Skoda Estelle (120) fix-up questions...

[mklrnn]

Hi. I'm not sure if I should post in maintainance or performance...A Skoda Estelle 1990 (120L) was donated to me last sunday, and I intend to fix all I can, a little more and then "legalize" it.
I have some questions...as the subject line said.

Problem #1:
It doesn't seem to cool. the enginge goes from normal temp to 90 degrees in about 5 minutes, and the termostat doesn't seem to open. I took the thermo out, boiled it in a pot, and voila. It opened! Now, what I don't understand is why the hot water doesn't come runing out to the radiator.
The next stop in my quest for the fault was the water pump. Though I wasn't able to completely remove it, I removed one of the tubes from the pump (the big one, coming from the expansion tank), and having removed the fan belt I turned the pump, and...surprise, surprise! There came coolant.

Additional information that may or may not have anything to do with the problem...
* When I drained the cooling system...From one pipe (I think, it flows TOWARDS the radiator) came the slightly blue-colored coolant, that I put in (the expansion tank was empty on the cars arrival), and from the other pipe (the return to the engine) came somewhat clear water.....

Another question about the flood **** (located on a tube between the heater and the radiator)...should it be opened or closed?

Now, I'll go back to my Haynes manual, and wait for replys...

[ncarring]

Sounds like you should take the radiator out and flush it through....

[mklrnn]

yes........the trouble is, that the coolant never GETS to the radiator. The water doesn't seem to leave the motor block at all! Not even to the heater!

The coolant SHOULD flow from the expansion tank into the water pump trough the engine, circulating inside until the thermostat opens. Then it should run trought the pipes to the front of the car, into the radiator (as if the pipes weren't enough to cool it down... ), out from the radiator, and into the water pump.
Then there is the heater circuit. It goes from the water pump into the motor block, out next to the thermostat and if the heater valve is open, it flows trough the pipes, and returns into the water pump from the right (seen from the rear of the car, of course...) If the heater valve is closed, the coolant just flows trough the seemingly unnessessary tube connecting the pipes to and from the heater, back to the water pump, where it circulates again.

Did I get this right?

Now. When refilled, the cooling system is full with water everywhere. But the engine gets very hot very quickly, and the tube from the thermostat doesn't feel warm at all! Neither does the tubes to the heater (besides the steel one that passes by just above the spark plugs, which probably absorbes heat from the engine itself...as the one before the waterpump, above the exhaust pipes...) I have NEVER felt the radiator get warm. Neither have the coolant in the expansion tank been warm at all when the engine's at 90 degrees! Shouldn't the heat spread trough the system?

Where could the problem be, and what is it?

PS. Just want to say that this forum has given me many good tips! Nice!

[stopan1j]

The 120 you have has a cast iron head.

The most likely problem is a head gasket failure, combustion pressure is probably leaking into the cooling circuit and preventing water circulation. This is very common. Easy job on 120 as it uses conventional head bolts that are torqed to tighten rather than angular tightening on the aluminum headed 136 engine.

Other causes can be :-

1. air in system, this can be cleared via the method in the Haynes manual, when refilling the system the drain tap at RHS of bonnet should be open to allow air out when filling. I suggest also starting the engine and opening the value until water flows freely. When filling an engine completelty I suggest removing teh small hose on the thermostat housing that goes to the expansion tank fill and let the air expell from here when water flows refit.

2.Check the mall bypass hose between the water pipes near the spark plugs isn't blocked, or the small metal tubes its conected to they can block with sludge.


3. Cracked/distorted head.

Its very very unlikely to be the water pump when this fails its the seals/bearing and causes a leak not circulation problems

You may see bubbles if you remove the expansion cap and reving the engine although not always shows.


99 out of 100 its the head gasket.

John

[mklrnn]

Still don't know what the problem is, but once, when I just cranked the engine for fun after playing with the thermostat mounting, the whole thing worked!
Now, I've removed the thermostat. And It goes OK now. the heater gives heat, and the radiator cools (or is it the lines... )
I heard of a friends friend, who drives a modified, tuned, etc. Volvo...that his thermostat only works when it wants to too... I think I'll change it.

Update on the rear brakes...one cylinder ok, the other was stuck.....will try to find a dealer........more details on the progress on my homepage. http://www.fkf.fi/~mronn/skoda/