Need more info on Fuel Economy and General Maintenance list

I just read the thread on tips for better fuel economy and general maintenance items, and I have some questions I was hoping I could get some help on.

For instance....
replacing the PCV valve > what is it? where is it located?
Transmission flush & refill & filter > How do I do that? What are the dangers/concerns?
Differential fluid > same questions...
O2 sensors / Thermostats / MAF > where can I find those?

Also, I have a '98 blazer 4dr... I'm having problems with it starting in extreme cold, like below 15-20 degrees. I replaced the battery and put some HEET in the tank, but I still got issues. If it's 20 degrees or above, she starts right up. Below that, and she cranks, but doesnt completely turn over. In fact, if she's been sitting a while, she'll start up, then immediately die. Then she'll crank and crank. I've been lucky enough to finally get her started, but I wasn't so lucky one day (the day I replaced the battery).

A friend said it might be the cold start sensor, and I've been looking in here for that solution, but I've yet to find it. I've seen where fuel pressure may be an issue, and I'm going to try and check that this weekend... I'm planning to change my fuel filter as well.

I'm in Chicago, and the weather just started getting cold...

You guys have some great advice.. keep up the good work!

All excelent questions, that we should probably include in that sticky.

And welcome to Automotive Forums

replacing the PCV valve > what is it? where is it located?
It's located on a valve cover. It's usually an L shaped object with a fuel hose sized hose going to it

Transmission flush & refill & filter > How do I do that? What are the dangers/concerns?
Make sure that you get the right oil, and the right filter. Get a new gasket as well
The bigest hastle here is that you'll have to work under the truck for most of the job, and there isn't a drain plug. It can be a messy job if you mess up.
Loosen all the transmission pan bolts, then remove 1 side completely.
Slowely loosen of the side bolts, and start removing them as the pad slowely tips draining the oil out.
Remove the pan, the old filter, make sure that it's the same as the new filter. Clean all the surfaces, Then reverse the order using the new parts suplied. Fill this through the transmission dip stick tube.

Differential fluid > same questions...
Basicly the same as transmission.

O2 sensors
In the exhaust pipe. There might be 1 or 2 or more depending upon the year.
It's a sensor in the exhaust with a wire going to it.

Thermostats
Top of the motor, You'll see the round housing with a sleave that the top rad hose bolts into. Change your rad cap to a Stant brand. Unless it's already a stant.

MAF
Good question, my truck is to old, and doesn't have 1 so I don't know


Your truck starts fine until the other vehicles start having their problems with the cold as well. A tune up will help a little, but you might have to install a block heater to ensure that it'll start.

A block heater goes into one of the frost plug holes, and you plug it in.
This heats the water in the block just enough to keep it starting easily.
With some the block will be warm to the touch.

Good Luck

welcome to af... moter size, type of transmission (manual or auto transaxil) and year of vehical (also 8th vin charicter) and sorry, dont mean to offend, but if you need help to find a positive crankcase valve (pcv) you realy shouldnt be attempting a tranny or pig (rear end) service... the maf doesnt get replaced unless its bad, its a fairly expencive part that just gets cleaned... and its between the air box and the cpi unit or throttle body, depending on fuel delivery style... o2's, there are 4 on 96 and newer, one on each downpipe bank, one behind the y, and one behind the cat... t stat is in the housing at the block end of the top radiator hose, and finally the best advice i can give, if you do any work yourselfe, do not use Autozone, Advance auto, or any other bottum end parts store, dealer, napa, carquest is exceptable, but those places quality of parts is better then the quality of Autozone or Advance auto... hope ive helped and no offence ment by the tranny service and rear end, but they are kinda importent parts that if you screw the hootch on, WILL get expencive in a heartbeat

when doing a tranny service be sure to not let any rag materieal come in contact with the valve body (insides) this can wreck your transmission, and i (as a tech) do not reccomend transmission flushes, just a pan dorp and refill, and also, the tranny gasket from the factory is cork, i reccomend the extra $$ and putting a rubber one on instead of a new cork one, and when dropping the pan, make sure you clean the pan out, get the magnet back to where it belongs, and clean the gasket serfice on the pan and the tranny... and the magnet on the cover of the pig is glued in place, dont remove it from where it sits, and depending on year, the pig may require full synthetic fluid to go into it

DM is right.

I don't mind servicing my differentials, but I like to let a transmisssion shop service the transmission.

They pump all the junk out.

Don't just go to a Mr Lube type place. They just pump the old fluid out, and the new fluid in leaving an old probebly dirty filter in there.

your right obp, they leave old filters in and they get out of it legally becauce the 'flushed your system' a filter change is not something they do, and it is pointless to change the fluid and leave a shitty filter in, think about it, you replace your Napa gold or silver (wix is also fine) oil filter every time you change the oil, why would you change the transmission fluid and not get the filter with it?!?!????

On a 98, the PCV valve is in the driver side valve cover.

My 98 has three O2 sensors, one at each manifold, and one after the cat.

