Strange coolant behavior

[bobby james]

Re: Strange coolant behavior

I had a bunch of coolant issues with my S4. My car would take a long time to start warming up (or so the temp gauge said). It turned out the thermostat needed to be replaced because it wasn't reading the temps correctly so the car would actually be warming up but the coolant wasn't running through the system because the thermostat still thought the car was cold. This caused the car to heat up without any coolant so when the coolant was actually released the car was already hot as hell and the coolant would start bubbling. I don't know how many of these issues you have but Lawrence at Calgary Autoworks would probably be able to help you out.

Also, sometimes my car blows hot on the a/c as well, so if you figure it out let me know!

[Jester B]

Re: Strange coolant behavior

Interestng ideas, thanks for sharing your experiences. I am going to try the bleeder screws in the morning and maybe the poor mans version of the temperature test (hand on hose rather than infra reader). Next step will be back to George for another new tstat. That is what I really think it is.

[ridelikeme]

Re: Strange coolant behavior

its your heater core... guaranteed... i have a spare sitting in my closet from my old B5, let me know if you want it.. its brand new in packaging still

[R_Ethug]

Re: Strange coolant behavior

lol if thats the case better call kyle and get ready for the tear down!

[The_Jerbel]

Re: Strange coolant behavior

It's not THAT bad Ryan.

[R_Ethug]

Re: Strange coolant behavior

LOL yes it is after looking at kyles photos

on a positive 2.7t note i think we may get an allroad 2.7t for the next car

[RSS]

Re: Strange coolant behavior

LOL yes it is after looking at kyles photos

on a positive 2.7t note i think we may get an allroad 2.7t for the next car

Maybe now with two 2.7's you can atleast get one of them up to Stage 3

[R_Ethug]

Re: Strange coolant behavior

stage 3+3=6!

[The Brice]

Re: Strange coolant behavior

I'm thinking faulty T-stat possibly, it still sucks to replace although not as bad as the heater core. Mind you I've never had to swap out the core "yet" but it certainly sounds like much more of a pain in the ace.

[The_Jerbel]

Re: Strange coolant behavior

It doesn't sounds like a bad T-stat to me. I would say that your heater core is giving out on you. Either that or you've got some air stuck in the system and the coolant is not completely getting to the HC. When you did the water pump/t-stat, etc. You need to burp the system when filling with coolant. If you have air in the system it can cause problems like the one you're having.

[The_Jerbel]

Re: Strange coolant behavior

I didn't have time to go into detail before, but the reason I said what I did is this:
If you have a bunch of air in the system, particularily in the heater core or its hoses, there won't be much coolant passing through there. When you sit at idle the engine is not turning the water pump very quickly, you get minimal coolant flow through the HC, and get marginally warm air. When you rev the engine, the water pump spins faster, pumping a little more coolant through the HC, allowing the heater core to get hotter and the fan to blow hot air for a minute. When the rpm's drop again, you are back to warm air.

[Volkstech01]

Re: Strange coolant behavior

regardless of idle or higher rpm, it shouldnt be noticable in the cab with regards to heat while sitting @ a light or out front of the store. Not the core I would say.

[The_Jerbel]

Re: Strange coolant behavior

That's my point. There is a chance it could be the core, but more than likely it's just air in the system.

[VWSM]

Re: Strange coolant behavior

That's my point. There is a chance it could be the core, but more than likely it's just air in the system.

THERE IS A


there is a specific way to bleed that system,
vacumn suck and refill or off that heater core hose.
every shop should have an infra red thermoter and a vacumn gauge.
thermostats at my shop are tested before installation,to much work to r@r
on these new cars.

put them in a glass jar heat up the water till it gets to 82-87 degrees c
and it should open.
2 out of 10 are faulty.

[turbomeyers]

Re: Strange coolant behavior

i vote not the heater core or it would never get warm . many tdi passats have this issue (b5.5) from brand new , i cant remember what the fix is but i never changed the cores .