[Snowboy]

What does a tune up consist of?
I have been thinking of takeing my truck in for a tune up and not sure of what they will do for the $120.

I’m getting crummy gas mileage, Truck shakes a little when idle and I get a humming but was told that could be the AC clutch but it hums when the AC aint on.

I have done the following to the truck already.

New plugs 1 year ago
New Rad hose
New serpentine belt
New plug wires
New distributor cap
Tranny fluid change
Rear and front driveline fluid change
Tranny filter change
Transfer case fluid change.
Brake fluid 2 years ago.
Dex Cool change last year
Intake manifold gasket (had no choice)

GMC 3/4 Ton 5.7L 350 Gas Year 1996

 

[cardoctor]

their not doing much for $120.00

in my shop a tune up would consist of


cap
rotor
if it has a distributor
plugs
air filter
fuel filter
ign. wire set
clean throtle body
check timing
bottle techtron fuel cleaner
cost alot more than $120.00


john

 

[wyldman]

For $120.00,they won't do much.Probably just new plugs,and check everyting else.

Like cardoctor said,there is a lot more to a tune-up.I don't neccesarily just replace everything either,but most of the basics get replaced,rather than checked.

 

[Snowboy]

Air Filter

I use a K&N Air Filter someone sugested i get rid of it and put in a stock filter ? The K&N might be causeing my fuel consumption problems.. I used to get 500km to a 80l tank in the Hi Way now i get maybe 400 if im lucky...

 

[JohnnyU]

Before I did anything else, I'd get rid of that Dex-crap before it destroys your engine. Go GREEN! John (cardoc) was just saying how he has seen many engines fail due to the dexcool, I beleive it. Who wants to run 'muddy water' through their cooling system?

About your mileage, you might want to consider a fuel filter, a fuel system cleaner, or maybe even O2 sensors (unless they are the high mileage ones) that could be what is causing your decrease in fuel economy...

 

[Joey D]

I like the Dexcool, never had a problem with it in 2 trucks. Change it every 2 years still.

If it's a Vortec motor a tuneup is very costly. The plugs are expensive as they are platnum, as well as the dual o2 sensors.
Have it run on a diagnostic machine and see what it reads instead of just replacing parts.
Stay away from a 120 dollar tuneup.

 

[BWhite]

K&n

I have heard but I do not have any empirical evidence to confirm or dispute that . If you over oil the filter (K&N tells you not to ) the excessive oil will collect on the mass air flow wire or grid (if your truck has one ) and cause false readings to be sent to the PCM . This will of course cause problems .

As Cardoctor stated you need to check the baseline timing and clean the throttlebody . It can carbon up and cause the buttterfly to stick, rather quickly if there is any crankcase blowby.

 

[Snowboy]

My Dex col used to look like mud water it looks ok now. Like i said before this is what i have done already.

New plugs 1 year ago
New Rad hose
New serpentine belt
New plug wires
New distributor cap
Tranny fluid change
Rear and front driveline fluid change
Tranny filter change
Transfer case fluid change.
Brake fluid 2 years ago.
Dex Cool change last year
Intake manifold gasket (had no choice)
Fuel filter
Motor Vac service.

The spark plugs are 2 years old and are Bosh Platnium.
Fuel filter is 2 years old as well.

I am thinking that i could have screwed up the Mass Airflow sensor with beeing a lil heavy with oil on the air filter, if thats the case its not worth replaceing beeing that it outways the extra $$ amount in gas.

I have had 2 o2 sesnors replaced once they triped the check engone light.

Think i should throw in some injector fluid cleaner ?

 

[JohnnyU]

Ah, You didnt list the fuel filter on your first list. Don't replace the K&N, just wash it and reoil. Its very simple, and good to do periodically, that way yo get all the dirt out of it, and can start again.

I wouldn't use the snake oil that you put in your tank. I would take it to a dealership or other sercive garage and have them perform a fuel injector/system service. I think the stuff in the three cans works best. I think that stuff you buy is just Diesel anyways....

 

[BWhite]

I was assuming you have had it checked with a scan tool for any recent codes

 

[Snowboy]

I was assuming you have had it checked with a scan tool for any recent codes

Recently like this year no. The dealer just told me it would cost me more then its worth to see what the problem is.