The recommended intervals are a little off in that thread. Transmission service should be done every 30,000 miles. (15,000 for special duty applications) or 2 years. The recommended interval for O2 sensors is 100,000 miles.

that is weird, my 98 has 4, hm, looks like i got the 'high matnence' modle

I've heard a few others say that they had 4 O2 sensors, too. I have yet to figure out why some would have 3 and others have 4, there must be some reason.

8th vin is a?

It's got the standard Blazer engine vin "W". The Blazers aren't like the pick-ups where you see both "W" and "X" regularly........ now that I think about it, I don't think I've seen a second gen Blazer with anything other than a "W".

i beleve you could get the 2nd gens with an x back in the cpi days, but dont quote me on it

i beleve you could get the 2nd gens with an x back in the cpi days, but dont quote me on it
Oops, too late. I already quoted you. :lol:

lmao!

Thanks for the welcome, and no offense taken on the pcv comment. I'll probably leave the first tranny flush to one to my mechanic friends and get an idea of how much is involved. The reason I ask about concerns/dangers is I've heard there may be a sensor of some sort on the tranny that can be damaged, but I haven't seen it mentioned anywhere.
I apologize for my ignorance, but I've never had the time, schooling, or vehicle to play with so a lot of this stuff is new to me. This is my first truck, and it's gotten to the point where its needing some major services done, and I'm tired of paying for it when I can do most of it myself. I do have some common sense and ability though, so I'll get a haynes manual and do what I can....
I've got a 98 blazer, 4 dr, 4.3l automatic, 8th vin char is a 'dubya'...
1 last thing.. is there a cold start sensor on this truck?

Hey no worries. We were all "newbies" at one point. I remember a time when I didn't know what or where my PCV valve is either. Good call on the Haynes, it's an invaluable tool.

As for a cold start sensor, I'm not sure. Never heard of them on our trucks, though that doesn't mean they don't exist. Aside from a block heater, one further recommendation would be to use an oil with lower viscosity. If it is less dense and flows more freely your engine will start easier. Given the cold temperatures it sounds like you face, this is probably something you should do anyway.

Most of the jobs you've listed are ones that the beginner with no experience can handle. Oil change, PCV swap, Tstat swap, MAF cleaning are all VERY easy. Changing your diff fluids is pretty simple too. Tranny service is easy if you are cautious in the way you take the bolts out of the pan. There are a bunch of them, and as long as you loosen them from one side to the other, allowing the pan to slowly tilt to one side and fluid to drain off in a controlled manner you should be fine. I learned from a friend who worked in a tranny shop who kept spilling hot tranny fluid all over himself! :lol2:

Good luck guy, and welcome to AF.

they 97 and up should have 4 because they need one at the top of each header and pre cat and post cap.... it depends where the truck was sold generally the one with 4 is in an area where it must be hooked to a computer to get an emmission stick like here in the tri state.. the 2 after the header are an up stream and down stream i know all this because i just went through it in my rsx both my up stream and down sdtream went ... theyr were 300 a peice and they arent diamond cut platinum with my name engraved can any say ass rape!!!!!!!!!!!

one more comment from me (well atleast one more lol) heet is a good product, but it contains patrolium distelets (sp???) the are not good for injectors and valve seating, a little every now and then is ok, but a lot or often is bad

One way to keep condensation to a minimum is to keep your gas tank full in cold climates, the emptier it is, the more water will form inside as the temp changes, thusly causing you problems. also, if your getting crappy gas will cause it too, do you always fill up at the same station?

I'm looking at on old service record for my auto tranny flush, and i'm not seeing 'filter change." I'd a thought it'd be normal practice. Isn't that almost like doing nothing at all? i mean theres still gunk there, right? I'm starting to feel cheated! At least next time im going to ask more questions... how often should this be done? i've heard every 15-30,000 mi! I'm not looking to waste away $$, but I definitely want to keep this truck for a while, preferably in good condition.

I typically always fill up at the same station... Although there's the occasional venture off the beaten path and you see the needle a little too close to E... As for the tank being full, I try not to let it go past 1/2 full (not bad for a pessimist) before I top it off... In the summer, I drive on fumes, but when the cold hits, I keep it full...

I'm looking at on old service record for my auto tranny flush, and i'm not seeing 'filter change." I'd a thought it'd be normal practice. Isn't that almost like doing nothing at all? i mean theres still gunk there, right? I'm starting to feel cheated! At least next time im going to ask more questions... how often should this be done? i've heard every 15-30,000 mi! I'm not looking to waste away $$, but I definitely want to keep this truck for a while, preferably in good condition.
for a flush, specally at quick lube places, they dont drop the pan, so they can't change the filter... you need to call a tranny or full service shop and ask them to schedual you a time to drop off the truck for a transmission filter change

thanks doug.

no problem, i know its not what you want to hear, but its how it is, look at probibly an hour to an hour and a half labor plus parts, im not even sure how much a 4l60e tranny kit goes for anymore