Opel Astra + Rev Counter fluctuating in Idle

[mbeylis]

Hi all,

I drive an Opel Astra CSX 2.0

I have noticed recently that my cars idling fluctuates up and down when the car is idle (e.g. stopped at a robot) even if the car is in gear or not

The car also doesn't seem to have the same power from pull off that it used to and the engine management warning light comes on at random intervals. Also the "Check Coolant Level" warning light comes on often now too, I generally just top up the water for this and it goes away (I think I might have a whole in the radiator?)

Not sure if any of this is related to the idling and lack of power problem

They car has just recently been serviced so cant exactly or shouldn't have to service it again

I probally should take the car to General Motors so they can tell me what the engine management warning light means. Reluctant to do this as I dont have much faith in GM from past experiences. They don't seem to know what they are doing and like to charge to replace random parts

Any ideas?

Thanks
Mark

 

[blaaislaai]

How much does it fluctuate? 1000revs or only a few?

 

[mbeylis]

Hi

Not sure the exact amount, will take note next time I am driving and let you know

In general in the past I remember the car idling well below 1000rpm in idle

Now it seems to idle up and down from below 1000rpm to about 1500rpm

This in conjunction with the engine management light coming on randomly and loss of power seems concerning

 

[Pitbull]

Air/fuel mixture is wrong on the car.

Would be the Airflow regulator.

If that happens switch the car off and on again. But have it check out so they can fix/adjust it. They put a little thing in your exhaust and they wil fix it, pretty simple and cheap.

Either that or there is a timming issue. But if it comes and goes it's the air flow regulator.

 

[mbeylis]

Air/fuel mixture is wrong on the car.

Would be the Airflow regulator.

If that happens switch the car off and on again. But have it check out so they can fix/adjust it. They put a little thing in your exhaust and they wil fix it, pretty simple and cheap.

Either that or there is a timming issue. But if it comes and goes it's the air flow regulator.

Hi,

I have been wondering to myself if it wasn't something like that.

I have also noticed that sometimes when changing gears there is a loss of power

Engine management light definitely only comes on randomly

I will take it to a mechanic and tell him to specifically look at this

Thanks

 

[Nocturnity]

You could also have clogged injectors or bad coils. Happened on my Turbo Coupe.

 

[mbeylis]

You could also have clogged injectors or bad coils. Happened on my Turbo Coupe.

From what I have heard cleaning out the injectors is an expensive undertaking?

 

[Fazda]

That EMS light is there for a reason...don't ignore it..rather take it to a garage, even if you don't trust their mechanics!!

 

[mbeylis]

That EMS light is there for a reason...don't ignore it..rather take it to a garage, even if you don't trust their mechanics!!

I totally agree, rather safe than sorry

I recently took my car to a mechanic for another problem and he managed to make the light go off. Said it was a loose connection

I guess I should check that it isn't that again

 

[steve-rsa]

Clean the idle control valve - it is a common problem on these cars.

www.migweb.co.uk will have a how-to or the local opelowners forums.

 

[Anarchy012]

Clean the idle control valve - it is a common problem on these cars.

www.migweb.co.uk will have a how-to or the local opelowners forums.

my Gsi had this problem, a simple clean fixed it. I remember while reading on how to fix my problem that there is also an issue with the cog, of the cam belt i think, which gets worn and it messes with the timing, this could cause the light to come on to warn you maybe? I think the loss of power could be to this worn cog?

 

[Chuck1]

Replace the MAP (manifold absolute pressure) sensor. Problem solved

 

[mbeylis]

my Gsi had this problem, a simple clean fixed it. I remember while reading on how to fix my problem that there is also an issue with the cog, of the cam belt i think, which gets worn and it messes with the timing, this could cause the light to come on to warn you maybe? I think the loss of power could be to this worn cog?

Ok

have been going through various forums on how to clean the Idle Control Valve

Not totally sure what I am supposed to be doing so might rather leave this to a mechanic

Not too sure what the Idle Control Valve looks like, seen some pics, and do you have to take it off and if so do you spray the carb inside or outside or both

To many variables here I think

 

[mbeylis]

Replace the MAP (manifold absolute pressure) sensor. Problem solved

Whereabouts is this sensor and is it a big job

Yet again me thinks I will be going to a mechanic

 

[steve-rsa]

Ok

have been going through various forums on how to clean the Idle Control Valve

Not totally sure what I am supposed to be doing so might rather leave this to a mechanic

Not too sure what the Idle Control Valve looks like, seen some pics, and do you have to take it off and if so do you spray the carb inside or outside or both

To many variables here I think

There is no carb on your car. Seriously it is a 10 minute job and 90% will be your problem.

Where are you locared?

 

[mbeylis]

There is no carb on your car. Seriously it is a 10 minute job and 90% will be your problem.

Where are you locared?

Live in Boksburg

Work in Midrand

 

[Gnome]

Seriously everyone is getting caught up in the idle , f##k the idle. You have 3 mayor problems there:

1) Your engine light comes on periodically, that in itself is a problem. Maybe have GM check your car with Tech2, they charge R450, you can come post the errors here or let them deal with it, only problem is the ECU only logs faults if the engine light is on for > 30 seconds so it may not be logging the error in which case you should take the GM n00b with you in the car and the Tech2 to see wtf it's bitching about.

2) Coolant needs topping up, I've seen Corsa's go 13 years without a coolant change and the level is exactly the same as day 1, why? It's a sealed system, so either you have a hole somewhere, which would USUALLY causes lots of water to leak (but it seems you only have a very small leak? ), the problem I think is more, problem 3

3) You say performance is down? The idle control valve has zero/nothing to do with performance, you can disconnect it and idle using your foot on the petrol pedal or set the throttle cable, if you put your foot down, ICV or no the car should pull 100% the same.
The problem is that your car is slowly losing water, which may mean you have a blown/leaking head gasket or a really small leak. Unfortunately a blown or leaking head gasket is more likely. You need to get the CO2 test done on your car. It's basically a test where they stick a little chemical paper into your coolant bottle if it turns a certain colour you have a blown/leaking head gasket. Compression tests are a more crude way to test.

