So I went to go check out a mustang the other day. Super good price (6k) for 120k miles. He said he put a Detroit rocker cam in it but never got it tuned so it’s running rough. Now my problem is I’m not sure if I should buy it or not. Because if it truly just needs a tune, it’s a steal but I just don’t know if there are other issues or something he is trying to hide. It drove better then I thought, it wasn’t the smoothing and was bucking at low speeds but overall it didn’t feel too bad. He obviously didn’t know much about cars tho which kinda scared me. What do you guys think, if you think it’s just a tune then I will go buy tomorrow but do you think it could be a bigger issue with the motor?

 

Disclaimer: I'm just a guy that has owned two of these cars. I'm no mechanic. I do very basic wrenching for fun; no internal engine work. There are far more knowledgeable people around, but here are my thoughts, for what it's worth:

• The 05-mid-08s can have issues with water leaks from various places, where rain water ends up soaking the front footwell floorboards, and if you're very unlucky, that water also pours over the Smart Junction Box, located in the passenger footwell area, behind the kickpanel molding. You're probably not going to be able to pull that molding off and inspect the SJB for corrosion before buying, but if there's ANY indication at all of mildew/mold smell, or damp carpeting, that would be a red flag. Since you did drive it and I'm assuming you didn't see any weird electrical issues (cruise control randomly turning on/off, brake lights staying on, even with ignition off, key out, car locked up, etc), that's a good sign, I guess.
• Does the airbox look stock? It seems weird that one would put in aftermarket cams and 1) not get a tune, and 2) not get a different air intake. I'm surprised it's not throwing MIL codes.
• The spark plug change interval on these cars is 100K miles, and prior to mid-08, the job of changing them out could be a nightmare. Plugs would snap off in the head when trying to be removed. If you can get any information as to whether they have been changed, that would be some piece of mind.
• Any other visual mods? Exhaust? Suspension? Under Drive Pulleys? Personally, the more mods the car has, the less comfortable I would be buying it, especially since it's not tuned (and the owner doesn't appear to be a "car guy"). You can't do hardly anything engine/performance-wise without a tune.
• Any paperwork to go with those Detroit Rockers? It might be a long shot, but...worth an ask maybe? Detroit Rockers are a popular camshaft, so that's something, at least. It just sucks that you can't really know what's in there for sure without cracking the engine open.

Honestly, in my humble opinion, these engines are pretty bulletproof. I literally (stupidly) let my 08 GT sit for...2+ years? I didn't do any of the things right for long-term sitting. I didn't even drain the gas tank or put any stabilizer in. It was started "every once in a while", and sometimes driven up and down the driveway a little. My "revival process" was to change oil, trans fluid, diff fluid, battery, fuel filter, and tires. The damned thing runs like it never sat at all. Pretty amazing, if you ask me.

Good luck. Let us know how it goes

P.S. If you do decide to buy it, Brenspeed sells those camshafts and does e-tuning (or dyno tuning if you're in their area).

 

brenspeed would definitely be the tuning company I go with, considering they made these cams. To answer a few of your questions, I asked who put the cam in and he said he didn’t know. But it definitely did have a cam in it plus the valve covers were painted so it all adds up. He said he had a mechanic check everything out and it was all good (obviously idk if that’s completely true) but it wasn’t super heavily modded. All it had were exhaust, camshaft, wheels, and coil overs. No weird noises either, it felt decent but it honestly just felt like it needed a tune. But no aftermarket air intake which I thought was weird too, I don’t even care about modding it right now I just want it running right. He seemed a little worried about me driving it and was like definitely don’t floor it. Which is understandable because it’s not my car plus it’s not running the best right now. I know these motors are solid and it would be rare for the engine to blow at 120k miles unless it was awfully abused and modded wrong. He said he was selling because he couldn’t afford to tune it and winters coming up. Thanks for your opinion it helps me out a ton. Not completely sure if I’m gonna buy it or not but I will let y’all know.

 

At 6k, the car looks like a steal. The real question that should decide whether it's worth buying is how many other things might need fixing?
If the overall condition of the car is good and it only has the odd minor fault, it might be worth a punt. Go over the car with a fine tooth comb (or ask a trusty mechanic to do it) and compile a list of items that either need fixing now or will need fixing in the next 12 months.

 

To good to be true is always a hard one to punt on. IF you do go this route id get the vin number and send it to brenspeed to see if they know anything about the car. It has cams and no tune. That seems really odd. The guys at that shop are good dudes. I have them do all my ****. Another note worthy issue that will likely become more common is low tranny oil in these cars. When the oil gets hot, it expands and then it comes out of the tube. Basically they built the car with no catch can so over time the tranny fluid will get low with aggressive driving. Something to keep in mind

 

i appreciate all the help, I ended up buying the car. Drove it home no problems but almost hit a deer (just my luck). Anyway, I’m buying a tuner today and should have a tune sent to me within a couple of day. Hopefully everything will be all good after that. Car doesn’t run too bad but I’m definitely not driving it until I get the tune, it’s not worth risking damaging any engine components.

 

Nice

 

I have a 2006 v6,
that's got 55,000 miles
but never had water/melting snow issues
(but yeah that's common,)
& they shift hard,
which is also common

but I'd say get someone to check it over

 

Let us know how you made out, after the tune. I'm thinking like a previous poster, who would install equipment and not have it tuned. Sounds suspicious. Hopefully, everything works out well for you.

 

How did the tune workout for ur car