850 Replaced thermostat and temp sensor. Now, 2 questions (re: coolant & smog check) Topic is solved

[Osprey]

Thanks, both of you. I'll check all of that, though I'm starting to think that I'm getting in over my head.

Speaking of the coolant level sensor, I ran the car while the coolant reservoir was empty and I didn't get the Coolant Level Low indicator on my dash (which does light, along with the rest of the indicators, when I first turn the key, so the bulb works). It should light up when the reservoir is empty, shouldn't it?

If I can't find the leak and decide to take the car into the shop, would it be safe to drive it there so long as the engine temperature on the dash doesn't get near the red? That's the gauge that'll tell me if I'm not doing any damage yet, right or no?

[WhatAmIDoing]

Fill it up with distilled water and drive like a granny. If its a really long trip, pull over and check every 15 minutes. Keep several gallons in the trunk. If water is pouring out onto the ground, then obviously don't drive it. If the system runs dry, the temp gauge won't help you as it reads water temp. No water touching the sensor means it will not read remotely accurately. The level sensor is easy to break. Make sure it is fully seated and try reseating the connector. You need to figure out how bad the leak is, as in how long does it take for the tank to reach empty.

Check turbo coolant hoses, lower rad hose, heater core and associated lines. These are the ones that fail suddenly and would cause a substantial lose of coolant.

[Osprey]

Great news: I'm an idiot!

I looked over everything that you guys recommended and found no leaks. Then, just before I was about to close the hood and book a shop appointment, I took one more look at the thermostat housing and saw a little coolant behind it. I originally said that the housing wasn't leaking, but I guess that I expected it to be more obvious to account for the volume of lost coolant.

Anyways, I removed the housing and it was definitely leaking from the back. I looked carefully at the O ring and compared it to the old thermostat that I originally took out and I noticed for the first time the slit in the inside of the O ring. The new thermostat had come with the O ring detached and I foolishly assumed that it went under the head of the thermostat, like a rubber washer would, so that's how I originally installed it. I realized an hour ago that the O ring has that slit in it and that the head is meant to go into it. I re-installed the thermostat (correctly this time), secured the housing, topped off the coolant and... no more leaks. I also started the engine and... no more leaks.

So, my problems all came down to me stupidly not installing the thermostat correctly. At least I realized my error at the last second. I was all prepared to take my car into the shop and end up paying $500 or more to have them go over the whole system and replace hoses and other equipment that didn't need replacing. I was also dreading that they might tell me that the head gasket was blown, which I've heard can cost over $3000 to fix and would not be worth it when that could go toward a newer used Volvo.

Besides that I'm an idiot who should probably stick to repairing computers, not cars, I did learn something useful today. You guys said to check the level sensor beneath the coolant reservoir. I did that and the wires were completely severed. So, it's no wonder that I didn't see the low coolant dash indicator light. Fortunately, it looks like an easy, cheap fix.

Anyways, thanks again everyone for all of the help, even though I wasted some of your time. In the end, you still gave me the encouragement to continue searching for the problem and that led to me finding it. Now I'm back to trying to pass the smog check, but that's nothing compared to what I was worried about yesterday and today, so I'm going to sleep much better tonight.

[abscate]

You have to dive in and start somewhere in the world of mechanics. One always feel stupid when you find the mistake but I see someone who just saved himself $1000

[Osprey]

All of my issues are gone, the smog check passed and my registration has just been renewed. I'm updating this for the sake of completeness and in case it helps anyone out.

First of all, replacing the thermostat and coolant temperature sensor DID solve the P0116 code. The check engine light hasn't come back on since I cleared that code. I'm not sure which of the two was actually bad, but I suspect the sensor, since I've read that that failing is a cause of the radiator fan running after the engine has been turned off, and that's no longer happening for me. Still, it was easier to just replace them both at the same time.

Second, since clearing the P0116 code, I needed to reset the readiness monitors in order to pass the smog check. I used the suggested drive cycle here:

https://www.matthewsvolvosite.com/drive-cycle.html

When I started, I already had 3 monitors complete and 5 incomplete. When I finished, 6 were complete and 2 were incomplete. The 2 incompletes may've just been because I didn't do some of steps well enough (it's hard to drive on the freeway and watch RPMs, speed and time all at the same time). Since I'd heard that you can often pass smog inspections with 1 or 2 incompletes, that was good enough for me. Fortunately, though, after one 10-minute drive on local roads to and then from the grocery store later that night and a 15-minute drive on local roads to the smog inspection station today, the two incompletes were completed and I passed with flying colors. What a relief.

Anyways, hopefully, my experience helps others like others have helped me.

[scot850]

Well done and hopefully you realise that not all repairs are extremely hard, and there are a lot of people he to give you guidance if required.

Neil.

[Osprey]

Thanks again. I did realize that to begin with, which is why I undertook this repair (which isn't my first), but knowing that I can get help if things don't go as planned is most certainly a comfort.

I'm no stranger to opening up and repairing things, but cars are more of a challenge for me, partly because they require so many different tools. I can do just about anything in most computers or electronics with just a handful of tools, but cars seemingly require a different tool for every job. For example, I spent $75 just to remove the two stubborn Torx screws holding the thermostat housing on (I bought a quality impact tool, an impact grade socket adapter set, impact grade socket extension bars, a good Torx bit set and some PB Blaster). It was still a lot cheaper than having someone do it for me, and I count it as an investment, since I may use those tools again, but it's an example of a major factor (at least for me) in deciding whether or not to take a project on. We amateur mechanics don't already have all of the tools that you seasoned pros do, so even simple tasks are harder to accomplish.

[scot850]

You will soon join the throngs of tool store hunter/gatherers and yard sale tool finders league!

Neil.

[abscate]

Thanks again. I did realize that to begin with, which is why I undertook this repair (which isn't my first), but knowing that I can get help if things don't go as planned is most certainly a comfort.

I'm no stranger to opening up and repairing things, but cars are more of a challenge for me, partly because they require so many different tools. I can do just about anything in most computers or electronics with just a handful of tools, but cars seemingly require a different tool for every job. For example, I spent $75 just to remove the two stubborn Torx screws holding the thermostat housing on (I bought a quality impact tool, an impact grade socket adapter set, impact grade socket extension bars, a good Torx bit set and some PB Blaster). It was still a lot cheaper than having someone do it for me, and I count it as an investment, since I may use those tools again, but it's an example of a major factor (at least for me) in deciding whether or not to take a project on. We amateur mechanics don't already have all of the tools that you seasoned pros do, so even simple tasks are harder to accomplish.

If you form a local Volvo group you can share costs and build up a nice set. I know that is a bit Communist but it I still a way to keep the tool bill down. At current labor rates and the wide variety ofdecent quality stuff out there, tools pay for themselves quickly. Kobalt line at Lowe’s is quite decent for the money