Engine damage - strange symptoms

matt_fsr

matt_fsr

matt_fsr

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Wondering if anyone can shed some light on this? My absent-minded g/f recently left the coolant filler cap off the Skoda engine when topping up, and on the trip to work boiled nearly all the coolant out of the car. :(

From what I've heard/read this usually results in a damaged/blown cyclinder head gasket, but the symptoms the car is having dont seem to match up with this.

Yes, it's even slower than its normal miserable 68Bhp provides, but the engine now doesnt get up to normal operating temperature, and on some trips doesnt even lift from the bottom of the temp gauge. I'm *fairly* sure thats accurate, as the heater doesnt give out as much heat as it used to, and sometimes wont kick in. Fuel economy is also shot, down to around 32Mpg, instead of around 40.

Anyone got any thoughts on what might be wrong? I dont mind trying a few easier/cheaper jobs on it before getting a new CH gasket fitted.
 
Massive air blockage in the coolant system.

But it possible you've caused overheating damage to the engines internals, possible to fry the piston rings from this?

Take the oil filler cap off and see how much pressures coming out of it.
 
panthro said:
Dumb question, but did you refill it to the correct level before driving it again?
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G/f did realise that there was problems, the car got topped up on water the day she did it, then once it was home I drained the cooling system and topped up correctly with water/antifreeze mix.

I've run the engine to circulate the coolant, any other ways to get air that might be there out of the system? Ta
 
Give all the hoses a good squeeze, you will be able to hear the air.
Did you have the bleed valve open when you topped it up?
 
matt, check that the little return hose that goes back to the coolant bottle is not blocked. the system should effectively bleed itself

as for the car being odd, there is no definitive answer. given the symptoms id be inclined to think rings but id start with plugging it onto a laptop and start from there
 
Have a look at the procedure for a coolant change on that particular car. There are most likely some bleed points that will need opening up to get all of the air out whilst refilling.

Another possibility is that the thermostat has got stuck when the car was running hot and low on coolant which combined with cold weather would prevent the car from heating up properly.

Poor fuel economy and power will be a side effect of low coolant temperature as the ECU will be constantly overfuelling. This will fix iteself once the reason for running cold is established.
 
LizardKing said:
Give all the hoses a good squeeze, you will be able to hear the air.
Did you have the bleed valve open when you topped it up?
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I topped up then ran the engine with the filler cap off for a short while, and topped up a little more fluid.

I don't know if there is a proper bleed valve for this car, part of the problem is this engine isnt in the Haynes manual for the car, so I'm a bit stuck. Whenever I ask for a part from VW it's always the wrong part, even down to the sump plug nut. :(

Will have a check of the coolant lines tonight, see if theres any bleed valves and see if I can get any more coolant through the system.

Kaiowas - thanks for that about the ECU fuel issue, hoping it could just be that causing the problems.
 
didnt catch whether its a diesel or petrol but bet ya bottom dollar if its diesel and been boiled dry its ******!
 
Sounds pretty obvious - thermostat is goosed, causing the low coolant temp, and poor economy.

Probably a good idea to tell us what engine, but I'm guessing a petrol at those MPG figures.
 
It's the 1.4 petrol 8v OHV engine. Dire... i know.

The good news is it looks like its' not CHG! :D

Got my dads old compression tester on the cylinders last night, worst reading was 160PSi, best just over 180PSi.

Popped 4 new spark plugs in it while we were on, she's organising getting a new thermostat fitted ASAP. Hopefully that'll fix it, I'll keep you posted.

Thanks again for the tips, seems to make sense if the thermostat is jammed open and not letting the engine get up to proper temperature.
 
matt_fsr said:
It's the 1.4 petrol 8v OHV engine. Dire... i know.

The good news is it looks like its' not CHG! :D

Got my dads old compression tester on the cylinders last night, worst reading was 160PSi, best just over 180PSi.
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Just FYI, good compression readings don't rule out gasket failure; cylinder pressures during combustion are far higher than you get from compression. That said, a stuck thermostat is far more likely to cause the symptoms you are seeing, and overheating can make them stick open.
 
its important (well makes life easier) if you pour the coolant in quite slowly, as if you just slosh it in it can drag more air in and push air thats already in there further round the system
 
Dogbreath said:
Just FYI, good compression readings don't rule out gasket failure; cylinder pressures during combustion are far higher than you get from compression. That said, a stuck thermostat is far more likely to cause the symptoms you are seeing, and overheating can make them stick open.
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Yep, true thanks - Just seems that everything I've read about gasket failure says your engine will overheat all the time, and you get white gunge around the oil filler cap, as well as mixing of fluids. (oil in water, vice versa etc)

None of that is happening, so I'm guessing the cylinder head gasket is OK.

Rocker-box gasket is in need of replacing as its leaking oil, and theres a perished rubber pipe leaking a bit of oil, but thats small beans :p
 
You have to REALLY cook an engine to nail the HG from just overheating. Like I did to my prelude when the hard shoulder was closed and I had just got past the services...

Was forced to drive a few miles on the motorway with the temperatue guage indicating hotter than the fires of damnation itself. Just as I was turning off the roundabout into a side road to stop the radiator top hose exploded, and I did my one man Red-arrows impression.

That was a toasted engine. Had to replace the whole thing :P
 
You can test the thermostat by putting it in some hot water and seeing if it opens, would be a shame to replace a working thermostat :)

Is there a skoda forum that has a section on How-to's ? might be worth looking for a guide if the manual and haynes manuals are lacking.
 
matt_fsr said:
Yep, true thanks - Just seems that everything I've read about gasket failure says your engine will overheat all the time, and you get white gunge around the oil filler cap, as well as mixing of fluids. (oil in water, vice versa etc)
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Many people just regurgitate the same old information about HGF without really understanding what's going on, what the gasket goes and how it can fail. You've got 3 different things that the head gasket has to keep seperate from each other, oilways, the coolant jacket and the combustion chambers. The gasket can fail in a variety of different ways allowing any of these independent systems to mix with differing symptoms:

Oil+coolant mixing will give you the 'mayo' in one of or both the oil and coolant systems plus possibly fluid transfer from one system to the other (so one level may go down whilst the other goes up)

Oil+Combustion mixing will give blue smoke out of the exhaust, oil level dropping, pressurisation of the oil system etc

Coolant+Combustion mixing will give white smoke out of the exhaust, overheating, coolant loss, pressurisation of the coolant system, air bubbles in the coolant etc.

Total failure will give a combination of all of the above. It's also possible for the gasket to fail to the outside (such as an oilway or coolant path leaking outside the block) or for you to get failure between combustion chambers (which would give no real noticable symptoms other than poor performance)
 
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