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

Osprey · Post by **Osprey** » 02 Apr 2018, 19:38

Hi, everyone. First of all, thanks for all of the great information here. I've successfully used it several times over the years, even though I don't post much.

I've been failing smog checks on my 1997 850 GLT, so I checked the codes and was getting the common P0116. Partly thanks to past posts here, I learned that that meant that the thermostat and/or temperature sensor needed replacing. Since everyone recommends doing both at the same time, I did that today. Everything went pretty smoothly, but, now, I have a couple of questions.

Question #1: Should I be concerned at all that the coolant level in the reservoir is a lot higher now? It used to fill the reservoir up only 1/3rd or so of the way. After draining it from the system and pouring it back in, the reservoir was nearly full, but drained to about 2/3rds, where it's stopped. I've started the car and let it idle for 5 minutes and it hasn't drained any more. Obviously, that means that there's less coolant in the system (in the hoses and such) than before, which makes me a tad concerned that the engine might overheat when I start driving. Is that not a concern, is it safe to drive and will the excess coolant drain the system when I do drive?

Edit: After 5 hours of the car just sitting, the coolant level is noticeably lower (meaning that it's drained into the system), so I just needed to give it time. I feel a lot better now and that question is pretty much answered (though Neil's replies were still helpful and appreciated).

Question #2: Will I fail the smog check if I do it while I still have the P0116 code? Is that an automatic fail or are the readiness monitors more important to smog inspection stations? Since resetting the code last week (and having it come back because I hadn't fixed the problem yet), I've driven the car enough to complete 7 of the 8 readiness monitors. I think that I've read that you can usually still pass if you have no more than 2 incompletes, so I should be good on that front. The issue is that, if I reset the codes again, in order to remove the P0116, all of those readiness monitors will reset and I'll have to drive the car a bunch all over again to complete them. My temporary vehicle tags are running out very soon, so that would be a hassle. Will I have to do that or is it OK to go for a smog check while still sporting the P0116 code (and accompanying Check Engine light)?

Thanks a lot if anyone can answer one or both and thanks again to everyone's posts that have helped me in the past.

Post by **scot850** » 02 Apr 2018, 19:56

Can't help you with the smog check, and it may help if you let us know where in the S you are as laws vary as I understand it. I'm not familiar as we don't have any smog laws up here where I live.

The cars often need to 'burp'. This can take a little while, but open the temp setting on the heating to max when you can as it may help the 'burp' process. If you did not add coolant to the system other than what you remove, you cannot 'make' coolant in the process. Carry, some pre-mixed coolant with you and check each time the engine cools as to where the level has settled. You may have to add a little. I try to run the coolant between 1/2 and Full level between Min and Max. If you loose some it could be the coolant reservoir cap is not holding pressure. Look for residue coolant traces around the lid.

If you reset a code, I don't believe it should rest all the other monitors, only the one displayed. Happy to be corrected on that. I believe that only happens when you disconnect the battery.

Neil.

Osprey · Post by **Osprey** » 02 Apr 2018, 20:31

Thanks for taking the time, Neil.

I'm in Nashville, Tennessee, in one of the few counties (Sumner) that requires smog checks (just my luck). As for whether the readiness monitors reset when the codes are reset, I think that they do because the app that I'm using (OBD Auto Doctor on Windows 10 Mobile) displays the readiness monitors beneath a header that says, "Since DTCs cleared."

I'm not sure if you understood my coolant question, perhaps because I didn't explain it well. I'm not really concerned about the level, about leaks or about adding any. I'm happy with having the same coolant amount that I had before. It's just that 1/3rd of the same coolant amount used to be in the reservoir and 2/3rds of it in the system (the hoses and such) and, now, 2/3rds of it is in the reservoir and only 1/3rd of it is in the system. I'll feel better when the proportions are the same as they originally were, since it'll suggest that the coolant is everywhere that it was before and should be. I'm asking if it's normal for it to take time and actual driving for the coolant to be distributed, because I don't want to take it for a spin and have it overheat because the coolant isn't distributed like it was before.

