Total mystery : sheared off cambelt but valves ok!?

General discussion forum about the 240sx, and a great place to introduce yourself to the board!
Grifter
Posts: 95
Joined: Wed Oct 29, 2014 7:49 pm
Car: S13 ca18det

Post

& it's loud


Grifter
Posts: 95
Joined: Wed Oct 29, 2014 7:49 pm
Car: S13 ca18det

Post

Well. Back to square one
Tapping came back then engine kept on getting jammed. Suddenly it slipped timing. So ive reset the timing again only to find the intake cam journal had become toast again. Now im thinking bearings may be losing oil at bottom end cause one of the local mechanics has said that could be the reason. Although I've got no bad knock but I do hear a rumble within the gearbox at acceleration.
Checked oil pick up and was ok although a string of sump sealant was stuck inside which I removed. Oil is dark black with a mirroring effect on top

User avatar
PapaSmurf2k3
Site Admin
Posts: 18997
Joined: Thu Nov 21, 2002 3:20 pm
Car: 2017 Corvette, 2018 Focus ST, 1993 240sx truck KA Turbo.
Location: Merrimack, NH

Post

No bueno!
Good thing you got that s*** off the pickup.

User avatar
float_6969
Moderator
Posts: 17366
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Post

Did you ever check oil pressure? The rattling you're describing sounds like a bad rod bearing.

Grifter
Posts: 95
Joined: Wed Oct 29, 2014 7:49 pm
Car: S13 ca18det

Post

I've checked the oil pressure & seems normal like between 65-78psi
The camshafts are all good & straight.
When you say Rod float, do you mean the cams or bottom end bearing
What about the gearbox rattle cause I'm being told it maybe the end bearing on the crankshaft

User avatar
float_6969
Moderator
Posts: 17366
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Post

The oil pressure should be greater than 11psi at idle, and between 51-60psi @ 3K RPM.

The rods, like the connecting rods. There's a bearing where the rod connects to the crankshaft. When the clearance on that bearing becomes too great, generally due to wear, it often makes a noise similar to what you're describing. I suspect the noise isn't in the gearbox, but the engine.

Grifter
Posts: 95
Joined: Wed Oct 29, 2014 7:49 pm
Car: S13 ca18det

Post

Ok float cheers for explaining it hmm I dont reqlly wanna start messing with the bottom end il but il defo give it a try im gonna start getting another head on asap say I was going to check the bottom bearings can it be done with engine in car or does it need to come out.

User avatar
float_6969
Moderator
Posts: 17366
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Post

I suppose you could do it with the engine still in the car but it would be more work than simply removing the engine.

Grifter
Posts: 95
Joined: Wed Oct 29, 2014 7:49 pm
Car: S13 ca18det

Post

Happy days tooj out the engine replaced & sweet as a nut. Result. Be loading the video soon Thanks float and psmurf
Oh & the rattling sound was coming from the exhaust hitting the the middle long shaft sorted that and the noise disappeared!!

User avatar
PapaSmurf2k3
Site Admin
Posts: 18997
Joined: Thu Nov 21, 2002 3:20 pm
Car: 2017 Corvette, 2018 Focus ST, 1993 240sx truck KA Turbo.
Location: Merrimack, NH

Post

Nice!

Grifter
Posts: 95
Joined: Wed Oct 29, 2014 7:49 pm
Car: S13 ca18det

Post

Ahh man if it couldn't be any worse I think I've developed a boost leak. After being on the track for about 10mins to start off the car started a tiny misfire which gradually got worse. Now my motor really struggles to get any where near 6k revs its slow and doesn't wanna go higher revs
Starts up fine until you start to rev it then doesn't wanna go higher
Ive changed the plugs coils crank sensor and tps cause I got a 43 code from the ecu
But i changed it still its throwing the 43 code
I know for definite the tps sensor I put on is good
It could be my intake manifold gasket cause im getting This WHOOSHING SOUND FROM THE INTAKE MANIFOLD ON IDLE
When I step on the gas i can hear a suction kind ov sound before it recs up every single time

Grifter
Posts: 95
Joined: Wed Oct 29, 2014 7:49 pm
Car: S13 ca18det

Post

Ok all done it was a blockage in the piping but I still hear the whooshing sound will change the gaskets soon anyhows :mike


Return to “240sx General Discussion”