Engine click/knockIng sound

[kelseyr32]

So I am down to the last problem with my rb20 when I start the car it makes a Loud knocking sound that goes away when that car is warmed up I think it might be a spun rod bearing. The weird thing is the car is the car is running perfectly smooth all my hesititsio issues I had are gone. Is it possible to have a spun rod bearing and the car runs perfect otherwise?

[Skym]

Use a mechanics stethoscope and find the problem area. It sounds like a hydraulic lifter problem if sound goes away or is less when engine is warm (oil is thinner when up to temp and thicker when cold). It usually means lifter has sludge / film buildup between the two sections of lifter and needs to be removed, diassembled, cleaned, reassembled and put back in engine. Or replaced if it has seized.

Also check cam cover gaskets, as when leaking you can hear the lifters clicking, etc. It's normal to hear FPR ticking away, injectors clicking.

[markc32]

piston slap if its knocking low tone...lifters are TICKS...

u can only hear injectors tick if the hood is open and u put ur ear near the rail....

if its hood shut morning start up.....knocking is piston slap.....ticking would be lifters...

[Skym]

True, I usually have the hood open when I hear those sounds. Got me curious about ticking, clicking sounds, will listen again (you are probably 100% correct). I agree that piston slap could be another area, as piston expands when engine is warming up. Bore scope should help you to see marks on cylinder walls?

Probably the best way to tell if it's a bottomend bearing problem, is oilpressure should be lower than normal. Also use aftermarket oilpressure gauge, not stock oilpressure gauge.

Also check waterpump.

[kelseyr32]

If I can figure out hot to covert a video from my phone onto here I'll post a video I maybe be explaining the sound wrong

[kelseyr32]

here is a link to the video http://www.youtube.com/watch?v=-lqk2a98Xzs

[markc32]

when u rev it, does the noise speed up too?

[markc32]

im 99 percent ur engine is knocking...

also get a stethoscope and point at each cylinder...this way u know its for sure its internals failing..

[kelseyr32]

A little bit but once I drive for like 5 or 1O mins the sound goes away and you would never know anything was wrong. Also the sound is not always that loud sometimes it's a lot quieter. I'll try again with a stethoscope but so far I haven't been able to pin point exactly where it's coming from

[kelseyr32]

A little bit but once I drive for like 5 or 1O mins the sound goes away and you would never know anything was wrong. Also the sound is not always that loud sometimes it's a lot quieter. I'll try again with a stethoscope but so far I haven't been able to pin point exactly where it's coming from

[markc32]

like skym mentioned...lets see if lifters have to do with the noise...if u cant take them out and clean them...try using lifter cleaners?

what weight engine oil r u using?

theres always a light knock that goes away meaning ur bearing just showing signs at cold engine...but goes away...

[Skym]

Lifters on my cars engine were alot louder using 10w60 oil and engine struggled to idle, response was sluggish, etc. Was alot quieter using correct 10w40 oil for oiltemps, factory oilpressure, so from that I know oil weight affects the sound of lifters, idle smoothness, response of engine. Factory oil is 7.5w30 for stock engine. Closest off the shelf is 10w30 or 10w40 if have higher oiltemps with intake, exhaust, etc.

But that sounds like waterpump or fan on waterpump (replace washers under mounting bolts, etc and check fan clutch, balance of fan, etc, as it's a common failure area on Skylines when they get older), as it gets louder near front of engine where waterpump is. Or could be CAS bearing. Use a mechanics stethoscope and put on CAS, just behind CAS and on waterpump. etc. If they are ok, then probably lifters.

Cambelt, waterpump, crank, cam seals, idler, tensioner bearings, mounting bolts for bearings, etc are usually changed at 110,000km.

[kelseyr32]

When the sound first started happening I was when I changed to iridium plugs which can't be the problem. But anyways yeah I was reading on a timing belt thread all I had replaced was the belt I didn't knOw to change te water pump and tensioner pulleys. I am not even close to a mcxhanic and didn't want to touch the timing myself but the guy said my water pump was changed before but who knows not since Ive owned the car. I have also had the cas replace an put the stethoscope on it too. I will take the timing belt cover off over the weekend if I have time and have a look Ill also try some thicker oil and lifter cleaner

[kelseyr32]

So. I tried a stethoscope again I can here it when I put the stethoscope on the timing belt cover above and around the harmonic balancer

[markc32]

u have to go around the engine and start from the back cylinder and all the way to the timing area....this way u know where it is as the loudest spot...try again