Category: Cars

I was able to get the fuel rail freed up enough to pull the #8 and #9 injectors. I ran them both through an ultrasonic cleaner for about 20 minutes and swapped them, so what was the #9 injector is now in the #8 cylinder and vice versa. So one of three things will happen…

1. The problem is gone, meaning the ultrasonic cleaner fixed the problem.
2. The problem moves to cylinder #8, meaning I need to replace an injector.
3. The problem stays with cylinder #9, meaning I probably have a bad coil pack (which is still under warranty). There is a very remote chance of a bad plug on #9.

To avoid uncertainty, I am considering swapping the plugs between cylinder #9 and #10. I am however NOT a fan of pulling the coil pack again… if everything else goes well this afternoon and I have time to do it, I’ll do that

For a while now, I’ve been chasing a coolant problem on the Mercedes. You can drive the car as much as you want, and never loose any significant amount of coolant (more on that later). However, on occasion — sometimes every night, sometimes not for a week — it will dump anywhere from a half pint to a quart of coolant on the driveway as it sits overnight. Never when it’s hot; only when it cools down.

The shop I talked to said it was likely the radiator. There’s an aluminum radiator with plastic tanks, and as the materials cool down and contract at different rates it can open up a marginal seal and leak coolant. OK, I can see that happening. Radiators aren’t expensive; a good quality, brand new one can be had for under $175. I had plans to replace mine.

I have, however, had the cooling system open. While replacing the coil packs and the air/oil separator, I had to remove the thermostat housing. From what I have read, it’s virtually impossible to get the cooling system completely full and purged of air without using a vacuum fill tool.

How could this be something so simple as air in the system? After refilling the coolant, I ran the car for quite a while with the front and rear heat on full, and spent some time squeezing the upper radiator hose to encourage any trapped air to exit. Well, the other night I went to check the coolant level, and found it overflowing the expansion tank when I removed the cap. Slowly squeezing the radiator hose resulted in some gurgling and the coolant level dropped when I released it, so there was definitely trapped air.

So the question becomes — is this all just because there’s air that needs to be bled out? Or, is it sucking air IN through the leaky O-ring as the engine cools, perpetuating the problem? I guess we’ll find out. I have the tool to fill and bleed the system, and today I took a look. After draining the coolant, I pulled a vacuum on the cooling system. I was able to get about 0.65 bar of vacuum, but when I shut off the air it was obvious there was a leak. I decided to take a look at that leaking O-ring. It was worse than I remembered, with evidence of coolant around the area. I think it had been sucking air in during cooldown and wreaking havoc.

I did see what the shop referred to as corrosion on the driver side turbo frost plug. It was just a little evaporated coolant; the plug is directly below the coolant lone that was leaking. I managed (after a couple hours of cussing and all) to get the O-ring replaced and the line secured. Now I’m able to pull .8 bar of vacuum, with no leakage at all after a couple minutes sitting with no additional evacuation. I refilled with coolant and will watch what happens, but I think that will fix it. I found zero evidence of any other problems — no leaks around the radiator or anywhere else.

Shop estimate to repair cooling system: $3281.23
Parts cost: $7.88
Tools & Materials: $101
Shop time (service bay rental): $120.00
Total spent: $228.83
Total Saved: $3052.35

And that includes the cooling system fill/test kit, which I’ll no doubt use many more times.

Parts have started arriving for the Mercedes. The Rock Auto order arrived Friday with the brake parts and washer pump, plus a couple of filters for the Volvo my wife drives. On Saturday Pete and I replaced the rear brake rotors and pads. The old ones were not yet down to the wear sensors, and had maybe 3/16 or so of pad material left. Serviceable, but worn. The rotors looked to be in good condition, but of course there was a noticeable ridge at the edge.

Having two people really sped things up. The calipers and rotors came off without a fuss. We cleaned off the new Brembo coated brake rotors and installed them, followed by the new Akebono Euro pads. I got the two massive rear tires back on and torqued down the bolts. The test drive was utterly uneventful. Brake pedal feels just a bit more firm, and there is of course no shudder or noise whatsoever – as I would expect.

Cost quoted by shop (incl. tax): $698.85
Total parts cost (incl. tax and shipping): $188.82
Total savings : $510.03

In other words, we saved about $170.00 per hour for our labor to replace the pads & rotors. Put another way, I shaved about 73% of the cost off of the rear brakes by spending a Saturday afternoon in my garage.

Yesterday the box from FCP Euro arrived with the ABC accumulators and hydraulic fluid. One more parts order and I’ll be ready to tackle the ABC issues. I’ll have to remember to call DIY Garage and reserve a bay for next weekend.

So, I took the Mercedes in to a local independent repair shop specializing in Mercedes and other Euro cars. Everyone — and I do mean everyone – that I asked told me that these were THE guys to go to with problems. I had a few nagging little things wrong that I didn’t feel like fixing myself, so I took it in with a laundry list of stuff to look at. The car would frequently dump some coolant on the driveway overnight after being driven, for example. I have a persistent problem with the #9 fuel injector being clogged or sticky, which had me chasing non-existent ignition issues for months. The ride is harsher than it should be. The A/C doesn’t work for the first 5-10 minutes on a hot day, again only when you drive it for the first time before it’s warmed up. And finally, the transmission shifts from 1-2 and 2-3 are very harsh, but only when the car is cold — after a few minutes of driving, it’s smooth as silk.

