My new Bosch brand ECT sensor has arrived from iPd, so I thought I’d take a moment to talk about part numbers for anyone reading who may also want to replace this part but not know which one to get specifically.
Volvo has part numbers assigned to almost ever piece that goes into their cars. However not every part is actually made by Volvo. Parts that are shared across not only Volvo’s but other company’s cars are usually made by third parties called “original equipment manufacturers” or OEMs. In Volvo’s case, one of the biggest OEMs is Bosch, a German manufacturer of, well, lots of things. Bosch also has a part number for their own products separate from those assigned by the companies that buy from them.
In my case, Volvo’s number for the ECT sensor used in my particular model and year of Volvo is 1346030. Bosch originally numbered this part as 0280130032. However, at some point Bosch decided to renumber this part as 0280130069. Why? I have no idea, but it did leave me scratching my head a little until I gathered enough evidence from the internet to confirm that this is the case.
So I now have a Bosch 0280130069/Volvo 1346030 ECT sensor to replace the FAE 33090 sensor that probably replaced the original Bosch 0280130032.
Today I attempted to test my ECT sensor. The procedure went like this:
Boil some water
Connect my multimeter up to the sensor
Dip the sensor into the water and take occasional temperature readings. Compare the resistance readings to the temperature to see if they should be where they are expected
I did all this and got wildly unexpected results. Way higher resistance than I expected. For reference, here is the chart showing what I should have seen.
Looking at the sensor I noticed that it actually wasn’t Bosch branded. It was made by Spanish manufacturer Francisco Albero S.A.U (aka FAE). I’m not sure that company was ever an OEM supplier to Volvo, so I’m sort of suspecting that this sensor had been replaced at some point and that the not so good FAE replacement has since failed. Regardless, I have a Bosch replacement on the way. Since this thing is such a pain to access I want a good part going in before I reattach the intake manifold.
After disassembling the intake manifold I was left with four loose and very dirty looking fuel injectors. I had originally intended to clean them myself, but in a moment of startling honesty I admitted that I’d more than likely either ruin them or not really clean them very much. So I looked around the internet and decided to turn this job over to the aptly named Mr. Injector. Unlike me, he has both the experience and the equipment to do this right, and his prices aren’t terrible especially when compared to having to buy new injectors because I broke one in my own half-assed attempt at fixing it. So I boxed them up and sent them off to Idaho.
His site told me that I’d be getting a baseline electrical, spray pattern, leak, and flow test followed by disassembly of the “soft” parts, an ultrasonic bath, a flush for contaminates, and finally a new set of tests to measure the improvement in function. Then they’d be oiled, have their soft bits replaced, and finally repainted with corrosion resistant paint. About a week from when I sent them they arrived back at my house and I must say I am very impressed.
As you can see they’re obviously much cleaner looking, and the flow test suggests they’re much cleaner on the inside as well. Interestingly, one of the injectors was still in very good condition while another was merely in fair shape. Overall they were still functioning quite well, but I’m glad to know that they’re now in tip top shape with new filters and pintle caps. And he also sent me candy! That’s service.
This past weekend was a bit of a bust in terms of car work. Aside from several obligations, a big tree branch broke off and fell onto the roof of my garage. I did have a moment the other day to put the multimeter onto my MAF sensor to what I could see. According to my intake system green book, the MAF should show a resistance reading of between 2.5 and 4 Ohms between pins two and three, and mine was reading somewhere around 3 Ohms. A visual inspection shows the wires still intact, and I’m assuming it’s clean because I had already cleaned it many months ago and haven’t really driven since then. So, I’m willing to move this part into the “working” pile along with the IAC. Stay tuned to see if the two engine temperature sensors can go there too.
No matter what Volvo passenger vehicle you own, no matter how old it is or how clapped out it might be, it now qualifies for free roadside towing. Volvo is extending the free towing service it provides in-warranty customers via its roadside assistance coverage to every Volvo model, “no matter what vintage,” according to the automaker, which has dubbed the service Tow for Life.
Good on Volvo for not completely forgetting their older cars. I hope I never have to use this service.
The Idle Air Control valve, commonly just called the IAC, is a servo motor controlled valve that helps maintain the engine at idle according to the demands of the engine control unit (ECU). Given that my engine was having a hard time idling for more than a few seconds a failure here would not be surprising. I had already taken it off, so I figured I’d get it on my workbench and poke it a little to make sure it’s still working as expected.
The IAC is a pretty simple device. It’s a tube with a servo motor inside that opens and closes a valve to control airflow into the intake manifold. How far open the valve is depends on the voltage supplied. 12 VDC should open the valve up all the way. I also referenced the Volvo “green book” on the intake system and found that the resistance across the two input terminals should be 8 Ohms. So those are the two tests I performed. I’m happy to report that my IAC is just fine. It wasn’t difficult to test, but just in case here’s a video to illustrate how I did it.
So it’s been a year or so since I bought this Volvo. When I first took it home it (obviously) drove, but not well and would probably not pass inspection. It was a project from day one. Now that better weather has arrived, I’m determined to get the car running reliably well and road worthy. At that point I can pivot to making sure the rest of the car is good.
So, given a day with a few hours free my oldest son and I began taking off the intake system. These parts include (starting from the out and moving in):
The air box and filter
The mass airflow sensor (MAF)
The throttle body
The intake manifold
The idle air control valve (IAC)
The fuel rail, fuel pressure regulator, and fuel injectors
The engine coolant temperature, engine temperature gauge sender, and knock sensors
The plan was to first drain the coolant system and remove the radiator and fan to provide some working room and then start removing the above listed parts. They would then be cleaned and tested for function before being either replaced or put back on.