SR mysterious rattle....

[ILikeMy240sx]

Symptom: Noticeable rattling at part throttle at about 2500~3000 RPM. Very loud and fast rattle at full throttle and at around 5500 RPM. Oil pressure at idle (900 RPM) when warmed up is around 25 PSI and at 3200 RPM 75 PSI. The noise seems to be coming from the top of the engine. First I thought it was the timing chain, so I took off the valve cover and started up the car for few seconds. I noticed that all the oil is squirting on to the cams and heard a loud rattle where the exahust cams were when reved to around 3000 RPM.

Engine: Stock rebuild 2000 miles ago. This includes rings and all the bearings. Clearance was checked on all the bearings. Just replaced the head with a used one. Also used cams, rocker arms, lifters, shims (all the moving parts on the head from a different head)

I cannot seem to figure out why this noise is keep happening... Any inputs will be appreciated. Thanks!

[corey240]

i know my engine isnt quiet. when im on the throttle its stacks clicking and the more thrtottle the faster the clicking. i assume this would be my injectors because the fact that when i put my head by my injectors and somone hits the gas irts coming from them. maybe that helps

[fregisr]

when you said all new rings, does that include the connecting rod bearings? because that could cause your piston to not come up and down smoothly and makes rattling noise

[sr20-thoj]

if you just finished your rebuild and its making noise.. you should definitely check your bearings again.. same thing happened to me.. i didnt check.. and grinded my bearings and crankshaft apart.. had to replace them.. so recheck them..

[ILikeMy240sx]

I rebuilt the bottom end with new piston rings and new con rod bearings, main bearings which were all selected by matching up the numbers on the block and the crank. Also I used a plastigauge to check for all the clearance which was all in spec.

I am going to pull the motor apart and see what's up... This would be the 4th time I take this thing apart.. I am so sick and tired of SRs... jeez...

Anyways, sr20-thoj, what kind of noise was it making and where was it coming from and when did it occur?

thanks much!

[UK-SRi]

Check your HLA's, its not a self-bleeding design, if they get air in them it gets noisy.

Mike

[ILikeMy240sx]

HLAs have been bled before putting them in. It's not the HLAs for sure because I cannot push down on them and I made sure those suckers were quite satisfied when I jerked them off to bleed them.

[mallbor240SR]

whats an HLA?i think im having the same problem, its been like that for about two years now, i thought it was the timing chain so i took the upper guide out and replaced the timing chain tensioner but that didnt solve the problem, a couple of people have told me that it may be the water pump, but it seems to me that the noise its coming from the valve cover, so if yo find out wtf is that noise coming from let me know please.

[sr20-thoj]

it made a clinging noise similar to the timing chain when it rattles.. at first i actually thought it was the HLA also. thats why i didnt bother with it.. sounded like it was coming from the head.. but i was wronggg.. dont worry.. ive taken my motor out 7 times.. gonna be my 8th time this summer.. gonna get new clutch.. and pistons.. so yeah.. but good luck with the prb..

[ILikeMy240sx]

Yeah.. the more I think about it.. the more I think it's the rod bearings because I pretty much replaced all the wear components in the head but the same type of noise as before I replaced the cylinder head... The only things I did not bother to check or replace were the wear component in the block it self since I did not want to take the motor out...

Jeez... 8th time.. this is my 4th time and I am already getting very very very sick of looking at SRs...

BTW, did replacing the crank and bearings fix your problem?

[ca18deTbeGinNer]

hey, i just started having this problem that all you have had. but at first i thought it could be my exhaust manifold gasket being vibrated cuz i was missing a stud and bolt. fixed that but problem is still there. is that rattling, well my noise is a ticking, noise a sign for a re-build?? could it be that it just needs a valve job or a rocker arm problem??? and from the rebuilds, have that solved the problems??

if anyone has had the same problem and solved it...i need help FAST!! im moving to vegas and i dont want to drive it from nor-cal to all the way down there with this problem.

please help guys!!thanks

[ca18deTbeGinNer]

forgot to mention that when i put the missing stud and bolt, my manifold gasket look tore up...gonna see if replacing the manifold gasket fixes everything. i will let you guys know tomorrow!

[ca18deTbeGinNer]

hey, i just started having this problem that all you have had. but at first i thought it could be my exhaust manifold gasket being vibrated cuz i was missing a stud and bolt. fixed that but problem is still there. is that rattling, well my noise is a ticking, noise a sign for a re-build?? could it be that it just needs a valve job or a rocker arm problem??? and from the rebuilds, have that solved the problems??

if anyone has had the same problem and solved it...i need help FAST!! im moving to vegas and i dont want to drive it from nor-cal to all the way down there with this problem.

please help guys!!thanks

just got the gasket replaced and BAMMM!!!!!! no more noise!!!! muAHaHaHaha....maybe you guys should try replacing the gasket instead of pulling the motor ?? just a thought to save you guys sometime and head aches!