After a week I got a call from the mechanic with their quote to sort out everything. It was (I swear I’m not making this up) $14,319.86. According to them…

• The coolant leak was from the driver side turbo. I’m aware of that tiny little leak; it’s a $.35 O-ring that looks like a pain in the ass to replace, so I left it. I’d gladly pay a shop 3-4 hours labor to replace it. They want to pull the turbo and replace the coolant lines for $3200-plus. Unfortunately, they say the car didn’t puke any coolant while they had it like it has for me… a symptom for which they told me by phone before I took it in probably indicated a bad radiator. So, after paying over $3K to fix a bad O-ring on a coolant line, I’d still have the same original problem that I wanted fixed.
• The A/C problem could be the compressor, or could be a bad suction hose. They propose replacing both for a little under $1750.
• According to them, the ABC pump (actually the power steering pump, which also supplies hydraulic power to the ABC suspension) is leaking and the accumulators are bad. Another $3.6K plus to fix all that…
• $400 for a transmission fluid and filter change. I just did that a few months ago, but I didn’t flush the torque converter so it probably does need new fluid.
• $700 for the rear brakes. No, they haven’t fallen off, nor does that include new calipers. Just the brake disks and pads.
• $247.70 for an oil change. Right. I pay about $6 for a filter, and $23 for five quarts of Mobil 1 full synthetic. The air filters they want to replace (at $68 for the pair) were just replaced a few months back and are quite clean. And cheap, at roughly $26 for a pair.
• $4,338.40 to replace the brand new spark plugs and both freshly rebuilt coil packs that I just put in back in March or April, to chase a non-existent ignition problem that I already know (and specifically told them) is actually a sticking fuel injector.
• Though I specifically asked them to pull the fuel injectors and clean/flush/test them, there was no mention of that at all. The diagnostics point to the coil packs… just as I had told them when I dropped it off. Sigh…

Needless to say, I was a bit surprised. One thing that surprised me was that they are apparently using full retail Mercedes dealer parts counter pricing on parts, than marking that up. Marking it up quite a bit, in fact. An example: They listed the A/C compressor at $784.00. Now, I can buy a brand new one from a Mercedes-Benz dealer for $497.59 ( a bit over 33% discount) – or pay even less for the same part from one of a couple of very good parts retailers who guarantee their parts for life.

That’s just one example, end not the worst one. There’s a 55% markup on the brake rotors (plus I can buy new Brembo rotors for even less), and a whopping 68% markup on the power steering pump. Holy crap…

Now, don’t get me wrong — I’m not complaining about their $117 per hour shop rate; I don’t think that’s too high at all. I also don’t have a problem with shops making a little on parts. They’re going to have to lay out the cash and wait for me to pay, there’s risk involved, yadda yadda yadda. But come on. That’s just egregious. I’m guessing they count on the fact that, first, not many Mercedes-Benz owners would consider turning a wrench on their own car; and second, some seem to take some sort of perverse joy in spending large amounts of money to keep their cars running. With some people it seems to be a point of pride to show off four- and five-figure shop bills. That has never appealed to me, to be honest.

So, I have parts coming to do this stuff myself. I am fairly disappointed that I have still not found a shop where I can take this car, have it repaired and maintained by a competent mechanic, and pay a fair price for the work performed. I’d happily pay their shop rate to avoid doing this, but I’m not going to shell out fourteen grand for what really should be a couple thousand bucks’ worth of parts and labor. We’ll just have to differ in opinion on the power steering pump… I’m willing to replace the accumulators and see how long the pump lasts before taking that step. Even so, that was a drop in the bucket of their $14K-plus quote. So here’s what I have planned for the next couple of weeks, as parts arrive and I have the time to devote to getting greasy:

• Rear brakes: I ordered new Brembo brake rotors and Akebono pads. Let’s be generous and include the shipping cost and say that all cost me about $185.
• ABC accumulators: I ordered new parts from FCP Euro and Mercedes-Benz of Laredo. Great people to deal with, by the way. Call it a little under $490, with shipping and 5 liters of hydraulic fluid.
• I’ll do the transmission flush myself for around $60 to $80 worth of transmission fluid. The filter was just replaced, so there’s really no need to crack the pan open again for that.
• The oil was just changed a couple of months ago, I’m not sure why that was even on the list. The car itself should have told them that. It’s showing 8 months until the next service due.
• I’ll continue to feed it fuel injector cleaner to address the injector issue. I have been alternating between Techron and Red Line. The problem is about 90 to 95% gone… if I have to, I’ll pull the fuel rail and injectors and flush them myself, I just figured if I were going to have the car in for the radiator and all, I’d have them do that too.
• I’ll look for another shop to do the A/C service. I can buy the hose for about $155 (the shop wanted $275 for it!) and have a place that specializes in A/C do the work. I doubt very much it’s the compressor; the collapsed suction hose is a known issue with these cars.
• I put some fluorescent dye in the coolant, and I’m waiting for it to dump it again so I can trace where it’s coming from. While a new radiator is not terribly expensive, there are a couple of other potential sources for the coolant and I want to make sure I fix it once.

Some of this needs to be done soon, as we’re planning another long vacation road trip soon. I definitely want to fix the suspension and coolant issues and replace the rear brakes, and I’d really like to have it all sorted before we leave. We’re fortunate enough to have a place in Bellevue that rents service bays with hydraulic lifts, so I should be able to do everything in a day, possibly two. I’ll follow up with more details on the work performed and the total cost — I’ll even track the hours to estimate what a shop would have been justified in charging.

Oh, and when I dropped the car off, my windshield washer was fine… when I picked it up, it’s not working. Awesome. Don’t know if they knocked a plug loose, or if it was just a coincidental spontaneous failure. We’ll see when I get the fender liner out to replace the ABC accumulators and pulsation damper..