Looking for some Technical opinions and would be much appreciated.

[BReynolds]

I recently purchased a 2003 lx 470 which has an engine knock at cold start. It lasts about 1-2 seconds then goes away. I’m guessing it could be bearings from bad maintenance or maybe old spark plugs.. or maybe even a bad injector. It has 143k and don’t know if it has the original plugs. I just did an oil change with Mobil 1 synthetic 5w-30, with a Toyota filter and the knock is still there.
I was hoping that someone might have a little insight, or maybe even have experienced some of the same symptoms that I referenced above and could elaborate.
Is Seafoam worth trying? Any test to eliminate the knock that I’m mentioning?
Again, really appreciate any input on the matter as I’m not used to having noise like this on a Toyota motor.

 

[suprarx7nut]

If bearings are the problem a test from Blackstone will make that very clear. Easy and cheap.

The exhaust manifold can have a leak that sounds like a tick for a brief period of time so you wouldn't be the first to think an engine noise was bearing knock when it was just an air leak.

 

[BReynolds]

If bearings are the problem a test from Blackstone will make that very clear. Easy and cheap.

The exhaust manifold can have a leak that sounds like a tick for a brief period of time so you wouldn't be the first to think an engine noise was bearing knock when it was just an air leak.

I didn't even know about Blackstone. Thank you for mentioning them as I just looked them up.

 

[Eyedaho]

Another possibility if you hear a "knock" on cold startup that goes away is piston slap, which can decrease as the engine warms and makes the clearance tighter.

 

[2001LC]

Some "Toyota tick" is normal. It is more prevalent, on the USA manufacture 4.7L of the Tundra & Sequioa. For which, I like to check the VIN # found on BK 2 head, to see if match to vehicle.

If Japan manufactured 4.7L, as it should be in a 100 series. Excessive knock, during cold start-up. In most cases, indicates poor oil service history. Which can result in reduced oil pressure. Testing oil pressure can be revealing.

In the few cases, where we hear excessive knock. I like to try 2 cans BG's EPR (which I do often regardless) engine oil flush. Then add 2 x cans of BG's MOA, to fresh oil.

 

[BReynolds]

Some "Toyota tick" is normal. It is more prevalent, on the USA manufacture 4.7L of the Tundra & Sequioa. For which, I like to check the VIN # found on BK 2 head, to see if match to vehicle.

If Japan manufactured 4.7L, as it should be in a 100 series. Excessive knock, during cold start-up. In most cases, indicates poor oil service history. Which can result in reduced oil pressure. Testing oil pressure can be revealing.

In the few cases, where we hear excessive knock. I like to try 2 cans BG's EPR (which I do often regardless) engine oil flush. Then add 2 x cans of BG's MOA, to fresh oil.

It's definitely not a tick. A small knock for a second or two then clears up. I've driven it for a while at different intervals and no noise at all. Only morning startups when it's cold. The oil pressure is usually at a quarter at idle and goes up a little when tach goes up.
I just ordered over 2k worth of parts and am rethinking that as I don't want to put money in the 470 if there's an engine problem due to bad maintenance.
The person I purchased it from said that they did oil changes but didn't show up on a CARFAX. Who knows...
Thanks for your input!

Just ordered the BG's EPR and MOA to try. What oil do you recommend?

 

[Bisho]

I use Pennzoil Ultra Premium - you can get it for a decent price on Amazon.

If you can upload a video it would probably help out the internet diagnostics. If you hook up a code reader there might be a pending fault.

 

[NE Snowman]

I’d go with the blackstone report and see what comes up, they’ll find metal. If no metal you could open up valve covers to get an idea on oil changes. See how much varnish is on the top of the engine.

 

[4Beast]

One other thing to think about is that the exhaust manifold leak often actually sounds like and engine knock and goes away as the manifold expands.