TheSamba.com :: View topic - Noise Issue

Fri Jul 29, 2016 11:22 am

Having an issue with my '63 bug. In the mid to higher rpms the exhaust is making a strange noise. The closest thing it reminds me to is a Subaru with unequal headers. It is a stock 40 hp engine with the stock muffler and peas hooters. Just wondering what it could be. I appreciate any help. Thanks.

Fri Jul 29, 2016 12:40 pm

What does the noise sound like? Is it backfiring? Rattling? To troubleshoot it, you need to provide more information!

Just a few suggestions:

The first thing I would check is all the connections and seals for the exhaust (manifolds, intake manifolds, etc.). I would also take a look at the seals on the heater boxes/j pipes.

Take a good look at the intake manifold seals too.

Check your vale settings and timing.

How is your carb health?

Fri Jul 29, 2016 1:11 pm

and see if the heads are loose it makes a strange noise sounds like leaking muffler

Fri Jul 29, 2016 5:05 pm

The tubes inside a muffler can break loose and make a funny noise. Also, the guts inside the tailpipes can get loose and sound funny.

Fri Jul 29, 2016 5:59 pm

So I recently took the engine out because I had clogged heat risers and when I was putting it back together after unclogging it, I put all new seals and clamps for the muffler. The noise was not made until I was running it one day and my firewall insulation covered my fan and the car overheated and burned my spark plug wires. The sound it makes sounds like a rumble and it's only when I accelerate. So far I have: new points, adjusted timing, new spark plug wires, new spark plugs, adjusted valves, adjusted carb.

Fri Jul 29, 2016 6:11 pm

ill bet the heads are loose

Fri Jul 29, 2016 6:36 pm

What are the symptoms of loose heads?

Fri Jul 29, 2016 6:48 pm

GREASE MONKIE wrote: What are the symptoms of loose heads?
Kind of a fut fut fut sound at idle. Then it gets more pronounced upon acceleration. A blocked cooling fan inlet is a very bad thing. Not to mention the burned spark plug wires. That means things may have gotten very hot in the engine compartment.
Go out to your car and see if you can push pull the rear crankshaft pulley front to back. If there is more that a very slight (meaning 1/64th of an inch) movement. Your gonna need to investigate further.
Good Luck.

Fri Jul 29, 2016 6:55 pm

I actually noticed I started to leak a little bit of oil before it didn't leak one drop.

Fri Jul 29, 2016 6:57 pm

I also think the heads are loose, but now that we know about the overheating you may have pulled heads studs. If that's the case, I would look for another engine as you may have warped the case too. Only way to know is pull the tins and re torque the heads.

Fri Jul 29, 2016 7:14 pm

Alright I will look into that. I'm going to do a compression test tomorrow see how it does if the compression is good I'm going to tighten the heads of not just rebuild it. Thanks.

Thu Aug 04, 2016 9:26 am

Take a good look at the fan itself too. A bad bearing can create that sort of sound when the fan rubs intermittently on the shroud.