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sethlamb
11-06-2010, 05:47 AM
98 a4 2.8. Temp gauge never gets past a qtr of the way. Heat is very faint. Not super hot. The repair shop i was at said the thermostat opens up at the correct temp and nothing is wrong with it. What else could it be? Very rarely the gauge will go up half way but then it drops back to a qtr of the way. What gives?

J Ozzie
11-06-2010, 06:00 AM
Id double check that and the coolant Temp Sensor. Does your oil temp stay low as well?

next time search man.. there has been huge talks about this and why and how to fix it.

sethlamb
11-06-2010, 06:24 AM
yea.....the oil gauge doesnt move either....

discontained
11-06-2010, 08:10 AM
I have the same issue in my 1.8, if its below 58 degrees outside the car wont get to normal operating temps. The heat will be warm but not hot. I have to turn my electric fan off to get it to go up to at least 1/4 of the way. I replaced my coolant sensor (green) and my thermostat, flushed my system, all the stuff.. So i dont know either just thought I would add that. Good luck

coolgraymemo
11-06-2010, 10:13 AM
Check for Air in Coolant Reservoir,
Check/Replace your Coolant Temperature Sensor,
Replace Thermostat,

DRock3d
11-06-2010, 11:04 AM
My gauge will move up 1/4 of the way, oil temp won't budge. It doesn't bother me too much but defeats the purpose of the temp gauges and I hope it isn't too late before I realize the car is about to overheat.

sethlamb
11-06-2010, 12:33 PM
The mechanic that last worked on the car told me its pretty involved to change thr thermostat. I dont wanna run and do that unless i know its the problem. Is there any way to check if the thermostat is faulty?

99blueb5
11-06-2010, 12:53 PM
no its not pretty involved to change the thermostat, i could change the ECT(engine coolant temp sensor) they go bad all the time and show false readings, if it isnt warming up all the way that is ussually stuck open thermostat

sethlamb
11-06-2010, 01:07 PM
How long should it take to change a thermostat on a 2.8 30 valve?

rovimos
11-06-2010, 01:33 PM
does the engine make any weird noises?

sethlamb
11-06-2010, 02:54 PM
Not really. For some reason since the coil and plugs were changed the car isnt as responsive.

99blueb5
11-06-2010, 03:47 PM
Not really. For some reason since the coil and plugs were changed the car isnt as responsive.

someone installed the incorrect plugs or mixed 2 wires around

J Ozzie
11-06-2010, 05:08 PM
its a known issue with our cars.

A new thermostat: $10.70
Thermostat O-Ring: $.50c
Water Temperature Sender(comes with O ring): $15.83

J Ozzie
11-06-2010, 05:09 PM
Not really. For some reason since the coil and plugs were changed the car isnt as responsive.

were the plugs gaped properly?

sethlamb
11-07-2010, 09:42 AM
Yes. Bosch plugs come pre gapped but we checked anyway

Amorphic
11-07-2010, 12:13 PM
had the same problem. change my coolant temp sensor and thermostat and it was fixed.

sethlamb
11-07-2010, 01:12 PM
How long did it take u to change the t stat and the temp sensor?

Accord4tehloss!
11-07-2010, 04:57 PM
Wait if im not mistaking the thermostat on the v6 is behind the timing belt making it alot harder then the 1.8t

Avant Nate
11-07-2010, 05:21 PM
Change the CTS first, about 2-3 mins.

DRock3d
11-07-2010, 05:36 PM
So today I turned my car off and turned it back on two minutes later and the coolant temp gauge was straight up and down then went down to 1/4 once I started driving. What is the diagnosis for this?

walky_talky20
11-07-2010, 06:23 PM
So today I turned my car off and turned it back on two minutes later and the coolant temp gauge was straight up and down then went down to 1/4 once I started driving. What is the diagnosis for this?

It still could be either. I had the same issue on my 1.8T. Both times had the same symptoms: Not showing full temp, and the temp falling even lower when driving at speed. The first time I changed the T-stat. Fixed for 1.5 years. Next time, same symptoms and it was the coolant temp sensor.

Some of your symptoms though (heat from vents isn't hot, oil temp does not move) point to the t-stat ONLY. Those symptoms don't fit with a bad CTS. So I think you should change the t-stat.

rtavares88
11-07-2010, 06:28 PM
i had the same problem with the 1.8t i can be almost 100% sure its the thermostat. unfortunally to test it you have to pull it out and put it in hot water and watch to see of the needle closes.

walky_talky20
11-07-2010, 06:31 PM
i had the same problem with the 1.8t i can be almost 100% sure its the thermostat. unfortunally to test it you have to pull it out and put it in hot water and watch to see of the needle closes.

Yeah, but you never have to test it. They are cheap, if you go to the work of pulling it out, you're putting in a new one anyway. Regardless of whether the old one tests bad or not.

sethlamb
11-07-2010, 07:06 PM
I hear it takes mad long to change the t stat on the v6 any answers?

Avant Nate
11-07-2010, 09:24 PM
buy a good T-stat. I put a Stant one in and it would allow coolant through at high rpm. Replaced it with a Behr and no problems for a year. The lip was more pronounced on the Behr and it is still a PITA to have to do it twice.

DRock3d
11-14-2010, 10:27 AM
So I'm not sure how this happened but I VAG COM'd last night for the first time ever and I checked fault codes and it said there was an intermittent issue with the coolant temp sensor. I cleared the code and my coolant gauge has worked fine ever since. I <3 Vag

somebody5788
11-14-2010, 10:31 AM
I hear it takes mad long to change the t stat on the v6 any answers?

Add about .2 of an hour to a timing belt job. May as well do a full timing belt while it gets done.

Like walky said though. IF you are not getting heat then the thermostat is probably the problem. If you get heat and your gauge reads cold it's probably your CTS. If you don't have heat but the gauge reads then you probably have air in the system.

While running cold will not really hurt the car it will not be running at it's optimal temperature where it gets the best fuel economy. This in turn could potentially shorten the life of you cat's.

It's normal for the gauge to go up if you shut the car off for like 3 min and then turn it back on. The stagnant coolant is not cooling so the coolant absorbs more heat before the engine starts to cool off and will register on your gauge.