I've got an ej18, 123k miles on it, and lately I can hear a knocking sound on acceleration, usually only in 2nd or 3rd gear, and it's very faint, as in so faint that I can only hear it if it's absolutely quiet and I have the windows rolled up and the vent fan and radio off. It only knocks under load, and it seems to be RPM dependent. It's louder going up steep hills. I'm worried it's the beginning of rod knock, but I'm not absolutely sure. I don't think it's anything with the heads or lifters because it's load dependent, and I don't think it's axles because it's RPM, not speed dependent. Does anybody have experience with this?

Could be a rod knock, yes. They are usually only audible under load just as you noted. Any metal in the oil?

 

Hard to say without driving it but I would say there's a good possibility that you have a rod knock.

 

GD

You can have an oil analysis test done to see if there is high copper content in the oil that would indicate bearing wear.

" It only knocks under load, and it seems to be RPM dependent. It's louder going up steep hills"

 

Hi,

 

When I read this earlier today I was thinkiing...spark knock...pinging type of deal.

 

If you know what that sounds like, that probably isn't it. If it is, try better fuel.

 

Doug

At next oil change, you might try going to 20W-50W oil. If the heavier oil quiets down the knock, then I would say that it is rod knock.

how long has it been doing it?

what's the history of the motor - ever overheated or run low on oil, long oil change intervals?

 

should get louder before it blows so you *should* have some time.

 

check the timing tensioner too, when they fail the tensioner can start and "knocking" as it gives on various loads. though the EJ18 style rarely fails, it's worth a look since tensioners also can do it under load like this.

It's been doing it for thousands of miles now. I'm going to send some oil to blackstone at the next oil change to see if they see bearing materials; if it comes back clean, I'll start looking elsewhere.

needless to say, ANY engine can throw a rod if it is abused. but a bad rod bearing would not be my first guess on an EJ18 or an EJ22.

 

keep looking.

EJ18's do not have knock sensors, so the computer will not retard timing to stop it from knocking like EJ22's and 25's will. Try premium gas for a tankful and see if it stops. If it does, then either the EGR system is clogged up or not working, or the pistons have too much carbon on them.

 

Don't put 20w50 in any modern engine. It's a self-fulfilling prophecy, the thick oil won't spread properly in low clearance bearings, so the bearing starves for oil while you have great oil pressure in the galleries. The oil starved bearing wears quickly, opening up the clearances, and now the oil can get in, so the bearing stabilizes. However, you now need to run 20w50 for the rest of the life of the engine because the bearings are trashed. Best thing is to just not go down that road.

UPDATE: It seems it was a slightly loose exhaust manifold heat shield. D'oh. Engine a-ok.

Lucky you.

Hang on to the 1.8.

I've had 3 in my 'fleet' and they have all gone a long ways.

Still are in fact.

r