CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

LOSS of power/compression after cleaning cold air intake and oil change

I have a 2013 Ford Mustang 5.0 GT. It’s a manual. I just changed my oil and oil filter and cleaned my COLD air intake. I went to take it for a test drive and I have a complete loss of power/compression and have barely any acceleration. I have a hole in my exhaust i need to have fixed and I know that can cause a compression issue, but it wasn’t causing nowhere near this amount of problems before I did this oil and air filter maintence. Please help…

Did you actually do a compression check? with a gauge? I suspect that something went wrong when you cleaned the CAI. Worse case I heard of that someone left a rag in the duct. They put the rag there to keep debris out while cleaning the element and forgot.

1 Like

No I have nothing to check gauge it…could it be that his cars not used to that amount of air? And his o2 sensors were bad and used to limited supply and now that he has a steady amount going through that his cars struggling? His filter was extremely dirty and hasn’t been cleaned in over 2 years…

You probably got the MAF wet (Mass Airflow Sensor)… Pull it out and spray it with carb spray or MAF cleaner… reinstall and see whats what. Thats would be my #1 suspect with what you describe. Is your Air Filter soaking wet? Check…

On this vehicle you must be throwing codes…pull them and follow the clues.

1 Like

Cleaned the air filter, or replaced it?

If this is a K&N filter that you have to oil, did you do it properly? I have heard of excessive oil causing issues.

1 Like

Yup…if it was oiled and dirty…and now wet oiled and dirty…we got problems. Easy to check tho

Problem is solved. I was an idiot and checked his coilpacks and spark plugs and one was only halfway plugged in. Was causing a misfire. Thank you all for your help.

That would surely do it… but they shouldn’t have been disturbed in your process. Which is why we were looking elsewhere… LOL… Welcome to mechanic land. You have to use all your senses I can tell you…

Haha. I forgot I was checking those while my oil was draining lol. and I didn’t realize that I didn’t plug cyclinder 1 back in all the way.

Your ecu HAD to be throwing codes for that… Engine light was on…Yes? She was trying to tell you something methinks. Oh well…go for a drive and have fun

Haha engine light was on previous to me working on his car due to a hole in his borla exhaust kit that needs fixed.

So I didnt know, and I’m at his house without my diagnostic tools lol

whew, and folks here wonder why i ask inane questions sometimes. ok, often. my motor has no power/compression but i just assumed it had no compression since it had no power. that is not a connection i would make. my motor lost compression?
if i removed/cleaned maf and the car would not run i would probably make a wild A** guess i messed up the MAF. NOT that the motor had no compression

1 Like

What?? Lol. It basically felt like it lost compression cause he would go to stomp on it and it just felt like he had no compression but still sounded like a beast.

We go through this all the time. When people describe a problem it is often tainted by what they believe, think they know, or imagine.

No worries… you found the problem. This is a success in our book.

But your leap to believe engine compression was at fault was not a correct leap for the situation you described. Now if you ran thru a deep puddle with that intake and it sucked water…then you can suspect compression…and the symptoms would manifest as such. Too much to describe here but… hey…car is fixed…Its all good

1 Like