2003 Saturn L300 Thermostat

It requires removing the upper intake manifold for starters, and to do that you'll need a special tool to release the clamps going to the manifold. Then you have to remove the lower manifold and fuel injector rail. If you need more info I can help you out, but it is a bit entailed.

is it necessary to remove the injectors and lower manifold? or can it be done just by removing upper manifold? i have a manuel that says the latter yet the pic they provide shows everything removed.

You dont need a special tool to release the intake boot clamps all you need is a small pockect screwdriver you insert it into the gap of the opening where the clamp locks over itself then move the screwdriver up.The clamps pops open i have done it a ton of time while resealing the leaking oil cooler plates and thermostats.To close the clamp i use the small channel lock end cutters they work great.You do need a gm fuel release too to remove the fuel lines and reverse torx sockets and torx sockets to remove the bolts.You also need to be careful when remove thermostat extension tube from the thermostat housing that you dont break its retaining tab.You do have to remove the upper and lower intake plentuims and intake spacer plate.

is it just me or is that a whole lot of work just for a simple thermostat? do i need to replace all gaskets/seals/o-rings while doing this?

I think for the average do it yourselfer it will be challenging.You can reuse all the seals except if you only replace the thermostat and not the whole housing i would replace that seal.Another thing you have to watch out for is tearing the intake boots.

i have removed the plenum, the fuel rail/lower intake, the spacer and now i find that the thermostat housing cannot be removed. it won't fit. i cannot remove the extension tube due to the dip stick tube is in the way. any suggestions?

Untill you pop the thermostat tube out of the housing the housing wont come out.Leave the housing bolted down then remove the bolt by the dipstick tube that goes into the tab holding the tube in place.Then try pulling and rocking twisting the tube out of the housing.If that doesnt work then you will need to pry gently on the retaining tab close to where it connects to the tube.You have to be really careful that tab is pretty easy to break.Also that housing is a tight fit you have rotate it and pull it out.Also i hope you got two new orings for the end of that thermostat tube?

i have done all that. the tab for the tube is behind the dipstick tube and i cannot remove the hose from the end of the tube because some ******* who built this engine has the hose clamp tabs behind the the timing belt housing. where would i get those extension tube o-rings? what happens if the tab is broken on the extension tube?

saturntech9 ,i just want to say thank you as well. my problems are not doing the work itself. my problems are the what if i break this or that. you have been a big help.

If you break the tab you will have to replace tube that tab is the only thing that holds that tube from coming out of the housing.You just have to work that tab loose from its place another thing that really helps you probably didnt notice is there is a 10mm nut over in that area.Remove the nut and pull that tab off the stud the nut screws on.There probably lies your problem i bet you never removed that nut.As far as that hose clamp the best way to get that clamp off is with a pair of remote cable operated hose clamp pliers which you probably have never see before.The best place to get those orings would probably be a caddy dealer.Since they use the same motor in there catera.The other gm dealers would probably be puzzled if you asked for those orings.Let me know what happens and what ever you do dont break that tab.

there were two bolts one for the tube and one for the dipstick tube, i have removed both of those which was a pain because the power steering line ran right in front of both of them. are those orings a special or could i just take them in and match them up? and i would love to meet the engineer who designed this engine just to kick him in the schins repeatedly while shaking his hand so he couldn't get away. so a caddy dealer huh? a certified saturn repair dealer wouldn't have those?

I said a 10mm nut not bolt remove it its to the right if the bolts you took out then grab the hose and pull the tab off of the stud the nut goes on.That should give you the room you need.If it was a saturn dealer at one time or its a saturn specialist then they should have them or the caddy dealer.Take that nut off like i said it really helps.Let me know what you find.

ok. there is no nut. there were only two bolts one to hold the dipstick tube and the other to hold the extension tube. the tab is free and can move freely however the dipstick tube is in the way and keeping me from pulling extension tube out. any suggestions?

Further over to the right there is a 10mm nut that holds the power steering hose in place by a tab.I remove the nut and slide the tab off the stud.Then pull the hose down and that gives me enough room to pull the tube out of the housing.Thats how i do it.

holy sh--!!!!!!! i thought that line was welded on. now, how important is replacing those o rings? they look good to me and i'm not so sure i can pull the entire tube out.

