flashing red coolant light

[shellbug]

UGGG, my car is doing this again this winter. Everytime it is under 50 degrees in the garage, when I start it up for the first time that day, the red coolant light starts flashing and buzzing but goes off after I start driving. I have taken it in last year but they claimed there was nothing wrong. Also a couple of times the heater blows colder air when I am idling but warms up when I start driving again, could those things be related?

[pvpeacock]

Mine does the exact same thing, but I haven't taken it in to the dealer yet. It starts out flashing red and beeping and as soon as I leave my driveway it stops beeping and changes to a blue light. Then when it warms up, the temperature light goes out.

[FarrisK]

I'm no expert on the 2.5 gasser, but as a general rule of thumb:

Flashing red lights with a buzzer mean don't drive the car.

Take it to the dealership, and if they say nothing's wrong, ask them to inspect the water pump (both of you should still be under warranty with 2006 Bugs, IIRC) for wear.

[DZLBUG]

Originally Posted by pvpeacock

Mine does the exact same thing, but I haven't taken it in to the dealer yet. It starts out flashing red and beeping and as soon as I leave my driveway it stops beeping and changes to a blue light. Then when it warms up, the temperature light goes out.

I already explained this in your thread, I'll copy and paste it below for shellbug.

"Helps to read your owner's manual. Flashing red means low coolant level. What is happening is that when you start the cold engine, the level is low. As you start driving the coolant starts moving and heating up, this causes it to come into contact with the coolant level sensor which makes the flashing stop.

Top off your coolant reservoir and problem is solved. Small top-offs with just distilled water are OK. But if you live in a cold climate, it is best to top-off with coolant/distilled water mix to keep the freeze protection up.

Use VW or Pentosin G12 or G12+ coolant only. No green, orange or any type of "global" coolant. Mixing the two will result in a foamy/gummy/nasty mess in your cooling system. Your dealer is the best place to purchase the correct coolant. Coolant to water ratio should be 70/30 (60/40 for G12+ I believe) for optimal freeze and boil protection. When in doubt...follow the bottle."

Always read and understand the manual so you know what the car is trying to tell you.

Blue coolant light = engine cold
Flashing blue coolant light = fault in the coolant monitoring system
Flashing red coolant light = low on coolant
Steady red coolant light = engine overheating, pull over and stop engine IMMEDIATELY and do not run until the problem has been identified.

[YummeeCookee]

Originally Posted by DZLBUG

Use VW or Pentosin G12 or G12+ coolant only. No green, orange or any type of "global" coolant. Mixing the two will result in a foamy/gummy/nasty mess in your cooling system.

Is this really a huge deal? I filled my coolant reservoir with one of those global coolants. Apart from the nasty mess, what other harm will it to to my car?

[FarrisK]

Originally Posted by YummeeCookee

Is this really a huge deal? I filled my coolant reservoir with one of those global coolants. Apart from the nasty mess, what other harm will it to to my car?

(I got that from the Vortex. Not my creation. )

Imagine all that crap in your engine... mixing coolants causes a lot of mess in all the coolant passages, and IIRC can cause corrosion on the different alloys in the block itself.

[topless kitty]

dan j reed is the man, listen to anything he tells you. he's a VW god.

in case you didn't know.

[DZLBUG]

Originally Posted by YummeeCookee

Is this really a huge deal? I filled my coolant reservoir with one of those global coolants. Apart from the nasty mess, what other harm will it to to my car?

Yes it is a big deal. Get it out of there unless you want what was pictured above. Can also cause corrosion...particularly in your heater core. You don't want to know what a PITA that is to get to if it springs a leak.

G12 is cheap. Do it right.

[Smileybug]

The pain you will go through once that gunk gets into the entire cooling system and engine block will not be worth it. Do it right!

I have an '84 Jetta TD that had been sitting for 3ish years. The coolant tank had a ton of gunk in it (looked like just nasty bad coolant+deteriorating lines). Wasn't mixed coolants gunk, but just as gross. Replaced the reservoir, flushed the radiator and heater core, and its still coming out brown. It take a long time to flush it all out and you don't want to clog up everything. Its really not worth it.

[Ikkin]

I've wondered too, if both issues are related.
Last year, my heat didn't work, it was warranty work and was repaired. I'll have to dig out the receipts now, as i think it was due to bad coolant something or other.

Last month, i got the blinking red coolant light. I had driven longer then normal, and it was a huge sleeting blowing rain storm out too. Coolant level was fine, i thought that with all the rain, something may have gotten wet. Nope, still had the alarm, and took her in for service. It was warranty work again, they said the sensor, for low coolant level, was bad.

Hopefully you still have some warranty left and can get your issues worked out, or maybe you have, let us know!

[pvpeacock]

I finally took my bug into the dealer for a number of items, one of which was the flashing red coolant light every time I start the car. They fixed it under warranty and told me they had to replace the resevoir. Unfortunately, they didn't give me any more details.

[erikj1012]

Great info! Do you know where Pentosin G12 can be purchased if you need it right away (can't wait for mail)?

[Smileybug]

Word has it that Napa carries it. The dealer is also an option of course. I've yet to see it at any auto parts store around here(I've checked O'Reilly's, Autozone, and Advanced). I tend to get mine online or from my VW mechanic.

[jdmracing]

My wife's was doing the same.
I dont know what fixed it but, we fixed a few other things, and just noticed its not came on in several days.
Things replaced:
MAF
EVAP
Engine Speed Sensor (Crank sensor)

Now, did any of those fix it? I have no clue.
Will it start doing it again now that I said this?
Most likely

Not much help, just some info...
Good luck!

[Smileybug]

None of those have anything to do with your cooling system. Check your coolant level, I bet its low.

[VW Lady Bug]

If the blinking red coolant light comes on at start - shut off and fill with the proper coolant (G12 all the way). If it comes back on again shortly - you have a leak.

If the dealership replaced the reservoir there was probably a leak or a crack (had a similar issue in my Mk3). I picked up a spare coolant bottle at a show for $10 and replaced it myself... the vendor was kind enough to let me pour water in it to confirm that it was good.