It's Stooge time! Today's show is on how to remove the thermostat in a 348. But first............ Last week I took my car to get smogged tested and it failed. In Cali they put you on a dyno and test the car at two different speeds. Here are what the numbers were: maximum allowed readings mph__HC__CO____NO 15___112__0.72__778 25___86___0.60__717 measured readings mph__HC__CO___NO 15___158__0.74__467 25___117__0.58__336 I was over mainly on the Hydro Carbons, just barely on Carbon Monoxide at 15mph, and in the middle of the readings for Nitric Oxide Before I went to test my car I made sure the cats were nice and hot, and when I got there I got lucky and was able to test the car right away. No time for the cats to cool off. After the failed test the smog tech told me that the car was running rich. So I went back home double checked everything, and then cranked the MAF settings all the way up to 950!! Went back and ran it again. NO dice. Failed. The tech showed me that the car was trying to lean out, but that the ecu was overriding and kept richening up the air/fuel ratio. So now what? The MAFs cranked all the way up didn't lean it out, my crank sensors are new, the O2 sensors are new, the coolant temp sensors are new, the first time I ran it the MAFs were set to 383, there is even a new throttle position sensor on it, and the last time I had the exhaust off the matrix inside the cat still looked just fine. Yet it is still running rich. Hmmmmm??? Then I remembered a post gothspeed did about the 355s running too COOL! AH HA! The ECUs will adjust the enrichment of the fuel based on the coolant temperature. Per my shop manual, at first start up the initial warm up from 0ºC - 60ºC (140ºF) the ECUs will richen up the mixture, and gradually lean it out. After that point the ECUs switch to a post initial start up enrichment, and continue to richen up the mixture based on coolant temp and engine speed up to 80ºC (176ºF). Once the engine gets to it's steady operating temperature (over +80ºC/176ºF) the ecu's stop the enrichment process. BINGO!!! That last couple of months I have noticed that my engine had been running cooler than normal. It was running in the 160º - 175º while at highway speeds, and would get up to around 185ºish in stop and go traffic, until the fans kicked on (which is a 185ºF). I didn't pay any attention to it because I thought "Hey great the car is running cooler. It's summer time, the outside temps are in the high 90s and into the 100s. So it's a "good thing" my car is running cooler. Less chance of it over heating no?" WRONG! Because by my car running cool it was also running rich. The next day, after the first smog test, I swapped out the old thermostat for a new one. Made sure both MAFs were set to 383, disconnected/reconnected the battery, let the ECUs go through relearning the warm up parameters, and when for a little drive. Took it back to the smog shop and put it to the sniffer test. The numbers dropped. measured readings mph___HC___CO___NO 15____124__0.69__451 25____89___0.58__349 Now I was only just barely not passing. By simply putting in a new thermostat, and because the engine was running at the proper temperatures, the ECUs were no longer dumping extra fuel into the engine, thus the drop in the readings. Though the 25mph NOx did go up a little bit. My guess is because it's running leaner. However, because the engine had been running too cool/rich for several months my cats were working overtime to try and burn up the excess fuel. So they got worn out = I need me some new cats to pass smog. The lesson here kids is, DO NOT ignore your temperature gage, ESPECIALLY if it says your car is running cool. Now with the new thermostat in my car, the temp on the highway is right in the 190º range. Running happy as a pig in mud. Oh, one more thing. When the car was running too cool I did notice that my gas milage dropped. I was getting about 20-21mpg highway out of it. When before I was getting 24-26mpg depending on how much my foot was into the loud peddle. So make sure your thermostats isn't worn out, and if it is, CHANGE IT! Ok now for the do-it-yourself thermostat removal.
