Still have a thermostat issue

NonBusto27 · Post by **NonBusto27** » Mon Apr 11, 2011 6:00 pm

Over the weekend I changed the oil, replaced a thermostat that was in pieces and replaced the thermostat temp sensor. When i started the car i noticed that the engine light went off and it stayed off for a couple days, now comes monday and the light pops on again with the same P128 code. It has tons of radiator fluid in it so i don't know why it is throwing the code again. I also have code P517 which i don't know what thats from or can find out what it is. Any help would be greatly appriciated.

OB · Post by OB » Mon Apr 11, 2011 6:20 pm

I assume you meant P0517, which IIRC is a code for the Battery Temp Sensor.

Regarding the first code, it's possible that the new t-stat was somehow installed backwards. Not sure if it could cause this code, but did you thoroughly bleed the air out of the system after you swapped the t-stat? Before you do anything else, try a full battery reset (disconnect ground side for 15-30 mins) if you haven't already.

NonBusto27 · Post by **NonBusto27** » Mon Apr 11, 2011 6:38 pm

AH yea that stupid battery temp sesor, don't know why the car has that thing to begin with. anywere i go and mention i need one they don't know what it is or why the car has one. I'll try the battery reset when i get home. I matched the thermostat to the houseing before i mounted it. whats the easiest way to get the air out of the system? Oh does the radiatior cap come off or is it stuck on there?

Post by **occasional demons** » Mon Apr 11, 2011 9:05 pm

Did the t'stat have the jiggle valve (bleeder) at the top? (If it had one)

If it didn't have the valve, getting the trapped air out is going to be a PITA. You may have to loosen the temp sensor to let air out, and re tighten it once coolant starts coming out.

The filler cap should come off, not 100% sure what you are asking, because how did you fill it without removing the cap? I am hoping not via the reservoir/expansion tank.

NonBusto27 · Post by **NonBusto27** » Mon Apr 11, 2011 9:13 pm

for some reason i can't get the cap off, i open it all the way and it doesn't wanna come off. I don't know if it is stuck or not. I don't want to break it or the place where it mounts too. my thermostat was pretty much a circle on the gasket but a little bit of it was a square and i matched the 2 together. Since i couldn't get the cap off i really didn't have any other option to filling it but by taking off part of the upper hose and filling it with what i could and the reservoir tank. If that was really bad then i'm just gonna have to flush it and re fill it someother way.

Post by **occasional demons** » Mon Apr 11, 2011 9:31 pm

The cap should come off if you push down and twist counterclockwise. Once it stops then it should pull straight up. Sometimes the rubber gasket will hang up in there, but it will usually come out with a little effort.

If you happen to break the filler neck, it isn't outrageously expensive: 5278156AA Thermostat housing $14.25 Just hope the dealer has one in stock.

NonBusto27 · Post by **NonBusto27** » Mon Apr 11, 2011 9:59 pm

Yea i'll go and check and see about getting it off

Danteneon · Post by **Danteneon** » Tue Apr 12, 2011 8:44 am

IIRC, the cap has a double lock. Push and turn to stop, then push again and turn. Cap should come off.

Post by **occasional demons** » Tue Apr 12, 2011 9:40 am

It does, but I generally just push down, and keep turning. It will go past the first catch 98% of the time. Just don't do it if it is hot, or you suspect it will begin spewing. The second catch is to help deflect the hot coolant if it pukes violently. You may still burn your balls, but you face will still be able to make grotesque expressions as it happens.

Danteneon · Post by **Danteneon** » Tue Apr 12, 2011 10:04 am

I figured I'd put that out there in the off chance he does what so many other people do...just push the cap enough to get the 1st lock off.

Post by **occasional demons** » Tue Apr 12, 2011 12:19 pm

I knew where you were coming from.

And also some aftermarket caps can be a PITA to get to press down far enough. I have encountered a few that I genuinely thought I was going to twist the top off the radiator to get it loose. (Non neon)

esfan · Post by **esfan** » Tue Apr 12, 2011 12:56 pm

IIRC if you change the coolant, you'll need to replace the cap right? My cap just went off easily when I push and twist.

NonBusto27 · Post by **NonBusto27** » Tue Apr 12, 2011 6:46 pm

Yea i went and double checked it yesterday, and noticed the other lock so i pushed it down and it came off nice and easily. Yea i know not to take off or loosen the cap if it is hot. So what would be the easiest way to bleed the system so there is not air in it so i don't get that engine code again.

Post by **occasional demons** » Tue Apr 12, 2011 8:28 pm

Did it have the jiggler valve I referenced above? if so, it will self bleed. It will take a few minutes of slowly topping off the t'stat housing, but you will notice small bubbles coming out.

Or,

occasional demons wrote: If it didn't have the valve, getting the trapped air out is going to be a PITA. You may have to loosen the temp sensor to let air out, and re tighten it once coolant starts coming out.

