99 Passat V6: coolant thermostat

Aug 03, 2005 8 Replies

I'm seeing my coolant temperature gauge fluctuating between 0 and normal (190 deg. C). I think there's a loose connection to the coolant thermostat. Can anyone point out where I need to look for the thermostat on this model?


Thanks.


There are no "connections" to the thermostat - that's a mechanical thing that regulates the flow of water to the radiator.

If you mean the temperature sender its around the back of the engine. Hop on over to

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& search the forums - I think there is a "how to" on replacing it. ISTR its a bit fiddly on the V6. VAG temp senders do fail quite regularly & at 6 yrs old yours is definitly a canditate - its unlikely to be just a "connection issue". Its not an expensive part & should take less than 15-20 minutes to replace (most of which will be fiddling around trying to work out how to get it out & the new one back in & connected up again!

I.

"Iain Miller" wrote in news:PDVHe.8990$ snipped-for-privacy@newsfe6-win.ntli.net:

Sorry, I meant the temperature sender. I also didn't mention that the temperature sender was replaced just a few months ago when my water pump got replaced. I would hope it hasn't gone bad already!

Passenger side behind cylinder head. Thermostat is behind timing belt.

More likely your thermostat was replaced when you replaced the WP - they are pretty much "joined at the hip"

I.

"Iain Miller" wrote in news:aHcIe.3595$ snipped-for-privacy@newsfe6-gui.ntli.net:

You're right. I did get my thermostat replaced at that time, not the temp sensor. It's nice to have knowledgeable people like you out there!

Thanks.

Thanks for this thread/info. I first noticed a zero coolant temperature displayed on my 99 Passat V6 (bought Nov1998 and now at 90K miles) last February. A vigorous finger-thump on the display made the needle quickly return to its normal upright position. I've noticed this problem/solution about four times since then. My water-pump/thermostat failed Nov2004 at 83K.

--- Frank

That sounds more like a problem with the gauge than with the sender.

-- Mike Smith

Check your water coolant is it ok, need toping up. Can you see water like milkshake?? Than this is VERY serious problem fix ASAP as water and oil mix tougher in radiator, my Patrol passat had same problem and spent £2400 last month. Advice to empty and refill coolant.

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