banging from the head

scotty · Post by **scotty** » Fri Jan 05, 2007 1:38 pm

I opened it up and found nothing inside the cylinder. One of the push rods got bent and was rubbing against the side of the block. Mystery solved.

A few of the exhaust studs are looking a little stripped, does anyone know what size they are? Thanks

Victor_laury · Post by **Victor_laury** » Fri Jan 05, 2007 3:56 pm

scotty wrote:Hey Vic, I live in Atwater

Oh my god! Hey neighbor! I can most likely see your house from my hill!

Post by **dbrick** » Fri Jan 05, 2007 7:41 pm

5 main 1600 part number is 08223-83210. $0.46 on datsunpartscc. Call local Nissan dealer, see if # is still good, or Dean would probably have them.

spyder · Post by **spyder** » Fri Jan 05, 2007 10:48 pm

So how do you bend the pushrods?

Post by **dbrick** » Sat Jan 06, 2007 1:22 am

spyder wrote:So how do you bend the pushrods?

Ahh, the big question has been asked.
Someone correct me if I am off base...When you checked the valve lash after you got it home, was the valve with the bent pushrod loose? It should have been loose, if it wasn't, the pushrod was already bent the last time the valve lash was set.

The 1600 I sold to Bill K has a very nasty valve type noise, comes and goes a bit, haven't been able to find it yet. Bill will fix it by putting in a stroker, a bit of a shotgun approach, but the noise will be gone.

scotty · Post by **scotty** » Thu Feb 08, 2007 2:27 am

Put it all back together with a new push rod and it fired right up. but it's still banging. Don't know why the rod got bent in the first place. Anyway, I got some advice and it's to see if the noise gets louder or softer when you disconect a plug wire at each cylinder. Louder is a wrist pin, quiter is a rod bearing. No change in noise could be almost anything. Does this make any sense?

spyder · Post by **spyder** » Thu Feb 08, 2007 11:43 am

The oil pan is easy to get off. You can check the rod bearing this way. If it is a wrist pin, I think it would slowly develop unless the piston cracked or perhaps one of the pins is slipping out ot the piston hitting the side of the bore. I had this happen and was able to see it by dropping a small bulb into the spark plug hole and peer in.

mikew · Post by **mikew** » Thu Feb 08, 2007 7:32 pm

Did the noise start happening all of a sudden or did it slowly get louder over time?

As was suggested early in this thread - it could be a dropped valve seat - has happened to me before too - frustrating thing was that it took weeks to find the problem...

When the seat dropped out of the head, it floated around banging and crashing as the valve opens and closes and the piston rises and falls, but then sometimes it would pop back in and the noise would go away..... The first time it happened the nasty noise lasted a couple of minutes then went away (as the seat popped back into position) and didn't come back for weeks.

Might also explain your bent pushrod if part of the seat managed to get between the valve and piston.

Did you notice and damage to a combustion chamber or on the top of a piston?

mike

scotty · Post by **scotty** » Fri Feb 09, 2007 1:07 am

The noise started suddenly, then disappeared for a while. I had a seat drop on my last head, and it was obvious when I removed it. I guess I could have done more to check if a seat was loose when I had the head out. How would you recommend checking, do I need a valve spring compressor?

scotty · Post by **scotty** » Fri Feb 09, 2007 1:09 am

Also, I noticed no damage or scratches on the pistons or cylinder walls.

scotty · Post by **scotty** » Sat Feb 10, 2007 4:50 am

Pulled the head off and rotated the engine by hand. the 2 inside pistons would rise together, but on the way down one would descend an inch higher than the other. Tough it and it slides down even. I guess that's a broken wrist pin?

Post by **spl310** » Sat Feb 10, 2007 7:16 am

It could be a broken wrist pin, broken piston, or a rod that is failing. Either way, it needs to be fixed. The good news is that 1600 tidbits are reasonable!