The high nitration results were the only measured quantity that was outside normal values.  I’m not exactly sure what a normal nitration level should be, but I searched the web for some answers.  I posted the question on two forums, asking what could cause the nitration level to be “high”. The answer I got: the cylinder head could be running too hot, my EGR valve could be stuck partially open, or something related to my turbo.

The EGR was actually stuck open, giving an error code that I cleared with VCDS (VAG-COM).  I cleaned the EGR and everything seemed fine.  This is what I thought caused the high nitration.

Today, I got around to testing my radiator fans, which should come on when the AC is running.  There are two fans, one larger fan on the driver’s side (left), and one on the passenger side (right), directly behind the radiator.  When I checked to see if both were running (they should both be on), only the passenger side fan was operating!  This may have caused the engine to run hotter than it should have, although the temperature reported in the cluster always showed 190F.  According to others, the temperature in the cluster isn’t always accurate.

I ordered a replacement fan made by Febi/Bilstein, part number 6X0959455F.  Hopefully I get it early next week, or tomorrow if I’m lucky and they ship from White Marsh again.  The removal does not look too bad, and I can probably get the old fan to work again with some cleaning.  The only reason I’m ordering a new one is the convenience of having a working fan.  The new fan was $90 after shipping.  Compare that with ~1 hour or more of messing around with a fan that may or may not work reliably again, and you can see that it all comes down to convenience.  If I can get the old fan working again, then I’ll have a spare for the future.

In the end, I think the oil analysis was useful.  Because of a single abnormal result, I focused on possible problems that could have caused it, and found two that I would not have discovered without the analysis.  I’ll probably do the oil analysis regularly now, just to see if I can follow this trend and determine if I fixed the problem.

Now I just need to replace my alternator pulley, serpentine belt tensioner, and replace my supsension, and my car will be good to go for the summer.

]]> http://iamstuffed.com/blog/2009/05/29/oil-analysis-results-revisited/feed/ 0 http://iamstuffed.com/blog/2009/05/16/oil-change-and-timing-adjustment/ http://iamstuffed.com/blog/2009/05/16/oil-change-and-timing-adjustment/#comments Sun, 17 May 2009 03:25:59 +0000 iamstuffed http://iamstuffed.com/blog/?p=238 Tonight, after reading 17 research papers in three topic areas, I decided to change my oil and adjust the camshaft timing a little.

I found this link on tdiclub.com:
http://forums.tdiclub.com/showthread.php?t=215202

It basically lists the steps to adjust the cam timing so that it’s back in spec, and hopefully fix the idling issue most people have. On my car, the engle idling RPMs pulse at seemingly random intervals. Since I did the timing belt change myself, and I had that whole ordeal with having to replace the crankshaft flange and seal, I thought maybe the timing was slightly off.

In VCDS, the Torsion value was 2.0. According to tdiclub.com, the valid values are between -2.5 and 2.5, with 0 being ideal. I followed the directions and eventually got the value to -.5, so I called it quits after that. The first attempt must have put it out of spec because the car wouldn’t stay idling, it would just quit. After I adjusted it to -.5, I had to clear the error code (camshaft sensor out of range, or something like that) and put everything back together.

I also changed the oil. It seems like a waste to extract out the 1000 mile old Mobil1 TDT 5w40 oil, but I just want to make sure no metal bits, or extra material from the sealant or flange remained in the oil. I replaced the oil filter and put in new oil, but left the Amsoil BP90 bypass filter. That filter I won’t replace until 50,000 miles.

I’ll do another oil analysis at 10,000 miles from today. Hopefully the wear rates are better than the VW spec oil.

I installed my Dieselgeek Bypass filter kit, finally. I waited until I did my ~100k oil change (a little early because of the upcoming trip to TN) and switched to Mobil1 Turbo Diesel Truck 5w40 oil. Even though the oil is not approved by VW to use in my engine, people at tdiclub.com have been getting good oil analysis results. I even took an oil sample of the oil before I removed it, so I had a baseline to compare with the Mobil1.

My brother and I went to Tennesee so he could adopt a Boston Terrier from a rescue. I think the mileage was about 400 miles each way and I was getting close to the 100k mile mark on my odometer (timing belt change time) but we took my car anyway. It has more space, and gets better mileage than his car. On the way to TN, we averaged 46 mpg! The dog was super nice, and ended up being a well behaved dog (with the exception that he farts like a titan!).

I was a little worried about my timing belt, since I’ve read nightmare stories about people waiting too long to change the belt. When the timing belt breaks, you usually need to repair the head of the engine, and maybe some other odd bits. At the minimum, it’s an expensive process to fix the engine. At the maximum, you need a new engine! I think I calculated the miles and left a 60 mile buffer once we returned to my house.