Besides what do i say when iw ant this done ? Hi can you scan my truck for any trouble code's and how much will you charge me ?

 

[Snowboy]

Ah, You didnt list the fuel filter on your first list. Don't replace the K&N, just wash it and reoil. Its very simple, and good to do periodically, that way yo get all the dirt out of it, and can start again.

I wouldn't use the snake oil that you put in your tank. I would take it to a dealership or other sercive garage and have them perform a fuel injector/system service. I think the stuff in the three cans works best. I think that stuff you buy is just Diesel anyways....

What ya mean snake oil ? Diesel in a GAS thats like throwing oil into the tank, what are the 3 can stuf you talking about ?

Dave

 

[Honest Mike]

Just to go back a little here...Dexcool antifreeze sucks! It turns to mud and that cant be any good for the inside of the engine, radiator, or heater core. Now back to the tune up. First off, let me just say that I like to use OEM parts, especially when it comes to the wire set, cheap wire sets suck. A complete tune up in my shop, on a vehicle with a distributor, consists of: cap, rotor, wires, plugs, gas filter, air filter, pcv valve, check and set timing, clean throttle plate, and I also like to change the engine oil, oil filter and give the vehicle a complete grease job, if it has fittings, grease steering stops, if it has them, and top off all fluids, and lastly check the air pressures in the tires. Air pressures obviously have nothing to do with a tune up, but I check customers air pressures everytime I do their oil changes. I dont replace the o2 sensors with a tune up. If the check engine light is on, and the customer wants it fixed, and the reason for the light is the o2 sensor, then they get replaced. Everyone has their own way of doing something, this is my way. Mike

 

[Honest Mike]

I was trying to edit the post above to add a couple more thoughts, but the 3 minutes expired! :headwall Chuck, can you please lengthen that 3 minutes a little? Maybe to 10 minutes or even a half hour? That would be great! I wanted to add that some vehicles have more than 1 o2 sensor. Some vehicles, such as my Camaro for example, have 4, and they can be quite costly. So changing them, just for the sake of changing them, doesnt make sense to me. Some o2 sensors can be bought for like $15-$20, while others are maybe 3-4 times more money each. Mike

 

[Snowboy]

So why does GM use DEX cool then ?

So seeing as i have done most of what you guys have told me, it looks like my throtle body could use a cleaning ? I have done the cardon removal last year. They call it motor vac.

Oh hey i found a link. motor vac

Too bad it didnt do what they say it does.. No surprise there.

If there was something wrong with the o2 sensors they would trip the check engine light like it did once yes ?

Dave.

 

[grasshopper]

Snowboy, check your fan clutch. I had a 305 that was getting cruummy mileage, and I tried everything plugs, wires, timing etc. Someone checked my fan clutch and it was siezed. I put a new one in and it made a huge difference on mileage, not to mention it was a lot quieter and had a bit more HP.

 

[Snowboy]

Snowboy, check your fan clutch. I had a 305 that was getting cruummy mileage, and I tried everything plugs, wires, timing etc. Someone checked my fan clutch and it was siezed. I put a new one in and it made a huge difference on mileage, not to mention it was a lot quieter and had a bit more HP.

The Fan comes on and off fine. No problems with it there. The only fan with problems is the noise the blower for AC & Heat makes but at least i have heat.

Thanks thou Grasshopper

 

[wyldman]

I like the Dexcool, never had a problem with it in 2 trucks. Change it every 2 years still.

If your changing it every year,your defeating the whole purpose of Dexcool,the long life.If your doing it regularly,just use the green stuff.

 

[Honest Mike]

Chris, what is your oppinion of Dexcool? Do you like it? Do you agree that normal green is better and stays cleaner looking? Mike

 

[JohnnyU]

My name isn't Chris, but I'll throw in my $.02 anyway.

I think Dexcool was a good idea, but it wasn't up to par, the idea of a long-life coolant is a good one, since many people don't like to take the time to do the PM on their vehicles. But since the product doesn't seem to last, I think the green stuff is tested and proven, and cheaper!