23 August 2005

More Typo Patches

I’ve got a couple new Typo patches that I’ve made in the last week to add features that I wanted. They’re both working here on this site right now. One makes a toggle so people can limit the Atom and RSS feeds to show the top of the article, but not the extended content. The other breaks the sidebar off into its own cached element so it can be updated more frequently but independent of the article it is appearing beside.

#316 Add toggle for extended article text in RSS feeds

The default behavior of Typo is display the whole article in the RSS feed. This is nice for people who want to read all the content in their RSS reader. However, certain tricks with CSS may not render well and users of Safari’s RSS reader will have to scroll a long ways if articles are lengthy.

This patch adds a toggle to Typo’s admin interface that limits the RSS feed to showing only the top article text and not the “extended content” (if there is any). Reloading my RSS feed will result in not seeing the article full of the repairs I made to the Audi, but only the first part that provided an overview.

Some people use similar features in other blog software to drive traffic to their sites by providing only a teaser in the RSS feed. I like to think of it in an overview sense rather than trying to get more advertising traffic, but to each their own.

#345 Separating sidebar into its own cache

Typo’s current behavior is to render the the sidebar at the same time of the article and leave it in the static page cache. This is problematic for people who have things like RSS feeds or Flickr feeds in their sidebar. The only workaround so far was to sweep the whole cache regularly, forcing every page to get rebuilt.

This patch uses some JavaScript to pull a fresh copy of the sidebar as the page is loading. The cache file for the sidebar URL can be swept separately from the rest of the cache so the sidebar can be updated without forcing rebuilds of all the other pages. It also helps to guarantee consistency of the sidebar across all the pages for the site.

One of the downsides of this patch in its current state is that Google AdSense ads in the sidebar won’t load. Generally Privoxy and PithHelmet keep me from ever see these ads anyway, but I’ll have to dig deeper to figure out what is going on. Right now, it appears this is an issue with getting JavaScript within the updated content to run. I may also just contact AdSense support and see what they suggest.

There also seems to be an issue with UTF-8 not getting properly decoded in the sidebar snippet that is being downloaded. This may just be a web server configuration hangup.

17 August 2005

Ruby-doc.org Not Working

I’ve had some frustration in the last day or two trying to access ruby-doc.org. As it turns out ruby-doc.org’s name servers don’t actually exist. But a play-by-play will make this easier to explain.

The nameservers for .org say that ruby-doc.org is served by ns1.tagbomb.com and ns2.tagbomb.com. So now we need to find ns1.tagbomb.com.

The nameservers for .com say that tagbomb.com is served by ns1.ev1servers.net and ns2.ev1servers.net. Alright, off to .net land…

The nameservers for .net say ev1servers.net is served by ns1.ev1servers.net and we can find it at Ah ha!

When we talk to it says that ns1.ev1servers.net is indeed at and you’re talking to it. When we ask it about ns1.tagbomb.com (which we were told it should have an answer for) it says it does not exist.

So there we are. ns1.tagbomb.com and ns2.tagbomb.com don’t exist but are the authoritative name servers for ruby-doc.org. No authoritative name servers means no access to the domains. (Although you are okay with certain name servers that allow their idea of where ns1.tagbomb.com is to be poisoned by the .org nameservers)

I hope they fix this soon, not having access to documentation is annoying and doesn’t reflect well on the language.


It’s fixed
now. James Britt was quick about it after it was brought to his attention.

13 August 2005

Replacing Audi TT Coolant Temperature Sensor

As I wrote a couple days ago, the Audi TT had evidence of a bad coolant temperature sensor. Today I made the repair and took some pictures along the way. The rest of this post details the steps involved in this fix. Because being litigious is still the new hotness, the following disclaimer applies:

If you follow the instructions you see here for this repair, you could seriously damage or destroy your car, the building it is in, and/or yourself. If you are not comfortable with these possibilities take your car to an authorized, certified, notarized, and super-sized mechanic to get this repair done.

  • Audi TT with bad/flakey coolant temperature sensor

  • New green coolant temperature sensor (part 059-919-501-A)

  • New o-ring seal for above (part N-903-168-02)

  • New plastic retaining clip (part 032-121-142)

  • Flat-bladed screwdriver

  • Phillips-head screwdriver

  • Your own fingers

Audi TT Engine Audi TT Engine

First off, this shouldn’t be attempted if the car has been run at all in the last several hours. Completing this work without getting injured requires opening up the coolant system (which is under pressure and extremely hot if the engine has run recently) and bumping around other dangerously hot parts. For my repair I let the car sit overnight and worked on about noon the next day, more than needed, but I’d just as soon not get burned.

In order, to get to the parts we want to work on we’ll first have to remove the plastic engine cover and the plastic battery cover. There are two Phillips-head screwclips that hold the engine cover in place. They unhook with a half turn counterclockwise. Pull the front of the cover up and forward and set it aside somewhere. The three screws that hold the battery cover on are normal screws. After unscrewing them (and putting them somewhere you won’t lose them), push the cover back and left a little and pull up from the back edge and it should come out easily.