After we got home, I parked the car and worked on it in the evenings and the weekends. During the week, I drove Andrea’s Mercedes and she drove her Aurora. Sometime after we got back from TN, I received the results of the oil analysis. The comments on the oil analysis indicated something about the nitration being high.

I researched what that could mean, and multiple sites said it could be the turbo, egr, or something else, I forget. The VCDS (VAG-COM) diagnostic software indicated an error with the EGR, so I removed it and cleaned it.

On the friday after the TN trip, I started the timing belt change.

I spread out the work between friday night and saturday. On saturday, I started in the morning, and didn’t finish working on the car until late late in the night! This was my first timing belt change, ever, and the most I’ve ever done to a car up until that point. I just followed the instructions and everything seemed to go reasonably well, until I attempted to tighten bolts without a pulley.

On Sunday, I put everything back together, and test drove the car. I actually turned the crank a couple revolutions to make sure the timing was correct, and nothing was colliding. Everything seemed perfect, and I didn’t notice anything wrong, so I put my metal skid plate, and packed everything up.

The next day, I drove my car to work, in the pouring rain. When I got to work, I got out of the car (in the rain), and noticed some rainbow spots appearing under the car. Since the rain was coming down at a pretty good rate, the rainbow spots were pretty noticeable and they kept appearing. I thought maybe I spilled some oil, or it was the oil I found on my transmission mount, so I went into my office and started working. After some time, I got more and more worried about those rainbow spots on the ground, so I went back out and noticed that they kept appearing! I even started the car and moved to a different parking spot (all while it was still raining), and the spots trailed my car. My car was definitely leaking oil, and at a good rate too! I checked the oil level (in the rain), made sure it was at the max, and drove home.

Over the next few weeks, I had the pleasure of fixing my botched re-installation of the harmonic dampener. I tightened the bolts without the pulley at one point, going past the crankshaft sprocket and cracking the oil seal flange behind it. The fix: remove the crankshaft bolt, crankshaft sprocket, the oil pan, replace the oil seal flange and the seal, and reinstall the oil pan, crankshaft sprocket, and new crankshaft bolt. Prior to that point, I had no idea how to do any of that, but I read on the interweb and figured it out!

$130 Crank Yank from MetalNerd.com:

Crankshaft bolt removed:

After removing the crankshaft sprocket, this is what I found:

I actually found a small bit of metal on the bottom of my oil pan. Hopefully there was no other damage, or no other metal bits; that piece may have been dropped there whenever I took everything apart.

Here are the rest of the photos. Removing oil pan, cleaning it, and then resealing it with silicone and reinstalling everything.

The red Dirko silicone sealant (high temp, Hylomar equivalent by Elhrig)

Seal installer and installed seal:

Oil pan:

All done:

I reinstalled the sprocket, reinstalled the harmonic dampener, and reinstalled the timing belt and serpentine belt. So far, I’ve driven about 1000 miles since I changed the timing belt, and that includes not driving my car for two weeks. Even with my expensive mistake ($110 for the flange, $10 for the seal, and $130 for the Crank Yank counterhold tool), I still paid less for the timing belt change than the dealer charges, plus I got to learn how to work on my car. I will have to admit though that there were several times when I thought I was well over my head, but rational thoughts prevailed!

Now I feel like I can fix anything.

Before the oil change, I took a sample of oil from the oil pan using a vacuum pump sampler. I bought an oil analysis kit from Oil Analyzers that came with a prepaid shipping label. I filled it up with the pump, changed the oil, and will send it off tomorrow. After some positive feedback from using Mobil 1 Turbo Diesel Truck 5W40 oil in PD engines, I decided to give it a try instead of the normal VW spec 505.01. At tdiclub.com, there are more and more people having camshaft and lifter problems in their PD engines, even though they used the VW spec oil. Either the oil isn’t as good as VW claims, or the design of the engine isn’t as robust as their older diesel engines. Either way, I want to try to limit the damage the oil could have caused; I’m going to try using the Mobil 1 oil for a couple iterations, while taking samples between the 10K oil change interval to track the progress of the oil. It *should* do better than the VW oils, since the Mobil 1 oil is a better synthetic. We’ll see!

Soon, I’ll change the timing belt too. Everyone recommends that the valve cover be removed to inspect the camshaft and lifters, so I’ll be doing that as well. Hopefully my cam and lifters are okay. Even if they don’t look okay, I’m not entirely sure I’ll do anything about it. More than likely, I’ll just keep trying to minimize the future damage. A new cylinder head from metalmanparts.com costs about $1700, which would include everything I would need to replace (hopefully), should there be a problem. At least I know the approximate dollar amount of the fix for a hypothetical worst case problem.

I’ll post the lab results from the ~8100 mile sample from my car. I’m not entirely sure it’s an 8100 mile sample because I don’t remember the exact mileage of my last oil change. I know I always change it at roughly the 10,000 mile interval, but it may have been a couple hundred miles over or under the 90,000 mile mark. I’ll track the mileage a little better now, especially since I have to put the info on the labels for the lab to track.

