00 1.6 Cool Engine rough running high fuel consump - ganthool star

I know very little about cars. I bought this Vauxhall Astra 1.6 8V LS recently and discovered that it is running very roung and the temperature guage normally stays below the starting marks and only goes up when stuck in traffic but comes back as soon as it is out of the traffic. In addition to this I noticed the fuel consumption is too high and the exhaust emissions are highier than normal. I get the timming belt and water pump changed as they were due. It improved the situation but it is still running slightly rough and the fuel consumption is too high as compared to my previous cars.

Could anybody in the forum help me to sort out this problem. Thanks in advance
00 1.6 Cool Engine rough running high fuel consump - Dynamic Dave
This radiator for this car is the same one they use for the larger engines. In short, it can be overcooled. Not helped if the thermostat is stuck open - which is probably the case with your car. It's a pity you didn't get the thermostat changed at the same time as the belt and water pump as you need to remove the cambelt to access it.

What some people end up doing is to block the off the lower half of the radiator (ie, below the bumper line) with an offcut of lino or some other waterproof material.
00 1.6 Cool Engine rough running high fuel consump - SpamCan61 {P}
Many Vauxhalls of this era appear overcooled, I took SWMBO's 1.8 Zafira from Christchurch to Swanage and back on new year's day,outside temperature minus one and the coolant temperature gauge never made it into the blue. Still did 37mpg on the trip. Check the top hose to the rad. doesn't start to get warm as soon as the engine is started as this is the sign of the thermostat stuck open.
00 1.6 Cool Engine rough running high fuel consump - helmet
As Dave says, blocking off of the lower part of the grill with lino, does help a little bit, as I have done it to my wife's W plate 1.4 Astra G.


I did a little bit of digging last week, and came across a guy who managed to solve the problem of the knackered Astra thermostat, by placing a Renault 5 thermostat into the top hose near the radiator, without the need to remove the VX one.

There is a link on the VX forum, but you may have to register to see it. It also has a link to the particular thermostat on E.Bay so you know what your looking for:


Read the entire thread, especially reply 13 by Krowlands.

Edited by helmet on 11/01/2010 at 18:48

00 1.6 Cool Engine rough running high fuel consump - ganthool star
Thanks every one who tried to find some solution. I followed the link in thread 3 (helmet) and then did some more research on various vauxhall owners clubs and found the thrermostate failure is a common problem on these cars.

However I bought a Renault 4/5 thermostate and a hose clip (total cost £ 6.5) and took my car to the mechanic garage (you don't need a garage if can do it yourself, it is hardly 10 min job) and they fixed it for me in the radiator upper hose on the engine side. Please note that the thermostate should be in the direction. the spring part should be facing the outlet of the coolant towards the engine. In other words the spring and the cylinder should be in the engine's hot water to make them expand and open the thermostate.

I have changed it today, it is working at the moment perfectly fine but will keep an eye on the gauges etc.
00 1.6 Cool Engine rough running high fuel consump - Englishbullterrier
Please let us know the outcome........ebt
00 1.6 Cool Engine rough running high fuel consump - ganthool star
It is running fine and my car is now heating upto the normal temperatures. The thermostate I bought was set at 88deg C and the fan cuts in exactly when the temperature show me about 92degC.

To me it is just a genius solution to the poor vuaxhall design and their funny wisdom to locate the thermostate so deep inside the engine block and I really appreciate the person who invented this solution.


Value my car