'02 vw passat coolant


I have a vw passat '02 w/100k miles

the coolant light came on back in early dec. and I purchased a coolant recommended to me -Zerex dex cool and added very little.

It was running fine until Monday morning when it was -5. I added some more and the engine light came on after driving for 3 minutes.

I did notice that there was ‘froth’ inside on the cap when I opened the coolant resevoir. Is the engine light on because of the coolant or it it something else?

thanks in advance for any advise!

Is Dex Cool the recommended coolant for your VW? Some coolant types are not interchangeable and will not mix well.

I think you should investigate the “froth” a bit further. Open the radiator cap and see what it looks like inside.

Hi there ,
the dexcool did have a chart on the back for european vehicles. and it showed it was suitable.
I did go and open the resevoir today. I wiped off the’froth’ from the cap and around the mouth of the resevoir. I started it up again but the engine light came on.

VW has there own coolant G-12 as I recall

 That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here. It may well be something else.

I meant “Is DexCool recommended by VW?”

The answer will be in the owner’s manual.

You are correct about the G-12, and I don’t think it likes to be mixed with anything else. If you drained all the old G-12 out and replaced it with DexCool, it should be okay but I believe they two shouldn’t be mixed.

Some of these Volkswagens don’t have radiator caps, closed system. The only way to add coolant is through the expansion tank.

You do need to get the coolant thing straightened out. There’s a good chance you’re due for a cooling system service anyway.

But its probably not related to the check engine light - possible but “check engine” doesn’t actually mean anything like you’re low on coolant or oil or something. Follow JE Meehan’s advice and get the car scanned for codes. When you get them report the exact codes.

Thanks for the advise, I’ll do that .

Though it appears that Zerex (now a Valvoline company) appears to make the widest line of coolants, I don’t think that they make a coolant specifically to VW’s formulation, but check. They recommend Deathcool for VW before MY 1996. For MY 1996 and after they recommend Their G05. It looks like the OP got bad advice. I would not recommend the orange stuff in that car.

Honestly, for the difference in price every few years, I would go with VW’s coolant except that means you have to carry some with you in case you are not near an open VW dealer and need a little coolant. Fortunately our cars use G05.