NonBusto27 · Post by **NonBusto27** » Tue Apr 12, 2011 8:38 pm

it does have a little thing on top that has a copper color too it. Is that what your talking about? I'd rather not touch the temp sensor since it was a PITA to get off.

Post by **occasional demons** » Tue Apr 12, 2011 8:53 pm

If it has that, then it should bleed. The valve is designed to let air past it but when coolant is pushed against it via the water pump, the jiggler will seal the hole, so it doesn't take too long to heat up.

Coolant will flow out the heater tube nipple to maintain circulation. (Just below the t'stat) You can try loosening the heater hose (Near battery) to bleed some air there. But as they dip lower than the head, it isn't the most effective way.

OB · Post by OB » Fri Apr 15, 2011 7:21 pm

esfan wrote:IIRC if you change the coolant, you'll need to replace the cap right? My cap just went off easily when I push and twist.

You only need to change your radiator cap if it is faulty in some way. There is no maintenance interval for it, pure myth. They outlast engines more often than not.

OP - Bleeding the system is critical. A good sized air bubble can cause overheating and eventually a blown head gasket or engine failure. A check engine light is the least of your worries. Take the rad cap off, start the engine, turn on the heater to full hot/full speed, and run the engine until it is hot. Once the t-stat opens the coolant flow will force the majority of the air out the rad cap neck, which is the high point in the system. As soon as the warm coolant is flowing from the cap neck, put the cap on, drive the car, let cool, and repeat if necessary. Top it off when you're done, while it's nice and hot, and set the level in the overflow. Bada bing bada boom.

iskyfly · Post by **iskyfly** » Fri Apr 15, 2011 8:29 pm

OB wrote: OP - Bleeding the system is critical.

occasional demons wrote: it will self bleed.

so if it self bleeds, then why go through the process of

OB wrote:Take the rad cap off, start the engine, turn on the heater to full hot/full speed, and run the engine until it is hot.

also, the reservoir tank has an overflow vented to outside, so isnt this an open system where any bubbles will just eventually "burp" via the overflow?

thanks

Post by **occasional demons** » Fri Apr 15, 2011 10:35 pm

iskyfly wrote:
OB wrote: OP - Bleeding the system is critical.

occasional demons wrote: it will self bleed.
so if it self bleeds, then why go through the process of
OB wrote:Take the rad cap off, start the engine, turn on the heater to full hot/full speed, and run the engine until it is hot.
also, the reservoir tank has an overflow vented to outside, so isnt this an open system where any bubbles will just eventually "burp" via the overflow?

thanks

Quote the whole thing...

occasional demons wrote:Did it have the jiggler valve I referenced above? if so, it will self bleed. It will take a few minutes of slowly topping off the t'stat housing, but you will notice small bubbles coming out.

iskyfly wrote:also, the reservoir tank has an overflow vented to outside, so isnt this an open system where any bubbles will just eventually "burp" via the overflow?

Yes, but it takes a bit longer than the method OB suggested. It is more for the small amounts that will still be there, but will eventually work themselves out. But the main function of the expansion tank is to give the expanding fluid somewhere to go, and hold that fluid until the system cools, so air is not sucked back into the system. Air in the system allows the metals to oxidize. That is the main reason why overflow/recovery/expansion tanks were implemented.

iskyfly · Post by **iskyfly** » Sat Apr 16, 2011 1:26 pm

thank you

Post by **racer12306** » Sun Apr 17, 2011 9:10 am

iskyfly wrote:
OB wrote: OP - Bleeding the system is critical.

occasional demons wrote: it will self bleed.
so if it self bleeds, then why go through the process of
OB wrote:Take the rad cap off, start the engine, turn on the heater to full hot/full speed, and run the engine until it is hot.
also, the reservoir tank has an overflow vented to outside, so isnt this an open system where any bubbles will just eventually "burp" via the overflow?

thanks

Why do you like taking little blurbs from peoples posts out of context?

If you are going to quote someone, quote the whole damn thing.

furyman67 · Post by **furyman67** » Sun Apr 17, 2011 9:18 pm

you can always jack up the front of the car to raise the rad cap up higher tp bleed the air out

Tom

iskyfly · Post by **iskyfly** » Sun Apr 17, 2011 10:36 pm

racer12306 wrote:Why do you like taking little blurbs from peoples posts out of context?

i don't and i didn't.

NonBusto27 · Post by **NonBusto27** » Sun Apr 17, 2011 10:40 pm

My check engine light is off for the moment but if i comes back on and that code pops up I'll for sure check and bleed the system. Thanks for all your guys help and imput

OB · Post by OB » Mon Apr 18, 2011 2:48 pm

furyman67 wrote:you can always jack up the front of the car to raise the rad cap up higher tp bleed the air out

Tom

This is accomplished even easier by simply parking the car on a slanted driveway. Only really necessary if the cooling system is being stubborn while bleeding. Good point though.

Post by **occasional demons** » Mon Apr 18, 2011 3:29 pm

If it is really pissing you off, you can jack the radiator cap up, and drive a new car under it.