Bad engine knock

[trexified]

I have a bad engine knock or rattle at start up when cold. It seems to be getting worse. Mechanic thinks its the timing chain slapping in the engine due to high miles (169000 mi). I noticed (think) its happening worse when the heater is on. Called the mecanic he says the only other thing it could be is a bad ac pump. What do you think? Its so bad i can hear it in my house at warmup 4 months ago it was whisper quite. When the engine warms up and finally goes away its whisper quiet again.

[pwschuh]

What have you tried to do to isolate the source of the noise? A 3ft length of rubber tubing used as a stethoscope can help narrow down specifically where the noise is coming from.

[trexified]

My mechanic said it sounds like its coming from the valve train area. My ear says its the front right side.

[spy1309]

It might be a valve slap.....the engine has hydraulic valve lifters, if one is not working properly it will create a space between the valve and valve lifter and create a taping noise, when the oil is warm is thin enough to circulate.
Before any expensive repairs use some internal cleaner to clean all pasages of gunk and change oil with a good quality syntetic oil like Mobil One.
A timming chain slap would not go away when warm even do it has a hydraulic tensioner also controlled by oil pressure.

[trexified]

What kind of internal cleaner? Is it an oil or gas additive? I apologize for being so ignorant.

[spy1309]

Something like this.
https://www.walmart.ca/en/ip/motormedic ... 0077654272

Before you change the oil with the car parked and engine warmed up you dump this in the engine even ( don t worry about overfilling ) let the engine idle for 15 min , DO NOT REV THE ENGINE .....DO NOT DRIVEIT.....after 15 min dump the oil , change filter and refill with syntetic Mobil 1
https://www.walmart.ca/en/ip/mobil-1-5w ... 0016943647

You can add a can of Rislone to clean as you go
https://www.walmart.ca/en/ip/rislone-en ... 0194078531

If the issues is with cloged passages it should clear in 1000-2000 km

[spy1309]

Trexified did you solved the issue?...it would be nice to update us so you can help other members with your solution.

[Rob774]

OP, can you tape it with your phone and Youtube it to us?

Thanks.

[trexified]

Update.
Well the problem is fixed. I think I had double trouble. The cleaner worked and took out the hard knock. There was a small knock left but my mechanic kept saying it was a timing chain slap. Thats what some of the other FORDS do. Ok hes solved alot of problems on my vehicles over the years. WELL I talked my wife into taking it 8 hours away with the family. (mistake) On a friday night my small knock went to a squeal, then I heard it. My 2 month old serp belt snapped. I knew when the charging system light came.(OH GAWD) Thankfully I was in my hotel parking lot. But We were planning on heading home the next day. (a saturday). So frantic calling started at 7 the next morning Shop 1 no. Shop 2 yes but we close at noon so if we cant get it fixed by then it will be Monday. Shop 3 no Shop 4 Yes and we are open till 6 today and we are open on sunday! Halleluia! So long story short it was the harmonic balancer. Four hours later it was fixed! knock gone!

[pwschuh]

Good news and thanks for the update.