Hey guys, first post here. I purchased a 2005 XLT 3.0 a few weeks ago, with 86,000 miles on it. When I first start it up, it has a slight engine knock, but goes away after it warms up for a few minutes. Took it to the mechanic today, and he suggested I run some sea foam through it for a few days, then change the oil. When I went to buy the sea foam at NAPA, the clerk suggested I do not do that. Any ideas? Thanks for the help, appreciated.

 

Welcome to the forum

The mechanic is hoping you have a restricted oil passage and that Seafoam might clean it out, you can use ATF(automatic transmission fluid) instead if you have some, either is fine to use

Its like an oil flush, you should only run engine that way for a few days, no longer than a week

Clerk is correct, in a way, while "sludge" is not good, cleaning it out can also cause issues, lol

Say you have a Blood clot causing you to have heart issues, you take medication that breaks up the clot so no more heart issue, but part of that clot goes to your brain and you have a stroke.......not good but heart is OK

You could have partially blocked oil passage(clot) causing the knock until oil gets thinner(warmed up), and cleaning it out could cause clot to move to a bearing oil hole.........not a good thing

I would use the seafoam or ATF, see if it helps open oil passages.........IF that's even the problem, you could have collapsed lifter or failing rod bearing, so cleaning won't help.

 

Thanks for the welcome, and the reply, appreciate it. Do I have to drain a bit of the oil before adding the seafoam, or just dump some in?

My mechanic said if it was a rod bearing, it wouldn't get better after it warmed up. I'm nothing near a mechanic, so I wouldn't know, just what he told me.

 

If its auto trans check the torque converter 13 mm nuts

 

It is an automatic, thanks for the heads up, appreciate it.

 

Unless dipstick is already at the FULL line you can add a 1/2 Quart of seafoam or ATF with no issues to put it at the full line.

If its at the FULL line now then buy a cheaper oil filter and pull the old one off
Put the new one on
Then add the seafoam or ATF

 

Thanks again man.

Something else I forgot about, the clerk at NAPA sold me some fuel additive/cleaner. He told me to dump the whole thing in the tank, with a quarter tank, which is what was in it. Then, he said to take it out of town, and go ***** to the wall in it, then come back and fill the tank. I did just that yesterday, and so far, I've started my truck twice today, and it didn't make the knock either time, knock on wood.

 

I use Seafoam in the gas tank once a year, seems to keep my idle smoother