Valvoline R&P 5w-30 1.4k mi; 2001 Mustang Bullitt 276k mi

[GriffinB]

Ah the ol' hot air intake setup. Yes getting a factory air box is the best move.

Another problem with the K&N besides horrible filtration is oil contamination on the MAF sensor.

It is actually a CAI, it pulls cold air from the fender well, albeit the crappy "shield" the previous owner made or came with the kit definitely allows it to get some of that nice HOT engine air, more power right.

Yep I've read about that as well, I did clean my MAF sensor because of this trying to chase a detonation/pinging issue but it to not alleviate it. I tried looking on eBay and found no luck at all sourcing a factory air box for a Bullitt. It should be the same as a stock GT besides the throttle body so maybe I could use some sort of silicone adapter/coupler.

 

[KnappAttak]

Yep my exact thoughts as well and why I would like to get rid of it, I'd prefer a stock air intake tube so I can use a stock paper filter but the tubes for Bullitt's seem to be unobtanium.

I was considering this AEM Dry Flow filter as I hope it will filter better than a K&N and I won't have issues with overoiling. Or do you have any other suggestions for a better filter?

You'd need to find a paper stock type air filter to replace the K&N, or as much as I hate to say it, keep using the K&N until it starts to plug up with dirt at which point it will actually filter better and catch more particles. People fall for the K&N airflow all the time, and they do flow well, but they only keep larger particles out of the engine, but they don't keep dust and dirt out.

 

[GriffinB]

You'd need to find a paper stock type air filter to replace the K&N, or as much as I hate to say it, keep using the K&N until it starts to plug up with dirt at which point it will actually filter better and catch more particles. People fall for the K&N airflow all the time, and they do flow well, but they only keep larger particles out of the engine, but they don't keep dust and dirt out.

Maybe I can pour some dust on the K&N lol, I’m sure my engine would love that. A normal paper filter will also filter better once it has captured particulates as well funnily enough. So replacing your air filter when it’s a little dirt actually hurts the filtration of your air.

I see part outs of Bullitts every once in a while that may be my best bet to find a stock filter assembly.

 

[wsar10]

You're really asking a lot of this engine in my opinion, but not giving it any real reason to provide it... Maybe I missed something.
Auto cross at almost 300k??
A clean engine bay goes a long way and usually paints a good picture of the rest of the maintenance. I see the worst kind of air filtration possible (a hot air intake with a gauze filter) that will definitely kill an efficiency or protection.

Some of the issues in the report may have evened out over a normal OCI. Based on some of your comments here I would be working toward a rebuild to get to common ground.

 

[GriffinB]

You're really asking a lot of this engine in my opinion, but not giving it any real reason to provide it... Maybe I missed something.
Auto cross at almost 300k??
A clean engine bay goes a long way and usually paints a good picture of the rest of the maintenance. I see the worst kind of air filtration possible (a hot air intake with a gauze filter) that will definitely kill an efficiency or protection.

Some of the issues in the report may have evened out over a normal OCI. Based on some of your comments here I would be working toward a rebuild to get to common ground.

But there are no grounds for concern to rebuild this engine. Here are the results of a compression leak down test I recently did:

Compression Test Results:
#1: 184psi
#2: 186psi
#3: 187psi
#4: 185psi
#5: 176psi
#6: 181psi
#7: 183psi
#8: 185psi

Leak down test was amazing, not a single cylinder was leaking more than 4psi with most being around 2psi of leaking.

Does this indicate my engine needs to be rebuilt? To me it indicates a very healthy engine. Also considering these great numbers I’m not sure if the engines been rebuilt before, the previous owner I bought it from said the guy he bought it from didn’t say he did anything major, but who knows. Engine seems original as the valve cover sticker indicates 06/2001 which is when my car was made. An actual readout of oil pressure would help indicate the condition of the bearings but I don’t have an actual gauge.

So what exactly indicates this needs a rebuild. I’m genuinely curious and am always wanting to learn more about oil. You guys know a lot more than me.

 

[KEVINK0000]

Oiled foam filter from UNI, until you find factory airbox. Use proper super tacky foam oil, no maf fouling, no dirt intrusion. Dry flow and KN, not really filters for street use in my experience, both mcy and auto.