Ok folks -- I've got an EJ18 motor with 107k, it seems to knock like a mo-fo under heavy load when it's cold outside (<40F) and before the car is warmed up. If it's warm outside, or after it's warmed up, it goes away. Any ideas?

Ok folks -- I've got an EJ18 motor with 107k, it seems to knock like a mo-fo under heavy load when it's cold outside (<40F) and before the car is warmed up. If it's warm outside, or after it's warmed up, it goes away. Any ideas?

 

assuming it has enough oil...

 

it sounds like piston slap, but i've never heard of it in an ej18 and only maybe in an ej22. usually it's an ej25 issue.

 

or maybe a loose t-belt.

very odd for an EJ18, but maybe they can have piston slap? classic piston slap is a knocking sound when cold at start up that goes away when warmed up. it's benign and you can drive the car forever like that.

 

sometimes timing belt tensioners fail and make a knocking sound too, which can easily be mistaken for an engine issue. but - that's usually with the new style tensioners, i've enver seen the old style tensioners fail which is probably what yours has. not sure if they can knock too but i'd imagine they can. remove the drivers side timing belt cover (very easy, just 3 10mm bolts) and watch in there when it's making the noise, you can see the tensioner pulley moving and giving some. or listen to the timing belt covers with a mechanics stethoscope.

 

if it's ever been run low on oil then an actual engine knock could be the cause in which case the engine is hosed. you'll need another block. the good thing is EJ18's aren't worth anything because demand it low and they very rarely fail. easy to pick a known good one up cheap. i bought one with 80,000 miles and 60 day warranty for $150, runs great. i used it for a swap, not to replace a bad engine though.

It's got plenty of oil. This has been an ongoing chronic issue since I got the car a year ago. I've got a car with an EJ25 so I know what piston slap sounds like there, and it's not nearly as bad. Piston slap on THAT car goes away literally within 60 seconds of starting it on cold days, whereas this lasts for probably nearly 10 mins.

 

The ej18 does have HLA's. Any chance it's that?

Edited November 1, 201015 yr by kc8apm

My ej18 had loads of piston slap! Of course it had a very hard life being beat over back roads in VT and 230k on it!

as for piston slap, there are varying degrees and the EJ18 may sound different than the EJ25?

 

if it's HLA's that should be obvious as it would likely come from one side and not the other...unless multiple ones are fouling.

 

maybe it's the oil pump? has it ever been resealed? the rear backing plate screws notoriously come loose on all EJ engines (same pump). i don't know that i've pulled one that didn't have at least one screw loose. not sure what the symptoms would be if they were all loose but i'd imagine something would happen - maybe that's what's happening?

 

if you want to keep the car a long time maybe you could plan on a complete timing kit replacmenet ($80 on ebay) and resael the oil pump while you're in there. 60,000 trouble free miles after that until the next tbelt change.

Well, if it is piston slap, how long should I expect it to last, I mean as the car warms up? Also, I've had the car for the last year, during which I've put 17k miles on it, and it's done it since day one, so I figure if it was something catastrophic it might have happened by now. I've just begun noticing it again, because it's getting cold outside in the mornings again (PA). Also, I've noticed that putting in higher octane does not make a discernible difference in the knocking...

Also, on the EJ25, when it slaps on startup, it's very rhythmic, like it's happening on say, one cylinder. On the EJ18, it sounds like popcorn popping inside the motor when it's under load.

Well, if it is piston slap, how long should I expect it to last, I mean as the car warms up?

piston slap should be gone by the time the car reaches operating temperatures. thing is, some are bad enough that it only gets quieter once car is warmed up and doesn't completely go away - just depends, not always the same. if it decrease directly with temperature it seems like it's a good candidate for piston slap, but hard to say since you sound confident it's not it's good to explore other possibilities too.

 

if this thing does have HLA's....which i think it does...then frequent oil changes are huge. we deal with this all the time in the older gen stuff. sea foam, MMO, and even ATF are added to free what may be sticking HLA's. in those cases usually the sound is noticably from one side or area...wherever the problematic HLA is.

 

or it can be oil supply related, meaning the oil pump needs resealed. in those cases usually it's all over the place because it's affecting all of them.

 

does your sound like it's from one side or both....or centrally located? that might help a good bit to determine that.

My 99 Legacy with an EJ22 began making a knock at about 237K. I replaced the oil pump, timing belt, sprockets, tensioner and rollers. The sound stopped until I took a 1,000 mile trip to Nebraska this past month (245K). When I started the car up after sitting for a week, it knocked to beat the band. It was a quart low. After it warmed up the knocking stopped. Now it knocks whenever its been sitting out in the cold for a few hours, but stops when the temperature gauge reaches normal temp. Is this just piston slap, or is there an oil supply problem ? The sound comes from all over, but seems centered in the cam/valve area. Any recommendations ?

I had this problem on my ej22 when I first got it and it ended up being one of the timing belt idle sprocket's bearings were shot. So I replaced that and the belt and it went away. It's worth a look see better than having it fail while your driving and getting stranded .