I own a 96 Pontiac Trans-Am. The car was just purchased by me. It currently has 96,000 miles. When I purchased the car 3 months ago it ran perfect. The last few days the vehicle has been stumbling below 2,500 rpm. Once you get over 2,500 rpm the car runs great. Took it to a local mechanic. He scanned the computer and got code p0300 intermitent misfire. He recommended a complete tune. The parts he said I needed to change were the cap, rotor, plugs, plug wires, fuel filter, water pump, thermostat, upper radiator hose, lower radiator hose. His price for this was $800.00. Does his diagnosis seem correct, and is his price right? Thank you for your help.
He’s looking to make a big boat payment before Christmas.
A water pump, t-stat, upper and lower rad hoses are not part of a ‘tune up’.
The misfire (IF he read the code correctly) should be addressed first.
A good tune up may be in order but there are other methods.
Being new to you, the vehicle should have a compression test done, even if only for peace of mind.
Perhaps all this needs is a plug wire and/or plug. In fact, you can check this yourself.
After dark, pop the hood, start the engine and look at the plug wires. Is there a small fourth of July fireworks display? Bright blue spark arcing anywhere?
Something else you can do cheaply: buy a can of carb/throttle body cleaner and spray the throttle body and see if it runs better. If not, the IAC (idle Air Control) valve may need changing.
Check for any vacuum leaks. (hoses, air intakes)
At any rate, get a second professional opinion.
Thank you for your comments. I spoke with the mechanic about the need for the water pump and hoses. His response to me was that the distributor cap was behind the water pump. He also said the cooling system had to be drained and the waterpump removed to remove the distributor cap. At 95,000 miles he did not want to re-install the original w/p but instead wanted to go ahead and flush the cooling system and change the belt and hoses since they were already off. Does this sound reasonable? He said the only additional cost would be for the parts no labor.
Agree that first you should find out if it is just a plug wire or a plug. If your mechanic cannot do that he is a “parts hanger” rather than a mechanic. In the medical profession such a person is called a greedy quack. I had an identical problem with my father-in-law’s Buick which I borrowed to take on a trip. Even the Walmart mechanic was able to pinpoint the problem and said it was a plug wire which had deteriorated, and replaced it for about $25. The car ran great for the next 3000 miles back home. Your mechanic should properly diagnose what the problem is first. His computer should pinpoint exactly which plug or wire is malfunctioning. If all the plugs are erratic, it could be the distributor cap. Agree you should get a second opinion, and leave this guy behind.
At 12 years old, and the parts original, replacement of those parts does sound like some good preventative maintenance. If not done now, one day, the engine gets hot, and BLAM!, it overheats from poor pumping action, “stuff” in the old coolant, or a busted old radiator hose. All the other stuff proposed is just routine, scheduled (who missed the schedules?) maintenance which has been “deferred” for too long. /// With V- engines, much of the expense, in labor, is caused by the need to remove various OTHER components, and maybe roll the engine, to gain access to the parts one wants to change. After the deferred scheduled maintenance is performed, further exploration for the cause of the problem, may still be necessary…such as … a lot of stuff… ignition system parts, fuel system parts, maybe other “stuff”.
This is Auto Zone’s website: Click on it to see how it’s done http://www.autozone.com/servlet/UiBroker?ForwardPage=az/cds/en_us/0900823d/80/1c/e4/19/0900823d801ce419.jsp You could just change the spark plug wires, and spark plugs, and see where that gets you, performance-wise.
Something’s not right here. Your engine doesn’t have a distributor cap or rotor. It utilizes coil packs. And any mechanic would know this! So he’s suggesting replacing components your engine doesn’t even have! And because of this, I would recommend that you bring it to a mechanic who knows what he’s talking about, and knows what he’s doing.
Tester
It’s not a 5.7L ?! And Auto Zone has the wrong parts listed for it, and the wrong illustrations and instructions showing a front mounted distributor and spark plug wires ?!//////// http://www.autozone.com/servlet/UiBroker?ForwardPage=az/cds/en_us/0900823d/80/1c/df/6f/0900823d801cdf6f.jsp Click and scroll: And this ain’t it?
