Taptaptaptaptaptaptap Noise?

Russellb · Postby **Russellb** » Thu Jun 07, 2012 5:50 pm

[quote="Uncle Arthur
I don't believe this is physically possible in the MX5 engine is it?[/quote]

IF it has spun a bigend bearing then the Pistons can hit the head
But with out hearing the engine Its hard to tell whats wrong

The last time I ran the race car on 14psi with STD rods it Broke 1 and bent 3.
1 was so bend that the crank balance weights where hitting the bottom of the piston
and making a horible noise.

not saying that it is the problem as there are over 400 parts inside the engine and anyone of them
could cause a noise is it fails

bear2230 · Postby **bear2230** » Thu Jun 07, 2012 6:37 pm

Russellb wrote:[quote="Uncle Arthur
I don't believe this is physically possible in the MX5 engine is it?

IF it has spun a bigend bearing then the Pistons can hit the head
But with out hearing the engine Its hard to tell whats wrong

The last time I ran the race car on 14psi with STD rods it Broke 1 and bent 3.
1 was so bend that the crank balance weights where hitting the bottom of the piston
and making a horible noise.

not saying that it is the problem as there are over 400 parts inside the engine and anyone of them
could cause a noise is it fails[/quote]

Holly F$%k Russell dont tell me that.

Postby **NitroDann** » Thu Jun 07, 2012 7:18 pm

A big end is much louder than piston touching the valve so it aint a big end.

Dann

pcmx5 · Postby **pcmx5** » Thu Jun 07, 2012 7:21 pm

non turbo but I had lifter noise on startup (lasted about 10 seconds at most) for a year or two and then about a month ago REAL noise that didn't go away, sounded like every lifter had gone at once.Replaced lifters and all is well again.

Very surprised about how sudden it escalated and the noise, feared much worse.All this at 110,000 klms NA8A.

Peter.

manga_blue · Postby **manga_blue** » Thu Jun 07, 2012 7:29 pm

NitroDann wrote:A big end is much louder than piston touching the valve so it aint a big end.

Dann

Not. Piston slapping the head is usually much louder than the big end noise when it happens. If you listen closely then you can detect the underlying knock or rumble of the big end.

Normally you wouldn't describe the piston as just a tapping noise. It's worse than that.

Sticking valve?

Postby **NitroDann** » Thu Jun 07, 2012 7:36 pm

It depends on the piston to head clearance, but in a B series motor the big end would have to be pulverised for the piston to even just touch the valve.

Dann

Hellmun · Postby **Hellmun** » Thu Jun 07, 2012 7:55 pm

Could it not be as simple as the clearances being out after many kilometers and a simply re-shimming the lifters at a machinist to fix? Wouldn't take long to check the clearances... How many kilometers on the car? High boost on compression stroke would cause plenty of force on the cam lobe so it can be just wear.

Postby **NitroDann** » Thu Jun 07, 2012 7:59 pm

High boost on compression stroke should cause no more wear than normal the head is seperate from the bottom end.

Anyways, didnt read enhine variety could a lifter needing shimming, but unlikely to be just 1.

Dann

manga_blue · Postby **manga_blue** » Thu Jun 07, 2012 8:02 pm

I was talking about piston striking the head. The only time I heard it in a BP was when Cookie spun a bearing at Winton. You could hear the piston clattering right across the pits. I've done it a couple of times in other cars, sounds horrible.

You're probably right about stuck valve though. If a piston can't bend them then they won't stick.

It's shim-over-bucket, isn't it? What does a thrown shim sound like?

bear2230 · Postby **bear2230** » Thu Jun 07, 2012 8:21 pm

Thanks guys for all the help. Mechanic just called said Just started it hardly any noise will check it again in the morning
I asked if it was a lifter and his reply was Don't know yet will keep u posted
I will report back tomorrow
Thanks again.
Better get that spare moter over to Daniel owch...

Richard

Russellb · Postby **Russellb** » Thu Jun 07, 2012 8:56 pm

NitroDann wrote:A big end is much louder than piston touching the valve so it aint a big end.

Dann

Never said that the piston hit a valve
It can hit the head if a big end bearing spins
but wont hit the valves due to the reliefs in the piston crown

Like I said Hard to tell with out seeing and hearing the car

GRID NAZI · Postby **GRID NAZI** » Thu Jun 07, 2012 9:28 pm

Hi Bear2230

Could you please give me a bit more information?

IE. when the boost was up what happened?

when the boost was removed what happened?

what was done when boost was put up? everthing!!!

the more info you have. The less it MIGHT COST!

GRID NAZI · Postby **GRID NAZI** » Thu Jun 07, 2012 9:37 pm

NitroDann wrote:High boost on compression stroke should cause no more wear than normal the head is seperate from the bottom end.

Anyways, didnt read enhine variety could a lifter needing shimming, but unlikely to be just 1.

Dann

PLEASE EXPLAIN?

zero00 · Postby **zero00** » Thu Jun 07, 2012 9:39 pm

dumb question

How old is the oil?

bear2230 · Postby **bear2230** » Thu Jun 07, 2012 10:46 pm

GRID NAZI wrote:Hi Bear2230

Could you please give me a bit more information?

IE. when the boost was up what happened?

when the boost was removed what happened?

what was done when boost was put up? everthing!!!

the more info you have. The less it MIGHT COST!

Car was in for a Wallbro fuel pump as the stock pump was at its limit. Boost was set at 15 and 173kw and going like a train. I then got him to turn down to 12 and around 150kw as I was more comfortable with that power.
Adjusted through the Haltech
All still good and running perfect. Car was parked for a couple of hours and when restarted tap tap tappidy tap.
Friggin thing has never made that noise before.
Car has 25000km and Oil was changed 1 month ago.