just curious...did the knock go away after the engine warmed up...I have the infamous cold engine knock on my 01 expy, i have been told it's piston slap, bad cat's or a leaky exhaust.. please let me know if changing the gaskets helped...truck runs great..but that early morning knock makes me crazy
Ok replaced the mani's and gaskets yesterday and wow what a difference. The truck seems to have more power, and runs alot smoother. Now that the knock is gone, I do hear a slight tick but its nothing major.
just curious...did the knock go away after the engine warmed up...I have the infamous cold engine knock on my 01 expy, i have been told it's piston slap, bad cat's or a leaky exhaust.. please let me know if changing the gaskets helped...truck runs great..but that early morning knock makes me crazy
You'll get more help if you start a new thread. Include the year, engine size, and how many miles it has on it.
I didn't want to start a new thread because there are several that already go into the cold start knock...I try to sort through them and match it up to the noise I'm hearing...it seems there are many differant opinions on what actually causes the knock sound...here's some more info...2001 expo, 109,000 miles. recently had all plugs changed, have tried every combo of oil, 5-20,10-30, and only use motorcraft filters, but for 5 minutes at startup there's that loud knocking noise, had it since 89,000 miles, i got 4 differant answer's from 4 mechanics, dealer 1 said piston scuff, dealer 2 said piston slap, private mec. said cats are bad, private mec. 4 said leaky exhaust, once truck is warm, engine purrs like a kitten, but those first 5 minutes...it's almost embarrassing driving down the streets...I've read just about every thread on the cold knock...I'd like to get whatever it is fixed, but just don't know what is causing that noise...thanks again
Your issues may or may not be the same as the person who started this thread. Yes, there are many threads involving similar symptoms that you are experiencing. The suggestions and solutions given in the various threads are tailored to the person that started the tread. It is also discourteous to the person that started the thread to have it hijacked.