TheSamba.com :: View topic - Help! engine making strange noise after re-installing

Fri Apr 29, 2016 3:59 am

No idea what this rattling noise is after I re-installed the engine, I could really do with some help & advice please!

The engine came out last November and I have changed the following:

- gearbox has been rebuilt by Cogbox
- new release bearing & stage 1 clutch
- fuel pump changed from mechanical to electric + new hard line
- valve/rocker clearances changed (they were all a bit tight) plus new 0.0015" shims under the rocker assembly to get the clearances.
- new clutch cable
- new kafer-bar engine brace
- installed Mocal oil thermostatic bi-pass valve to stop cold oil going to the external cooler

The engine was running fine before I pulled it. It starts first time, nice & responsive, no splutters, oil pressure seems good on the gauge

You can see in the video it's a sort of rattling / tinny noise, it's there all the time, but doesn't change much with the revs. I though it might be something caught in the fan so I disconnected the fan belt and the noise was still there!

Thought it might be the release bearing, but it doesn't change or go away when I press the clutch, or when driving.

HELP ! :cry:

Fri Apr 29, 2016 4:58 am

Crawl underneath it, may be something (engine tins?) loose on the bottom end.

Fri Apr 29, 2016 5:32 am

John S. wrote: Crawl underneath it, may be something (engine tins?) loose on the bottom end.

That is on my list thanks

Fri Apr 29, 2016 6:18 am

The good news is the noise sounds external. It almost sounds like a loose or extra washer was dropped between the cylinder tin and heads and it's vibrating.

What kind of pushrods are you using? The valves sound a bit loud. What did you adjust them too?

Fri Apr 29, 2016 7:48 am

wcfvw69 wrote: The good news is the noise sounds external. It almost sounds like a loose or extra washer was dropped between the cylinder tin and heads and it's vibrating.

What kind of pushrods are you using? The valves sound a bit loud. What did you adjust them too?

Funny you should say that because I have lost some washers in the rebuild of the tin !

Yes I just re-checked the valve clearances i did them to 6 thou but two were way too loose when I checked them just now. I must not have had the pushrods pushed into the cups all the way.

Just re-did the valves they sound ok now, loosened the kafer brace so the engine came down about 5mm to check it wasn't vibrating on firewall. Noise still there, but I will now see if I can find any washers under the tin !

Fri Apr 29, 2016 9:03 am

Just taken tin off, nothing loose or hiding in there :-(

Fri Apr 29, 2016 9:05 am

carl4x4 wrote: wcfvw69 wrote: The good news is the noise sounds external. It almost sounds like a loose or extra washer was dropped between the cylinder tin and heads and it's vibrating.

What kind of pushrods are you using? The valves sound a bit loud. What did you adjust them too?

Funny you should say that because I have lost some washers in the rebuild of the tin !

Yes I just re-checked the valve clearances i did them to 6 thou but two were way too loose when I checked them just now. I must not have had the pushrods pushed into the cups all the way.

Just re-did the valves they sound ok now, loosened the kafer brace so the engine came down about 5mm to check it wasn't vibrating on firewall. Noise still there, but I will now see if I can find any washers under the tin !

If you're not 100% sure about your push rods, stick a magnet on them to make sure they are not steel. If they are, you adjust them to loose 0 vs. 6 thousandths. I have steel (chromoly) pushrods on one of my engines. I adjust them to loose 0. Even at that setting, when the engine warms up, they are louder than the aluminum ones.

Fri Apr 29, 2016 9:54 am

Holy cr@p batman! I've just checked and the magnet sticks to the pushrods !! :shock: thanks wcfvw69 for the info

So I'm going to set them to zero, which I assume is setting them just tight enough that the rods can still spin but there's no gap?

Fri Apr 29, 2016 10:55 am

Nope :-(

Re did all the clearances and the horrible noise is still there :-(

Fri Apr 29, 2016 11:27 am

Ok time to eliminate one more noisy thing in your engine compartment!
Remove the fan belt and start the engine. Don't let it run very long just enough to verify that it's not the fan making the noise.
Good thing on the push rod find though. They can be real noisy when the engine gets hot. Just set the valve lash to a loose 0+. You want the valve to make contact with the seat. Not be held open by the cam, push rod, rocker combination.
Good Luck.

