Gray_Like_My_Hopes

Hey everyone. New guy here who just jumped into the Mustang family. After a long search, about three weeks ago I bought what seemed to be a clean, mechanically stock 2004 Mustang GT Premium with 128K. I found a bunch of steering, interior, and brake problems on the test drive, but the rest of the car was sharp and the engine sounded great.

...Until I'd owned it about a day. Then it developed what sounds like a lower end knock, but it's random and so far has been hard to pin down. If I start it cold it may knock a tiny bit, but not usually. If I start it hot it doesn't knock. If I get it hot and then let it cool down about 20-30 minutes, then it'll usually knock for about 5-15 minutes. Loudest at idle but it changes with the revs.

Given the random nature would I be correct in thinking a timing chain tensioner or guide is going out? Any help would be appreciated.

Also, I guess this is my build thread. Work so far has involved taking off some of the ricer cosmetic mods the owner put on. Along with the engine work my next target is the loose steering rack and the parking brake.

Z28KLR

"Knock" isn't good, that usually means main bearings. "Tick" would generally describe timing chain generated noise. If popping the hood and listening around different areas doesn't work then you may need to invest in an automotive stethescope and use that to help pinpoint the area where the sound is coming from.

Gray_Like_My_Hopes

I've already spent some time with one and it's a little hard to pin down. Sounds louder at the oil pan but with the stethoscope it's not as loud as I'd expect. Maybe further back. Can't tell. As far as a knock vs tick that''s a judgement call. I have some videos I'll upload when I get around to it.

Would a main bearing or rod knock come and go? It always does the same thing. Drive it for an hour or two, let it cool off a little, then start it again and it knocks.

Camster

Any valid service history with this car?
I'm thinking that it was either driven hard,or poorly maintained.
I almost get the feeling that you have a partially clogged oil pump pickup.
My sister had an 87 5.0 T -bird with bad crank/rod bearings.Produced a steady,heavy knock.Too few oil changes for her very short trips.The screen was definitely restricting oil flow.
I'd have someone check oil pressure before you get too deeply in.

Gray_Like_My_Hopes

The owner didn't have good service records, but with what he did have and what I could confirm visually on the car it hasn't been completely neglected. New intake manifold, new brakes, new tires, new alternator, new fuel pump. Supposedly oil changed every 5K (has a sticker too) and supposedly a clutch, but I don't think the clutch was done correctly. All dealer work.

No body damage, clean, etc. He may very well have scammed me but he did own the car for the last 11 years so it's not a quick flip.

On the downside, he didn't pay any attention to the suspension. I have a lot of loose parts to track down and replace.