 1.6 thermostats are completely different. Although both do suffer with failings.

Difference is normally the 1.3 fails and doesnt heat up, the 1.6 usually fails and over heats.

The rally cars used the 1.3 engine btw

sorry but to clarify, your saying that my 1.6 thermostat maybe showing the engine as hotter than it is, or that the engine is actually over heating?

When the thermostat fails on the 1.6 it usually jams shut meaning you get no circulation and the car overheats (gauge in the red, lots of steam etc)

Quick fix is to remove the stat, but then the engine over cools.