View of the coolant temp. sensor Another view of the part Views of the coolant

temperature sensor still plugged

in and lit with a flashlight

At this point you should be able to see and get to the coolant temperature sensor. It’s a little dark, so for my work I slid a large flashlight into place to illuminate the part and to be able to see what I was doing. The sensor is on the right hand side of the engine block down beneath a few other hoses and an electrical bundle. The pictures should give you a good idea what you’re looking for.

Open and close the radiator reservoir to the left of the engine just to make sure there is no pressure in the system. Better safe than sorry.

The retaining clip The retaining clip (right)

that holds the temperature sensor

in (not the metal hose clamp left)

Now that we can see the part that needs replacing we need to get it out of the engine. To remove the part first we must remove the small plastic clip that holds it in. Take note at this point of the angle at which the sensor sits in place, this’ll be important when we place the new one in. Using a flat-bladed screwdriver it should be straight forward to lever the clip out. Don’t be brokenhearted if the clip snaps in half like mine did, it’s old brittle plastic and that’s why you got a new one. The screwdriver or some needlenose pliers can roust out any leftover bits if yours does snap. Just make sure those bits are out of the way, you don’t want them inside your cars coolant system.

A view with the sensor pulled out The port for the sensor

with the sensor pulled out

Once the clip is off the sensor should pull right out easily. Some coolant will spill out, but not too much. The old O-ring may stay down in the port, you can use your fingers to fish the O-ring out. As with the plastic clip, it’s best to dispose of the O-ring rather than try to reuse it. Not having coolant spewing out of the engine on the road somewhere is worth the $1 part cost.

The sensor connector The sensor connector with

it’s release tab visible

There is enough slack in the cable bundle that you can pull it up to a more reasonable location to work with it. Use a flat-bladed screwdriver to push on the release tab while pulling out the old sensor. It should come out pretty easily.

Now to install the sensor the process just moves in reverse. The new green sensor will only fit into the connector one way and you should be able to feel and hear the snap when it is together.

The new sensor in the connector The new sensor in the connector

Take the new O-ring seal and get it a little wet in the port and then push it down into place with your fingers. It may take a little bit of work getting it pressed all the way down in all the way around. After the O-ring seal is seated you can push the coolant temperature sensor back down into place. Remembering the angle it fit in at is key here.

While holding the sensor down in the right spot at the right angle, the new plastic retaining clip can be snapped back into place to hold the sensor in. The metal end of the sensor should be all the way underneath the clip. It is very important to make sure that this is right. If it isn’t the sensor will blow out of the port (along with a lot of coolant) when the system gets up to temperature. Pull and push on the green plastic (not the cables) to make sure there isn’t any sloppiness in how it is fitting into place.

Now that the sensor is plugged in, pushed in, clipped in and everything looks okay, it’s time to close up the hood and go for a test drive. Don’t stray too far from home in case the sensor didn’t seat correctly. The main goal is to get the engine up to temperature and make sure the coolant system can get up to pressure without blowing the sensor out and spilling coolant all over the road. This appears to be easy as long as the O-ring sealed and the clip is in the right place. Keep an eye out for coolant on the road behind you. If you do have a spectacular coolant blowout, don’t try to drive the car with no coolant, it makes the engine sad. And be mindful of the high temperatures, the normal coolant running temperature is between 80°C and 90°C, that’s 175°F and 195°F. To reiterate, doing anything around the coolant after the engine has been running for a while is ill-advised unless hot liquid burns with ethylene glycol is your idea of a good time.

So there we are, all done. Our TT made a successful 70 mile drive today with it’s new temperature sensor and all is clear and well. Safe travels.

11 August 2005

17704 - Error in Mapped Cooling System

It’s not a month out of warranty and the TT has had it’s first ever “check engine” light incident. Using a handy tool I ordered, I was able to discover the fault for about the cost of having the dealership diagnose the problem. The message is a little cryptic, but provides a good hint as to what is awry.

17704 - Error in Mapped Cooling System (usually temp Sensor or Thermostat)
P1296 - 35-10 - - - Intermittent

Googling the error code provides a plethora of results discussing what causes this error. The first step in confirming the problem was to figure out if the coolant temperature sensor was actually misbehaving. I cleared the code out and then had Eileen keep an eye on the laptop’s graph for the coolant temperature sensor as we drove to some errands.

Sure enough, as the engine coolant slowly rose to operating temperature, for a couple seconds at a time the sensor would send an absurdly low reading and then return to showing the correct value. While the problem didn’t look like it was happening that often and may not be enough to trigger another fault, it’s obvious the sensor is not feeling quite right (that is unless there are chunks of ice flowing around in the coolant system).

On the way back home we stopped by Chaplin’s VW and visited their parts desk. I had the part numbers, but the parts guy knew exactly what I was after when he read the description I had on the Post-It next to the part numbers. Apparently this isn’t too uncommon a fault for the 1.8T motor that the TT shares with some A4s and a variety of VW models.

Evidently the accounting for warranty repairs between Volkswagen AG and the dealerships encourages them to make the parts for frequently needed warranty repairs cheaper. In this particular case, the parts were $9.10. There was some suggestion that the mass airflow sensor was cheaper nowadays ($60 rather than $300) for similar reasons.

It turns out there are some nice articles online at AudiWorld about replacing the flakey coolant temperature sensor that causes this. I think I may try to document the repair process myself with some more pictures. We’ll see how that goes.