Post by **scot850** » 02 Apr 2018, 22:56

The coolant header tank/reservoir only has a very small part of the total coolant. If you are concerned you can run the engine in your drive until it gets up to temp and allows the thermostat to open. That way you don't need to worry about the engine overheating as you should catch it quickly if it did.

I confident if you get the engine temp up to normal and the thermostat opens, have the heater on full heat and run for a couple of minutes and switch the engine off and let it cool. Then check the level when cool. Open the header tank cap slowly and see if the level drops further. If it does top it up and you should be good to go. Volvos can be a little tricky to get the air out the system. It may take a few cycles of up to temp and cool to fully get the level back to normal.

Neil.

Osprey · Post by **Osprey** » 02 Apr 2018, 23:43

Thanks again. Yeah, I realize that the reservoir should have only a small part of the total coolant, which is why I was concerned that a majority was still sitting in it. I just checked the level after 5 hours (of the car just sitting) and it was noticeably lower, though, so I feel a better now. I'll try running the engine again and turning the heat on max, as you suggested, and maybe it'll level out more overnight. Thanks.

If anyone has an answer for the second question, I could still use one. If no one knows, I'll probably take the car into the smog station tomorrow with the P0116 code still on the system, but it'd sure be nice to know beforehand if that's a waste of time. Thanks.

Post by **abscate** » 03 Apr 2018, 02:16

Most emissions testing require both the CEL To be off and most ot all of the monitors to be ready , so that you can’t clear it just before testing to cheat the test,

You have to clear that code and run 100-200 miles before testing for smog.

The EPA issued Federal guidance that allow some slack of one or two monitors to be not ready, and some , but not all, States, follow this guidance. We have threads here with the EPA guidance documents and some State discussion, but these things do change , so your local testing authority is the best reference

Osprey · Post by **Osprey** » 03 Apr 2018, 13:40

Thanks for the reply, abscate. That mostly answers that question. I might try calling the station and asking if I can still pass with the CEL on, but I wasn't sure that they would be willing to answer, since stations haven't been willing to divulge why I failed in the past.

Yeah, the Federal guidance is what I was referring to, regarding the possibility of passing with 1 or 2 monitors not ready. Since I last reset the code, I had to drive no more than about 50 miles to complete 7 of the 8 readiness monitors, so I may have to do that again. It's a lot better than driving 100-200 miles in just a day or two, though.

Thanks again.

Osprey · Post by **Osprey** » 03 Apr 2018, 14:55

Uh oh. I checked the coolant reservoir today and it was completely empty. It's definitely leaking (I can see it under the car), but it's not leaking from the thermostat housing or hoses that I messed with when I replaced the thermostat and coolant temperature sensor. It appears to be leaking from behind and/or underneath the engine. I can't see from where exactly. Why would it be leaking now, from areas that aren't near where I was working, and not before? Could it be that I released pressure when I did the maintenance and the same seals aren't holding? If so, I don't have the tools to check or know how to get the pressure back (and running the engine is dangerous because the coolant isn't getting to the engine). I'm not sure what to do at this point, other than take it into the shop, which is what I was trying to avoid when I started this DIY project

.

Post by **abscate** » 03 Apr 2018, 19:29

If you are well above freeze point just replace with water until you track the leak down. There are lots of small hoses that can spring a leak

Post by **scot850** » 03 Apr 2018, 20:06

As tyou have a 97 GLT (so should be a low pressure turbo) check the following:

1) There are I believe 2 turbo coolant hoses at the rear of the engine near the turbo that like to fail randomly.
2) Check the pipe at the rear of the block from the header tank. The pipe can crack with age and also check the header tank is not cracked or the level sensor pulled out from the bottom.
3) Check the water pump is not leaking. Remove the timing belt cover to check.
4) The lower radiator hose runs to the back of the block near the turbo it perishes with age.

Good Luck!

Neil.