its crazy how many problems the little coolant temp sensor
11-22-2004, 04:12 PM
#1
Elder Member
Thread Starter
Join Date: Apr 2001
Posts: 28,404
Likes: 0
Received 0 Likes
on
0 Posts
its crazy how many problems the little coolant temp sensor
was causing me. wierd start ups, wierd idles (sometimes in neutral the rpms would climb for no reason), etc. swapped it out and everything seems to be running 100%. i started and shut it down about 6 times or so, then let it run for about 5 minutes.
11-22-2004, 06:23 PM
#2
Member
Join Date: May 2001
Posts: 17,322
Likes: 0
Received 0 Likes
on
0 Posts
When they go south they usually convince the ECU that the coolant is cold. The ECU then enriches the
mixture as it is supposed to when the engine truly is cold. Oft times the sensor occilltes between temperatures 'reported' and the ECU falls into and out of enrichment. IIRC the cold engine sequence either takes the O2 sensor out of play or at the least alters the influence the O2 sensor has on controlling the mixture.
11-23-2004, 09:21 AM
#4
AudiWorld Member
Join Date: Feb 2003
Posts: 436
Likes: 0
Received 0 Likes
on
0 Posts
would you say this is common across all A4s
or more 1.8s than 2.8s...I've observed that my engine temp gauge takes 5-10 minutes to level at Normal. It stays at 0 (cold) initially. Seems abnormal to me.
11-23-2004, 09:28 AM
#5
Member
Join Date: May 2001
Posts: 17,322
Likes: 0
Received 0 Likes
on
0 Posts
I'd say it is 'common' across all OBD cars. It is the same function and when they fail it is typical
that they report cold. That said, the fact that it takes 5-10 minutes for your gauge to reach normal operating temperature is NOT indicative of a bad sensor. It is normal for it to take a while to heat the engine, engine oil and coolant to operating temperatures.
11-23-2004, 10:57 AM
#6
AudiWorld Member
Join Date: Feb 2003
Posts: 436
Likes: 0
Received 0 Likes
on
0 Posts
one last thing...
For the oil gauge, I am used to waiting about 10 minutes (even after driving the car) and I know that is normal. But this is the first cold season that I've noticed such a 'waiting' period with the engine temp gauge. Usually it's up instantenously. So naturally, I assumed there's something broken.
11-23-2004, 12:19 PM
#7
Member
Join Date: May 2001
Posts: 17,322
Likes: 0
Received 0 Likes
on
0 Posts
I'd answer by asking you a question ... How instantaneously does a pot of water on a gas stove come
from ~40 degrees F to 210 F?
During the summer months when it is possible to have the coolant at 80 or 90 degrees F it will take substaneously less time to rise to full operating temperature but even then it will be far from instantly.
During the summer months when it is possible to have the coolant at 80 or 90 degrees F it will take substaneously less time to rise to full operating temperature but even then it will be far from instantly.
Thread
Thread Starter
Forum
Replies
Last Post
Jniebles
A4 (B7 Platform) Discussion
1
11-01-2012 06:28 AM
Biscuit141
Audi 100 / A6 (C4 Platform)
1
12-22-2004 04:29 AM