Afterwards, everytime the car shifted, it made a loud noise (clunk) and shifted hard. Some intense reading at mercedesshop.com and a few days later, I decided to fix the shifting by diagnosing the vacuum lines going to the transmission. Using a MityVac, I found that the vacuum line going from the vacuum pump to the valves for the turbo/EGT were leaking like crazy, so little or no vacuum was reaching the transmission. I solved this by plugging the line that was leaking. Since that particular line was for the turbo/EGT and the seller plugged the line to the turbo, the line was useless anyway.

With the line plugged, the shifting got much smoother. In fact, the shifting became too soft! Whenever it shifted into higher gears, it would rev a little before dropping rpms. After some more reading, I fixed this new problem by adjusting the vacuum control valve(VCV). The MityVac showed that the transmission was getting approximately 12″ of vacuum and when I revved the engine by pulling on the throttle linkage, it would drop to 5″ or so. I untighted two 10mm bolts on the VCV, turned it clockwise, and retightened. I’m not entirely sure what the twisting of the VCV does, but I’m glad it worked.

Eventually I’ll post a pictures of what I modified and adjusted and update this post.

We filled up Andrea’s car. 391.7 miles and 14.457 gallons = 27.1 mpg. I think the next fill up should give us the true mpgs of her car; this time, I filled up the car until I could see the fuel in the filler tube. Go diesel!

I like to use an oil extractor to change the oil on my VW Golf because it’s quick and mess free, but for Andrea’s car, it took me an hour to extract the oil. The oil was just too thick! Earlier in the day, we drove around trying to find a local store that sold an oil extractor that held more than 7L, but no luck. The extractor I currently have only holds 4L; this meant I had to stop half way to empty the extractor and continue. When I stopped half way, the tube accidentally splattered some oil on the wall. So much for mess free!

Over the next free weeks, I’m going to search for an extractor that can hold enough oil for all the cars. These are the most likely candidates:

Pela Pro 14 (14L)
Motive Power Extractor (10 Qt)
MityVac 7400 Fluid Evacuator (7.3L)

I’m leaning towards the first one, since it holds more and looks like it uses a sealed/solid container. I can’t tell from the pictures of the Motive or MityVac products if they also have a solid bottom piece.

While at his house, he replaced two vacuum valves and one black vacuum thingy, and fixed some of the vacuum hose connections. It turned out that one of the vacuum lines had a BB in it (from a BB gun?), and some cables weren’t even connected to anything.  He mentioned something about Crazy Rays and getting parts there for later, so he can replace the remaining black vacuum thingy.  He definitely knows his stuff!  Crazy Ray’s looks like an awesome place to get parts for an old car.

He took the leaking injector out and took it apart.  One of the metal mating surfaces had a burr or gouge in it, so he filed it down and sanded it and put it back together.  After test driving some more, it ended up leaking again, so he found another spare injector and just used the top portion of the spare with the bottom casing of the leaking one.  After installing it a second time, the leak was fixed!  He showed the injector to me and explained that the nozzles looked like they were new so I can probably hold off on buying new injectors.

The turbo seems like it’s working now and the fuel leak has been fixed, so tomorrow Andrea will be driving it to work!

The car is a 1993 Mercedes-Benz 300D 2.5 with 188K miles!  The mileage might seem high to most people, but after driving my 2005 VW Golf TDI for 95K miles with zero problems, and after researching the Mercedes diesel engines, I don’t think Andrea will have to worry about the engine failing.  Just do a quick search on craigslist and see how many old 1980s/1990s 300Ds are for sale and you’ll see that most are in the 200K+ mile range.  It is an old car though, so I’m sure eventually it will have electrical/mechanical issues.  For now, it seems great though.  Mechanically, everything that I’ve tested is working.  When the time comes for repairs, hopefully they’ll be minor enough that I could tackle them.  I think the only two things I won’t attempt to do on the car are transmission and engine related.

Andrea has been driving to UMBC on opposite days that I’ve gone, so we’ve been driving to work separately on four of the five work days of the week.  Previously, we were splitting the cost of diesel for my car, since we drive everywhere together and my car is super efficient compared to her Oldsmobile Aurora.  Because of this, we were saving a lot of money.  Now that we drive separately, Andrea has been paying to fill up her Oldsmobile and has been getting really crappy mileage (~18 mpg?).  This “new” Mercedes should get her around 30, which should save her a considerable amount of money in the long term.

Go diesels!  I hope I hope I hope nothing major happens in the next year or two.  That would be super.

In the immediate future, the car will need: new tires, new mirror control switch, and a pillar trim piece.  Maybe I’ll also need to check the timing chain, but I need to read more about how to measure the chain stretch.

From what I’ve been reading, there’s no such thing as a cheap Mercedes.  We’ll see if that’s true.