Pre-Purchase Inspection - Teach Me

I've never had to have one done, but need to on a car we're looking at. It's a 2003 Mustang GT with what I think is gear noise from the diff. The car is otherwise virtually like new, and the owner is obviously anal about maintaining it. He says he doesn't hear anything, although it was obvious to both me and my son.
Anyway, he suggested a PPI. This is a really nice car, so I'm willing to go that route. I'm thinking I want to have this done at a Ford dealer, but other than that, know every little about the process. So any information on PPI's would be appreciated.

The test drive is the easiest and best part of a pre-purchase inspection. You can determine if the drivetrain has excessive noise from needing maintenance, you can also test out the brakes, steering system, and suspension by feeling if the ride is rough from worn out shocks and struts. You can also do the push test to also check them out. You also need to check the tires because that will also give you a bad ride. If you're familiar with that generation Mustang, you will know what other things that don't work well with that car and can check it out or specifically have the Ford dealership or another shop look at that. You also want to ask the owners when the last time they changed coolant, oil, trans fluid and brake fluid too.

In reply to Mr_Clutch42:

I've already driven the car and checked it out myself. But I feel I need to have someone else look at the noise, as I don't have access to putting the car on my rack.
What I'm looking for is information on who typically does these inspections, do they drive the car, what it costs, etc...

it'll vary. I had one done on a k1200s at the BMW dealer in Dallas and it was $90. They did their typical 70 point inspection or whatever it was, rode the bike, then emailed me a detailed report. They missed a few things, one pretty major (clogged converter), but it did give me the piece of mind to purchase a plane ticket and ride the bike 700 miles home in one day.

I've had a few done on Porsche's at a local shop. He charged $150 and REALLY went over the cars. Again I got a detailed report. In both cases the PPIs paid for themselves by turning up little things the owners didn't know and allowing me get a little more off the asking price. In the case of my 911 the owner and I had reached a stopping point in negotiations, but after the ppi I got another $250 off.

If you have a respected local performance shop that specializes in Ford's that's who I would use. I'm sure they've seen their share of bad diffs! Otherwise I'd go will you're favorite local Ford dealer.

I'd skip the dealer and find an indie with a good reputation. The sort of place that does race prep and knows the Mustang platform's weaknesses. Ask the local NASA American Iron guys who is reliable locally. There is usually one master tech from the Ford dealer with a home garage and a race car in every town.

Or... price a diff at a local recycler, mentally put the $250 PPI money toward it and just drive the car.

In reply to Giant Purple Snorklewacker:

Well that's part of the problem. I'm not familiar with the area, he isn't willing to come all the way out to my area, and the Ford dealer is looking like the only option. I also don't know any NASA guys in either area. Do you really think the Ford dealer isn't going to be able to diagnose a pretty obvious noise coming from the rear of the car?

In reply to bravenrace:

I think a "good" dealer will do due diligence and actually check the car out but most will just assign it to some schlep who can't be trusted to do real work and he will use it as a smoke break after he does a couple burnouts in the lot and gives it a pass. The problem lies in finding a good dealer - it's easier to find a good indie by asking racers where they get their cars prepped. Racers don't tolerate bullE36 M3 prep.

Start at the NASA chapter website - there will be a list of approved shops who can tech cars.

The PPI from a service center or dealer is so hit or miss. I was assisting a co-worker purchase a newer car and I heard some rear axle noise. The dealership with the car didn't hear anything or find anything and a PPI inspection from a highly recommended local repair shop didn't find anything. All this made me feel like I needed hearing aids. Then three months later after purchase of said car during a oil change at the shop that performed the PPI inspection they recommended re-placement of failed rear differential mount bushings.

Like Mr Clutch said find someone who knows the car to do a PPI and read up on the forums for that year. Used car buying when the price is over 9k just makes me nervous. Give me a cheap beater and I don't worry about a thing.

I had Nissan PPI my Skyline after buying it. Was around $100.

They found that the valve cover gasket was leaking as well as the reverse light switch on the transmission but were not leaking much. Everything else they found I knew. Strangely they must of not ever looked in the airbox because the intake was berkeleyed, all the rubber was deteriorated, and the filter was in horrible condition.

Since you don't know the area, you also don't know what shops/mechanics he may be buddies with. You need to ask yourself:

If the shop agrees with you about the rear end noise will he believe them, or argue the fact? If he does believe them will he drop the price enough to make up for the inspection & repairs?

In reply to petegossett:

Good points. I believe he's already at his rock bottom price on the car. I can eat a small repair, but not a serious one. So I just need to know what it is so I can decide if I'm going to buy the car or not. However, I just got a price from a Ford dealer of $129 to do it.

You may want to consider getting a fluid analysis from Blackstone labs. In addition to the engine oil, you may want to get the transmission fluid and diff oil checked out to.

In my experience, unless you have a similar or identical car to compare it to, it is difficult to deduct much about the condition of the car from driving it. While it is likely that you are going to feel major problems, minor problems may slip you by.

I had a PPI done at Honda for an S2K I was purchasing from a small independent dealer and it definitely worked to my advantage. Got them to replace the battery, belts, front brakes and rear tires (because they saw it in writing from the dealer). They also brought me to the back to see it up on the lift and point out the modified suspension (which I already knew about) so I could inspect and make sure all was to my liking.

With something like diff noise it could be hit or miss like some have said above, but if you are seriously considering purchasing and can't afford to incur a large expense I would at least consider the local Ford dealer as a worst-case scenario.

Would telling us the area the car is in help us to recommend a specific shop?

In reply to JohnRW1621:

Maybe. It's in Medina Ohio.