A quick and dirty test is to check if you have a thin layer of oil in your coolant OR white stuff on your oil filler cap.

my Gsi had this problem, a simple clean fixed it. I remember while reading on how to fix my problem that there is also an issue with the cog, of the cam belt i think, which gets worn and it messes with the timing, this could cause the light to come on to warn you maybe? I think the loss of power could be to this worn cog?

Good one, worth a check.

The crank shaft pulley has a key-way where it fits into the crank gear, it can wears down if the crank pulley wasn't correctly fitted/torque'd. It's more a problem on Corsa's than the Astra tho. The engine is timed from the crank pulley wheel (called a 60-2 wheel) so if it's misaligned (it starts moving around because the keyway is worn out) the ECU cannot correctly determine what the position of the engine is causing mayor headaches. There is a sensor sitting below that wheel called the crank shaft position sensor, the wheel has 2 missing teeth when moving past the sensor it is detected. The ECU then knows that the first piston is located exactly at the top of the cylinder, called TDC. If TDC is not correctly determined the injectors/spark are out of synch.

Replace the MAP (manifold absolute pressure) sensor. Problem solved

That car uses the air mass method, it doesn't use a MAP sensor to determine the mixture. Still the GM MAP sensor is very reliable and also very expensive, I'd only replace it at the very end. Never really seen one break myself but of course it happens.

Sheesh, need a break now, too much typing/editing, if I wasn't such a Opel fan....

 

[mbeylis]

Seriously everyone is getting caught up in the idle , f##k the idle. You have 3 mayor problems there:

1) Your engine light comes on periodically, that in itself is a problem. Maybe have GM check your car with Tech2, they charge R450, you can come post the errors here or let them deal with it, only problem is the ECU only logs faults if the engine light is on for > 30 seconds so it may not be logging the error in which case you should take the GM n00b with you in the car and the Tech2 to see wtf it's bitching about.

2) Coolant needs topping up, I've seen Corsa's go 13 years without a coolant change and the level is exactly the same as day 1, why? It's a sealed system, so either you have a hole somewhere, which would USUALLY causes lots of water to leak (but it seems you only have a very small leak? ), the problem I think is more, problem 3

3) You say performance is down? The idle control valve has zero/nothing to do with performance, you can disconnect it and idle using your foot on the petrol pedal or set the throttle cable, if you put your foot down, ICV or no the car should pull 100% the same.
The problem is that your car is slowly losing water, which may mean you have a blown/leaking head gasket or a really small leak. Unfortunately a blown or leaking head gasket is more likely. You need to get the CO2 test done on your car. It's basically a test where they stick a little chemical paper into your coolant bottle if it turns a certain colour you have a blown/leaking head gasket. Compression tests are a more crude way to test.

A quick and dirty test is to check if you have a thin layer of oil in your coolant OR white stuff on your oil filler cap.



Good one, worth a check.

The crank shaft pulley has a key-way where it fits into the crank gear, it can wears down if the crank pulley wasn't correctly fitted/torque'd. It's more a problem on Corsa's than the Astra tho. The engine is timed from the crank pulley wheel (called a 60-2 wheel) so if it's misaligned (it starts moving around because the keyway is worn out) the ECU cannot correctly determine what the position of the engine is causing mayor headaches. There is a sensor sitting below that wheel called the crank shaft position sensor, the wheel has 2 missing teeth when moving past the sensor it is detected. The ECU then knows that the first piston is located exactly at the top of the cylinder, called TDC. If TDC is not correctly determined the injectors/spark are out of synch.



That car uses the air mass method, it doesn't use a MAP sensor to determine the mixture. Still the GM MAP sensor is very reliable and also very expensive, I'd only replace it at the very end. Never really seen one break myself but of course it happens.

Sheesh, need a break now, too much typing/editing, if I wasn't such a Opel fan....

Hello

Thanks for the detailed reply Gnome, appreciated

You seem to know a lot about Opels

I agree that taking the car to GM just to test to see what the Engine Management Warning Light is complaining about is probably worth the R450

The car has been moaning on a more regular basis about the coolant level, when I say more regular its probably every 2 - 3 months or so as opposed to maybe once a year in the past so like you say there is likely a leak somewhere

A friend of mine has suggested the radiator as he has an Opel like mine and his radiator had a crack in it

I will see about getting my CO2 levels looked at

On a side note, speaking about the Head Gasket. About a year back I was at a petrol station and the attendant forget to put my oil cap back while topping up the oil. The result of this was a couple of KM's down the highway my oil warning light came on and suddenly my cabin was full of spoke. I pulled off and opened the bonnet only to see my cars bonnet full of oil and where the oil should be was none. I pulled into the nearest garage and in it took 3 bottles to fill it up again. I had the car checked out afterward and told that nothing was wrong although I have never been fully convinced

Thanks

 

[Rouxenator]

How many KMs do you have on it ?

When my Astra went in for its 2nd cambelt service last year with 150,000km on the clock I had to replace this hose assembly at the same time since it worn through by the netting cover from another hose :

At the same time they replaced the water pump since they already removed the cambelt and it would save labor cost should I had to do it something in the future.

 

[Stokstert]

Hell Rouxie, only 150k Km and your hoses look like this. Have you ever opened your bonnet before? You should have seen the coming trouble long before it came to this stage of decay.