First thing I did was remove the left side rear wheel, and take out the fender liner. (Actually I took it out and never put it back in) Image Unavailable, Please Login
Place a catch bucket under the radiator, the take out the plug on the bottom corner of the big left side radiator. It's easier to drain the left radiator because the drain is on the bottom corners. Where as if you try to bleed the small upper radiator on the right hand side it's gonna get all over the bottom oil cooler. Once the coolant starts to drain go pop open the radiator cap on the expansion tank. This lets it drain faster. After you drain the radiator reinstall the drain plug. Thread it in as far as you can by hand first, then snug down it with the screw driver. This way you reduce the chance of it getting stripped, it's plastic. It also speeds up the process when you go to refill the cooling system. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
The easiest way to get access to the thermostat is from the top. Removing the engine cover will give plenty of work room. If you have a Spider or a TS you can have the top down/off, and move the seats all the way forward so you can stand in the car and lean over to remove the thermostat. Remove the four bolts holding the engine lid to the brackets and set it aside. It is best to have some on help you remove the engine cover. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Before I started to unscrew the hose clamps I disconnected the fuel vapor purge line from the plenum. Gets it out of the way so it's less frustrating to turn the ratchet. With that line out of the way unscrew the hose clamps on the top hose. Then remove the hose, giving you access to the thermostat housing. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Next disconnect the throttle cable from the linkage, and then slide it out of the retaining bracket attached to the thermostat housing, and set it to the side. Image Unavailable, Please Login Image Unavailable, Please Login
Before you try remove the housing, shove some paper towels into the neck of the housing to soak up as much of the coolant in there as you can. You want as much coolant out of the neck as you can get, so when you remove it you don't spill coolant all over your timing belt cover and especially the crank sensors. So keep stuffing rags in there until you don't get out anymore coolant. Image Unavailable, Please Login
Next thing I did was to remove the Idle Air Control Valve, and the fuel regulator vacuum line, on the right side of the plenum. I makes access to the nut on that side of the housing easier to get to. To remove them: slip the vacuum line off the nipple unclip the IACV connector loosen the IACV hose clamps unscrew the retaining bracket holding it to the plenum (not pictured because I took them off and never put them back on) disconnect the IACV from the plenum and throttle body intake tube, and set it aside. As if you guys can't tell, I don't like having stuff in my way when I'm working. It's less frustrating for me to spend a little extra time moving things. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Now remove the three nuts holding the housing to the water pump. And remove the housing to expose the thermostat. I used a wobble and an extension to make it easier to access the nuts under the plenum, and on the side were the IACV was. It's also a good idea to have rags stuff around the front of the thermostat to catch the remaining coolant when you take the housing off. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Then remove the old thermostat. I popped it off by pressing the bracket on the top with my finger. You DO NOT want to dig on the sides, where the rubber gasket is, with a screw driver, because you can scratch the thermostat hole and possibly cause a leak because of the gasket not sealing properly. Image Unavailable, Please Login Image Unavailable, Please Login
Now remove the old o-ring seal and save it in case you forgot to buy a new one with the new thermostat. The new thermostat I bought came with a different type o-ring. It wasn't molded like the original one was. It looked more like a regular o-ring. BUT, it did have the little groove in the inner diameter of the. So when you go to put on the new o-ring, or the old one, be sure to fit the thermostat inside the little groove, so that thermostat gets sealed on both the top and bottom when you put it back in. You'll see what I'm talking about when you take the old one off. Image Unavailable, Please Login
Here are some pics of the new thermostat. It's made by BEHR and the part number stamped on the rim is B.296 7C 82. I tried to cross referance that part number but wasn't really coming up with anything. Maybe one of you guy has better luck finding the cross reference than I did. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Here is the new thermostat installed ready to keep my coolant temps right where they should be. Image Unavailable, Please Login
A quick little tip. If you don't have one of these, go buy one. It's an extension grabber. I use it to hold the nuts while I start them on the bolts in under the plenum. You have less of a chance dropping the nut when you are putting it on, and saving you the headache of trying to fish it out from under the intake. Image Unavailable, Please Login
Well fellas, That's how you remove the thermostat from a 348, Stooge style. Total time was 2 hours. One hour to remove it, and that included fussing with my cell phone camera 30 minutes to put it back in. The biggest pain in the ass was getting the radiator hose back on. 30 minutes to refill and bleed the cooling system Happy Wrenching.
Nope, Didn't use the old gasket, bought a new one with the new thermostat. And no I didn't use any Hondabond, not needed.
I don't think new cats will solve your problem. These cars are nearly passable without cats. Cats just make sure the air coming out is cleaner than the air coming in.
My car has been running cool lately. Temp would be normal ( dead center ) on the freeway and then sometimes just drop to the 1 of the center number. I guess I have a sticky thermostat? Barely passed last year, just 2 below max HC. Good thread Ernie. Kai
Nice thread Ernie. My temp is about perfect, but I swear sometimes I think it runs cool. Hard to tell in SoCal plus with the way I drive. I have NoDoubt pink chips (a smidge more fuel) and I always hit the max allowable HC's on my test. That was with goth 300-cell cats. Now I have 200-cell cats and I am switching chips back to stock. I can't wait to see it I pass of fail. Ask me in January. FYI, the CA smog level are different for my car as Ernie's. I have a '93 and can get away with only 50 PPM HC's. Ernie and I were talking about this earlier and we decided that no matter what you do to your car, keep the stuff you take off, especially the cats. Hey, I wonder if your air injection system is stuck open or leaks after warm-up. That might get you a richer mixture as the ECU's try to richen up the exhaust flow.
Update. What a difference new cats makes. Passed the smog test with flying colors. maximum allowed readings mph__HC___CO____NO 15___112___0.72__778 25____86___0.60__717 measured readings with new cats mph__HC___CO____NO 15___27___0.05___113 25___29___0.15___137 So pay attention to your coolant temp boys. Because if you run too cool, it will run rich and burn up your cats. And if it's running too cool, change that thermostat.
Not sure of the "7C" part as that doesn't mesh with BEHR part numbers. If you look in the BEHR Aftermaket Parts Catalog (Ferrari is not listed) B.296.82 is listed for these cars Fiat 128, 128 Coupe, 128 Familiare Fiat X 1/9 (128 AS) Innocenti Koral B.296.82 cross references to Fiat/Innocenti part number 422 030 9 For whatever that is worth.
