Hi guys,

I have a 2 part symptom that I'd like to get some opinions on.

Last night I went to start my car to warm it up. Outside temp was -18 CELCIUS. The cimate control was set to windshield defrost to heat up the front windshield. This drives the fan up to its max setting even though the engine is nowhere near its idling temp.

The car was on for about 20 mins which is more than enough time for the car to warm up even at -18.

When I finally got into the car I found that the air coming out of the vents was not very hot which is not normal. Also, I noticed that the needle on the temp gauge had only reached the 1/4 mark on the dial as opposed to the middle normal idling temp (90).

Would anyone know what the HELL is going on??? I'm gonna go a vag scan when I get home but in the meantime I'm hoping it's an easy fix....

Anyone?

 

Sounds like the thermostat is stuck open. Low engine temp and little heat. If the engine temp was normal, I would say you've got a plugged heater core. But since it's not up to operating temp, it must be a stuck thermostat.

20 minutes of driving should be plenty of time for the engine to warm up and provide toasty Audi heat, even when the temp is 0 F.

 

Well,

I just brought it into Tapp in Ottawa (great bunch of guys) and they did the heater core flush and although the HC wasn't blocked or clogged it was good preventative maintenance. The problem was actually smaller than anticipated.

As I said in a previous post, there were some air pockets that had accumulated and that is why I wasn't getting as much heat as usual. Also, the tech discovered that the "J" plug was leaking coolant (commonly called the J plug because it's a plug that is shaped like a "J"). This may have been the culprit. As coolant leaked it eventually reached a level low enough that the res was starved for coolant. This causes air to be trapped in the coolant lines which results in a blockage. Short term solution is to just keep the coolant topped off until I can bring the car in to have the "J" plug replaced.

Pretty sure it wasn't the thermostat this time.

 

yea i was going to say when u have no heat first thing to do it see if u are having air bubbles in the system. let the car warm up and open the coolant cap and let the car gurggel and repeat this process a couple of times. If it works u saved ur self $$$$ if not ur problem might be more. But replacing the jplug shoudlnt be to much $$$ or am i wrong pablo?

 

We call it the Rhino plug cause its shaped like a rhino's horn. And its a pain in the but to change because it usually breaks inside when trying to remove it. When that happens you have to remove the thermostat housing and push it out from the inside.

But it could be the culprit... because its letting air into the thermostat housing.

 

Actually guys it IS the J plug. The tech and I saw it with our own two eyes lol. So now I have to just bide my time until I can get it in and have it replaced. The temps up here in Ottawa Ontario are well below 15 Celsius so there's NO way I'm gonna wrestle with it in my little garage. They are telling me it is around 1 hour plus the plug. Not too so All I need now is to get the car in to have it done. I just hope it doesn't break off.

 

UPDATE,

I've endured a few really cold days since the heater core flush and it is still not warming properly. The car egets up to 90 and stays there so I'm pretty sure it's not an ECTS or thermostat or water pump issue.

Since the guys at Tapp didn't flush the heater core with super hot water (just used plain ol' COLD tap water from the hose), I think I'll try flushing it out with super boiling hot water and CLR. I want to try the 2 litre bottle and CLR trick, does anyone know if there is a DIY page out there for this?

 

We get away with flushings heater cores with compressed air. Usually do it 3 or 4 times. Its common for them to get clogged because this A4 is getting older now and people aren't flushing their coolant as preventative maintenance anymore

 

That's true... a 100 dollar maintenance cost will triple now but hey, I knew it going in sooooo my fault, I know. In anycase, the Rhino plug is leaking too so IT has to be repaired first and then we can flush the heater core. Update to come later this week.

Thanks for reading guys

 

Replace Coolant tank & Coolant Flush 1.8T DIY (PICS)
Flushed my heater core with CLR. Lots of pics.