Fri Apr 29, 2016 12:08 pm

Pulley tin between the pulley and the case. Maybe.

Fri Apr 29, 2016 12:28 pm

Brian wrote: Pulley tin between the pulley and the case. Maybe.

Yes.. That's a good suggestion!

And yes, set the gap to where you can spin the pushrod yet not get any tiny feeler gauge in between the adjustment.

It will be MUCH quieter adjusted to zero when the engine is hot though. As I mentioned, they are still louder than the aluminum push rods.

You need to do a thorough diagnostic evaluation with identifying where that rattling is coming from. It's very tingie sound like thin metal rattling against something.

Fri Apr 29, 2016 12:39 pm

67rustavenger wrote: Ok time to eliminate one more noisy thing in your engine compartment!
Remove the fan belt and start the engine. Don't let it run very long just enough to verify that it's not the fan making the noise.
Good thing on the push rod find though. They can be real noisy when the engine gets hot. Just set the valve lash to a loose 0+. You want the valve to make contact with the seat. Not be held open by the cam, push rod, rocker combination.
Good Luck.

Yes I've tried that, ran for about 10 -20 seconds with no fan belt on and the alternator stationary :(

Brian wrote: Pulley tin between the pulley and the case. Maybe.

yes this did cross my mind too, I've removed the front engine bay tin and checked for any clearance issues behind the crankshaft pulley

I also tried removing the starter motor and video'd the flywheel going round when cranking the engine slowly - visually checked that the clutch bolts are still attached & not loose. All seemed fine.

Removed the spark plugs & turned engine over by hand, no binding for metallic scraping noises, nice and smooth & quiet.

Three things I wondered...
1) Is the flywheel rattling against the starter motor cogs if the solenoid isn't retracting properly? - inspected the starter cog it looks OK, no evidence of excess marks
2) Could the noise be the release bearing? - not sure about this as the noise doesn't change if I put the clutch in & out
3) Is it oil starvation because the oil bi-pass thermostat I fitted is faulty or fitted wrong? - I checked the return pipe and it seemed to have plenty of oil in it so I'm not sure it's this

Fri Apr 29, 2016 1:18 pm

Is your new electric pump making your hard line vibrate against something hard?

Fri Apr 29, 2016 2:10 pm

fastfil wrote: Is your new electric pump making your hard line vibrate against something hard?

Don't think so as no noise when priming

Fri Apr 29, 2016 3:35 pm

carl4x4 wrote:
yes this did cross my mind too, I've removed the front engine bay tin and checked for any clearance issues behind the crankshaft pulley

We're talking about this one right? I had a tin screw come loose when I was in the dunes and it sounded 100% like that. Spend minutes trying to figure out wtf was wrong, then I touched it and boom stopped.

I don't think it would be oil, check your level with it running.

Fri Apr 29, 2016 3:44 pm

Brian wrote: carl4x4 wrote:
yes this did cross my mind too, I've removed the front engine bay tin and checked for any clearance issues behind the crankshaft pulley

We're talking about this one right? I had a tin screw come loose when I was in the dunes and it sounded 100% like that. Spend minutes trying to figure out wtf was wrong, then I touched it and boom stopped.

I don't think it would be oil, check your level with it running.

Definitely will check this tomorrow morning thanks

Fri Apr 29, 2016 5:46 pm

Is there a rag in the fan? it looks like the belt jumps when I hear the noise I am hearing.

Casey

Sat Apr 30, 2016 5:02 am

We have progress ! :-)

Bump started the car without the starter installed and the noise has gone !!

I remember the starter being hard to fit when installed and the bolts had to draw it into place for the last couple of mm, that's why I thought I'd check it.
Here's a photo of the gearbox side, anything look strange? Does the bush look ok? I don't know what a bad one would look like...?

Sat Apr 30, 2016 5:18 am

Look at those shiny surfaces at the top or the gear's teeth. Probably it is the source of the noise.