Hi,

I need advice on some issues i'm having with my car.
the car is a Volkswagen Passat auto drive (1999 model) and it's giving me serious issues.

first, anytime I put on the a/c, the car engine goes off. went to a mechanic and all he did was to increase the idle speed of the car. now if i'm not using the a/c, the rev is so high and I feel it contributes to a high fuel consumption (i'm not a car guru).

how do I resolve this issue so I can use the a/c at the idle speed that d car was originally (note: I had been using the a/c without issues for a long time)

secondly, I noticed that anytime d car is idle after some distance of driving, the water+coolant in my reservoir begins to boil and pour on the floor till its empty. I can't place any particular leak point. also, the thermometer does not indicate a rise in temperature but the engine hot indicator comes on after this.
it's really beginning to frustrate me.

pleeeeeeeeeeeeease anybody, HELP ME!!!!!!!! WHAT DO I DO?

Op,

The fisrt problem seems like an IAC (Idle Air Control) issue. I don't know what system yours is, but if it has IAC, I would suggest you clean it with Carb cleaner, lubricate it and re-install. It should stop the engine from going off when additional load is added or when de-accelerating. It could be that your IAC is stuck closed. Adjusting Throttle stop to increase idle speed will not fix the issue, even though it may appear fixed. It would also increase the fuel consumption, since the rpm will be high at idle. If your car were manual transmission, You would find it difficult to shift into gear 1 and reverse gear.

As for your cooling system, it appears air is trapped in that cooling system. Did you work on the cooling system that needed removing and refilling the cooling system with coolant? Probably, it happened when the thermostat was removed? Or is the thermostat still in there? Anyway, you need to bleed the cooling system.

From your description of the cooling system, it seems yours have coolant reservoir where the coolant is poured in, not directly into the Radiator? If that is so, check the coolant reservoir cover seal. If the seal has broken, absence or not so good, replace the cover.

What I explained above is how I would troubleshoot a Peugeot with similar issues. So I dont know if the same can be applied to VW. Good luck!

Ikenna

thanks.
i actually had the gasket changed by a mechanic sometime in march this year when the car had constant overheating issues.

could that be the reason?

dellyosh: thanks.
i actually had the gasket changed by a mechanic sometime in march this year when the car had constant overheating issues.

could that be the reason?

Then, its likely they have removed your thermostat as well.

Before we go into the t-stat matter, check the coolant reservoir cover/cap seal and bleed the cooling system. Because its alo possible that they didnt bleed your system when the head gasket was replaced. Trapped air in cooling system can be unforgiven to cylinder head when engine gets hot.


As for your t-stat, if you are not sure if its still there or not, there is a simple method of finding out. I dont know about VW, but you can try Peugeot method. Find it in the link below:

http://peugeotarena.com/how-to-test-peugeot-engine-cooling-system-thermostat-while-its-still-in-engine/


Good luck.


Ikenna

Nastydroid: sell the car

To someone that likes trouble, abi? ...indeed a very "intelligent" advise

I had this kind of coolant leakage on 2006 toyota prado. The cap was the culprit.

I changed it and almost a year now, never topped water again.

I think those caps have a pressure release mechanism when bad cause continues leakage and boiling without the engine itself overheating until water is all out. I dont completely understand how it works but you can try a new cap, if it doesnt stop, do as Ikenna suggested.

Nastydroid: sell the car

To who?