You dont have to pull the tube all the way out to replace the orings you just use a small 90 degree pick to remove the orings.I would replace the orings because if they leak do you want to do this job all over?Also i always spray a little silicone spray in the opening of the housing so the tube slides right in.Glad you found the nut i was taking about that makes it possible to pull the tube out far enough to remove the housing.

ok. mission accomplished. don't see any visable leaks. there is some smoke from what i am guessing is just residual coolant left from opening up the system. will know in a few days for sure. have taken on a test drive around the block. let sit and idle to temp still no warning lights or obvious problems. thanks again for all the help. i should mention that i have 2 left over torx bolts. not sure where they go. i double checked everything. i also changed the spark plugs i had bosch platinum +2 and now i have bosch platinum +4. will that help with better performance and mpg and what not or am i just dreaming?

Your welcome iam always here to help as far as the better mileage from the plugs i think thats wishfull thinking lol.So you had a code P0128 thats why you changed the thermostat?

yes i had a code that said the coolant temp did not match the regulated thermastat temp. yes p0128. is that not the right fix?

No thats right the saturn vues had the same problem they used the same engines in the 2002 and the 2003 but the vues had a different intake so changing the thermostat was a lot easier.

now the next problem i have to tackle is the transmission. after driving for awhile the trans shifts hard and the service light comes on. when car is turned off the system resets and has to warm up again to get the same problem. is this trans problem or cat problem?

Hard shifting is caused by a pressure issue not a cat when the cats get clogged on those cars they wont shift till you let off the gas pedal.Most of the time the problem is caused by a bad pressure control solenoid in the valve body.You can change the solenoid by poping the transmission side cover loose and using a long screw driver and extendable magnet to change the solenoid.I replaced a ton of them that way if you let it go too long like that you will damage the transmission.The main thing is drain the transmission fluid thru a rag and see if there is any metal in the fluid.Also what is the exact code number you are setting for that transmission problem?

how involved is changing that solenoid? i was guestimated by a dealer it would cost 2k to change.

No thats outrages labor is about 8hrs plus 180 for parts.You seem pretty handy with tools you can just change it yourself you only have to pop the side cover loose and do it with a long screwdriver and a extension magnet.Also any codes?

it will take 8 hours to change out one solenoid?

They dont charge by how long it takes because everyone can do it in different times.So they charge you labor at flat rate every job has a flat time they charge you.Probably 6-7hrs flat rate.I can do one in about 2hrs or less but keep in mind i have replaced a ton of them.

so then is it that easy, just open the side of trans and pop out old insert new? or do you have to remove a bunch of other stuff just to get to the side of the trans?

There is plastic cover remove battery battery tray fuse box etc.Its not the easiest but you tackled the thermostat which isnt the easiest.So did you check for transmission codes?Also you have to unplug the solenoids and remove a U shaped clip holding into the valve body.

how do i get the codes? i have to turn the engine off and then return the key to the run position for the scanner to work. whilst doing so the car resets everything. and i get no codes to show.

If there was any codes there still would be codes after turning the key off.When it shifts hard does the wrench light ever come on?

i have about a 20 minute drive to work and about 5 minutes before i get there the hard shifting starts and the wrench light comes on. same thing on my way home. tonight i got home and ran the scanner and found no codes.

If that wrench light is coming on then there is codes stored in the computer.Maybe your scanner just read them?

I have the same problem with the Saturn 2003 L300 v6 as for the thermostat removal except for my problem came from a cracked radiator tank and overheating. My jack neighbor poured some Bargs gasket sealer not realizing the car had a plastic tank. Replaced with new radiator and antifreeze the car continues to overheat. Are there any tricks that you might reveal to unfreeze the thermostat so that the coolant will circulate through the radiator?

Hi,

Would it be possible for you to repost this question in a new thread? I ask simply because we are trying to keep the threads specific to one topic. If you could, I'm sure someone will answer this for you.

https://www.2carpros.com/questions/new

Take care and I hope you understand.

Take care,
Joe