My car is a 5.7 litre V-8. To the other posters thank you for your advice. I looked under the hood and can not see the distributor or any plug wires. I parked it in the garage and looked for sparking with the lights out and saw nothing. Here in NorthWest Washington it is hard to find a good mechanic. I have been screwed over before. The mechanic that suggested the work put valve cover gaskets in it the day after I got it and did a great job. He was recommended by a co-worker but $800.00 seems like a lot.
Cartalk Research shows no Trans AM in 1996
My title says it is a 96 Firebird T/A. Has the 5.7 V-8, t-tops, leather, power everything. Vin number on car matches title.
A friend of mine had a car of similar circa, and he said that a tune-up was really expensive…labor intensive, I guess…but, yea, diagnose the problem precisely…Nowadays, those fancy (and expensive) computers can tell you exactly where the problem lies…I also think that that engine has coil packs, but I am not sure.
Good luck…
Your mechanic may be right. This car uses a goofy distributor mounted in an odd place whereas the later ones used a coil on plug setup.
You could try replacing plugs/wires only and go from there.
My mechanic suggested that as well. He said we could try the plugs, plug wires, and fuel filter first. He said if that didn’t correct it and he needed to change the cap it would get expensive. Is this what you would recommend?
That is what I would do if the car were mine. If that car has the original plugs and wires then the plugs were due for replacement long ago (forget that 100k miles bunk) and there is a good chance the wires should have been changed.
As far as I know the 5.7 did not suffer plug wire problems like the 3.8 did but since the wires are 12 years old they no doubt need replacement.
(Note. GM had a campaign going at one time on the 3.8 plug wires and replaced them on vehicles that were out of warranty. I do not think this campaign covered the 5.7 and the program is probably over now.)
I doubt the fuel filter is the problem but this is also something that should be changed on a regular basis; preferably around the 25-30k miles mark or even sooner if a problem is suspected. An engine can run fine on a partially clogged filter but a filter in this condition can shorten the life of the pump by making it work much harder.
Just think of it as jogging with someone’s hand squeezing your throat. You’re still breathing and jogging; just not as easily. 
First let me start by saying that I am really glad that other members of this board value my opinion (Tester, Roadrunner, Docnic). The reason for this statement is that I own the shop this T/A came to. I am the one who diagnosed the problem and gave the customer a list of recommended repairs. The car sounded familiar when I read the initial post then he mentioned the valve cover gaskets and that he was in Washington I knew it was the same car.
Second the OP has left out some pertinent information. This car has 96,000 miles on it and has had no maintenance done none!!! It is my professional opinion that a spark plug will not last 100,000 miles. The plug wires on this vehicle are oil soaked from previous valve cover gasket leaks. I informed the Op of this when he brought it to me to get them changed right after he purchased the car. This oil has caused them to swell and they are shorting to ground.
This T/A has the LT1 350 with opti-spark. This means the distributor is located in the front of the motor behind the water pump. In order to change the cap and rotor ($250.00 for the part) the cooling system must be drained, the water pump and the harmonic balancer removed. It is my opinion that re installing a 100,000 mile water pump and hoses is ridiculous. I informed the OP of this and told him it would not change the amount of labor by installing new. He would simply have to pay for the parts. I recommended at this time to remove the t~stat and flush the entire cooling system (ever read a water pump warranty) at this time. The antifreeze is 11 years old at this point and showing signs of deterioration (even GM says change it at 100,000).
The list of repairs also included changing the fuel filter. I run a fuel pressure test on this vehicle and the pressure was on the low end. After looking under the car I realized the car had 96,000 miles on the original fuel filter. Therefore I recommended changing that as well.
Just for your information a tune-up in my shop includes a compression check with the results of that check given to the customer. I had this car for 1 hour to diagnose the OP?s problem and charged him $0.00. The diagnosis included an ECM scan, ignition scope, brake check, and a good once over.
I hope this information satisfies all of you who replied. I am a highly qualified tech and have been certified for 20 years. I am not a crook or a parts hanger. Also, Roadrunner I do not own a boat.
~Michael
Thank you for your comments. I think that is the route I will take.
If you are Michael Richards then yes this is the same car and I will be calling you in the morning to set up an appointment.
Michael, rest assured I would not have made the comment I did nor suggested the possible repairs if I had of had the correct and complete information.
I only answered to the post as I read it.
Sorry if I have offended you. It was not my intent.
If I lived there you can bet I’d have a boat but you’re likely too busy to go fishing/boating anyway. You ARE speaking of Washington state and not Washington, DC?
I love this site!!!